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bucketracer
23rd February 2010, 12:47
I wanted to be the the 2000st reply, but Buckets4me beat me to it.

anyway, hi Dad, we think your the best.........:yes:

bucketracer
23rd February 2010, 12:54
well that does it then
I'm not wasting the money if I cant beat the mighty GT :)

Buckets4me have you had a look under Dads bench lately? a bunch of GT125 engines have appeared there, and there is also a large offcut of 2mm copper sheet in the corner. What does all this mean????

F5 Dave
23rd February 2010, 13:34
I heard the new rules would allow 200cc aircooleds like IT & KDXs or 125MX engines up to '95 taken out to 144 like in AMA rules.

jasonu
23rd February 2010, 13:54
I heard the new rules would exclude dickheads. Looks like you're out Dave.

F5 Dave
23rd February 2010, 16:51
Is that why you left the country?

We'll have to form a club of our own.
CR250s in minimoto frames.

koba
23rd February 2010, 17:39
Is that why you left the country?

We'll have to form a club of our own.
CR250s in minimoto frames.

I know a guy who squeezed a 250 fourstroke in a pitbike, I believe it has caused a fair bit of pain.

Bert
23rd February 2010, 18:23
I heard the new rules would allow 200cc aircooleds like IT & KDXs or 125MX engines up to '95 taken out to 144 like in AMA rules.

I'm interested to know where this is coming from; who has proposed / suggested there should be a change... why follow the AMA when the B.R.A NSW framework would suit our environment far better, especially with the slow gradual demise of 2stroke junior MX classes (85cc). http://www.ozbucketracing.com/

I would have thought that the last thing we need is another ~125 class.. 38-40Hp buckets on gokart tracks :shit:

Though it would be fun.

Kickaha
23rd February 2010, 20:29
why follow the AMA when the B.R.A NSW framework would suit our environment far better, especially with the slow gradual demise of 2stroke junior MX classes (85cc). http://www.ozbucketracing.com/



Why even look at following either of those when there's nothing wrong with our current rules, if It aint broken dont fix it!

speedpro
23rd February 2010, 21:15
The rules are pretty well spot on. TZ has proved it is possible for a 125 with a 24mm carb to make competitive power. The unlimited 100s should supposedly clean up but don't and those other bikes seem to go OK. As always it comes down to development and who is riding it.

Buckets4Me
24th February 2010, 05:50
The rules are pretty well spot on. TZ has proved it is possible for a 125 with a 24mm carb to make competitive power. The unlimited 100s should supposedly clean up but don't and those other bikes seem to go OK. As always it comes down to development and who is riding it.

second that
(but I have an old rm125 engine under the bench just in case)

Buckets4Me
24th February 2010, 05:51
Buckets4me have you had a look under Dads bench lately? a bunch of GT125 engines have appeared there, and there is also a large offcut of 2mm copper sheet in the corner. What does all this mean????

I had noticed the nice new looking one on the bench last time I was there :)

F5 Dave
24th February 2010, 08:20
Ahh C'mon it was a joke.

jasonu
24th February 2010, 13:52
[QUOTE=speedpro;1129660904]The rules are pretty well spot on. TZ has proved it is possible for a 125 with a 24mm carb to make competitive power.

Has he?

Buckets4Me
24th February 2010, 16:57
[QUOTE=speedpro;1129660904]The rules are pretty well spot on. TZ has proved it is possible for a 125 with a 24mm carb to make competitive power.

Has he?

he proved that last year 18-21 hp at the rear wheel with a 24mm carb (proved that the carb is the restriction as he is getting 22+hp out of a 100 with a bigger carb)
now he is trying for lots more power (and he has 2 options)
just waiting for the dyno results to see how it's going (the seat of the pants say he is onto something)

thats reliable Hp to (1 bike has been going 4 years)
now how many other bikes are doing that ? ? ? 2 or 4 stroke

speedpro had a 100 that was good till it spat him off big time
??? any other bike out there (not many fxr's that old or reliable)
JC cb125 twins arn't as reliable :) (but have been around longer)

bucketracer
24th February 2010, 18:30
Hey Buckets4Me I was poking around at work looking for some flat bar and found hidden in a corner a couple of RG400 cylinders and an RGV cylinder that looks like it is being converted to air cooling. I think Dad is up to something he is not telling us about...

