ESE's works engine tuner

[TZ350]

This could get interesting. What's the stoichiometric limit on pressure for a E85 fuelled, direct injected four stroke with an independently powered blower? :shifty:

It has been thought about, we have a few 100cc engines and some 4V water cooled heads in the shed somewhere.

[bucketracer]

Why not use a 250cc engine , just uncouple the cranks use 125cc to run the geartrain and use the other to run your generator or your fan, thats almost what you are suggesting.

Not as silly as its meant to sound, would it be legal? from the bikes point of view, its only being powered by a 125cc engine, the back wheel would not know about the other cylinder.

So do Buckets now have to conform to something only ever seen before and traditional and new ideas are forbidden. I didn't see that rule change slip through, must have been a Trogen Horse from the south.

[Yow Ling]

Not as silly as its meant to sound, would it be legal, from the bikes point of view, its only being powered by a 125cc engine, the back wheel would not know about the other cylinder.

So do Buckets now have to conform to something only ever seen before and traditional and new ideas are forbidden. I didn't see that rule change slip through, must have been a Trogen Horse from the south.

Who changed the rules? What does 125cc capacity mean to you? 125cc or 125 cc plus some more if we want?
The 450s are leagal in F3 because the 4th cylinder does not make any power, your extra cylinder is making usefull power, why not run the fan off a pulley on the end of the crank?

[bucketracer]

... your extra cylinder is making usefull power, why not run the fan off a pulley on the end of the crank?

No need if you can power it some other way, the only question is, does the bikes own motor have to run all the accessories too, including the electrics or can they be powered some other way.

Storing energy in an accumulator at home then using it during a race to re leave the bikes engine from the burden of turning its own water pump or making its own sparks cheating? does anyone do that? is it legal? I don't see it sanctioned in the rules anywhere.

[Yow Ling]

No need if you can power it some other way, the only question is, does the bikes own motor have to run all the accessories too, including the electrics or can they be powered some other way.

Storing energy in an accumulator at home then using it during a race to re leave the bikes engine from the burden of turning its own water pump or making its own sparks cheating? does anyone do that? is it legal? I don't see it sanctioned in the rules anywhere.

Nothing wrong with what you are saying there, How much displacment does the accumulator have ? None

Capacity for F4 2 stroke is 125cc or 130 with overbores, rulebook doesnt say in 1 cylinder , 2 cylinders or in 1 or 2 engines the rule simply states the cubic capacity for aircooled F4 2 stroke bikes, somehow you have come up with a loophole, pretend the other motor doesnt exist and doesnt affect the overall capacity of the bike its fitted to. I think Im over this Tintin is on Tv

[richban]

Who changed the rules? What does 125cc capacity mean to you? 125cc or 125 cc plus some more if we want?
The 450s are leagal in F3 because the 4th cylinder does not make any power, your extra cylinder is making usefull power, why not run the fan off a pulley on the end of the crank?




So Rob how is that new frame going? Have you decided on the geometry yet. length rake trail?

[Grumph]

This could get interesting.

What's the stoichiometric limit on pressure for a E85 fuelled, direct injected four stroke with an independently powered blower? :shifty:

Lower than that for a blown four stroke with both port injection and injection into the blower intake to cool the charge....First rule of using fuels with high latent heat of evaporation is to use it to cool the charge. The TQ which changed the speedway rules on blown motors had this exact setup and ran happily at around 30psi boost....

[Ocean1]

Lower than that for a blown four stroke with both port injection and injection into the blower intake to cool the charge....First rule of using fuels with high latent heat of evaporation is to use it to cool the charge. The TQ which changed the speedway rules on blown motors had this exact setup and ran happily at around 30psi boost....

Hmmm. The pressure limit is then defined by pre-ignition?

Which a direct timed injection need not worry about, eh?

Besides, if the above flies then we're allowed a free powered intake cooler as well! :cool:

[jasonu]

.

I think the engine capacity rule only applys to the engine that moves the bike. I will see if we can get some clarification.

Good luck with that one...

[husaberg]

Rob while i can't fault your transparency, I can't see how it will fly, the other accessories are either powered by the engines generating circuits or by total loss from a battery. All theses are a parasitic drag in one form or another. I can't think of any racing bike or car that had an auxiliary petrol power source. sure you could say you would be lugging the weight but it is an Independent power source of relatively infinite duration (until the fuel runs out) as far as i can see the only reason it is being considered is to lessen the loses of running it from the legal sized power source. This should set off warning signs in itself

If it had been legal or nearly legal you can bet it would have been tried by Frank Williams already.

why not use a 12 volt boat bilge blower if you don't want to drive a std fan off the flywheel.....They can be quite high output and are 12volt.
http://www.absolutemarine.co.nz/products/?id=4484

The generating lag or extra drag or weight of the batteries is the price one has to pay for such accessories........
I actually thought of the model aircraft engine as they are small but i guess they all run illegal fuel

However on a different note entirely there is a political tactic of offering up grossly unpalatable law change in hope of great public backlash in-order to pass an unpalatable law that will be seen then as the less of two evils.......the offer-er is seen as relenting to what they want and submitting to the will of the people............ I are of course not saying this has been happening with any proposed rule changes of course as i honestly sincerely doubt they are......................:wait:

[Ocean1]

if it had been legal or nearly legal you can bet it would have been tried by Frank Williams already.
:wait:

Meh. Frank wasn't an engineer.

http://en.wikipedia.org/wiki/Chaparral_2J#2J

[husaberg]

Meh. Frank wasn't an engineer.

http://en.wikipedia.org/wiki/Chaparral_2J#2J

Yes of course i hadn't consider the GE cars always controversial always popping up in one form or another.
I do note that the Chaperals with the aux engines allowable size not sure thought it was smaller but maybe open cc limit

Can-Am started out as a race series for Group 7 sports racers with two races in Canada (Can) and four races in the United States of America (Am). The series was initially sponsored by Johnson Wax. The Series was governed by rules called out under the FIA Group 7 category with unrestricted engine capacity and few other technical restrictions
and the F1 cars were driven of the engines as far as i know though.
http://en.wikipedia.org/wiki/Ground_effect_(cars)


http://www.youtube.com/watch?v=pukIEuzgd3U&feature=player_embedded


http://www.youtube.com/watch?feature=player_embedded&v=HZkUr5cG6wE

[TZ350]

So Rob how is that new frame going? Have you decided on the geometry yet. length rake trail?

Slowly, the big issue is that the tripple tree stem is 10mm to short for the head stock and modifying it is taking its time.

The rake/trail angles are problimatic too, I hoped to get them right by jacking up the back but have to have the head stock sorted first.

Probably go back to riding the old Beast for now.

[TZ350]

I can't see how it will fly, the other accessories are either powered by the engines generating circuits or by total loss from a battery. All theses are a parasitic drag in one form or another.

The battery is only a power drag on the wall socket at home not the bikes engine.


I can't think of any racing bike or car that had an auxiliary petrol power source.

That does not automatically make it illegal for Buckets and there is no reason why I could not do it successfully.

Anyway I don't want to argue this any more, the people I most respect have not embraced this (very clever :D) idea so I will just wait and see what clarification we can get.

Husa thanks for the link to the bilge blowers, if we have to go to plan B, I guess car heater fans would be worth a look too.

[speedpro]

The small fans that are fitted to motorcycle radiators look like they could shift a bit of air as well though I suspect they'd draw a bit of current.

[husaberg]

The small fans that are fitted to motorcycle radiators look like they could shift a bit of air as well though I suspect they'd draw a bit of current.

The most powerful 12 v motors i can think of are the CDIT 12V fert spreader or the 12Volt chainsaw i brought of TM for $20.......
perfect for stealth bonzai operations...........

[Frits Overmars]

The small fans that are fitted to motorcycle radiators look like they could shift a bit of airCorrect, a bit of air. They only have sufficient capacity to cool the engine while it is generating less than 5 HP, cruising in traffic at 10 kmh. As soon as more power is produced, the riding air flow must take over.

[136kg136ps]

Anyone do the maths on the volume of air needed,the loss of efficiency from switching the relative rates conduction and convection,the amount of energy needed to move that much air,the weight of the apparatus need to move it,abdiatic heating of that air by being compressed and run thru the passages...?It seems Frits comments indicate he already has an answer." Thermally unsound "is the term I believe he used to describe an air-cooled two stroke.

Rate of heat transfer in water K=.58 ,rate in air is K=.024 or 24 times less conductive.
Cuft water weights ~32kg, Cuft of air weighs .04kg or 800 times less.
Multiply the rate of flow your waterpump would require to cool that amount of HP in water and factor in that air carries away far less efficiently and the number seems rather large not to mention a commensurate increase in radiator surface area.

I may be off base but I previously engineered HP air compressor and gas turbine installations on boats with similar cooling issues and were required to submit detailed plans prior to beginning.

[teriks]

I can't think of any racing bike or car that had an auxiliary petrol power source.
:psst:
Chaparal 2J!

The two 17-inch diameter fans were powered by a single 45hp, 274cc, 2-cylinder JLO Rockwell snowmobile engine
http://antholonet.com/EngineersCars/Chaparral2J/Chaparral2J.html

[husaberg]

Anyone do the maths on the volume of air needed,the loss of efficiency from switching the relative rates conduction and convection,the amount of energy needed to move that much air,the weight of the apparatus need to move it,abdiatic heating of that air by being compressed and run thru the passages...?It seems Frits comments indicate he already has an answer." Thermally unsound "is the term I believe he used to describe an air-cooled two stroke.

Rate of heat transfer in water K=.58 ,rate in air is K=.024 or 24 times less conductive.
Cuft water weights ~32kg, Cuft of air weighs .04kg or 800 times less.
Multiply the rate of flow your waterpump would require to cool that amount of HP in water and factor in that air carries away far less efficiently and the number seems rather large not to mention a commensurate increase in radiator surface area.

I may be off base but I previously engineered HP air compressor and gas turbine installations on boats with similar cooling issues and were required to submit detailed plans prior to beginning.

This is all true but the one advantage of air cooling, is the limitless supply of near ambient air temp air. (Well maybe not the case buried in the bowels of a boat) Surrounded by water.



:psst:
Chaparal 2J!

http://antholonet.com/EngineersCars/Chaparral2J/Chaparral2J.html

Yes i linked it in response to Ocean, but the Canam series had an open limit open engine size.
I even posted a video of runing, it it sounds rather funky but would have to be the ugliest race car ever.........
I guess the MNZ will rule either pro or con.
If it rules in favour there will potentially be a lot of Forced induction bikes constructed.....Maybe running on E85 then they should be good for 55hp plus:msn-wink:

[Frits Overmars]

The one advantage of air cooling is the limitless supply of near ambient air temp air.As opposed to the limitless supply of ambient air to a radiator? :whistle:

[husaberg]

As opposed to the limitless supply of ambient air to a radiator? :whistle:

Granted i hadn't really thought of it that may although when you say it it is obvious:sweatdrop
but the primary cooling medium in the (single stage) air cooling is a total loss.
Where as i consider the two stage process where the air has to cool the water (the liquid the cooling medium) is recycled.
Whilst the air temp may be the same temp in both cases. I would consider that the liquid cooling medium is initially a vastly higher temp in A LC engine. Say About 60 degrees C.
I am likely wrong but i considered it a wee potential area to exploit to even up the odds for the "Thermally challenged".....
It was a stab in the dark.But if enogh air could be moved the odds could be maybe evened up a little.
was the one potential advantage (likely wrong on my part) i guess other than simplicity.

Of course H20 is still the clear winner in my eyes.

[Flettner]

Yes, all engines are air cooled. Perhaps not boat engines.

[TZ350]

283299
I nearly had Heart failure :blank: when I checked the Miniature RR rules on the MNZ site. There was no mention that F4 125 two strokes are to be air cooled.

I was surprised at how disappointed I felt, I am married to air cooling and have been enjoying the challenges of getting the best out of it. A 125 water cooled would be just so, ho hum after the unpredictable mistress that air cooling is.

283298
But, no the answer is in appendix D where it states that F4 125cc two strokes have to be air cooled.

Well crises averted and I can put all those RGV250 barrels back in the shed..... :D ... air cooling it is.

[speedpro]

I hate to get into this but it looks like someone has cut and pasted rules defining bucket engines into the "Championship Classes" section thereby removing those definitions from the bucket rule section. Unless you are competing in Championship races to me it looks like watercooled 125cc 2-stroke buckets is allowed. It would sort of defeat the purpose of course - developing a watercooled bike that you can't run in a championship race. Unfortunately I can't find any old rule books.

I wonder who did that.

[TZ350]

I checked with MNZ, yes its a typo, the F4 rule is still air cooled for 125 two strokes.

[richban]

Slowly, the big issue is that the tripple tree stem is 10mm to short for the head stock and modifying it is taking its time.

The rake/trail angles are problimatic too, I hoped to get them right by jacking up the back but have to have the head stock sorted first.

Probably go back to riding the old Beast for now.

Tricky. What are you aiming for with the rake/trail. I have been running My bike at 22.5 rake and not sure what the trail is. Must be close to 85 / 86mm. I have made it short as pos but still it has a wheelbase of 1320. Anyway these numbers work well for my bike and me. It tips in fast and steady and holds the line under power really nice. I will be trying to to get my RGV 250 as close as possible to these numbers. If I were you I would start with an MC21. So good, and all you need do is make it ligher. Anyway hope that is of some use.

[TZ350]

If I were you I would start with an MC21. So good, and all you need do is make it ligher.

I had a MC21 around here some place, wonder what happened to it? have you seen it? ... :laugh:

[richban]

I had a MC21 around here some place, wonder what happened to it? have you seen it? ... :laugh:

Oh shit. Somehow it wound up in my garage. I feel a little guilty but no you can't have it back. Plenty for cheap on Yahoo actions. Just got to get them here. Got any buddys in Japan.

[husaberg]

Oh shit. Somehow it wound up in my garage. I feel a little guilty but no you can't have it back. Plenty for cheap on Yahoo actions. Just got to get them here. Got any buddys in Japan.

Rob its time to hack that MC16 frame you know you want to...............

[TZ350]

Rob its time to hack that MC16 frame you know you want to...............

Yes I want to get rake and trail numbers like Richban suggested.

[husaberg]

Yes I want to get racke and trail numbers like Richban suggested.

They are very close to the NX4. But as Rich said the wheelbase is longer you could trim that with a couple of deft cuts with the hacksaw.

Gave up doing math and found this.....It might have been posted before but i can't be bothered looking to see.
http://www.offroadvw.net/tech/wes/fan.html

[Frits Overmars]

I have been running My bike at 22.5 rake and not sure what the trail is. Must be close to 85 / 86mm. I have made it short as pos but still it has a wheelbase of 1320. Anyway these numbers work well for my bike and me. It tips in fast and steady and holds the line under power really nice.If a rider is happy with the handling of his bike, then it is almost impossible for him to imagine that it could be even better. But it can always be better.
Rake is not so important; trail is. 85 mm is a good value if you have enough load on the front wheel. A 1320 mm wheelbase is good for a 250 cc GP-racer; it wil make a 125 cc bike sluggish, especially on the tight tracks I see on your videos. 1200 mm would be more like it, and the best way to work towards it is to steepen the rake, either by lowering the front, jacking up the rear or wielding an angle grinder.

[FastFred]

Gave up doing math and found this..... http://www.offroadvw.net/tech/wes/fan.html

• fan air delivery varies directly as the speed varies (linear relationship)
cfm2 = (rpm2/rpm1) x cfm1
• fan pressure varies as the square of the speed
SP2 = (rpm2/rpm1)² x SP1
• required fan horsepower varies as the cube of the speed
hp2 = (rpm2/rpm1)³ x hp1

I suspect the apparent maximum flow of the vw fan was actually due to the fan belt slipping at a certain rpm, therefore the fan speed did not increase any further.

I can see why TZ wants to use a leaf blower to keep the fan delivery constant.

[richban]

If a rider is happy with the handling of his bike, then it is almost impossible for him to imagine that it could be even better. But it can always be better.
Rake is not so important; trail is. 85 mm is a good value if you have enough load on the front wheel. A 1320 mm wheelbase is good for a 250 cc GP-racer; it wil make a 125 cc bike sluggish, especially on the tight tracks I see on your videos. 1200 mm would be more like it, and the best way to work towards it is to steepen the rake, either by lowering the front, jacking up the rear or wielding an angle grinder.

Yes totally agree. That is just how it is now. I keep playing and trying to improve it. I keep thinking god I wish I had worked harder on setup sooner. Maybe I would not have so many scars. Thanks for your input. Maybe when I get better with the tig I will try one from scratch. Well more like chop shop style.

[Flettner]

100cc water cooled twostroke, unlimited cylinders?
A cylinder is defined as a combustion chamber.

[teriks]

Yes i linked it in response to Ocean, but the Canam series had an open limit open engine size.
I even posted a video of runing, it it sounds rather funky but would have to be the ugliest race car ever.........

Sorry, sloppy reading on my part, and a bit worked up having recently read an article on the people behind the design.
It might be ugly, but I do like the two-stroke aspect ;)

[TZ350]

283357

It was good having this little chat about fuels recently, now I know this super oxygenated Elf stuff is legal I can dig out the two 40 liter drums I was given and maybe see what can be done with it.

[kel]

It was good having this little chat about fuels recently, now I know this super oxygenated Elf stuff is legal I can dig out the two 40 liter drums I was given and maybe see what can be done with it.