Buckets4Me
24th February 2010, 18:44
Hey Buckets4Me I was poking around at work looking for some flat bar and found hidden in a corner a couple of RG400 cylinders and an RGV cylinder that looks like it is being converted to air cooling. I think Dad is up to something he is not telling us about...

he is always up to something :)
pitty there wasent more of him and a winning lotto ticket
then we would see some cool buckets

TZ350
12th March 2010, 19:52
Picture-01 The plenum
Picture-02 Comparison of the new inlet tract with the an original
Picture-03 33mm straight shot into the crank case
Picture-04 New Delta rolling chassis

I have found a problem with running premix through my plenum. With a normal setup petrol/oil premix usually enters the motor wet and as the petrol evaporates the oil is left behind to lubricate things. But with my engine the wet fuel is evaporating in the plenum and leaving a lot of oil behind there and I wonder how much oil is actually making it into the engine.

So I have converted the motor back to a normal carb configuration, I had removed all the auto lube bits from the engine so I will now have to build a completely new one with auto lube. The up side is I have recently acquired a Delta and will fit the new engine to it. Chambers and I feel we have gone as far as we can with the GP frames and have been able to get ourselves two FZR250 Deltabox rolling chassis which we hope can be competitive handling wise with the FXR's.

The great thing about the Delta chassis is that its big enough to take almost any engine, 2-stroke single or twin, supercharged 4-stroke or even a Loncin or FXR if we get desperate.

Kickaha
12th March 2010, 21:04
have been able to get ourselves two FZR250 Deltabox rolling chassis which we hope can be competitive handling wise with the FXR's.

They are considerably better handling wise than the FXR frame

SS90
13th March 2010, 04:13
Picture-01 The plenum
Picture-02 Comparison of the new inlet tract with the an original
Picture-03 33mm straight shot into the crank case
Picture-04 New Delta rolling chassis

I have found a problem with running premix through my plenum. With a normal setup petrol/oil premix usually enters the motor wet and as the petrol evaporates the oil is left behind to lubricate things. But with my engine the wet fuel is evaporating in the plenum and leaving a lot of oil behind there and I wonder how much oil is actually making it into the engine.

So I have converted the motor back to a normal carb configuration,

Did you manage to get the bike on a dyno ?

gatch
14th March 2010, 21:15
They are considerably better handling wise than the FXR frame

Any idea what a "castec" frame from a honda spada would be like in comparison ? I don't know anything about the delta box..

TZ350
17th March 2010, 07:49
Alexi and Chambers flat out fitting a GP125 engine to one of the FZR Rolling Chassis.

F5 Dave
17th March 2010, 09:40
Cable ties. Check
Blocks of wood. Check
Spocket 12" from swing arm pivot. Check
Engine considerably higher than wheel spindles for super high COG. Check

Skunk
17th March 2010, 13:38
Cable ties. Check
Blocks of wood. Check
Spocket 12" from swing arm pivot. Check
Engine considerably higher than wheel spindles for super high COG. CheckYeah; you funny guy.

TZ350
17th March 2010, 14:22
Cable ties. Check
Blocks of wood. Check
Spocket 12" from swing arm pivot. Check
Engine considerably higher than wheel spindles for super high COG. Check

Std features with an FZR but not found on an RS chassis, you could upgrade if you want to.......:laugh:

jasonu
17th March 2010, 15:03
Cable ties. Check
Blocks of wood. Check
Spocket 12" from swing arm pivot. Check
Engine considerably higher than wheel spindles for super high COG. Check

Miserable prick!
Surprised you didn't mention the hefty weight as well...

F5 Dave
17th March 2010, 16:29
Well, if yer goanna do something. . . I've always gone out of the way to make the sprocket as close to the pivot as possible, if that meant cutting the engine case then so be it. But you can see an inch of daylight!

Then the engine is crazy high. Heck you could limbo under that engine. It's got more ground clearance than my dirtbike.

That sw is on quite an angle & there won't be the weight of the 4 cylinder engine compressing it. How about making some extender dogarms on the rear suspension to pull the rear down a bit? They are only steel plate. Then drop the forks an equivlent amount, you can see from the cable ties presumably what doesn't get stroked (don't need upper dust seals if after last few mm). You could cant the engine forward a bit too & add more gear oil. Tex's is like that in the RGV.