And it fits the bill perfectly
A. Cost; cheap, someone else paid for it.
B. Availability; found in TZ's back shed.
C. Toxicity; no lead.
D. Quality; well its Elf race fuel what else is there to say.
E. Power; :banana:

[F5 Dave]

Oh well if there's no lead it must be fit to drink.

Careful Rob, there's a picture of a cam on the can. The GP might only fire every 4th cycle running on that.

[senso]

Good night bucketers, here I come with another odd question..
Does anyone know how fast should I read an EGT and CHT probe?
I'm aiming at 1Khz in my custom dash(call it a home made data-logger), is it too fast, as I'm aiming at about 5 samples per engine revolution, maybe a little to fast for the thermo-couple to react?

Best regards.

[wobbly]

10 Hz is plenty to read an exposed tip EGT.
You may be able to sample 5 times per rev, but at 12,000 you only need to sample at 200Hz to get every combustion event.
Then the dash will update so fast you wont be able to read it, and the downloaded data wont be any more accurate than that done at 10Hz.
CHT is very slow to react,10Hz would be fine also.

Be careful with the Elf fuel as there are strict limits on the octain and oxygenates - check the numbers in the MNZ fuel spec.

[kel]

Be careful with the Elf fuel as there are strict limits on the octain and oxygenates - check the numbers in the MNZ fuel spec.

The Elf MITS fuel complies.

[dinamik2t]

You may be able to sample 5 times per rev, but at 12,000 you only need to sample at 200Hz to get every combustion event.
Then the dash will update so fast you wont be able to read it, and the downloaded data wont be any more accurate than that done at 10Hz.

Hey Wob! You would actually need to sample at 400Hz min, if you were to read successfully one value per cycle at 12k, to avoid aliasing.
You said that 10Hz is already enough though, so it doesn't matter anyway.. Cheers! :drinknsin

[wobbly]

Yes I understand that technically you are supposed to sample at 3 times the data stream rate to maintain accuracy, but in this case the egt wont change with any significance over 3 cycles
so it matters not.

[dinamik2t]

Yes I understand that technically you are supposed to sample at 3 times the data stream rate to maintain accuracy, but in this case the egt wont change with any significance over 3 cycles
so it matters not.

Yeah, no need to say 'you're right' Wob; I know I could have skipped the post altogether..:sleep:

Something irrelevant: would you happen to remember this pipe design and perhaps the engine specs/performance?
283362

[husaberg]

S having recently read an article on the people behind the design.
It might be ugly, but I do like the two-stroke aspect ;)


The Chaperal J2 Was so clever well executed it would squat to the ground (like the Brabham Fancar) when the throttle was blipped. But plagued by mechanical issues
Oh ugly doesn't fully describe it, it should have been banned on looks alone.
<img src="http://3.bp.blogspot.com/_Oj2_gYfFt2Y/RhrSm_XbwOI/AAAAAAAAASU/3sxS-hi-Gcc/s400/chaparral%2B2j%2B070409.jpg" width="325px"/><img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=244771&d=1313393287" width="340px"/><img src="http://www.formula1-dictionary.net/Images/ground_effect_ralf_schumacher_flying_plank.gif" width="410px"/>
But one thing i did gain that i had never heard of was the wooden Planks the F1 cars run under the tub. if they are worn by a certain amount after the race the car is disqualified. Clever and simple.


Only beaten by Harada's droopy tail.
Sure it may have been faster but it was an abomination in the style department. Actually i remember it being uglier, is this MK2. Either that or time has been kind to it.

[Ocean1]

The Chaperal J2 Was so clever well executed it would squat to the ground (like the Brabham Fancar) when the throttle was blipped.

Now why would it do that? Or did you mean when the auxiliary two stroke was blipped?

What it could do, (and unfortunately never got the chance to) was drive around upside down on the ceiling. At high idle the fans generated a force equal to 1.5 times the vehicles' mass.


But plagued by mechanical issues.

If a new product is 100% reliable it doesn't have enough features yet.

[TZ350]

... doesn't have enough features yet.

Sounds like my bike ..... :laugh:

[husaberg]

Now why would it do that? Or did you mean when the auxiliary two stroke was blipped?

What it could do, (and unfortunately never got the chance to) was drive around upside down on the ceiling. At high idle the fans generated a force equal to 1.5 times the vehicles' mass.
It was in the Blub, but it the video they do seem to run at a constant speed (showmobile engines)



If a new product is 100% reliable it doesn't have enough features yet.
Aye, but insert Keith Duckworth quote here..lol

[RomeuPT]

Yeah, no need to say 'you're right' Wob; I know I could have skipped the post altogether..:sleep:

Something irrelevant: would you happen to remember this pipe design and perhaps the engine specs/performance?
283362


The first segment is 25, not 35. Honda exhaust duct lenght is 56.

I would be interested in that too :)

[Frits Overmars]

Aye, but insert Keith Duckworth quote here..lolYou mean "Development is nothing more than correcting what went wrong in Design"?
I'd have to agree with mr. Duckworth, but since we are all human.....
Here's one from a certain Albert Einstein I like too:
"The simplest solution that fulfills all requirements, is the best". I abbreviated it to KISS.

[dinamik2t]

http://d24w6bsrhbeh9d.cloudfront.net/photo/4360234_700b.jpg
http://www.onlygags.com/wp-content/uploads/I-never-said-Half-the-crap-people-said-that-i-said-Albert-Einstein.jpg

(not your quote Frits, eh?:p)

[RomeuPT]

If we are back to exhaust dimensions.

I been thinking, the exhaust port volume is an important value for power production, has it works like a connection pipe from a pump (exhaust).

Now, why is the header of Honda 40 and 41mm if the cross area exit of the cilinder port is ~36mm, wouldn't a smaller change keep the flow velocity and assuming the header is a connection pipe too....

Regards

Romeu

[Frits Overmars]

I been thinking, the exhaust port volume is an important value for power production, has it works like a connection pipe from a pump (exhaust). Now, why is the header of Honda 40 and 41mm if the cross area exit of the cilinder port is ~36mm, wouldn't a smaller change keep the flow velocity and assuming the header is a connection pipe too....This connection pipe, together with the cylinder and pipe volumes forms a Helmholtz system; its length and diameters determine the frequency of this system.
The header length is rather fixed by the desired wave actions, so the header diameters must have a certain value in order to arrive at the desired frequency.

[wobbly]

I dont remember what that pipe was designed for, Ive done hundreds of them,but it has a 50mm long cylinder duct, and a 35mm long Ex spigot with no venturi - seems odd.
The length at 839 suggests a low Ex port around 83* from a Honda, but ask Neels, as it appears I did it for him??

The header at 41 or so diameter, usually matches the total effective Ex port area, and the duct diameter reduced to 75% of that area increases the velocity as well as the Helmholtz resonant frequency
of the system.

[RomeuPT]

I dont remember what that pipe was designed for, Ive done hundreds of them,but it has a 50mm long cylinder duct, and a 35mm long Ex spigot with no venturi - seems odd.
The length at 839 suggests a low Ex port around 83* from a Honda, but ask Neels, as it appears I did it for him??

The header at 41 or so diameter, usually matches the total effective Ex port area, and the duct diameter reduced to 75% of that area increases the velocity as well as the Helmholtz resonant frequency
of the system.

I thought it was this pipe. Is very identical to A-Kit pipe posted (in lenghts and angles), page 272

Can someone says by experience how much the exhaust cones assembly angles can change between each other to fit a bike, not making U bens etc, how much loss can be in that.

Some of my pipe designs so far:

[wobbly]

Yes that is a Honda pipe designed for the low Exhaust customer type cylinder, but the spigot length has been changed and the venturi removed in the sim print out.
Its not an A kit design, as that is shorter and is used with a 200* port timing.

The angle changes on your pipes look fine - but I hope you didnt just go ahead and weld them together.
EVERY weld on a mild steel pipe should be hammered on a mandrel, and the ones in the header linished with a flap wheel, or simply throw away 2 to 3 Hp.

[2T Institute]

<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=244771&d=1313393287" width="340px"/><img src="http://www.formula1-dictionary.net/Images/ground_effect_ralf_schumacher_flying_plank.gif" width="410px"/>
But one thing i did gain that i had never heard of was the wooden Planks the F1 cars run under the tub. if they are worn by a certain amount after the race the car is disqualified. Clever and simple.


That was Ferrari-gate when it leaked out that they had hinged at the rear and fitted strong springs at the front behind the plank that allowed the plank to tilt up and ride the kerbs or not wear as much in corners.

[Ocean1]

EVERY weld on a mild steel pipe should be hammered on a mandrel, and the ones in the header linished with a flap wheel, or simply throw away 2 to 3 Hp.

To make for a smooth transition?

Have you ever tried purge welding them with a TIG?

[speedpro]

EVERY weld on a mild steel pipe should be hammered on a mandrel, and the ones in the header linished with a flap wheel, or simply throw away 2 to 3 Hp.

I dummy my pipes up on the bike to check for fit and layout using masking tape and then remove the first 2 sections and weld them together, then hammer the joint and grind and sand inside so it's all smooth. Then the next section gets welded on and the joint/weld finished and so on. It takes ages.

[wax]

How do you do the last section. At one point when you join them together your not going to be able to get to the weld

[richban]

How do you do the last section. At one point when you join them together your not going to be able to get to the weld

Someone told me if you run argon through the inside of the pipe, its nice and clean on both sides. Does rely on a pression joint of course.

[senso]

How do you do the last section. At one point when you join them together your not going to be able to get to the weld

Start welding the pipe from the tail pipe?
Then your last weld will be the exhaust flange to mate in the cylinder.

About the thermo-couples, I already had the idea that with even exposed tip sensors 1Khz would be way to fast, but I will at being able to read them at 1Khz, and then do some filtering in software, and having that bandwidth allows me to try to sample right when the spark is generated or latter when the exhaust port is open.

[RomeuPT]

Yes that is a Honda pipe designed for the low Exhaust customer type cylinder, but the spigot length has been changed and the venturi removed in the sim print out.
Its not an A kit design, as that is shorter and is used with a 200* port timing.

The angle changes on your pipes look fine - but I hope you didnt just go ahead and weld them together.
EVERY weld on a mild steel pipe should be hammered on a mandrel, and the ones in the header linished with a flap wheel, or simply throw away 2 to 3 Hp.

Really, 2 ou 3 hp in a Race 125? That's still substancial.

That's the reason why the exhaust around here get better after riding some hours?

Some of the top 50cc around here in Portugal have two U bends in the exhaust :S

Regards

[Frits Overmars]

That's the reason why the exhaust around here get better after riding some hours?Carbon deposits in the pipe may smoothen the flow, but their main effect is to form a thermal insulator layer between exhaust gas and pipe walls, so the exhaust gas will lose less energy to the walls and more of this energy remains available for charging the cylinder.
A second effect is that the exhaust gas remains hotter which influences the speed of sound, hence the pipe's resonance frequency. If the pipe was already rather short, this effect can be negative.

[Flettner]

I insulate my chamber with mud.

[wobbly]

I always start at the header and work along, these sections are easy to hammer and linish with a 25mm flap wheel in a die grinder.
The rear cone is thus the last and I use a length of 19mm Hi Tensile bar with the end radiused, clamped in the vise,to hammer the last joint smooth.
Make very sure the ALL grinding grit is wiped out, when the engine first fires all the shit will end up on the piston face and cause havoc.
I use argon purge inside when making Ti chambers, but its not really the weld thats the issue with mild, its the slightly uneven joint overlaps.
A hammered header radius looks and performs better than the as welded sections do.
Tig is way faster and WAY cheaper than a gas welded pipe, but I still think gas welding looks better if done right.

[F5 Dave]

Hmm, ok lets talk pipe temperature insulation while the topic is up. We used to see lagged pipes, then that went out of fashion, possibly Ti pipe insulated better was postulated, but largely there was talk of the charge being returned to cylinder cooler was better.

Think it could have started with the snowmobiles as they supercool so lagging really helped. As an aside we've seen the lagging to avoid heating the cases.

Clearly there was the overall change in timing of wave. I've lagged & HPC coated my 50 pipe (awaaay back in the day) & all it achieved was rust, maybe 100rpm move & no power change. I HPC coated my 500 pipes (250x2) for convenience (its a roadbike), thinking it would not do squat but keep it looking nice & unrusty but heck did it whap the peak revs up, maybe 1000rpm. Stripped them & went for boring old paint.

[Frits Overmars]

We used to see lagged pipes, then that went out of fashion, possibly Ti pipe insulated better was postulated, but largely there was talk of the charge being returned to cylinder cooler was better.....Think it could have started with the snowmobiles as they supercool so lagging really helped. As an aside we've seen the lagging to avoid heating the cases.True, true. The part of the exhaust duct where the fresh charge lingers, should remain cool. That is the reason the ultrashort exhaust ducts of obsolete cylinders have been superseded by longer, watercooled ducts. But the rest of the pipe can still be isolated.

[F5 Dave]

Hmm, how far out do you think usable charge flows?

Thanks for response.

[husaberg]

Hmm, ok lets talk pipe temperature insulation while the topic is up. We used to see lagged pipes, then that went out of fashion, possibly Ti pipe insulated better was postulated, but largely there was talk of the charge being returned to cylinder cooler was better.

Think it could have started with the snowmobiles as they supercool so lagging really helped. As an aside we've seen the lagging to avoid heating the cases.

Clearly there was the overall change in timing of wave. I've lagged & HPC coated my 50 pipe (awaaay back in the day) & all it achieved was rust, maybe 100rpm move & no power change. I HPC coated my 500 pipes (250x2) for convenience (its a roadbike), thinking it would not do squat but keep it looking nice & unrusty but heck did it whap the peak revs up, maybe 1000rpm. Stripped them & went for boring old paint.


"Is there still a place for them?" I should think so; look at the Aprilia RSA125. There the cover does two things: shield the pipe from a cold air stream, but more importantly, as you can tell by the shield covering only the top half of the pipe: shield the crankcase from radiated pipe heat.
How much difference? We can only guess (which I avoid as much as possible) because nobody ever took the trouble of measuring the difference on a real track (were measuring the power would not be simple anyhow). The crankcase-shielding will give more power everywhere and the pipe-heat conservation will give more overrun which is extremely import for lap times.
249819

The insulated pipes also (for those that missed it) the first time arround i missed it before Frits mentioned the cases............

[Grumph]

Quick question for Frits or Wob - material for spacers on the piston pin for overhead rod guidance ? What works ?

Background - I was shown today two Suzuki TR500Mk3 cranks which use this method of rod location. The guy rebuilding them has had bad experiences with the spacers breaking up and is converting them to big end thrust washers.

Given that this era of racebike is now used in no more than 15 minute bursts I doubt if it'll cause a problem but I'm curious....

[wobbly]

7075 is the material of choice for the KT100 Yamaha that runs the upper end washers, but they are still no where near reliable as " proper " silver plated big end washers.

[RAW]

7075 is the material of choice for the KT100 Yamaha that runs the upper end washers, but they are still no where near reliable as " proper " silver plated big end washers.

7075 Aluminium has the highest ultimate tensile strength of all of the commercially available grades, However at elevated temperatures it becomes quite soft compared to most of the other commercially available grades, in short there's more to it than just the advertised room temperature data in the shiny brochure.

[RomeuPT]

I always start at the header and work along, these sections are easy to hammer and linish with a 25mm flap wheel in a die grinder.
The rear cone is thus the last and I use a length of 19mm Hi Tensile bar with the end radiused, clamped in the vise,to hammer the last joint smooth.
Make very sure the ALL grinding grit is wiped out, when the engine first fires all the shit will end up on the piston face and cause havoc.
I use argon purge inside when making Ti chambers, but its not really the weld thats the issue with mild, its the slightly uneven joint overlaps.
A hammered header radius looks and performs better than the as welded sections do.
Tig is way faster and WAY cheaper than a gas welded pipe, but I still think gas welding looks better if done right.

Thanks again, this is such a great topic, I cannot say otherwise...

Yes the exhaust's are tig welded, right :) I will hammer the curve a bit and try some grinding in overlap joints, mostly on the strong exhaust's...

I usualy make each cone with 6 or 7 of cut angle, so a joint will have a total of 12 or 14º angle. I think it was in the 2 stroke tuners handbook that each cone should not have more than 7,5 or so if I remenber...

I am using 1mm mild steel, cheap, resistant, relativelt easy to work, I think is the best compromise.

Possibly will try some stainless steel soon....

Regards

[wobbly]

You will find that 0.8mm cold rolled will make more power than 1mm every time.
If you want to get really tricky, make the header and last 1/2 of the rear cone in 0.6mm.

The upper end washers take a bashing over a much smaller bearing area than big end washers do, if the crank is not dead straight they fail from cracking - the lower strength
at elevated temps isnt an issue.

[F5 Dave]

You will find that 0.8mm cold rolled will make more power than 1mm every time.
If you want to get really tricky, make the header and last 1/2 of the rear cone in 0.6mm.
. . .
So we are talking cooling again? As the di get smaller but why at the end?

[RomeuPT]

You will find that 0.8mm cold rolled will make more power than 1mm every time.
If you want to get really tricky, make the header and last 1/2 of the rear cone in 0.6mm.

The upper end washers take a bashing over a much smaller bearing area than big end washers do, if the crank is not dead straight they fail from cracking - the lower strength
at elevated temps isnt an issue.