That tank should do you for a season's racing on one fill.

. . . Then cut the frame near the pivot where the weld is, remove 4 inches (like cut out the word 'BOX') & weld it back up.

bucketracer
17th March 2010, 17:50
Hmmmmm all good comments..........<_<...Dad and Chambers might have to look at it again..

Buckets4Me
17th March 2010, 19:08
Well, if yer goanna do something. . . I've always gone out of the way to make the sprocket as close to the pivot as possible, if that meant cutting the engine case then so be it. But you can see an inch of daylight!

Then the engine is crazy high. Heck you could limbo under that engine. It's got more ground clearance than my dirtbike.

That sw is on quite an angle & there won't be the weight of the 4 cylinder engine compressing it. How about making some extender dogarms on the rear suspension to pull the rear down a bit? They are only steel plate. Then drop the forks an equivlent amount, you can see from the cable ties presumably what doesn't get stroked (don't need upper dust seals if after last few mm). You could cant the engine forward a bit too & add more gear oil. Tex's is like that in the RGV.

That tank should do you for a season's racing on one fill.

. . . Then cut the frame near the pivot where the weld is, remove 4 inches (like cut out the word 'BOX') & weld it back up.

they can always do thant on the next one . Ha HA hA

Bren_chch
17th March 2010, 20:06
Well, if yer goanna do something. . . I've always gone out of the way to make the sprocket as close to the pivot as possible, if that meant cutting the engine case then so be it.

yeah maybe an inch of daylight is too much. ;)

i've got this issue with an engine i have built and fitted to an rs125 frame, the engine is soooo long, so i machined the casings as much as i could, some of the frame and moved mounts but its still quite a fair way off the swingarm pivot point as i also like to have them as close as possible to the pivot point. In saying that... on bikes with small hp like the bucket i really think it makes no odds if the drive is that far off the pivot point. but it is good practice to keep it close as possible.

Anyhow Dave, can you PM me your email addy, i got some photos for you. :D

Buckets4Me
17th March 2010, 20:12
Anyhow Dave, can you PM me your email addy, i got some photos for you. :D

you will get him into trouble sending him porn

Bren_chch
17th March 2010, 20:15
you will get him into trouble sending him porn

Its BUCKET porn!

Skunk
17th March 2010, 20:20
Its BUCKET porn!Share it then....

Buckets4Me
17th March 2010, 20:23
Its BUCKET porn!

thats still PORN if the wife catches him :)

post post POST post

TZ350
17th March 2010, 21:13
……make the sprocket as close to the pivot as possible………the engine is crazy high……..

That sw is on quite an angle……How about making some extender dogarms on the rear suspension to pull the rear down a bit? They are only steel plate. Then drop the forks an equivlent amount…….You could cant the engine forward a bit too & add more gear oil…….

That tank should do you for a season's racing on one fill……..

Then cut the frame near the pivot where the weld is, remove 4 inches (like cut out the word 'BOX') & weld it back up.

The engine does look crazy high. We would like to have the axels, crank, drive sprocket and swing arm pivot all in line, with one-quarter extension and three-quarters compression of the suspension at normal riding load.

We had planned on lowering it all like you suggest. I was surprised at how light the dog bones are, should be easy to make new ones out of some strap.

The tank does look ugly big, but its mostly hollow underneath, rocker covers, carbs, or air-box, not sure what went there but there is a big space underneath the tank.

If the sprocket is not close as possible to the swing-arm then I can see problems with chain tension and at 37rwhp the bike will probably want to squat when powering out of corners.

I have been looking at how Mxr’s deal with chain tension to see if we can copy that.

We had positioned the motor forward to get the weight distribution we wanted, hadn’t thought of cutting the frame and bringing the front wheel back. Something to think about thanks for the idea Dave.

Looking at the swing-arm angles, The Delta, Speedpros #6 and a real FZR250.

Yep mine is wrong, it's to steep, there is more to this engine transplant biz than meets the eye.

TZ350
17th March 2010, 21:25
Miserable prick!
Surprised you didn't mention the hefty weight as well...