Well :) , why it makes more power in a theory explanation?
What is the difference between cold rolled and a spread sheet?

Actually the ideia is good for the final cone, or baffle, because is the hardest piece to work with, using of course just one cone for it..

Sometimes the cones go a little oval, not perfectly round, would that be utmost important to performance?

Thanks

[RomeuPT]

So we are talking cooling again? As the di get smaller but why at the end?

If you want to keep temperature...
I am thinking if the steel get's in play with the ressonance effect, and 1mm would "eat" some of the "energy"?

[wobbly]

1mm takes a long time to heat up, and in reverse takes a long time to cool down on trailing throttle into a turn.
0.8mm is the best compromise between weld strength and power.
0.6mm isnt easy to weld with good strength, but it does work "better".
Using thinner sheet at the header, and the end of the rear cone - the hottest areas in a pipe means they will heat up faster, getting the engine onto the pipe faster
but also they will cool quicker, equalising to the lower overall temp quicker on the overun.

I gave TeeZee a RS125 A kit pipe I made a while ago in 1mm to the Honda dimensions - it was useless on the dyno, but maybe he can take a pic of the hammered welds at the header to
show how nice it can be done.

[RomeuPT]

1mm takes a long time to heat up, and in reverse takes a long time to cool down on trailing throttle into a turn.
0.8mm is the best compromise between weld strength and power.
0.6mm isnt easy to weld with good strength, but it does work "better".
Using thinner sheet at the header, and the end of the rear cone - the hottest areas in a pipe means they will heat up faster, getting the engine onto the pipe faster
but also they will cool quicker, equalising to the lower overall temp quicker on the overun.

I gave TeeZee a RS125 A kit pipe I made a while ago in 1mm to the Honda dimensions - it was useless on the dyno, but maybe he can take a pic of the hammered welds at the header to
show how nice it can be done.

Thanks, and after the exhaust is covered with carbon inside, it still makes important difference?

Most 2t people here in Portugal, mostly DT and DTR 125 do drag races with friends at friday night... The exhaust's are not for track use, but may the same rule apply...

Regards

[F5 Dave]

whoa. erm thanks I think. might be time to go for a walk & think about that,

[wobbly]

Drag racing its more important - starting with a relatively cold surface the thinner pipe will heat up quicker.
I could also add that after several huge single malts I just " maybe " believed the VIP storyteller, that thinner pipe walls pulse or resonate more - but who knows, all I care is that they are faster.

[Buckets4Me]

Drag racing its more important - starting with a relatively cold surface the thinner pipe will heat up quicker.
I could also add that after several huge single malts I just " maybe " believed the VIP storyteller, that thinner pipe walls pulse or resonate more - but who knows, all I care is that they are faster.


I can tell you from experiance that the thicker the pipe the longer it lasts (very usefull in the 2 hour on a wet day)

thinner walled chambers don't tend to last well after being droped run over and chrashed into

[RAW]

Drag racing its more important - starting with a relatively cold surface the thinner pipe will heat up quicker.
I could also add that after several huge single malts I just " maybe " believed the VIP storyteller, that thinner pipe walls pulse or resonate more - but who knows, all I care is that they are faster.

Wobbly, whats your thoughts on an entire pipe in 0.6mm mild steel ?
I use annealed sheet when I can get it, hammering not only makes the flow superior but it also is a stress relief method, this can assist with reducing the tendency for cracking

[speedpro]

I've only ever used .8mm MS and can't remember a pipe cracking. I've had little problems with attaching the nozzle at the end of the rear cone sometimes but not because of the .8mm MS. I leave the pipes very loosely mounted and they really rattle around

[wobbly]

When young and silly I built a couple of sets of 0.6mm pipes for LC racing when I worked for JL in England.
They became quite famous, as the last I heard they had won at every meeting and championship going, and were sold several times for over 2000GBP
They certainly were fast and lightweight, but I never was able to get a back to back with exactly the same design in heavyer material.
However every racer was adamant they were the best thing since sliced bread on track.

[TZ350]

Page 790 ....

[Frits Overmars]

... every racer was adamant they were the best thing since sliced bread on track.Sliced bread on track is a good thing ? :p

[husaberg]

incisive wit is a kiwis bread and butter........:niceone:

[fatbastd]

Let's mix a few more metaphors!

Sliced bread and butter on tack? I'd be a pig in sh!t!

[TZ350]

Been away for work for a bit and on the way back managed to get some time at Len Southwards Car Museum.

http://www.southwardcarmuseum.co.nz/

283646283647283648

Ok not a motorcycle, but it is air cooled and a V8 to boot.

283649283645283650

Just love these big beast engines.

[TZ350]

283655283656283657

OK, now for a real air cooled 2-Stroke, Geff Perrys TR500R and Trophies

283652283653283654

And Ron Grants water cooled TR750R

[husaberg]

Been away for work for a bit and on the way back managed to get some time at Len Southwards Car Museum.

http://www.southwardcarmuseum.co.nz/

283646283647283648

Ok not a motorcycle, but it is air cooled and a V8 to boot.

Guy out at Kumara used to bring in these. They were probably a trade/barter to pay the dairy board instead of currency (like the lada's and Zetors)
http://www.truck1.eu/img/Truck_Tipper_Tatra_148_S3-ful-1701/1701_6732874783492.jpghttp://upload.wikimedia.org/wikipedia/commons/thumb/5/5d/Tatra_truck_chassis.jpg/310px-Tatra_truck_chassis.jpg
Air cooled rugged and 6x6 funny chassis-less articulated or Swing axle rear end as well.
From memory the Big Quarry in the middle of Dunedin used to run them as well.

Air cooled i guess is an advantage in the far northern winter

[RomeuPT]

I gave TeeZee a RS125 A kit pipe I made a while ago in 1mm to the Honda dimensions - it was useless on the dyno, but maybe he can take a pic of the hammered welds at the header to
show how nice it can be done.

Please Teezee!

[Buckets4Me]

Please Teezee!

thats if he can find where it's now hidden :rolleyes:

[FastFred]

Please Teezee!

He has been away on site down south, but is back in at work today, guess he will get it done ASAP.

[TZ350]

1mm takes a long time to heat up, and in reverse takes a long time to cool down on trailing throttle into a turn.
0.8mm is the best compromise between weld strength and power. 0.6mm isnt easy to weld with good strength, but it does work "better".
Using thinner sheet at the header, and the end of the rear cone - the hottest areas in a pipe means they will heat up faster, getting the engine onto the pipe faster but also they will cool quicker, equalising to the lower overall temp quicker on the overun.

I gave TeeZee a RS125 A kit pipe I made a while ago in 1mm to the Honda dimensions - it was useless on the dyno, but maybe he can take a pic of the hammered welds at the header to
show how nice it can be done.

The hammer welds on Wobblys pipe are a beautiful piece of work.

[RomeuPT]

The hammer welds on Wobblys pipe are a beautiful piece of work.

Thanks TZ, it is needs a paint :)

[wobbly]

The pic is showing how I lay out the sections to fit a pipe onto a bike in CAD - the part I hate,welding and hammering comes later.
Then the sheetmetal function in SolidWorks generates the patterns.
The design is to try to get the fat part of the belly forward, away from the chain and swingarm, so the diameter can be way bigger - more power egor.
Its being cut out soon, but it looks like I will be in Waikato Neurosurgery having an op on my spine to try and " fix " me,so wont get welded for a few weeks.
I will post a pic when they and I ,are done.

[RomeuPT]

The pic is showing how I lay out the sections to fit a pipe onto a bike in CAD - the part I hate,welding and hammering comes later.
Then the sheetmetal function in SolidWorks generates the patterns.
The design is to try to get the fat part of the belly forward, away from the chain and swingarm, so the diameter can be way bigger - more power egor.
Its being cut out soon, but it looks like I will be in Waikato Neurosurgery having an op on my spine to try and " fix " me,so wont get welded for a few weeks.
I will post a pic when they and I ,are done.

I love working with solidworks too, but wound't I need to have the coordinates of the frame, chain, swingarm, engine, etc to simulate and to fit the exhaust...!?

[F5 Dave]

Looks better than building them with No.8 wire & wire donuts like I've done.

Good luck with the op.

[wobbly]

If you look at the pic you will see a construction geometry sketch within the assembly.
This was measured directly off the exhaust port face, and sets where the clearance is needed under the engine, and the exit angle of the port.
Then I did an alloy welding wire centreline with cardboard circles, measured this, and that is on the sketch as well.
The pipe doesnt need to follow the centreline exactly, the important deal is the smooth shape, and ultimately has to clear the swingarm etc.
In this design, due to the forward push on the header, the smaller diameter part of the rear cone is well away from the chain etc, so will bend up close to
the footrests, getting tucked in as much as possible.
This allowed the design to go up to 125 belly diameter, a stock TZ, even with crossovers, is struggling to fit at 110 max without dents all over the place.

[F5 Dave]

Remote PJ solenoid:

So I've got my whappin great KX carb sitting on the shelf & as I'm finally getting around to fitting my Ignitech (MB100) I'm thinking about the next steps. I've decided I need some more work before I fit the 36mm so want to retain my RGV carb for the moment. (& ideally on the 50 that has zero over-rev)

It (RGV downdraft Mikuni) has a jet fitted PJ tube external exit out the floatbowl. It feeds into a hole at the top of the carb, but I can poke a tube into the venturi at a better position than std.

But what would be cute would be a small external mountable solenoid to block the flow, as long as I could robustly bolt it to the side of the carb. The Keihin one doesn't really suit that adaptation.

Any thoughts?

[TZ350]

Remote PJ solenoid:

But what would be cute would be a small external mountable solenoid to block the flow, as long as I could robustly bolt it to the side of the carb. The Keihin one doesn't really suit that adaptation.

Any thoughts?

283693

I put the plug lead on and the spark plug is for size comparison and its maybe better suited to bleeding air into the PJ valve to kill the suction than directly cutting the fuel but this little 12V 360mA item from JayCar ($32 from memory) was what I was planning on using with my IgniTec for a PJ cut off.

[TZ350]

283694283695283696

Three holes for the injectors and one screw to hold it all on, how hard can it be??? but it has taken me ages to get it all figured out.

I am looking forward to getting the rest of the bits and trying the EFI system out. There is a bit of finishing to do, but hopefully I will be able to get a more or less back to back comparison on the dyno with the old carb.

283697

Found this on the net, looks like there are still a few good looking original Suzuki GP's about.

[husaberg]

Remote PJ solenoid:

So I've got my whappin great KX carb sitting on the shelf & as I'm finally getting around to fitting my Ignitech (MB100) I'm thinking about the next steps. I've decided I need some more work before I fit the 36mm so want to retain my RGV carb for the moment. (& ideally on the 50 that has zero over-rev)

It (RGV downdraft Mikuni) has a jet fitted PJ tube external exit out the floatbowl. It feeds into a hole at the top of the carb, but I can poke a tube into the venturi at a better position than std.

But what would be cute would be a small external mountable solenoid to block the flow, as long as I could robustly bolt it to the side of the carb. The Keihin one doesn't really suit that adaptation.

Any thoughts?

Ten carrots

Right i had a wee search on the net.
The genuine kit is a little expensive, I couldn't find the Keihin but here is the Mikuni, as you know i had already posted this.$303nz.
Maybe the Keihin kit is less expensive.

I haven't had the chance to look through Sudco yet.
Had a wee look at Sudco it seems the soilniod is not listed as a separate part bugger.

Here is one from the UK Mikuni person no prices.
http://www.allensperformance.co.uk/products-power jet kits.html

I also found this with the dimensions of a lot of inlet manifolds etc
http://www.allensperformance.co.uk/products-manifolds.html

TZ's keihin copy carbs i believe have a Powerjet the obvious way to me for a budget conscious bucket racer would be to modify this for electric use with a car solenoid.

There is another option but i am not posting that until i have got one myself.



Nice explantion on powerjets here no that theres anything wrong with wobs.
http://superkartaus.com/Forums/index.php?topic=77.0;wap2

Adjustable powerjet it looks like it would be easy to make as well addthis with an electric controll or just adjust the pulse to your needs as Wob said would be very6 Sexy but prob a bit OTT.

http://www.twostrokeracelab.com/search/label/Adjustable%20Powerjet

The rest of the site is well worth a look as well.

Here is a 12volt solenoid that looks capable assuming there isn't a car wrecker part to suit around.
I have priced the Genuine Mikuni kit a $200 US so it is a tad expensive.
Remember though what ever the set up it has to be so if it fails it will not lean out the mixture.For obvious reasons

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]-->
<tbody>
<form> Tubular 12V Solenoid

Compact size, Push type.- Coil resistance 25.6- 20 watt @ 25% duty cycle.- Pushing force 220 - 940g (25% duty cycle).- Stroke 1.0 - 6.0mm (25% duty cycle).- Total weight 23g.- Full data supplied with unit.

</form>

<tbody>

QTY




1+
$41.90



5+
$37.90



10+
$33.40

</tbody>



</tbody>


http://www.jaycar.co.nz/productResults.asp?MID=1&SSUBID=730&SUBCATID=983&keyform=CAT2

Of course if stepper motors are more your deal there is this.

<!--[if !mso]> <style> v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} </style> <![endif]--><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman";} </style> <![endif]--> file:///C:/DOCUME%7E1/Owner/LOCALS%7E1/Temp/msohtml1/01/clip_image002.jpg
12VDC 48 Step / 7.5° Stepper Motor

• Standard 48 step / 7.5° design.
• Flange mount 3.0mm hardened steel shaft.

Specifications:
• Rated voltage: 12VDC
• Rated current: 1.1A/phase
• Phases: 4
• Steps per revolution: 48
• Stepping angle: 7.5°
• Drive method: Unipolar chopper drive
• Resistance per winding: 20 ohms
• Starting frequency: 600pps (max)
• Holding torque: 700g/cm

<tbody>

QTY




1+
$23.90



5+
$21.30



10+
$18.90

</tbody>


http://www.jaycar.co.nz/productView.asp?ID=YM2754&keywords=12v+stepper+motor&form=KEYWORD



With todays technology the bar can now be raised to around 40 crank Hp without too much drama involved, and thus achieving around 35 RWHp.
Its just a matter of careful parts selection and very careful assembly.

The alloy inserts for the TZ350 was the customers choice - once its all proven, and we get a handle on what the engine likes, then I will do some bronze ones.

AvGas in NZ is all LL100, this is low lead 100 octain.But the rating is defined differently in avaition.Its approx equiv to 100 "pump" gas, but has a lean rating of 100 and a rich rating of 130.
MNZ Appendix E defines avgas as max 112 MON amd max 108 RON.

Avgas, or any leaded "race" fuel reacts completely differently to unleaded pump gas.
In general terms the unleaded hates compression, but loves timing.Avgas is the opposite in that it makes more power up to the knock limit with more com.
Unleaded makes better power when run rich,avgas makes more the leaner you go.
Tuning in the old days with RS and TZ engines meant using lean mains and small powerjets ( 35 ) as turning off a big jet over the top would mean being too lean in the overev.
Nowdays the unleaded fuel runs rich at peak power, then uses a big powerjet ( 55) to create some heat in the pipe over the top.

[bucketracer]

283697

Found this on the net, looks like there are still a few good looking original Suzuki GP's about.

Nice bike but hard to imagine as a fire breathing monster, these little old Suzukies are a real wolf in sheeps clothing.



283694283695283696

Three holes for the injectors and one screw to hold it all on, how hard can it be??? but it has taken me ages to get it all figured out.

30+hp then EFI, this would have to be a World first for a commuter bike from the 80's.

I hear there is another radical mod or two coming, but what could be even more radical than this ....:scratch:

[chrisc]

283697
Found this on the net, looks like there are still a few good looking original Suzuki GP's about.

Haha that really cracked me up. That's my old man Simon having a crack around the driveway before it all came apart as the donor for my RS-GP125. It definitely looked in better condition in the photos than in real life :sweatdrop

[TZ350]

Haha that really cracked me up. That's my old man ...

Yep I thought it was pretty good too, seeing him on the net.... :)

[F5 Dave]

Thanks for ideas gen kit looks good but too spendy for me. Pretty tall too. Air bleed not right for gas . OThers require a seal on end and machined seat.

[Buckets4Me]

<iframe width="560" height="315" src="http://www.youtube.com/embed/eu3NEPSBfUs" frameborder="0" allowfullscreen></iframe>

dads been talking about 2 stroke fuel injection (thinking he was the first)

<iframe width="560" height="315" src="http://www.youtube.com/embed/Y91Jms6MyCY" frameborder="0" allowfullscreen></iframe>

[wobbly]

ETec is insanely superb patented technology, the dickheads in the other video gave up as they couldn't get it to " work " even though they were touted as the next best thing to sliced bread on track.
Mixed wotnots and sarcasm fully intended.

[husaberg]

That PV blade directly opening the auxiliaries is quite cute.

http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=283756&stc=1&thumb=1&d=1370593028
Lozza often says the Gas Gas (i think it was the gas gas or maybe tm?) system is the ducks guts (Just like the mad max interceptor)
how does that one differ?... two stage blades? Never seen one Must google it........
is it a cross between the Kawa kips on the KR1 and the Blade PV?
<img src="http://thumbs4.ebaystatic.com/m/moW8scq3_CxhbL7BSmBc-Dg/140.jpg" width="340px"/>

[Frits Overmars]

......the next best thing to sliced bread on track. Mixed wotnots and sarcasm fully intended.Glad to see you strike back, Wob :2thumbsup.

[wobbly]

Yea maybe a bit like Beck poking his tongue out at Clapton, a respectfully intellectual exercise .

But in a dissimilar vein here is some pervage for the boys,this isnt on track, its on the rubbish tin - and yes I know the floor needs sweeping.
Pre 82 Classic Frepin copy frame I have FEA corrected with TZ400 and S model fairing Billy is hoovering up now.
Coming together for Philip Island next January.
Late model Yamaha blue - tank/fairing will be a bit like Roberts colours.

[Wolfie's Girl]

Hi all...
I have been reading this thread from the beginning. I haven't posted anything as yet due to the fact that I have not really had anything constructive to add. I have however been busy in the garage... To wit I have a couple of pictures to share with you. TeeZee asked if he might post the pictures that I sent him, but I said that I would rather post them myself so that I can give insight in to the build.

Here we have the first mock up...

283772283773

From this it was clear that I was going to need to pick some brains before I went any further as I have never attempted anything like this before. A virgin to re-powering a bike. So as I just live across the valley from F5Dave it was to him and another wonderful friend Mike Chandler I turned for advice. ;)

The build progressed at what seemed like a pretty slow pace, but I have been told it was actually pretty quick. First the rear engine mounts....
283775283776

[Wolfie's Girl]

Then I started to tackle the Front mounts, F5Dave gave me the idea to use the triangles to create the front mount, and it was then that I realised I could use the original front isolating bushes of the donor chassis to mimic the original mounting scenario...
283786

I made up the angle brackets and the bushes that were going to form the top of the front mount and then handed the frame over to Mr Chandler who got an unnamed gentleman to tig the brackets on. I think you will all agree he made an amazing job of it!!
283787283788

The bike was finished in time for the May club round here at Kaitoki, which was wet, and as I had only ridden it for the first time the day before in the wet all seemed well....:woohoo: Still I was a little worried about the pipe, as it looked like it would get close to the ground, but as I say, it was wet for the first two races....
When it dried I put the slicks on just in time for the third race. This was to be my undoing... I went out on the warmup lap and started to feel like I was getting some heat in to the tyres, so I could attack the corners with a bit more vigour and as I came up the straight for the first time with a bit of pace in I tipped in to turn 1 and the pipe ecked out and it was time for me to exit stage left at the fastest part of the track... :crybaby: I think that I now only have one corner left at Kaitoke that I haven't crashed on....:weep: Still it was a very positive outting realistically!! The bike performed amazingly well straight out of the box and I am really looking forward to the next round!!

283789283790283791

[chrisc]

Nice! Great pictures of the mounts.
Does it vibrate a lot? Anything done to the engine besides the pipe?

[husaberg]

Yea maybe a bit like Beck poking his tongue out at Clapton, a respectfully intellectual exercise .

But in a dissimilar vein here is some pervage for the boys,this isnt on track, its on the rubbish tin - and yes I know the floor needs sweeping.
Pre 82 Classic Frepin copy frame I have FEA corrected with TZ400 and S model fairing Billy is hoovering up now.
Coming together for Philip Island next January.
Late model Yamaha blue - tank/fairing will be a bit like Roberts colours.

Sure is pretty. frame the top shock mount design is a little odd though can't figure out why its like that.(yes i realise it is a replica)
form rather than function? Still rather purposeful and elegant.

[Ocean1]

Sure is pretty. frame the top shock mount design is a little odd though can't figure out why its like that.(yes i realise it is a replica)
form rather than function? Still rather purposeful and elegant.

Does look good.
Can I guess? Most monoshocks were the opposite of rising rate, the extended shock minimises that "incorrect" rate of change. It also feeds the rear suspension forces into the strongest part of the frame.

[Wolfie's Girl]

Nice! Great pictures of the mounts.
Does it vibrate a lot? Anything done to the engine besides the pipe?

Hi ChrisC, it isn't too bad. It doesn't vibrate anymore than the original '93 RS 125 engine of the donor bike. As to the engine mods, it has a little bit of porting but that is it, my arse dyno says about 17-18hp. I have just put an OKO 24mm on it this week, and I am not having much luck tuning it at the mo, it doesn't want to pull off the bottom, it's a little lean down low, and it won't idle at all, so i may put the original GP carb back on so that I can go up to the track tomorrow. I will hopefully get on the dyno to tune the carb if F5Dave gets his motor back together and we can get to the dyno.:yes:

[husaberg]

Does look good.
Can I guess? Most monoshocks were the opposite of rising rate, the extended shock minimises that "incorrect" rate of change. It also feeds the rear suspension forces into the strongest part of the frame.

er...The mount was my query.......
Ok must have not explained it properly........
The attachment should clear that up......


Fred McLean and Peter Pinion made their first TZ frame in Addington, New Zealand around 1976 (http://www.tz350.net/aftermarket_frames.net.htm) utilising 10-10 gauge cold drawn seamless tube steel with very few bends and radical bracing in line with their experiences building racing car chassis. The frame had no bottom frame rails and utilised just the top front engine mount and had a trick combined rear engine mount - swingarm pivot.

They claimed their complete TZ350 weighed 13kg less than a stock TZ350 of the time and apparently Marco Lucchinelli asked them three times to ride it when he visited New Zealand and wanted to take one back to Europe with him. It's said that just 6 or 7 were ever made.



Addington were the boys working for the railways.
http://www.tz350.net/images/frames/aussie_frepin_frame.jpg

[RomeuPT]

Frits I am using the flywheel program to calculate the roller for the dyno project, input four is saying to insert 0 "zero" for measuring by the rear whell. But when I insert zero it does not accept the value and is back waiting for the same input.

Am I doing something wrong?

Thanks

RESOLVED :D

[RomeuPT]

Are this values acceptable for a start? It's a dyno for 2 tuned strokes from 50cc to 200cc or more

Thanks

[Frits Overmars]

Are this values acceptable for a start? It's a dyno for 2 tuned strokes from 50cc to 200cc or more.They are more or less acceptable. If you wish to measure all the way from 6000 to 15000 rpm, you will certainly have to pass through the torque dip at 2/3 of max.torqe rpm and this may give a mispresentation of the total acceleration time; most of this time will be spent getting through that dip.
Of course you will want to measure an 'entire' power curve occasionally, but in order to establish the flywheel dimensions for a given task it will be wiser to feed the flywheel program with the initial and final rpm values of the power band, and a matching acceleration time of maybe 5 to 6 seconds.

[Ocean1]

er...The mount was my query.......
Ok must have not explained it properly........
The attachment should clear that up......

Ah, yes. No, the words were crafted OK, was the interpretation at fault.

The mount looks good though, deals with the load distribution into the frame well without undue weight...

[chrisc]

Hi ChrisC, it isn't too bad. It doesn't vibrate anymore than the original '93 RS 125 engine of the donor bike. As to the engine mods, it has a little bit of porting but that is it, my arse dyno says about 17-18hp. I have just put an OKO 24mm on it this week, and I am not having much luck tuning it at the mo, it doesn't want to pull off the bottom, it's a little lean down low, and it won't idle at all, so i may put the original GP carb back on so that I can go up to the track tomorrow. I will hopefully get on the dyno to tune the carb if F5Dave gets his motor back together and we can get to the dyno.:yes:

Sounds good! I really should have fitted my engine and got it running in my NF4 chassis before diving balls deep into the casings and cylinder with a grinding burr but ah well. Seeing yours going is some good motivation.
I believe ESE boys made some respectable power (20rwhp or slightly more?) with the stock carb before switching to a 24mm.

[wobbly]

Yea the frame is pretty much as Fred designed it in 79 except for some additional tubes to close triangles correctly, and I redesigned the rear engine mount.
The original had rubber bushes within the tube spacer between the swingarm bearing bosses.
This has the bushes fitted into alloy bosses welded onto the case - much stronger as confirmed by FEA of my CAD frame model.
That front mono mount is not how I would have done it,but changing the design too radically to save a few grams , wouldnt then be a period legal copy so much.
I added a couple of triangle corner plates to strengthen the swingarm mount bosses, as I have an original Frepin here, that had a 700 grafted in, and the RH swingarm mount
had been bent forward by the chain pull.
Not that the 400 will have as much snot as a 700 but good design is always better if it reduces deforming frame stress.
The mono is slightly rising rate, as the framework above the swingarm initially pushes at an angle and approaches a right angle to the shock centre line at near on full compression.

[TZ350]

Then I started to tackle the Front mounts, F5Dave gave me the idea to use the triangles to create the front mount, and it was then that I realised I could use the original front isolating bushes of the donor chassis to mimic the original mounting scenario...
283786

283791

I like the front engine mount arrangement, looks much better than ours and its great to see another GP/RS125 out there.


I believe ESE boys made some respectable power (20rwhp or slightly more?) with the stock carb before switching to a 24mm.

Yes, low 20's is possible with the original carb.

283844283845

We got most of our power by opening up the rear transfers and making the port windows as wide as possible. Low and wide transfer windows maximize the exhaust port blow down time area and therefore the power that's possible. In the end, the 24mm carb restriction proved to be not that much of a problem for 20+ hp.

[RomeuPT]

They are more or less acceptable. If you wish to measure all the way from 6000 to 15000 rpm, you will certainly have to pass through the torque dip at 2/3 of max.torqe rpm and this may give a mispresentation of the total acceleration time; most of this time will be spent getting through that dip.
Of course you will want to measure an 'entire' power curve occasionally, but in order to establish the flywheel dimensions for a given task it will be wiser to feed the flywheel program with the initial and final rpm values of the power band, and a matching acceleration time of maybe 5 to 6 seconds.

Your total transmission ratio looks like a crankshaft/clutch ratio. If that is also going to be the total ratio between crankshaft and flywheel, that will imply a gearbox ratio of 1 (could be top gear; no problem) and a final chain transmission, also with a ratio of one. And the latter could be a problem because you will probably not be able to fit a sprocket as large as the rear chain blade.

If I can't calculate a 250cc under 8000/7000 I would miss the whole botton end :/ and if I can't see 15000 I would miss a 50cc overrev. I have a lot of experience in C# programing, I will use the best of it to design the dyno software to be adjustable :)

Ok, using a NSR 125 stock as example, stock cluth, stock gearbox and transmission, 1850 mm tire piremeter, 350 mm flywheell, gear 4 (0.8258) I've got 0.6 ratio...

Thanks

[TZ350]

283874

283875

Final AMCC F4-F5 Bucket and sidecar results for the season curtsey of Dave D.

[TZ350]

I expect that with a bit more time on the dyno we will get Kels Av Gas curve to extend out like the red line does.

283883

Kel brought his air cooled KE125 engine around after running it at the track during Saturdays practice on Av Gas.

283880

The inside of the piston crown is quite dark.

But the (cheapish) glue inside the piston sealing the exhaust bridge oiling holes has held up OK.

283878

The area around the exhaust port under the ring has quite a wide wear mark.

283879

And a lot of staining on the piston itself.

283881

Staining in the cylinder.

283882

And in the transfer ports.

Is this signs of revving it well past its exhaust blow down STA, caster based oil or both?

[husaberg]

Kel brought his air cooled KE125 engine around after running it at the track during Saturdays practice on Av Gas.

And a lot of staining on the piston itself.

Staining in the cylinder.

283879

And a lot of staining on the piston itself.

283881

Is this signs of revving it well past its exhaust blow down STA, caster based oil or both?
I will let Frits and Wob answer but some acetone should remove it nicely:innocent:

[wobbly]

First reaction is that its a blowby problem with ring seal, as the only place it isnt happening is on the highly loaded thrust face around the Ex port.
It also isnt happening around TDC where the high gas pressure is forcing the ring onto the bore.
So - is the ring true in the bore, slide it down the cylinder with the piston to see if light shows anywhere.
Was the cylinder honed with a dummy head and a torque plate clamped with the studs.
An air cooled Yamaha KT100 will make no power and blow by badly , just like that ,if not finish honed hot with clamp pressure simulating the studs torqued up.
They end up near 0.1mm out of round when cold, and out of the jig.
The hot piston crown may just be a by product of the compromised heat path thru the ring ,to the bore.

[kel]

I also thought this was a blow by problem, but the motor is putting fantastic power to the ground (for a home built bucket), wheel spinning and wheel standing out of corners!
I had made a couple of changes since the last time out -
1. used a different oil, changed from Elf909 to Silkolene Pro KR2
2. rev limiter was lifted to 13250
3. main jet and needle were leaned off a touch, although richened up again later in the day
I was also riding it harder. (The bike showed its appreciation by throwing me down the track twice)

I had the head off a month ago (the last time it was run before this weekend) and the staining in the bore was not present, at that time the rev limiter was set to 12500.

Bore was honed by a kart shop but it was just a straight hone, no jig, no pre-heating, at least I don't think they would have gone to this length for the $20 they charged.
Bike has done enough hours for a new ring, might as well have a new piston as well, and have it all measured and set up properly. Wobbly can you recommend a kart shop that follows your honing procedure.

[TZ350]

An air cooled Yamaha KT100 will make no power and blow by badly , just like that ,if not finish honed hot with clamp pressure simulating the studs torqued up. They end up near 0.1mm out of round when cold, and out of the jig.

I made a set of boring and honing jigs for myself when I was running RD's back in the day. So yes I guess its time to make some more torque plates for our air cooled KE and GP engines. Probably be able to make one jig that suites both engines.

[Haufen]

EVERY weld on a mild steel pipe should be hammered on a mandrel, and the ones in the header linished with a flap wheel, or simply throw away 2 to 3 Hp.

Thanks for that, I was just about to build my next pipe without hammering the welds. (but I am sure my neighbours will understand :2thumbsup)

I've got another pipe build question: Do you join the pieces with different angles, header and diffuser for example, with an angled cut, too? Eg the end of the header and the beginning of the first diffuser both cut at 5 degrees each, to make a 10 degree change in direction. In this case, the area of the oval of the first diffuser would have a greater area (because the angle of the diffuser is bigger) and one would get a small step in the pipe.

At the moment, I do not change directions in the pipes where cones with 2 different angles are connected. But it would make life easier if I knew I could, or if I knew that this can be compensated by, for example, altering the cut angle of one part until both areas are the same.

[wobbly]

Yes you can change angles and have an angle cut in the same place.
It doesnt affect the pipes performance at all, but sure as hell makes a huge difference to the form of the build.
Pipes look " dumb " needing a straight join,with angle cuts on each side, and it also means the other angle cuts have to be steeper to accomodate the straight piece.
Here is a cut and join exactly as described - the last diffuser joining the mid, to give a straight line on the bottom.
When the pieces are done in CAD the cone ends are lengthened a little, then the cut goes across the correct length on the centreline, no step and no area change at the joint of the two differing angled cones.

[RomeuPT]

Yes you can change angles and have an angle cut in the same place.
It doesnt affect the pipes performance at all, but sure as hell makes a huge difference to the form of the build.
Pipes look " dumb " needing a straight join,with angle cuts on each side, and it also means the other angle cuts have to be steeper to accomodate the straight piece.
Here is a cut and join exactly as described - the last diffuser joining the mid, to give a straight line on the bottom.
When the pieces are done in CAD the cone ends are lengthened a little, then the cut goes across the correct length on the centreline, no step and no area change at the joint of the two differing angled cones.

What is the maximun bend you would recomend? Even if they are hammered?

I am working on a 125 project, using a YZ 125 2001. Does somebody have info about ignition timing/curve and exhaust dimensions?

Thanks

[wobbly]

Max cut angle on each face should be no bigger than 8* - this will not loose power if the cuts are hammered as per the pic of the RS125 pipe I did.

[TZ350]

http://ignitech.cz/english/aindex.htm

OK I was asked about getting an DC-CDI-Race-2 IgniTec Ignition to fire, this is what I remember about setting one up for the first time.

283909

If there is no spark at all it may be that the Kill switch polarity needs reversing.

ie you have a normally closed switch for ""stop when open"" and the IgniTec might be set up for ""stop when closed"" and ""run when open"", so the Ignitec would need need to be reversed.

Also, from memory the DC-CDI-Race-2 IgniTec does not fire below 300rpm. Push starting is faster than 300rpm but spinning the back wheel over by hand may not be.

A DC-CDI-Race-2 Ignitec is voltage regulated and will not fire below 8 volts (I think) or above 18 volts. Lots of on track miss firing is due to the battery voltage dropping too low when the Ignition is revving out under load.

283915

For accurate timing its important to have the ignition triggering of the back of the lobe, ie on a falling voltage.

You can change the polarity of the pickup here.

283914

For a single with only one coil and pickup and firing once a revolution the setup needs to be changed.

283912

This twin cylinder DC-CDI-Race-2 IgniTec ignition set up will now fire on only one channel, the other side is turned off.

283907

The next step is to work out the base advance.

With the piston at TDC measure the number of degrees between the heal of the lobe and the trigger.

You only need something thats in the ball park to get started with.

An eyeball with a protractor and near enough is good enough here as it gets adjusted later.

Although you are limited to a maximum base advance of 30 deg or 40 on newer software so you might have to move the trigger to get things right.

283911

The 21 deg base advance is entered here.

The next step is to make a flat line graph. Here we have made it 15 deg, only because we know that's what this motor likes.

Next step is to carefully put a timing mark on the flywheel at 15 deg BTDC.

And with a timing light adjust the base advance until the 15 deg flywheel timing mark lines up. When it does, that means the 15 deg ignition line is spot on.