90 something kg's..........about the same as my GP125......but nothing like a light weight RS.........:(

boostin
18th March 2010, 07:32
Well, if yer goanna do something. . . I've always gone out of the way to make the sprocket as close to the pivot as possible, if that meant cutting the engine case then so be it. But you can see an inch of daylight!

Hi Dave,

What is the general idea with getting the sprocket as close to the pivot? Is it some sort of neutral position for squat/wheelie ? (please excuse my ignorance!)

TZ350
18th March 2010, 14:59
It's got more ground clearance than my dirtbike. That sw is on quite an angle........

Thanks Dave, I got the tape measure out and found my rear shock is 20mm longer than Chambers one in his FZR.,,,,why,,,:scratch:

Pumba
18th March 2010, 16:45
Thanks Dave, I got the tape measure out and found my rear shock is 20mm longer than Chambers one in his FZR.,,,,why,,,:scratch:

Sounds like steve had been playing in the frames former life, actually I have a shock here in the shed for a FZR, not sure what model but you are welcome to it to see if it fits

Buckets4Me
18th March 2010, 17:15
I remember a post that went something like a pit bike shock of around the right length was put into the delta ????
my memory is a bit fuzzy

DID YOU SAY 37 HP ???????

Henk
18th March 2010, 17:43
Hi Dave,

What is the general idea with getting the sprocket as close to the pivot? Is it some sort of neutral position for squat/wheelie ? (please excuse my ignorance!)

The closer the sproket is to the pivot the less chain slack you will need. When the swingarm is in line with the sprocket and pivot the chain is at its tightest, the further from the pivot the sprocket the more slop you need at each end of suspension travel. This is why the BMW 450 has them concentric. Get the chain too tight at max travel and when it gets to its tightest pont it may try to tear the output shaft out of the motor or snap the chain. With dirtbikes the strictly correct way to set the chain tension is to pull the shock out, line everything up and tighten the chain so it has about 5mm of slop. lazy buggers line swingarm up by hauling it down with a tie down.

Pumba
18th March 2010, 20:46
I remember a post that went something like a pit bike shock of around the right length was put into the delta ????
my memory is a bit fuzzy

No that was the FXR frame he had

bucketracer
18th March 2010, 21:27
.

Tony Foal on motorcycle chassis and suspension:- http://www.tonyfoale.com/Articles/index.htm

Motorcycle Chassis Design and Construction and Other Technical Topics:- http://www.eurospares.com/frame.htm

F5 Dave
19th March 2010, 11:45
Yeah ideally as Henk says chain life & grief on the sprockets is a concern, as they found out in the early days of long travel dirtbikes, one could lose a chain pretty easily if it was that far away esp with wildly changing travel you can go from too tight to waay too loose. You will see modern MX bike with the sprocket virtually running against the sw plastic it's as close as possible on tall gearing.

Also this can bear the chain heavily on the swingarm. Rollers cost power if in the way (on the power side of the chain) & a small amount when on the trailing side. Any sideways or parallelism issue will be magnified & the 'whip' on the chain will cause drag or derail at worst.

The height relative to the pivot can produce pro or anti squat issues, yes on a small engine not such a drama, but a seriously too low sprocket will pull the rear down as it straightens the chain over the slider on top of the pivot.

That being said there are compromises & you can get away with a bit, it's just when you go beyond that there are problems. My 50 is further away than I wanted & I have to run the chain a little loose, but it is still ok. Engine weight forward is less of an issue on a small bike. but the bigger the bike the more the issue. I'd say the 250 is pretty big (long esp). Shortening it would make that issue go away.

TZ350
19th March 2010, 21:16
Chambers measuring the spring rate. The spring is being held in a plastic pipe and the ram of the press has a long pin fitted to it so the spring cant escape.

Chambers used a set of scales to measure the pressure on the spring and for every 10kg.... ie at each point 10-20-30...........50-60kg he would measure the amount the spring was compressed, this seemed to work pretty well.

A dual wound Honda RS125 spring measured at 0.60kg/mm and 0.72kg/mm and 85mm total fork travel

The dual wound FZR spring measured out at 0.45kg/mm and 0.71kg/mm and 130mm total fork travel

We also made some longer dog-bones to lower the bike but did not like the resulting angle of the suspension rocker and the swing-arm pivot bolt is still 50mm higher than the RS chassis.

Pumber has come to the rescue and helped us out with an original FZR shock which is shorter than the unit we have now, we will see what can be done with that next.

gatch
20th March 2010, 01:01
Would it be at all possible to cut the top shock mount and relocate it, higher in the chassis ?

Keeps the linkage ratios all the same etc. Then maybe make up some ally plates to mount the engine lower to keep sprockets and pivot in line ?

I guess then that would increase the steering head angle even more..

Maybe I'm just talking shit, haha.

SS90
20th March 2010, 07:22
OK, So now we have progressed on to Tony Foals' work...... and in doing so, we have somehow managed to overlook that the plenum idea was never completed.

Do you still have your Karate suit and Guitar in the wardrobe?

Yow Ling
20th March 2010, 07:37
OK, So now we have progressed on to Tony Foals' work...... and in doing so, we have somehow managed to overlook that the plenum idea was never completed.

Do you still have your Karate suit and Guitar in the wardrobe?

If you are that interested why not copy Thomases work and fit it to a Vespa, you can post your findings here.

SS90
20th March 2010, 08:29
What exactly is Thomas's work.... we only hear from Teezee (and his halfwit inbred delinquents), I can best some up this thread with " And now for something completely different"

SS90
20th March 2010, 08:30
If you are that interested why not copy Thomases work and fit it to a Vespa, you can post your findings here.

Is that better?... this thread was dying a death...now we can go back to the "old School" shit talking!

SS90
20th March 2010, 08:36
.

This is Thomas a Vietnamese race mechanic, you know that place where they have all those hot 50's and 125's are big bikes.

Thomas, ESE's Race Team's Tuner is fettling number 9. adjusting the port timing for Taupo.

Its hard to see but he has taped a degree wheel to the magneto flywheel so he can mark out the exhaust port height he wants.

None of this raise the port 3.5mm for a gazillion HP nonsense. He knows what timing he needs and sets the crank position there before marking the port and then doing the hells death port job that we all dream of.

You should see him setting up a carb. Talk about pain staking, he starts with a main jet so big the bike floods at about half throttle (apparently this proves the oriface of the needle/needle jet combo is big enough) and then he slowly step by step works back until it runs clean.

Most people start at the bottom with a carb and work up, He starts at the top and works backwards.

Never seen him blow one up. But then he is intelligent with the throttle and does not ring its neck when the engine is in distress.

Boy o Boy am I Looking forward to Taupo.

.


Pure genius........... I'll give Thomas €1000 Euro if he starts contributing.

My favourite bit is "Hell's death port job"........ you can't buy that kind of humor!

("Raise the port timing buy 3.5mm for a gerzzillion horse power")...Fark, now that is comedy!)

speedpro
20th March 2010, 10:45
I'm pretty sure my FZR chassis has the stock shock fitted. I certainly have not swapped it and the preload adjuster looks like a standard FZR style. On the minimum preload setting the sag as measured was in the ballpark as suggested by RT. The front forks are a real mixture of bits and I'm not sure which springs are fitted but they are FZR250 of some sort and with the cutdown preload spacers, again not sure from which model, they also have close to ideal sag settings as per RT. I only have to compress the springs about 5mm to start screwing the fork caps on. The basic suspension on a 3LN FZR is about right with a bucket engine in or at least it can be adjusted to be. I have no idea of spring rates but that didn't stop me getting the sag right.

TZ350
20th March 2010, 11:14
Hi Speedpro, we value your suggestions and now have two FZR250 chassis, our problem is that one had been fitted with a shock that looks like a FZR250 but is 20mm longer and the bike rides much higher than the std one we got from ShellRacing.

Also the ShellRacing FZR had the "progressive" part of the front springs cut off. We are newbies to chassis work and are looking at everything in an effort to understand what we have got and how it compares to the best handling bikes we have on the team, the RS/GP125's.

One of the things we have learned is, that springs, that are commonly called progressive are in fact dual wound and have two distinct spring rates.

For a spring to be "progressive" the coils at one end would have to be wound closely together and then progressively further apart. And when measured under load should require a progressively grater load to compress them. The FZR and RS front springs had two distinct compression rates.

The FZR and RS front springs have about a quater wound close and then the rest of the spring is wound with a coarser pitch without a progressive transition between the two sections.