Now when you adjust part of the curve to say 17 deg you can be pretty sure the Ignitec is firing 17 deg BTDC there.

Bucket goes through the setup routine in his post, including a short clip of him using the dyno to spin the engine over while he adjusts the base advance to get his flywheel timing marks to line up.


I got the job of setting up NedKellys IgniTech programmable Ignition. This is how I went about it with one of the Team ESE's bikes.

[RomeuPT]

Max cut angle on each face should be no bigger than 8* - this will not loose power if the cuts are hammered as per the pic of the RS125 pipe I did.

I don't know if it was said before, but about stainless steel, can we use a thinner 0.6 mm stainless steel as strong and ductible as 1mm mild steel? What about welding difficult, prices, performance (as stainless steel has lower thermal condutivity)...

Thanks :)

[wobbly]

An Ignitech will fire below 300 rpm if its connected to a battery.You can simply spin the rotor lobe back and forth past the trigger by hand and it will fire.
Also the RACE box has a test page where you can press a screen button and fire each channel to check everything is working electrically - past the trigger input.
Once the rotor is spinning, the input screen will automatically show the trigger polarity, so you can change it, or simply use auto that selects the trailing edge by default.
Again I say for the 1000th time - YOU MUST USE A RESISTOR PLUG AND CAP.
Nearly every day I get to fix these bloody things playing up simply due to this rule being ignored.
The other thing that can cause problems is keeping the coil drive wire away from TPS and power wiring,if not done you get false input triggering that makes the rpm as seen by the ECU double
or treble in value - it then invokes the rpm limiter and suddenly we have a " misfire " at 4000 rpm that shows as 12,000 on the screen.
But alot of this can be "seen " on the screen when the engine is running and is easy to diagnose.

Stainless pipes are an absolute bitch to make due to the material stiffness, use 304 as its soft and you MUST use gas purge inside the chamber or the welds will be shit and it will crack.
The material has no performance advantage over mild, it dissipates heat a little differently, but for a road bike it does look nice.

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/IMG_8860_zpsd6b580d7.jpg

http://i1056.photobucket.com/albums/t380/uniflow/IMG_8844_zps7b02a2a2.jpg

http://i1056.photobucket.com/albums/t380/uniflow/IMG_8817_zps9e758176.jpg

I run an ignitec, fires ethanol under high comp no problem. In fact the unit has been trouble free, not even fouled a single plug in two years of tuning on ethanol. Only problem I did find is if you use the coils Wobbly supplies just check that they are not open circuit before you use them, although I would say he puts the meter over them now before they are sent out.
Super adjustability, great for engines that are a little bit different. Cost effective too.
I'll be trying one of the Ignijet ( EFI and CDI all in one box ) units shortly, can't wait!
Pictures of the Saturday Epic Events trail ride, only EFI twostroke entered, imagine that.
A lot of modern fourstroke bikes lying on the side of the track? F9 never stopped once, this bike is a lot of fun to ride!

[F5 Dave]

The thing that got me was a newbie mistake. I didn't have the "Programming after Change" box ticked so any changes I made were on the screen & not pushed through to the box, unlike the old Zeel programmer I have where you can change on the fly but have to save at the end, the Ignitech you have the choice, but you have to be aware of it.

really the documentation is pants, but as you said, is obvious once you've shagged around.




h (http://ignitech.cz/english/aindex.htm)


For a single with only one coil and pickup and firing once a revolution the setup needs to be changed.

283912



Hmm, I've just got mine set to Classic, so do I need to set up in special as a single, or just leave the input open never getting a signal?


I'm struggling to get a Baseline sorted. It looks stable spinning the back wheel by hand but adjusting the baseline on the PC doesn't seem to change the position. I've even taken the rotor off & moved it as it seemed to be out of range, even though I have the same setup as Mike's MB (& have to remark 15deg).


PS mine is the P2.

[wobbly]

You cant leave the " input open never getting a signal ", the P2 will always fire both CDI with a single pickup when in classic mode.
The unused CDI will eventually die if it is run continuously without a coil connected.
Thats why I gave everyone the info on turning off the second cdi in the software.
Even easyer is to simply leave the ecu as its programmed, and parallel the cdi outputs into one coil.
That way you get twice the spark energy at the plug, as Niel has used forever on his F9 injection Ethanol burner.
The arc over voltage is the same but depending upon the inductance of the coil you will get up to 4 times the burn time of the arc as the caps discharge into the ionised gap.

As you say you can run program after change, but I prefer to do all the changes, check them,save the file with a new name, THEN program the box and finally hit " verify ".
This does a checksum, to confirm whats in the ecu matches the screen.

[F5 Dave]

Thanks, have been saving some files, but just at the start to try get some sparks happening (other than the test fire button which was a great releif).

erm, to be fair you didn't give me any info with the box. If you have some other tips I'd be keen as I'm still trying to sort out stuff, mainly the base advance.

[F5 Dave]

You cant leave the " input open never getting a signal ", the P2 will always fire both CDI with a single pickup when in classic mode.
The unused CDI will eventually die if it is run continuously without a coil connected.
Thats why I gave everyone the info on turning off the second cdi in the software.
Even easyer is to simply leave the ecu as its programmed, and parallel the cdi outputs into one coil.

So connect both outputs. What about the other input wire?

[F5 Dave]

. . .
Again I say for the 1000th time - YOU MUST USE A RESISTOR PLUG AND CAP.
Nearly every day I get to fix these bloody things playing up simply due to this rule being ignored.


My short reach plug don't have resistor but I have a WC head with an extender welded on so I can run one, but not this weekend. Fortunately the CDI is located under the seat so it has some separation. I'll find the highest resistence cap I have until then.




. . .

The other thing that can cause problems is keeping the coil drive wire away from TPS and power wiring,if not done you get false input triggering that makes the rpm as seen by the ECU double
or treble in value - it then invokes the rpm limiter and suddenly we have a " misfire " at 4000 rpm that shows as 12,000 on the screen.
But alot of this can be "seen " on the screen when the engine is running and is easy to diagnose.


The wires all are close for about a foot of the wire loom, but then branch out to the coil which is a ways from everything. Is that adequate.

Thanks for the help. I'm short on time till this sunday's race. Mines the P2, not P2 race.

[wobbly]

Easy for anyone to go online to Ignitech and read the manual, but to be fair also they dont, and should, have in big red capitals a line saying
" IF YOU DONT USE A RESISTOR PLUG AND CAP IT WILL SHIT ITS PANTS ".
P2 or Race - or any electronic ECU system needs RF suppression - all TZ and RS race engines have them from the factory.

All plugs including short reach are available in resistor 5K config, and I have seen a 10K resistor cap, that would work without a resistor plug as well.
Another option is to use spiral wound coil wire, made for race CDI systems such as MSD or better, I have run this without a resistor cap on the twin fire system using a race resistor plug and it worked fine.

[F5 Dave]

There are a lot of little things they don't say in the manwell, I wasted a night trying to get a spark just because I didn't click that you needed to push the changes into the CDI. Sounds obvious when you have played with it, but when you are looking at something on a screen & you change it, you assume it is changed. Why no Worky? :brick:

There is no mention of the single set up, so thanks for that info, but what of the other input?

[RomeuPT]

Stainless pipes are an absolute bitch to make due to the material stiffness, use 304 as its soft and you MUST use gas purge inside the chamber or the welds will be shit and it will crack.
The material has no performance advantage over mild, it dissipates heat a little differently, but for a road bike it does look nice.


Many thanks wobbly, I think I will stay with my mild steel pipes then :)

[TZ350]

but what of the other input?

I leave mine disconnected.....

[F5 Dave]

thanks. maybe I'll have to start the bike & check with the timing light, but did seem to be flashing ok turning by hand & with battery (plan to lose the battery in race use as charging cct works, or at least I'll monitor it later to see its holding up under load).

[F5 Dave]

Oh hold on.


So if I set a flat curve & then adjust the base advance, i'd have to set the first point at say 200rpm or I can't spin the rear wheel to 1000rpm perhaps? therefore it won't see the correction. Maybe?

I haven't been able to start the bike & wake kiddies while working on it at nightime.

[wobbly]

The first changeable point available is 300 rpm, it fires on the base advance up to 300 then switches to the programmed curve.
Its easy to set a straight line at TDC ie 0* advance,as then you can do it just with a DTI in the plug hole - no protractor or calculations needed.
Set it at TDC and mark the rotor and stator with a felt pen line.
Leave the plug connected on the head, but not screwed in , and its easy to spin the rotor with an electric drill and a socket on the rotor nut - no racket involved, kids snore on unaware.
Strobe the lines - advancing the base advance retards the firing point.
I like to keep the base advance near 10* then there is little chance of it kicking back and trying to start in reverse.
All this is super easy on the dyno of course using the starter on the roller to spin it over.

DO NOT run the charging circuit without a battery or a capacitor .
Without a load the rec/reg can fire out up to 80V and then some smoke comes out of the Ignitech.
With no smoke inside it tends not to work at all, and yes I can tell if this nastyness has been inflicted on the poor thing ,so then it will cost money to fix.

[F5 Dave]

Hey that's an even easier idea, I'll run with that.

I tried to think of a way to connect to my drill (my socket adaptors went the wrong way) but it was easy to spin the rear wheel with the plug sparking on the head, but I didn't consider I wasn't going fast enough. I can always use the airgun if I fill the compressor earlier,

-ahh its belt drive its quiet enough anyway. they sleep through the lathe & sometimes the grinder, - just though firing up the bike in the driveway or under the house would be a step too far.

The reg/rec I have is a *onda CR one & has a heatshrunk covered Cap wired to it, but good points.

I work in the electronics industry, but I let other people deal with the regassing of ICs which have sprung a leak these days.


0* is great idea & DTI easier to use if I need to move the flywheel on the taper.


Thanks Wob. When I get some more funds I must get one for the 50, but it is almost a waste to run without an external solenoid to PJ the smaller carb. That's one bike that could seriously use some more over rev.

[wobbly]

The ECU detects that only a single input is being activated by a trigger - in classic it then fires both outputs automatically and simultaneously.
Perfect for a Rotax tandem twin, thats why i got Ignitech to add a trim function for each cylinder.
In special mode you can elect to turn one output off, and run the whole thing as a single system.
Other menus allow such things as firing a 180* twin off a single trigger by using a multi tooth rotor so that the ECU recognises cylinder 1 then 2 in turn - waste spark is dumb and
unnecessary now we have this technology available.

[speedpro]

Other menus allow such things as firing a 180* twin off a single trigger by using a multi tooth rotor so that the ECU recognises cylinder 1 then 2 in turn - waste spark is dumb and unnecessary now we have this technology available.

All well and good. However unless your tandem twin is a 2T you still need some way of determining which cylinder is on compression and needs a spark this time around. The Ecotrons system uses MAP sensor fluctuations to determine where in the cycle one cylinder is.

[wobbly]

The Ignitech DC CDI P2 ( or RACE ) was designed for a 2T ( like a Rotax tandem for example ) using low ohm coils driven by a capacitor.
They make the usual 12V switching units as well, but both can be programmed easily for non waste spark on a 4T by using a cam sensor that identifies cylinder 1.
I have built both systems on old Ducati Bevels and running waste spark on a slow reving 4T works fine without the complexity of having to make a cam sensor setup, just two sensors
in the side cover at 90* with a single rotor lobe.
The CDI system makes identical power to the 12V on a dyno, but the riders swear ( alot ) that the cdi feels better on track re throttle response.
PS - never heard of a tandem twin 4T, enlighten me?

[Haufen]

Yes you can change angles and have an angle cut in the same place.
It doesnt affect the pipes performance at all, but sure as hell makes a huge difference to the form of the build.
Pipes look " dumb " needing a straight join,with angle cuts on each side, and it also means the other angle cuts have to be steeper to accomodate the straight piece.
Here is a cut and join exactly as described - the last diffuser joining the mid, to give a straight line on the bottom.
When the pieces are done in CAD the cone ends are lengthened a little, then the cut goes across the correct length on the centreline, no step and no area change at the joint of the two differing angled cones.

Thanks Wayne, good to know. When hammering, do you hammer before or after welding? Or both? I usually hammer after spot welding, then weld the entire circumference. The result turns out out pretty good, but it's sometimes hard to see the seam where to weld.

[speedpro]

- never heard of a tandem twin 4T, enlighten me?

Old Brit bikes are sort of a tandem twin being a 360 deg twin. Same ignition sequence, possibly. Your comment about the cam sensor to locate #1 is needless complexity if you already have a MAP sensor. MAP sensor fluctuations will determine which part of the cycle a cylinder is in. On a 4 stroke anyway. MAP sensors aren't so useful on a 2 stroke.

[wobbly]

Sure - its semantics but the Rotax is a tandem,one cylinder behind the other and they both fire together.
Brit bikes are parallel twins, both pistons moving together, but out of sequence on the firing strokes.
The old Ducati is a 90* parallel twin but fires sequentially at 270* apart.
Then you have a few essentially tandem V engines using knife and fork rods on the same pin,again the cylinders are longitudinally in line.
I agree, using the output of a MAP sensor to determine the crank position is one clever way to time for non waste spark.

[Dutch Fisher]

Wobbly Re:Ignitech .. What's your take on this reported problem http://www.pit-lane.biz/t3652p20-2-stroke-twin-350cc-development > post no.2

[wobbly]

There are several issues that I have worked thru to get the Ignitech to work its best.
Firstly is that they like low impedance coils - that is low DC resistance ( 0.2 ohm or less ) primary and a high inductance secondary.
The Suzuki RGV or Aprilia RS125/250 are the best common coils available, but I have used Crane PS92N cdi coils on Methanol burning Hydros where spark power is super important.
Stock Honda RS125/250 and CR250 coils are way too high resistance/low inductance to work well with this type of DC CDI.
Using both cdi to drive one coil doubles the effective energy available at the plug, and this is the way to get more power from say a RS125 Honda, especially if you swap out the coil.
Lastly using simply a battery alone isnt the go at all.
The voltage drops quickly under load with this setup, the DC CDIs work best when run with a battery that is being charged by the alternator at 14.2V continuously.
There is only one setup of MX rotor and stator that will drive sufficient current into an Ignitech for it to work best when using a cap instead of a battery.
The stator must have a 2 ohm winding and the rotor must be the later type with super strong magnets - you can feel them " clunk " over each pole as you rotate the rotor by hand.
You can see the voltage at the CDI drop ( on the computer screen ) during a dyno run - if the power supply isnt working as it should.
And as usual, the posts reveal that they werent using a resistor plug and cap as Seb4LO also pointed out, along with using the proper NGK race plugs.
So the spark would be all over the shop, not at the correct time to make power.
I dont know the exact calculation sequence the software uses, but I have found by trial and error that the best setup if possible,is to ensure that the addition of the base advance to the lobe duration
should be around the max advance used in the curve.
Having said that I have built several CR250 kart engines that have stock 6* of base and around 15* of lobe length, but the engine strobed exactly showing the 32* max advance as programmed.
And lastly I found that a lobe longer than around 20* length makes the calculations go haywire, and it will misfire badly at one rpm, then go perfectly well everywhere else.
There is a software button that says " wide lobe " and also one that says " no lobe length check ", but trying to translate from Czech what these actually do is impossible.
I simply cut the lobe length in 1/2 and it worked perfectly.

[chrisc]

Farmaken put me onto this.

277602

Sioux model 5977 1/8" collet right angle precision pencil die grinder from Progressive tools - www.e-progressivetools.com (http://www.e-progressivetools.com) E-mail jsgilbert1@msn.com ph. 336 933 9830 fax 336 993 9840

also

http://www.use-enco.com/1/3/pneumatic-pencil-grinder

also

http://www.browntool.com


The only problem with the Sioux is its head is too big to fit a 50mm bore with a cutter installed.

The best tool for the job is this, though more expensive initially its the only way to get the job done.

http://ccspecialtytool.com/182a-mc-small-right-angle-handpiece-adapter.

The other issue is that even the 182 tool will not allow you to fit counter rotating burrs, by fitting them backwards into the head.

The only one that does this is the 1MC head, means you can rub the bur in both directions across the port roof to get equal cutting action on both sides of the cylinder.

http://ccspecialtytool.com/1mc-right-angle-handpiece

The 182 works fine in both directions with fine diamond cutters, or cotton polishing mops, but for hogging out tripple ports etc the 1MC is the best.

Whatever you decide you have to settle on 1/8 or 3mm cutters and stick with that for everything or buy expensive collets and change all the time - a butt pain, I know.

I'm at a point that I need a right angle head porting tool to cut the port openings in the GP125 cylinder I'm working on. Without sounding like a cheap bastard, is there a very cost effective way of doing this without paying $500+ for some nice tools from CC speciality tools?

I did a bit of digging in this thread and found the above two posts. I take a recommendation like that from Wobbly as a very good one but still wonder if there's a cheaper way for a low volume of porting. I mean I'm not exactly going to be doing it day in and out to justify spending lots on tools.

[twotempi]

Try this and let me know what you think

http://www.ebay.com.au/itm/Dental-Micro-Motor-Marathon-N3-35RMP-High-speed-handpiece-contra-angle-straight-/140946288290?pt=AU_Business_Industrial_Medical_Sci entific_Equipment2&hash=item20d10daea2


:yes::yes:

[twotempi]

They have other models as well.

[husaberg]

Didn't F5 make/mod his own? it should be in his attached pics?


Well here's my latest project-ette.