Read about springs here:- http://www.worksperformance.com/html/multirate_desc.html A Progressive spring is not the same as a Dual-Rate Spring. A progressive-wound spring is similar to a dual-rate in that it has an initial and final rate. The drawback of a progressive spring is that the crossover point is not adjustable. How the spring is wound determines the characteristics of the spring. This type of spring is wound with a varying pitch, as opposed to a constant pitch used in linear rate springs.


I can see this suspension bizz all getting very complicated, and quickly.............

TZ350
20th March 2010, 11:20
Would it be at all possible to cut the top shock mount and relocate it, higher in the chassis ?

Keeps the linkage ratios all the same etc.

I think the theory is right but technicaly it's difficult for me to do.

gatch
20th March 2010, 13:02
I think the theory is right but technicaly it's difficult for me to do.

Its sorted then, build a chrome-moly chassus tube frame. Easy :D

TZ350
20th March 2010, 17:11
Talks about Harley’s but the ideas apply to any bike.

Excerpts taken from:- http://www.calsci.com/motorcycleinfo/Suspension.html

When we think of bumps, we think of large and small bumps. However, your suspension does not see things like this. To your suspension, there's square edged bumps and rounded bumps. The key to understanding how your suspension works is that small, square edged bumps are harder to handle than large rounded bumps. The shape of the bump is more important than the size.

Springs typically come in three types: straight wound, dual rate, and progressive wound.

Most shocks have a small amount of compression damping, and a much larger amount of rebound damping. This is what you really want: the shock moves easily when it is compressing to absorb a bump, then slowly lengthens to release the energy stored in the spring.

Because of this, while compression damping is very important to dirt bikes in general and supercross bikes in particular, compression damping is not very important for street bikes - unless you routinely hit 4 by 4s on the freeway, or drive in Manhattan.

Rebound damping happens after the bump is all over. If there were only one bump in the whole world, rebound damping rates could be set very high, and the spring energy could be dissipated very slowly. Of course, on real highways you're likely to hit another bump in a short time, so the rebound damping must be chosen to allow the spring to uncoil quickly and get ready for another bump.

For rebound damping, we just want to slow down the spring as it releases its energy. It is not so important exactly how this is done. If there is not enough rebound damping, the bike feels loose and disconnected from the road. In extreme cases, bumps may produce a waterbed like wave action in the bike. If there is too much rebound damping, the suspension may pack down: you hit another bump before the suspension recovered from the last bump. After several bumps in a row like this, your suspension may be nearly bottomed out and unable to respond.

Many dirt bikes also have complicated rebound damping systems with several different sized holes and literally dozens of spring washers. Even on dirt bikes, there is no evidence that these complicated systems are either useful or necessary. On street bikes, a simple velocity squared hole works fine, as long as the hole size and oil are correctly chosen.

Since the forks get shorter when you hit a bump, all forks are effectively air-assisted. Because of this, it is important to get the oil level set correctly when you change your fork oil, or the spring rate will be wrong.

Forks have an additional problem - flex. Because they are almost three feet long, relatively small forces on the front wheel can cause the forks to flex and the front wheel to wiggle side to side, even while the handlebars are held firmly.

On compression, the fork spring is compressing and storing energy. The Rebound Washer is pushed by the fork oil up against the upper stops. These stops have holes in them to let oil through. Oil is collected in the pocket between the Damping Piston rod and the fork tube. Also, oil flows through the Compression Holes, up the centre of the Damping Piston rod, and out the piston. The size and number of the Compression Holes determines the compression damping.

During rebound damping, the Rebound Washer is forced by the fork oil down against the lower stops. These lower stops form a seal. The oil trapped between the Damping Piston rod and the fork leg must travel through the Rebound Hole, down the Damping Piston rod, and out the Compression Holes. Since the Rebound Hole is much smaller than the Compression Holes, the rebound damping force is almost completely controlled by the size of the Rebound Hole and the oil thickness.

Your forks can be modified by changing the fork springs, changing the fork oil, and drilling new and/or larger holes in your damper rods. If modified correctly, your forks can work extremely well.

Excerpts taken from:- http://www.calsci.com/motorcycleinfo/Suspension.html

TZ350
20th March 2010, 17:27
I'm pretty sure my FZR chassis has the stock shock fitted. On the minimum preload setting the sag as measured was in the ballpark................ I have no idea of spring rates but that didn't stop me getting the sag right.

Ok from what I have read recently, spring rate is about having enough umph to push the weight of the wheel back down, on the other side of a bump and preload is about holding the weight of the bike and rider up.

The ideal is to have the bike and rider sail along flat and level with the wheels bobbing up and down as they roll over the lumps.

The big thing is, spring rate is associated with the unsprung weight of the suspension and wheel, not the weight of the bike.

The heavier the wheel and unsprung part of the suspension the stronger the spring needs to be.

Pre-load is about supporting the weight of bike and rider at the 1/4 - 3/4 position of suspension travel.

To get the smoothest ride, one wants the lightest wheels and unsprung suspension parts possible. Because the lighter suspension and wheels means you can use softer springs.

But a bike with the same weight wheels and suspension parts like a FZR250 turned into a Bucket, although some 30 kg's lighter it still needs the original spring rate to control the wheels.

But I can see other issues here with changing the ratio of unsprung weight to total weight of rider and bike by swapping the engine out for a lighter one.

There will be less reactive force in the lighter chassis/engine/rider combo to help store energy in the suspension spring as a wheel rolls over a bump.

This means there is less umph to keep the wheel in contact with the road on the other side of a bump and the lighter sprung mass will get flung around more as the wheels try to compress the suspension springs.

You will know what I mean if you have ever ridden in an empty ute with over load springs and then again with a load in the back. The heavier the load the smoother the ride.

Trying to understand all of this hurts my head.....:blink:..... but fits with what you have told me...

TZ350
20th March 2010, 23:44
From:- http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

1 - Front compression
This is when you want your front compression to control the "nose down" effects of braking so it turns in to corner properly

2 - Front rebound
You have let go of brakes, adjust front rebound so that the front forks extend at a controlled rate allowing you to keep your line.

3 - Rear Compression
You want the rear end to squat a bit as you apply the power.

Make sure that the rear rebound setting keeps the rear wheel in contact with the road.

A very easy to follow guide to suspension setup:- http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

TZ350
21st March 2010, 00:03
I just knew it was going to get complicated, from YSSUA the suspension people:-
http://www.yssusa.com/suspension_problems.html

The result of a too hard rear spring ratio is that the bike gives easy turning into corners but creates traction problems. Too soft rear spring ratio gives good traction in acceleration, but tends to under steer in the entry of a corner and will give the front a light feel. The result of a too hard fork spring ratio shows in the bike with good under braking, but creates under steer and feels harsh in corners. A too soft spring ratio gives easy turning into corners, but creates over steer and can cause the front to tuck-under or dive under braking.

What’s “Spring Ratio” ?????? for goodness sake…….

Henk
21st March 2010, 06:57
I assume they are talking about the spring constant. I wouldn't get too worried about it. It should be possible to get ballpark numbers for static sag at both ends offf the interwebs. I know that for dirt bikes we used to work with about 10 - 20 mm without rider and 65mm with rider as a start point. 5 and 20 feel about right for my FXR.
I haven't got too worried about this with the bucket since the suspension isn't being asked to deal with two foot whoops and wheelstanding over logs and the power and weight involvled aren't that great. I'd get the ride height about right at the rear if you can, and then try and get the front end sorted, you can do this by feel and messing about with oil levels and weights when you have the sag right, again I'd be looking for about 20mm sag with the rider on board. Then start in on the rear end if you find that you are having issues. I'm not convinced that a bucket is going to be making enough power to start overwhelming the suspension and tyres unless things are so far out that the rear end is almost rigid.

I am by no means a great suspension tuner and have gone with things that feel about right to me and that might not suit everybody since I prefer to have my suspension a bit soggy anyway after years of dirtbikes with 12 inches of travel.
The fact that I'm not that fast also helps the suspension.
If you can get the delta frames close to ballpark they are likely to be beter than the standad frames you are going away from in any case and one you have them working you can start zeroing in on gains.
Suspension tuning can be as much of an art as engine tuing I think you'll find as evident by the fact tat there are people that make their living doing nothing else.