I've borrowed RA dentist tools before & they can do the job but very slowly as they have micro bits.

I came across new old school (sorry I hate that expression) dentist drills that are lower speed but rotary driven & with bigger bits. Maybe I figured I could drive one from my dremel flexidrive & use these diamond bits I bought years ago in the chance that I could find something like this.

Good RA cutters small enough to fit in 50cc barrels or even 100s are more $ than I can justify. So how much for the dentist drill head brand new? Surely more? $25NZ landed to door. Yep that's right, free shipping ebay special.

OK so all was not simple dimple. How to interface the drive for a start. I made a fugly holder out of the end section of a diffuser & welded it to a bit of steel that was tapped (thanks Mike) to fit the dremel flexi (1/2" unf or some crazy tap I didn't have).

The other issue is the bits I'd bought were bigger shank than they said they were so I got a chap to turn them down (my lathe was too big), machine a retainer groove & a flat.

First try out tonight. It spins & is easy to use, but the bits aren't much chop, may have to sacrifice some tungsten dremel ones & the drive started slipping but I had a bent ended old bit to drive the coupling, I really need to weld a decent mating bit to slip into the coupling. Will update how sucessful this all is.
<img src="http://www.kiwibiker.co.nz/forums/attachment.php?attachmentid=271451&d=1349947291" width="340px"/>

[chrisc]

Try this and let me know what you think

http://www.ebay.com.au/itm/Dental-Micro-Motor-Marathon-N3-35RMP-High-speed-handpiece-contra-angle-straight-/140946288290?pt=AU_Business_Industrial_Medical_Sci entific_Equipment2&hash=item20d10daea2


:yes::yes:

There's a thought! Have you used these at all?

Heres a link to the burrs just to complete the post. Total of approx. AU$168 plus postage for burrs and machine

http://www.ebay.com.au/itm/10pcs-DENTAL-Tungsten-Carbide-Burs-High-Quality-/260919018459?pt=LH_DefaultDomain_0&hash=item3cbffc43db&_uhb=1

[F5 Dave]

[QUOTE=husaberg;1130563152]Didn't F5 make/mod his own? it should be in his attached pics?



i can't believe I said simple dimple:eek5:

[F5 Dave]

Well I finally got the igni base adjusting ok. Had to start the bike.

[Dutch Fisher]

Using both cdi to drive one coil doubles the effective energy available at the plug, and this is the way to get more power from say a RS125 Honda, especially if you swap out the coil.


So to use this method on a single crank V-Twin with separate triggers you need 2 ECU's ??

[RomeuPT]

Try this and let me know what you think

http://www.ebay.com.au/itm/Dental-Micro-Motor-Marathon-N3-35RMP-High-speed-handpiece-contra-angle-straight-/140946288290?pt=AU_Business_Industrial_Medical_Sci entific_Equipment2&hash=item20d10daea2


:yes::yes:

Buyed one of those dental 90 angle drillers, is coming :)

[RomeuPT]

Wob, looking at major exhaust's designs and having you said earlier on this thread that there is no case for a header angle under 1.6º, what happens when we go besides that value, even using a straight pipe?

Blowdown happens between 15 and 20% of the time after exhaust open, so, is that a reason we should start the second stage of header at that percentage lenght, starting to lower the pressure at exhaust port when we have contact with the crankcase? :)

Thanks

[wobbly]

Answering the first question - you can use twinfire as I call it, dumping 2 cdi into 1 coil in a twin - by purchasing a DC CDI P4.
This has 4 cdi in one box ( twice the size ) and uses a rather older version of TCIP4 software, but does everything you would need.
You will need some serious power supply capability to keep that system from pulling down the voltage.
Im doing exactly that in the new TZ400 im building with two of the huge Crane coils.

Re the header dimensions, the reason for the latest configurations is to try and get the best, widest spread of lowest depression in the cylinder, from the diffuser sucking on the Ex port
around BDC.
Initially the diffuser is actually too close to the port at the bottom of the powerband, and the depression max is too early in the cycle ( transfers not fully open for best bulk flow )
Then into the overev the max depression point is too late, as the transfers are closing.
So the header end point can be moved around a little to tailor the shape, and peak intensity point where we want max depression in the cylinder for best power at a certain rpm.

[TZ350]

Now wouldn't this be fun ..... :yes:

283963

http://www.trademe.co.nz/motors/car-parts-accessories/other-accessories/auction-602865885.htm

To see this running

https://www.youtube.com/watch?v=flZzJVilY-I

http://youtu.be/yKtYSkmvPV0

http://youtu.be/QrgTtZXuj4w

[Dutch Fisher]

Is using twinfire really adding voltage to intensify the spark temperature or adding spark duration, something that CDI systems lack

[RomeuPT]

Answering the first question - you can use twinfire as I call it, dumping 2 cdi into 1 coil in a twin - by purchasing a DC CDI P4.
This has 4 cdi in one box ( twice the size ) and uses a rather older version of TCIP4 software, but does everything you would need.
You will need some serious power supply capability to keep that system from pulling down the voltage.
Im doing exactly that in the new TZ400 im building with two of the huge Crane coils.

Re the header dimensions, the reason for the latest configurations is to try and get the best, widest spread of lowest depression in the cylinder, from the diffuser sucking on the Ex port
around BDC.
Initially the diffuser is actually too close to the port at the bottom of the powerband, and the depression max is too early in the cycle ( transfers not fully open for best bulk flow )
Then into the overev the max depression point is too late, as the transfers are closing.
So the header end point can be moved around a little to tailor the shape, and peak intensity point where we want max depression in the cylinder for best power at a certain rpm.

Thanks Wob.

I have a DC CDI-P running for over a year now. Pretty nice. Hope that ignitech will update software or change the hardware to tune the spark plug energy, as seen it could increase top end power...

On header entrance as example, if I remember, NSR 125 exhaust round exit is 37, and exhaust header is 38. DTR 125 round exit leaves at 32mm and the header in a famous aftermarket exhaust is 33. I am wondering if this is the rule of thumb to follow, or if it would be better to go 1,5 or 2mm wider instead of just 1mm that is sometimes the tolerance needed to eleminate outward kinks. Maybe I will try to go with a 25mm lenght round transition from 32 to 34 for example without any kinks.

If is was oval, then I would be wheel advised :)

Sorry if I am posting too many hard questions.

Thanks

[wobbly]

The twin fire setup does not add any voltage at the plug.
The two cdi output capacitors in parallel,simply doubles the available stored energy.
This translates into exactly the same arc over performance but increases the burn time duration, as the caps energy is drained into the ionised gap.
The only other way to increase burn length is to increase the inductance of the coil.
Using a PC based oscilloscope with an ignition analysis app,I saw the burn duration at x4 using twinfire and a Crane coil, over a standard single cdi and RS125 coil.

Re headers, at this stage the duct exit, and header entry I can only define in relation to the port effective area.
For a racing T port or tripple port setup the header should equal the whole effective area, and the duct exit = approx 75% of the area.
A CNC transition from oval to round makes the best connection between the two areas, with the oval width the same as the header diameter.

For a single racing Ex port ( that is - 72% and around 200* ) the duct exit and the header entry should both be around 90% of the Ex effective area.

Frits has pointed out, and I completely agree that the relationships should be based on the Blowdown capability, but that would need some time to find the correlation.

[Flettner]

TZ I've finally finished your valve, time has been at a premium lately. We will have to arrange delivery, perhaps I'll drop it off at your "secret test facility deep in the forest"? ( Auckland ).

Here is my secret test facility deep in the forest. This bike is just too much fun! This bike is just too reliable, change filter sleeves, put fuel in, ride. It has never been this reliable until EFI was fitted? Why?
http://i1056.photobucket.com/albums/t380/uniflow/IMG_8860_zpsd6b580d7.jpg

[F5 Dave]

Looks like you had a better track than we had at desert storm. Got seriously unpleasant. Nothing like a 2 stroke in the dirt though.

[Flettner]

I had a great time. Epic Events do a good job. I took the YZ as well and did a loop with that first but had most fun on the Kawasaki. Track did cut up a bit rough in the end as you would expect. I have never done a Desert Storm.

[TZ350]

TZ I've finally finished your valve, time has been at a premium lately.
We will have to arrange delivery, perhaps I'll drop it off at your "secret test facility deep in the forest"? ( Auckland ).

Yes I am ready for it now. If you like, you could bring your Kawasaki up for a run on the dyno after work or weekend.

284024

I have recycled the old triple port cylinder and fitted injectors to the back of it and got all the bits I need for the fuel pump and plumbing. Hopefully I will get the cylinder onto the bike this week.

The plan is to fit the cylinder and do a few runs using the carb for a base line then fit the Ball Valve and fuel injector plumbing and see where we get to.

[TZ350]

I had been working on simulating the old plenum idea with EngMod2T.

284045

Then I thought to ask my good friend EngMod what the 32mm Ball Valve might look like with a 24mm venture insert behind it.

284044

EngMod2T crank hp simulation of a 3 litre Plenum Red line vis EFI Ball Valve with 24mm venturi Blue.

I guess I will try the 32mm Ball Valve with the 24mm venture insert first.

[RomeuPT]

The twin fire setup does not add any voltage at the plug.
The two cdi output capacitors in parallel,simply doubles the available stored energy.
This translates into exactly the same arc over performance but increases the burn time duration, as the caps energy is drained into the ionised gap.
The only other way to increase burn length is to increase the inductance of the coil.
Using a PC based oscilloscope with an ignition analysis app,I saw the burn duration at x4 using twinfire and a Crane coil, over a standard single cdi and RS125 coil.

Re headers, at this stage the duct exit, and header entry I can only define in relation to the port effective area.
For a racing T port or tripple port setup the header should equal the whole effective area, and the duct exit = approx 75% of the area.
A CNC transition from oval to round makes the best connection between the two areas, with the oval width the same as the header diameter.

For a single racing Ex port ( that is - 72% and around 200* ) the duct exit and the header entry should both be around 90% of the Ex effective area.

Frits has pointed out, and I completely agree that the relationships should be based on the Blowdown capability, but that would need some time to find the correlation.

Great Info. Thanks

[TZ350]

284053

The head gasket is to thermally isolate the head from the cylinder, the cylinder normaly runs hotter.

284054

The GP piston normaly has a hole for the rear boost port, I have extended it in the hope that some of the mixture from the middle injector will cool the underside of the piston. The slot is about the length of the maximum time the injector will fire for. There are side vents in the piston too, in the hope they will aid transfer flow from under the piston.

Will it work? will the piston break? who knows? guess I will find out soon.

[speedpro]

Looking at that piston you should let Kel have first ride .

[F5 Dave]

Its the side holes close to the piston bosses I'd be most concerned about

[TZ350]

Its the side holes close to the piston bosses I'd be most concerned about

Me too, its truly a fingers crossed situation, hopefull any problems will show up on the dyno before we get out onto the track.

[gravmax88]

grabbed what i thought was a Piatti AMC engine cylinder.It turns out it was not what i thought it was.

It has a very British Hepolite piston +60 thou it has massive transfer cut always so very un-villiers.

It also has unusual transfer bulges outside of cylinder so again un-Villiers but no transfer slots and a flat top piston.
It may be the mark 2 version mentioned in the Villiers article i posted? Also judging by the bore it must be a 250.
it is unbelievably heavy compared to the 8e/9e.

Most unusually it has a heart shaped inlet port. poor quality pics sorry as now, i can't find my camera.:brick:
Can anyone make a call on what it is?

I guess you may have to be over 60 to answer the question sorry

Looks like a "Vale Onslowe" Cvlinder that was made for the villers bottom ends in the mid 60's. they were a London bike shop that were into karting back then. A few turned up in CHCH in the 60's and were a good thing at the time....

Graham Selwood

[husaberg]

Looks like a "Vale Onslowe" Cvlinder that was made for the villers bottom ends in the mid 60's. they were a London bike shop that were into karting back then. A few turned up in CHCH in the 60's and were a good thing at the time....

Graham Selwood

Thanks Graham i had heard of the name in the Villiers book i will have a google.........

http://www.trialscentral.com/forums/uploads/post-4121-1231702809.jpg

In the Greeves pic the fining sure looks the same:2thumbsup

[Frits Overmars]

Me too, its truly a fingers crossed situation, hopefull any problems will show up on the dyno before we get out onto the track.Better make sure you are not dependent on hope, luck, faith etc, TeeZee. And you could shorten your throttle cable. Those twists will spoil the rider's feel.
I think the slot in the piston in combination with the middle injector is a good idea. I'm not so sure about the other mods...

[Dutch Fisher]

Using a PC based oscilloscope with an ignition analysis app,I saw the burn duration at x4 using twinfire and a Crane coil, over a standard single cdi and RS125 coil.


Can you post the before and after waveform?

[cotswold]

Looking at that piston you should let Kel have first ride .

I will sit that out too :yes:

[wobbly]

I dont know if the oscilloscope has a screen "stop" and capture facility.
When I run the TZ400 system on the bench I will see if it can be done - or maybe I could use Gadwin to capture one cycle, not sure!

[FastFred]

Better make sure you are not dependent on hope, luck, faith etc, TeeZee....

284083

We have the one true wooden God, what can go wrong?

[TZ350]

Better make sure you are not dependent on hope, I think the slot in the piston in combination with the middle injector is a good idea. I'm not so sure about the other mods...

I am not sure about the mechanical integrity of the other mods either, but without expensive and time consuming modeling techniques there is not much more to be done than best guess and hope :sweatdrop .

In the scheme of things this little step into the dark is really not that big a deal, if it all goes tits up, the sun will still rise tomorrow, so we can live a little on the edge and see what happens http://www.kiwibiker.co.nz/forums/images/smilies/biggrin.gif

Whatever the outcome we will be able to build on knowledge gained.

[TZ350]

284092284093284094

With squishy things like base gaskets and a composite head gasket its a bit of a trick to get the cylinder stack height right for the required amount of squish.

Also piston rock makes it a challenge to measure the squish properly. I use looped pieces of soft solder at the sides of the piston but maybe all four quadrants would be better. Anyway like all measurements its up to you to work out better ways of making them.

[Moooools]

but without expensive modeling techniques there is not much more to be done than best guess and hope



Do what everybody else in the world does and find yourself some illegitimate software.
Solidworks or Creo and Ansys FEA.

May I suggest a torrent from thepiratebay.

As long as you aren't selling the products you are pretty damn unlikely to be chased down by a hoard of lawyers.

[TZ350]

Do what everybody else in the world does and find yourself some illegitimate software. Solidworks or Creo and Ansys FEA.

I hadn't thought of a pirated copy of Solid Works.

284097

I can see it shows the stress areas but certain failure or not? quite probably if you know how to use it, I guess, certainly good for optimizing things anyway.

In a couple of days the dyno will pass judgement for sure, and give the modification a clear pass or fail. But I can see now that if I had been at all familiar with using this sort of software I could have had a much better idea of the likely outcome, next time.

https://d2t1xqejof9utc.cloudfront.net/files/10738/DynamicLoadAnalysis.pdf?1333781293

Here is a Masters Thesis on dynamic load analysis, interesting.

[Moooools]

I hadn't thought of a pirated copy of Solid Works.

284097

I can see it shows the stress areas but certain failure or not? quite probably if you know how to use it, I guess, certainly good for optimizing things anyway.

In a couple of days the dyno will pass judgement for sure, and give the modification a clear pass or fail. But I can see now that if I had been at all familiar with using this sort of software I could have had a much better idea of the likely outcome, next time.

https://d2t1xqejof9utc.cloudfront.net/files/10738/DynamicLoadAnalysis.pdf?1333781293

Here is a Masters Thesis on dynamic load analysis, interesting.

I forgot solidworks has a built in FEA engine.

It will be able to tell you stress at each point (and also stiffness but probably less important for this application) and then use matweb or similar to try and predict how many cycles it will last. I would suggest doing a little reading of fatigue of non ferrous metals. Finite fatigue life and all that jazz.

No need to do dynamic analysis. A static structural analysis will tell you most of what you need to know. Just calculate forces on the piston from F=ma, Pressure on the crown from the combustion chamber and friction in the bore and apply them to the piston with the piston pin fixed in space. Getting the contraints accurate is most of the battle.

[speedpro]

I used to crack Suzuki pistons at every bucket meeting right through where those side holes are. I replaced them every 2nd meeting. It may be better without the piston port in the back wall.

[Ocean1]

Here is a Masters Thesis on dynamic load analysis, interesting.

Very comprehensive, will have a read.

Respect for using I-deas to model the rod, I found it a bitch for anything mesh related.

[2T Institute]

Looks like a "Vale Onslowe" Cvlinder that was made for the villers bottom ends in the mid 60's. they were a London bike shop that were into karting back then. A few turned up in CHCH in the 60's and were a good thing at the time....

Graham Selwood

Hello Graham aka Mr Crankshaft :2thumbsup

[husaberg]

Hello Graham aka Mr Crankshaft :2thumbsup

http://crankshaftrebuildingservices.com.au/

[burtpulizzi]

The activity of the animal beings has become acutely active everywhere on this earth. Bodies do not get time to booty a blow for a while. With the accretion use of altered gadgets of Gps Jammer (http://www.jammerall.com/categories/GPS-Jammers/), the possibilities of accepting the aboriginal of blow accept absolutely finished. The adaptable phones or the corpuscle phones are some of these accessories that accumulate the bodies consistently in blow with the alfresco world. The adaptable building are additionally accessible about everywhere these canicule and due to this the accessibility of the Cell Phone Jammer has become alike added quick and authentic. Today, you cannot break out of ability of these adaptable building as their signals can bolt your about anywhere. The bearings of bodies who accord to altered business professions has become actual analytical of wifi jammer as their authorities bolt them anywhere any moment.

[FastFred]

The bearings of bodies who accord to altered business professions has become actual analytical of wifi jammer as their authorities bolt them anywhere any moment.

284111

Its OK, you are amongst friends, we hear you brother ....

[TZ350]

No Glory Tonight.

284118

I wanted to use the original carb setup and establish a base line for the Triple Ex port cylinder before swapping to EFI.

284119

I was expecting to have to dial the Triple Ex in but it was a real dog to get going and after fiddling for a while changing jets, the Blue line is the best I could get.

The Triple Ex has the same timings, same carb, same ignition and the same pipe as the 1ex (Red Line) but more blow down. Not sure whats happening here .... :scratch:I will have to think about it.

[speedpro]

Could be reduced amplitude of the exhaust pulse leading edge affecting scavenging etc. Depending on how those three ports are laid out. Surely you have run it through the sim? Interesting little double peak as well pointing to a mismatch.

[Dutch Fisher]

I dont know if the oscilloscope has a screen "stop" and capture facility.
When I run the TZ400 system on the bench I will see if it can be done - or maybe I could use Gadwin to capture one cycle, not sure!

Look forward to it if you can.


Just what is so iffy about the RS125's combustion that it responds to the twinfire...

... and what do you need to look for in a 'normal' CDI equipped motor that tells you it would/could benefit from twinfire?

[TZ350]

Surely you have run it through the sim? Interesting little double peak as well pointing to a mismatch.

This cylinder has worked well before, my suspicions are:-

(1) that in changing the heads clearance volume when I went from a flat top piston to domed I have got the head shape wrong. New head required.

(2) In retreating from the extreme exhaust timing I had before of 78.5 ATDC I lowered the cylinder 1mm and now the timing may not be the 80 ATDC that I think it is. Will have to re measure and sim it.

(3) The piston when its at TDC may be exposing the lower edge of the exhaust port now, as it was pretty marginal before.

This may not be a bad thing as it gives me the motivation to fit a block in the lower part of the exhaust port floor that is higher than the piston crown at BDC.

There may be no good reason for the exhaust port floor to be level with the piston at BDC other than fashion. And it being higher than the piston crown at BDC may reduce short circuiting (Fritz talked about this), maybe this is my chance to find out.

[F5 Dave]

I was thinking 3 &/or aux ex bleeding due to different piston.

That being said I'd be happy to get that power atm.

[gravmax88]

Hello Graham aka Mr Crankshaft :2thumbsup

:eek5: Gidday Lozza.......I guess those of us with 20:1 flowing in our veins are destined to end up here.....

Have spent 3 days and only at page 500 or so........ phew......

I can still shiver at the thought of the sound a 250cc Yamaha DT2 engine makes in a kart at the end of the main straight at Manfield when using it for the first time with a Wiseco piston fitted!!!!
When you back off and the pilot jet is still too small.........you don't need any electronic det sensors to feel the death rattle then......:crazy:

Graham

[cotswold]

http://www.youtube.com/watch?feature=player_embedded&v=sQ2biYFE0Lk#!

2t going hard

[TZ350]

I was thinking 3 &/or aux ex bleeding due to different piston

Yes could be aux/ex bleed, I will check that too, thanks for the tip.

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Dug out the old head with the 1mm thick copper sprayed coating. It has a familiar combustion chamber shape that has worked OK on other cylinders.

If this cures the power problem, then I will get the combustion chamber nickle or chrome sprayed about 0.0025" and polish it to stop the discoloration of the copper that changed the shiny surface of the copper combustion chamber from a reflector to a heat absorber.

[TZ350]

I have never much felt inclined to have a hero but if I did it might be Smokey Yunick, because I like his thinking.

http://www.circletrack.com/ultimateracing/ctrp_0801_smokey_yunick/viewall.html

[TZ350]

284165284166 modified 1980 Suzuki GP125

Well that did not go so well, spat the head gasket and a bit of a nip up on the right hand side of the exhaust port.

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The good news is, the nip up did not jam the ring and the piston did not brake, and it has had a bit of a thrashing and seen 13K a few times.

I was keen to use a head gasket as I liked the way it thermally isolated the head from the barrel and allowed the head to run cooler.

This is the second time I have tried it and both times ended in failure, also the compressibility of the head gasket is ok for an open combustion chamber but made it hard to get the cylinder stack height right for the correct squish clearance.

Maybe time to give it up and go back to the all copper/fin type head gaskets.

[cotswold]

Saw this picture of a flat top piston running in a RS125R

[speedpro]

Are you certain the head and cylinder were clamped up tight rather than the nuts being bottomed out? I ask because I had a similar issue lately and that's what it was. It's a pretty big blowout as well covering quite a bit of the bore circumference.

[TZ350]

Are you certain the head and cylinder were clamped up tight rather than the nuts being bottomed out?

Different head and head bolts so quite possible ....

[twotempi]

I run "Viton" o-ring setup on an air-cooled twin for several seasons and never had a problem.

Checking that the threads are not bottoming is a good thing to check as I don't think the problem is the o-ring. Also check that the tube bolts nuts not bottoming on the cylinder counter bores as this will seem if all is OK but the head won't be clamped down tight. Easy to fix - shorten the tube nuts a few mm's

[TZ350]

Checking that the threads are not bottoming is a good thing to check as I don't think the problem is the o-ring. Also check that the tube bolts nuts not bottoming on the cylinder counter bores as this will seem if all is OK but the head won't be clamped down tight. Easy to fix - shorten the tube nuts a few mm's

Yes the O ring has been reliable, its the composite head gaskets that failed and took the O ring with it. I think you may be right about the tube head bolts, I will have a good look tomorrow.

[Flettner]

http://i1056.photobucket.com/albums/t380/uniflow/babe0419.jpg

Nothing wrong with an o ring head seal on air cooled two stroke.

[F5 Dave]

Bit silicone there

[TZ350]

Are you certain the head and cylinder were clamped up tight rather than the nuts being bottomed out?

284206

Yep your on the money. Rogue extra long cylinder head bolt got mixed in with the modified ones.

284207

I was concerned that the piston skirt was not completely covering the exhaust port at TDC.

284208

I scribed a mark on the piston skirt and it looks like I would be lucky to have 2mm coverage so I may yet have to build the floor up a bit.

[speedpro]

I'm sure it's been done already but raising the floor of the ex port would be an interesting experiment. Flow could be improved at part open but that would be offset by a restriction towards BDC. There could also be some advantage as the port closes with a better port shape directing the return pulse from the pipe more into the open port rather than it mainly just bumping up against the side of the piston. With the right pipe, say one with a milder rear cone it could result in less of a powerband. With the better port for the return pulse the pulse could have lower amplitude and still be as effective so the rear cones won't need to be so steep.

[2T Institute]

A "restriction" at BDC is exactly what you want in the exhaust duct.

[TZ350]

284247284248284250

Neil turned up today with the two bikes he has fuel injected, we gave them a bit of a trot on the dyno and they went really well.

284251284252284246

Neil also brought these parts with him, that he had made for me. A generator to power the Ignitec and EFI, and the Ball Valve with TPS.

I was going to run the Ball Valve inside a plenum but now I am going to try it with a 24mm venture insert behind it and see how that goes first.

[Flettner]

TZ, Thank you for all your time and patience today. We are happy with the results and very much appreciate your expertise with the dyno, I am at your service.

[Sketchy_Racer]

Looks like a interesting day on the dyno, are you going to thrill us with some numbers of the EFI dirt bikes? :yes:

[RomeuPT]

Saw this picture of a flat top piston running in a RS125R

A bit rich? Strange wrong scavenging sign maybe?

[TZ350]

Looks like a interesting day on the dyno, are you going to thrill us with some numbers of the EFI dirt bikes? :yes:

284277284278

EFI YZ250, (the graph is in mph because I could not easily get an ignition timing signal for rpm, next time).

284276284279

EFI Kawasaki F86M 350 Big Horn from the 70's.

284275

Yamaha blue line, Kawasaki red.

[F5 Dave]

Wow that 350 is impressive.

The last graph is not valid though, can't compare things with different gearing. Have to get ign trace going on both to make sense of it.

[RomeuPT]

284277284278

EFI YZ250, (the graph is in mph because I could not easily get an ignition timing signal for rpm, next time).

284276284279

EFI Kawasaki F86M 350 Big Horn from the 70's.

284275

Yamaha blue line, Kawasaki red.


That kawa should be a monster to ride 8)

[RomeuPT]

Wob, I need your help.

I have a 9.7cc Honda RS head that I am not using, and now I have got some VHM domes, I am thinking in milling the 9.7cc head and fit the domes.

What tolerance should I use between the head and the outer diameter of the domes?

Thanks

[TZ350]

Page 800 ...


Where I have got to with the EFI fuel injection system. You will have to click through to the original posts to see the attached pictures.



TeeZee if your getting into fuel injection there is a whole new language and concepts to learn.

Like “Speed Density” and “Alpha-N”, VE Volumetric Efficiency Table, AEM’s, IAT’s, TPS, VTA and how to use Excel spread sheets for smoothing 3D plots in CSV format.

Something below I scraped of the net to give you the idea……

Speed Density. So after much thinking about how to explain what true Speed Density is vs what we do here for instance, how AEM's are often setup, etc. I came up with the following idea, just explain what everything is and remove doubt.

MAF - if you dont know this one its a volume sensor. Thats it. Ours have IAT and a baro comp to make it more accurate but it simply measures volume entering the engine. If there are boost leaks its inaccurate, doesnt like VTA (letting metered air leave without pulling fuel), all the stuff we know.

Alpha-N - TPS x RPM. That is all that is with no VE compensation (i.e. boost). If I tell it that at 100% throttle and 6000 rpm it does it at all boost levels independent of air volume.

Speed density - estimates air mass by pressure vs temp. Then applies this to a 3D map. The "3D" we already have, its Load (pressure or volume) x RPM with a set value in each cell. Every point can be fine tuned so this is really Alpha N with compensation. Any VE changes needs a retune, doesnt matter the system. It only knows pressure and rpm not what the true mass of the air is (it has a trim table and most get ignored above certain levels).

I use the fuel temp sensor to mimic an IAT since its already in the car. The IAT reads gross temp not average. It can heat soak, be subject to a meth jet to close, all sorts of little issues. The actual trim table in the Evo ECU really isnt setup for IAT trim anyway. It has an algorithm that allows for minor alterations to fueling since its set for a MAF, and then trims timing vs air temp.

Fuel temp is more or less constant. The fuel heatsoaks going thru the rail hits the tank and then is sent forward again. It takes 15 minutes to get full heat into the fuel system (ask anyone with an A1000). It is a rough average of engine bay temp which is what the MAF does factory. I have done exhaustive testing and see no more than 5-6* variation from fuel temp as a source to what the MAF would read in the corner of the engine bay.

Now for the term everyone has been waiting for, Boost Comp. This is what MAFs do, most SD setups (AEM, Motec, Autronic, Vipec, etc.) do for fueling. It assumes VE is more or less constant until you hit backpressure in the turbine housing, head flow, cam size, and VE starts to drop off again.

I set the fueling at 16psi and in our maps this is 180% load or so. The values are constant out to 38psi. Hyper Boost Compensation is the proper name. Retuning is as easy as altering either the max boost portion of the MAPVE table to allow more or less fuel vs pressure, and in some cases the tip in portion of the MAPVE (121kpa column).

There is no such thing as true speed density. I havent seen any AEM ever do this or any other standalone. GM is the closest to True SD and its because tada they use a MAF as well to judge volume vs pressure.

There is also Alpha-N with Boost Comp. This is more or less what we do EXCEPT IT HAS NO TEMP input. It is solely rpm x TPS x pressure. Since we aren't doing fueling by TPS vs RPM at any point other than accel enrichment it is not accurate to call the SD we normally do on Evos Alpha N or N-Alpha or Alpha-Omega or whatever. Alpha N is different and is normally something reserved for ITB cars or quads (single cylinders) that have really non specific fueling and just need fuel vs tps x rpm.

Often we deal with the question, "Which is better speed density (SD) or mass air flow (MAF)". As with most things in life there are advantages and disadvantages for both. Its better to understand each strategy so as to make the most informed decision.

Mass Air Flow

Mass air flow sensor equipped cars fuel either directly from or by a blended model of both mass air flow and speed density calculations. The MAF sensor is located somewhere in the intake stream typically away from sharp bends and typically at least 8-10 inches away from the throttle body however these rules are not always followed. There are several different types of MAF sensors but for most GM applications it is a frequency biased "cold-wire" sensor that generates a signal between 0 and 15k Hz. MAF sensors read not just airspeed but the relative mass of the air which eliminates pressure and temperature as variables. They are usually positioned to sample from the middle of the intake tubing which should give the best average reading.

Since the MAF sensor samples from a specific spot in the inlet tubing changing the airflow in or around the sensor requires recalibration of the MAF sensor. Changing the airflow around a MAF sensor can be caused by a change in size of the intake plumbing, bends before or after the MAF sensor, and changes to the MAF housing.

Several applications that use MAF biased strategies also use Speed Density as a backup or for a blended fuel calculation. They also use Speed Density as a sanity check for MAF readings.

Advantages

Typically more forgiving and easier to tune
If the MAF sensor has been calibrated typically fueling remains consistent as modifications change. It can be said that the MAF equipped cars are a little more forgiving to new modifications
Since the MAF sensor measures air mass directly it can be said that a MAF equipped car might stay in calibration as the engine wears or in extreme environment changes (however this is not normally a concern for well tuned speed density applications).

Disadvantages

Sensitive to changes to the intake plumbing
Can be fouled by becoming dirty. Once fouled MAF calibration is skewed
Sensitive to cam reversion on large cammed cars. The MAF sensor isn't directional so air pulsing back and forth can affect repeatability and reliability.
Limits on performance. Most systems can not read at higher horsepower levels.

Speed Density

Speed density systems calculate the density of the air first by measuring the temperature of the inlet air and manifold pressure. With the density of air known the engine controller then looks up how much air it expects to be moving at a specific engine speed and manifold pressure. This is done in the Volumetric Efficiency table or VE table. Traditionally the VE table is 3D and has two axes Engine Speed (RPM) and Manifold Pressure or % Load. A engine that is 100% efficient moves exactly its displacement every two rotations in 4-cycle engines.

Advantages

Less restriction in the intake tract
More freedom in the intake tract
Able to measure air consumption on very high horsepower builds where a MAF sensor might be limited.
Able to read boost if equipped with a greater than 1 Bar map sensor
Free from errors encountered in MAF fouling.
Works better with large cams where reversion affects reliability.

Disadvantages

Is a little more difficult to tune
Relies on a well tuned Volumetric Efficiency Table
Less forgiving to new modifications to the engine
Might have errors in large weather changes however a proper tune makes this minimal if any error.

There are several vehicles that come with MAF sensors from the factory and there are several vehicles that come speed density from the factory. Really which fueling strategy you should go with on a aftermarket application is up to your modifications goals and expectations. If you are not the one to be tuning your setup please consult with your tuner for what he or she recommends.

Speed-Density is a method of estimating airflow into an engine in order to supply an appropriate amount of fuel and adequate spark timing. First, vocabulary:

ECM, ECU, Engine computer : used interchangeably to mean the computer operating the fuel injectors and running the engine
RPM : Revolutions Per Minute – how fast the motor is spinning
MAP : Manifold Absolute Pressure – (usually) the pressure of air entering the motor
ECT : Engine Coolant Temperature sensor – sensor used to measure the temperature of coolant circulating through a motor. Sometimes called different things by different manufacturers. I will use ECT here
IAT : Intake Air Temperature sensor – sensor used to measure the temperature of air entering the motor. Sometimes called different things by different manufacturers. I will use IAT here.
Displacement : the volume swept by a piston descending from the top to the bottom of the cylinder bore. More here.
AFR : Air Fuel Ratio – the ratio of air to fuel present in a combustible mixture. Usually stated as a ratio, i.e. 14.7:1 for the stoichiometric AFR for gasoline. Stoichiometric AFR varies from fuel to fuel.
Lambda : similar to AFR, except usually expressed as a number where 1.0 represents a stoichiometric mixture for all fuels. Lambda and AFR are the same concept expressed in different units.
Stoichiometric : a mixture containing the precise amount of oxidants required for complete combustion of all fuel present. See here or here for more information on chemistry involved.
Ideal Gas Law : PV= nRT (Pressure times Volume equals moles of gas times ideal gas constant times temperature) More to be read about this here.
Moles : a measure of how many atoms are present. See here.
Induction stoke : the part of a 4-stroke engine’s cycle in which air is drawn into the cylinder by the piston. See here for more information if you are not familiar with a 4 stroke engine’s operation.

Basic Goals and Method

The goal of Speed-Density is to accurately predict the amount of air ingested by an engine during the induction stroke. This information is then used to calculate how much fuel needs to be provided and may also be used for determining an appropriate amount of ignition advance.

The theoretical basis for this is the Ideal Gaw Law (more here.) rearranged to solve for “n” (the number of moles of gas present :

n = PV / RT

In order to use n = PV / RT to calculate the amount of air a motor ingests during the induction stroke we would need:

P is pressure in the cylinder immediately after the intake valves close.
V is volume, which we know from engine displacement.
R we know (it’s the Ideal Gas Constant see here for more)
T is the temperature of the gas in the cylinder immediately after the intake valves close.

Many of the things required to calculate the amount of air the engine ingests using the ideal gas law are missing, unavailable or at least incomplete. Some notable points where reality is less than ideal:

Our MAP sensor measures the pressure differential caused by the downward stroke of the piston in the intake manifold, not pressure in the cylinder as the intake valves initially close.
We are assuming that there is no residual exhaust left in the chamber to contribute to “poisoning” of the intake charge.
Camshaft overlap (i.e. when both intake an exhaust valve are open simultaneously – see here) makes fluid flow modeling considerably more complicated.
T that we need is the temperature of the gas in the cylinder. This is not usually MEASURED – instead it is ESTIMATED from the temperature of air in the manifold (IAT), the temperature of the cylinder heads (ECT) and other factors. “RT” is often referred to as the “density correction term” as it tries to account for how air density varies with temperature. Density correction is arguably one of the biggest problems with speed-density. (more on this later)

Speed-Density introduces the concept of Volumetric Efficiency (VE) to account for the differences between what it can observe and what is really going on. (mostly problems 1-3 above) Roughly speaking, VE is the ratio between the amount of air actually present in the cylinder and the amount of air we predict would be in the cylinder using MANIFOLD pressure (MAP) instead of cylinder pressure for our “P” Pressure term, REVOLUTIONS Per Minute (RPM) times Displacement (Volume / REVOLUTION) for our “V” term and an air temperature value estimated from some combination of ECT and IAT for our “T” term.

A motor said to be operating with 100% VE has the same amount of air actually in the cylinder as predicted by n = PV / RT. Most engines operate at considerably less than 100% VE in most operating conditions. The difference between actual airflow and theoretical maximum airflow is termed “pumping loss.” Some engines (most notably Honda engines ) can achieve slightly greater than 100% VE in certain conditions. Most engines operating under forced induction can be thought of to have a VE greater than 100% in some conditions.

Speed Density ECMs generally have one or more VOLUMETRIC EFFICIENCY (VE) tables that are a critical item to be adjusted. These tables allow predicted airflow values to be more closely adjusted to observed reality.

Strengths of Speed-Density

Speed-Density has many things going for it:

Pressure sensors do not pose any restriction to the flow of air into the engine, unlike a MAF sensor.
MAP sensors respond to changing conditions very quickly, enabling it to have fairly good transient response especially compared to Mass-Air-Flow
Compared to a carburetor, it allows much more control over the mixture at different engine loads
Simplicity: all the sensors required are extremely reliable.

Weaknesses of Speed-Density

Speed-Density is known for having several notable issues:

Density correction, density correction, density correction. You might not think that temperature is that big of a deal, but trust me it is! Seasonal changes can wreak havoc on speed-density systems. Superchargers or turbochargers that compress air and raise its temperature from adiabatic heating cause significant changes in density that must be accounted for. Altitude can also be really problematic. Many systems incorporate Barometric Pressure sensors to try to address this, but it’s an imperfect correction.
Large camshafts with extremely low vacuum due to high overlap close to idle. Camshafts that have low or pulsing vacuum close to idle present a challenge for Speed-Density. MAP sensor averaging can help. Alpha-N blending can help. It is still very tricky to use speed density to predict airflow with a pressure sensor with camshafts that do not build an appreciable amount of vacuum.
Volumetric Efficiency tables can be very time consuming to tune.
Engine modifications generally produce volumetric efficiency changes requiring re-tuning.
Quite a lot of math is required to do Speed-Density “by the book.” Because of this, most manufacturers implement something kind of like theoretical speed-density and cut corners or combine math operations in order to allow faster execution on puny computing hardware. (Remember, most ECUs made prior to 2000 have a slower processor than the average inexpensive cellphone circa 2010)

Sanity Checking a Speed-Density Tune

There are a few rules that transcend particular manufacturer implementations:

Volumetric efficiency rarely changes suddenly. VE tables should almost always have very gradual changes.
VE usually DECREASES as pressure DECREASES (i.e. more vacuum = less VE)
VE usually maxes out at an RPM close to peak engine torque at maximum observed load, which is usually where peak cylinder filling occurs.
Remember that VE tables are not the only thing that controls fueling. Temperature correction tables (ECT, IAT) are often implemented as multiplier/divider tables. Don’t forget about injector battery tables either! (see the separate article on Injector Tuning for more on this)

Alpha-N

An Alpha/N table allows the ECU to calculate some sort of output based on any combination of how much the throttle is open (Alpha), and how fast the engine is spinning (N). The Alpha term can range from 0% (closed throttle) to 100% (wide open throttle). The term "N" corresponds to engine RPM.

The two main Alpha/N tables are used to determine ignition advance and fuel injector pulse width. An Alpha/N ignition table would use throttle position and RPM to calculate what spark advance it should be using. Similarly, an Alpha/N fuel table would use throttle position and RPM to decide how long the fuel injectors should stay open.

Throttle Angle

The throttle angle term was tougher to figure out. While the RPM rows were spread out evenly across the operating range, the throttle angle columns were not. There is a good reason though. If you think about it for a minute, a difference in throttle angle is not a simple linear change like RPM. For example, changing the throttle angle from 1% open to 2% open is a huge difference (100%, in fact). Compare that to changing the throttle angle from 90% open to 91% open, which is only about a 1.1% difference. What this really means is that the effects of throttle changes are concentrated mostly in the range of small throttle openings. In contrast, at large throttle angles, the same small changes are almost meaningless. Therefore, the throttle angle, or 'Alpha' part of the table is strongly stacked towards providing lots of information at the end of the scale where the throttle is barely open, and has much less information about situations where the throttle is open fairly wide. This also makes sense when you consider that much of what a rider considers as 'driveability' issues occur when cruising down the road with the throttle barely open. Giving the ECU extra information about part-throttle situations makes for better driveability.

Alpha-N uses the throttle position (alpha) and RPM (N) to calculate the amount of fuel to inject as opposed to using the manifold absolute pressure (MAP) and RPM to calculate the amount of fuel to inject. Alpha-N is useful for long duration cams where the resolution of manifold air pressure (map) would be small.

Manifold Absolute Pressure, then, is just what it says: The absolute pressure which exists in the inlet manifold, usually measured in the plenum (if one exists). The MAP in an engine which is not running is equal to atmospheric pressure. If, on a "standard day", an engine is idling at a measured manifold "vacuum" of 14 inches,, the MAP is actually 15.92 "HG (29.92 - 14 = 15.92).

1 atmosphere = 760 mmHg = 29.92 inHg = 14.7 lb/in2 = 101.3 KPa


I think you would be pretty game to try anything other than an 'Alpha-N' setup. Pulsing on a single cylinder will make the engine hunt and low rpm. And MAF will restrict your inlet and is heavy as balls.

And download matlab instead of excel. Much better at dealing with large matrices.


Thanks Bucket and Mooools

To get started, most of the info for VE, Speed Density and Alpha-N maps can be gleaned from the EngMod2T simulations.

Because of the pulsing in the inlet tract that Mooools talked about and which is particularly bad in a 2-Stroke, the Fuel injection system we are getting has a Speed Density map for low RPM and uses Alpha-N for the high RPM end.

I have been told that as an optional add on, it can also have a mixture adjustment with exhaust temperature option. I am not sure how that works but hopefully it means we can give it a target ET and it will maintain it just like Wobbly has talked about for maintaining optimum AFR with changes in conditions during the day.

I am not sure how the injection timing works but the system triggers from the existing ignition pickup. Because I want to inject into the transfers while the are open and flowing, I guess it will be easy enough to fit a dedicated trigger at some other point to get the injection timing right.

Anyway hopefully Chambers and I will have our kits by the end of the week.




Chambers and my EFI stuff turned up today, only 4 days delivery time and it was Easter, how good is that! real good!



All the bits.



RF Shielded CPU



We checked and yes, the light you can see through the throttle body is equivalent to a 24mm carb.



Here are all the bits connected up on the wiring loom, real simple, real easy.



As an optional extra we got a wide band O2 kit to help with tuning on the dyno.


Some more lovely odds and ends that are in the kit.




This is where I have got to with my simulations for the EFI map data.

These start at 500rpm but I have not displayed the bit below 5,000 rpm because its pretty much all the same and a bit boring. And who would have thought that the engine would rev further on smaller throttle openings.

Because the gaps are getting bigger, when I have finished this series I will have to go back and do some in between ones for the lower throttle settings.


Power Curves




Which data will you take from the sims to feed the ecu with?



RPM, TPS VE and Fuel ...



Here is Fuel vis RPM and TPS.

There is a lot of good information to be gleened from the EngMod2T simulations that will be usefull in prepairing the initial Maps for the EFI.





http://www.freepatentsonline.com/6691649.html

Free Patents Online is a bit of a gold mine of ideas, its worth a look at the Two Stroke stuff.



Fuel injection runs again, The YZ 250 EFI port injection lives. Congratulations ... that makes it two, home brew, competition 2-Strokes running EFI that you have put together.



Injector Sizing and Locater page

http://www.nitrostreet.com/injectors.htm

A place to go to, to calculate the size of injectors needed.

Because it is a 4-Stroke site and assumes a full 100% duty cycle of 720 degrees as apposed to a 2-Strokes 360 degrees I had to halve my required duty cycle to get a 2-Stroke result.

Ie., my designed maximum duty cycle is 120 degrees or 33% then instead of 0.33 I had to enter 0.16 in the Duty Cycle field.



It was pleasing to see the numbers came out to be the same size as I had previously calculated from the simulated EngMod2T fuel demand curves.

DIY EFI ... might be worth a look. http://www.diy-efi.org/

EFI links list here. http://www.nitrostreet.com/efi.html#EFI%20related%20software%20for%20PC%27s


Things I am learning about EFI ..... edited scrapes below.

Speed Density

There are several different ways to control the air/fuel ratio. Speed density requires just two main inputs to establish a base fuel map: engine rpm and load. Speed density assumes that a certain amount of air will enter the engine at any particular combination of rpm and load.

This works as long as the engine remains unchanged. Modifications to the engine to increase airflow (and therefore power) at any point would tend to make the engine run lean, since the engine would inhale more air at that rpm and load point than it did when it was stock.

If you take in more air, a proportional amount of additional fuel must also be delivered to maintain the same air/fuel ratio. Speed-density systems cannot perform this function without reprogramming.

Mass Airflow

Systems outfitted with a mass airflow (MAF) sensors. This sensor measures the amount of air entering the engine, giving more precise control over the air/fuel ratio. MAF systems are more accurate.

Alpha-N

There is one other EFI control system that is generally used only in racing called an Alpha-N system.

This control system’s major inputs are throttle position and rpm. This system was developed because race engines often operate at idle and part-throttle with very little manifold vacuum.

This makes using a MAP sensor difficult. This system is less precise than speed density or MAF and is therefore generally only found in racing or on heavily modified street engines with big camshafts. A MAP sensor can still be used with Alpha-N, but it is generally employed as a barometric pressure sensor to detect altitude changes.




16 x 12 Input Tables or Maps for my EFI unit.

All the variables RPM, MAP, TPS, Load, VE and Lambda values can be adjusted.



Speed Density Map



Alpha-N Map



Desired Lambda Map

I am trying to get my head around these and figure out how much info from the EngMod2T graphs I can use here.



This could be a useful place for those contemplating fuel injection

http://www.efihardware.com/index.php



http://www.ecotrons.com/2_Stroke_Small_Engine_EFI_kit.html

I have been trying to figure out how to go about the initial mapping of my 2-Strokes EFI as I want something that is at least close to the ball park, to kick the whole EFI tuning process of with.

First up I need to build the Speed Density map which plots VE (volumetric efficiency) against RPM and MAP (manifold absolute pressure). The big problem is, VE data is not all that easy to get.

But they say you can determine VE from dyno data which is handy because I have a virtual dyno, EngMod2T.



Not to sure about what I am doing, so rightly or wrongly, this is how I have gone about it.

At the moment EngMod2T does not give a VE (volumetric efficiency) vis MAP graph but it does plot DR (delivery ratio) which is basically VE at atmospheric pressure. So I simulated a whole lot of runs at various atmospheric pressures to simulate changes in MAP to see if the engines VE (DR) changed with changes in pressure.

It didn't much, which is no surprise really as the DR or VE is just a ratio between whats theoretically possible at that pressure and what happens in reality. As the pressure changed the proportion of inside air to outside air remained much the same.



But of course the Power dropped of with decreasing atmospheric pressure (simulated MAP).



Because the Speed Density map is more about the lower RPM range I broke the standard atmospheric pressure DR graph into two parts and maximized the scales so I could see them better.

I made up a spread sheet using the DR values at Standard Pressure (1013) and proportioned them across the pressure range from 300 to 1050.

This is the Formula I formulated. (Actual Pressure / Standard Pressure) * Delivery Ratio ... for each RPM/MAP point.



And entered the values into the EFI's 16 x 12 Speed Density map.



Nice picture, I have no idea what the colors mean. But if you look along the blue edge you can see it pretty much mimics the DR (VE) EngMod2T graph. Hopefully that means I have got something right.

Only Lambda, Load, and Alpha-N maps to go.




Alpha-N EFI Map



Finally got the Alpha-N Load map, mapped against TPS and RPM.



Another colorful map. You can see the effect of the pipe going in and out of resonance as the RPM goes up.



Delivery Ratio Graph of multiple runs done in EngMod2T at different TPS (throttle) positions. The colorful Alpha-N map pretty much follows the EngMod simulations.



To get the resolution required I used the EngMod graphing options to expand selected sections of the graphs.






I have been trying to figure out where to place the injectors. My EFI setup calls for two injectors, one small and one big so its a bit of a puzzle to figure out where best to put them.



I needed a fuel rail and got this Honda Civic (D16Y8 engine) rail with 240cc saturated high impedance injectors and fuel regulator off Trademe. All sorts of injectors will fit this rail and it can be shortened up to suit my engine.



A bit of info on injectors and spray patterns.

[TZ350]

Wow that 350 is impressive.

284289


the graph is not valid though, can't compare things with different gearing. Have to get ign trace going on both to make sense of it.

True and not so true, depends on what your looking for.

From this graph, what you can say is, if they are both riding the same trail, the Kawa is able to hold a gear for longer than the Yam.

[Yow Ling]

So say you fitted a piston from a cylinder designed for a bridged exhaust (like a rm125) to a single port barrel like a h100, and didnt bother to glue the oiling holes closed, what is the downside ? how much would be lost, would it even run? Any theories or experience?

[bucketracer]

Not sure if Team ESE have actually tried that but TeeZee is having lots of problems with his cylinder and its looking like an imperfect seal between the piston skirt and exhaust port and crankcase is causing the problem.

Anyway its so easy to glue the piston to seal the bridge oiling holes with devcon F, why wouldn't you do it. TeeZee has shown it lasts OK too.

[F5 Dave]

So say you fitted a piston from a cylinder designed for a bridged exhaust (like a rm125) to a single port barrel like a h100, and didnt bother to glue the oiling holes closed, what is the downside ? how much would be lost, would it even run? Any theories or experience?
I ran a rm piston but didn't block the hole. Never got around to before and after, didn't expect Devon to last back in the day. Hope it's an air cooled RM piston Mike.

[Yow Ling]

OK thanks, heres the rest of the story, a young guy at work bought a H100 to ride to uni but the barrel was a bit rooted, I bored it to 54mm for a rs125 piston but went a bit oversize Brendan had a rM125 watercooled piston so that saved my arse when it measured 54.25mm but it had bridge oiling holes , well so did the rs piston I guess I was just in denial about plugging them. So long as the bike goes like a stock h100 all will be well, he may just need to re ring it from time to time

[Flettner]

http://youtu.be/UEQli7nuak4

[Grumph]

OK thanks, heres the rest of the story, a young guy at work bought a H100 to ride to uni but the barrel was a bit rooted, I bored it to 54mm for a rs125 piston but went a bit oversize Brendan had a rM125 watercooled piston so that saved my arse when it measured 54.25mm but it had bridge oiling holes , well so did the rs piston I guess I was just in denial about plugging them. So long as the bike goes like a stock h100 all will be well, he may just need to re ring it from time to time

The H100 liner is bloody thin at 54mm Mike...cracks WILL appear....

[Yow Ling]

The H100 liner is bloody thin at 54mm Mike...cracks WILL appear....

I didnt really check , I just assumed it was as thick as the spigot

284316

he can always bring it back, Ill send him down to KGs to buy another one !!

[Sketchy_Racer]

http://youtu.be/UEQli7nuak4

That is awesome, i'm still impressed by the old 350, that thing would had some punch!

I noticed that it *seems* like it really brick walls at the top end of the rev range, is this just the sound of the video making it sound flat or does it not have a lot of over-rev?

[Flettner]

It's hitting the rev limiter and the last fueling square is a bit rich I think.
Yes the Kawasaki is a lot of fun to ride, certainly some modern bike riders don't expect to see this old bike accelerate like it does although as soon as it cuts up rough, I'm out.

[2T Institute]

It's hitting the rev limiter and the last fueling square is a bit rich I think.
Yes the Kawasaki is a lot of fun to ride, certainly some modern bike riders don't expect to see this old bike accelerate like it does although as soon as it cuts up rough, I'm out.

Suspension is easy fixed, emulators in the front and a pair of YSS at the rear