Skunk
21st March 2010, 18:00
5 and 20 feel about right for my FXR.
I haven't got too worried about this with the bucket since the suspension isn't being asked to deal with two foot whoops and wheelstanding over logs and the power and weight involvled aren't that great. I'd get the ride height about right at the rear if you can, and then try and get the front end sorted, you can do this by feel and messing about with oil levels and weights when you have the sag right, again I'd be looking for about 20mm sag with the rider on board. Then start in on the rear end if you find that you are having issues. I'm not convinced that a bucket is going to be making enough power to start overwhelming the suspension and tyres unless things are so far out that the rear end is almost rigid.
Suspension tuning can be as much of an art as engine tuing I think you'll find as evident by the fact tat there are people that make their living doing nothing else.I think you're right with just about everything in that post. As you say - get it in the ballpark and go from there as every rider will want a different setup.

TZ350
21st March 2010, 21:31
How do you do change the stock springs, spring rate?

How do you do change the stock springs! Spring rate? YOU CUT THEM SHORTER! But not without calculating how much! to get from .72 kg/mm to 0.9 kg/mm the calculation is rather strait forward surprisingly! Just figure out the percentages!

0.9 minus .72 divided that by .72 = 24% holy moly!!!

you need to cut off 24% of the coils to get a 0.9 spring rate? Or you could just settle for 0.8 kg/mm or 10% cut off!

From:- http://www.vfrdiscussion.com/forum/index.php/topic/28721-calculatingmeasuring-fork-spring-rates/

Henk
21st March 2010, 21:38
Never got into the cutting things down game as with dirtbikes it was the right shock to start with. If you can't get the static sag to line up both loaded and unloaded with the preload adjustments available it's time for a different spring. About the only real mod we ever had to make was to lower the ride height on a couple of bikes for my wife and we did that with longer dogbones in both cases. We did throw springs in as well but cutting coils off? I'm not sure I'd want to go there.

Buckets4Me
22nd March 2010, 05:51
Never got into the cutting things down game as with dirtbikes it was the right shock to start with. If you can't get the static sag to line up both loaded and unloaded with the preload adjustments available it's time for a different spring. About the only real mod we ever had to make was to lower the ride height on a couple of bikes for my wife and we did that with longer dogbones in both cases. We did throw springs in as well but cutting coils off? I'm not sure I'd want to go there.

this is buckets not motorX welcom to our world

TZ350
22nd March 2010, 08:27
Now the boys have given up on the GP chassis they are getting right into building new bikes and engines.........

They are working on two Honda RS125 chassis, two Yamaha FZR's and an Aprillia RS125 chassis.

It's all to try and keep those FXR's honest.

Now that we have some good engines and chassis next seasion and the TRRS should be interesting.

F5 Dave
22nd March 2010, 10:18
Cutting down springs is a known procedure, its been disscussed here many times. Getting them straight flat edged is tricky & they need to be to avoid jamming the spring heavily against the inner tube. Also making sure you don't have a coil bind situation requires care.

With the FZR you have removed a lot of weight replacing the engine & no road fairing/lights etc. On the other hand yams of that era always had light front springs. The first post form the Harley site is twaddle, but what you'd expect & probably fit for purpose considering the intended audience. Henk, I thought you'd had KDXs? Front springs on those were pretty light & responded well to some stiffer springs (mind you my one was a 91, but the later ones apparently too).

Buddha#81
22nd March 2010, 11:21
Now the boys have given up on the GP chassis they are getting right into building new bikes and engines.........

They are working on two Honda RS125 chassis, two Yamaha FZR's and an Aprillia RS125 chassis.

It's all to try and keep those FXR's honest.

Now that we have some good engines and chassis next seasion and the TRRS should be interesting.

Seems alot of effort to keep a single mass produced cheap form of racing honest? hehehehe

F5 Dave
22nd March 2010, 11:43
Yeah but have you ridden a GP on the track? They're dreadful. Seriously a better option would be to buy one of these regularly exploding FXRs & jam the engine in that.

TZ350
22nd March 2010, 15:43
Seems alot of effort to keep a single mass produced cheap form of racing honest? hehehehe

OkeDoke your right.....but......:2guns:.....so there.....:bleh:.....and........:laugh:...........

Buddha#81
22nd March 2010, 15:52
OkeDoke your right but......:2guns:.....so there.....:bleh:.....and........:laugh:...........

Bwahahahahahaha!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!

Henk
22nd March 2010, 16:22
Henk, I thought you'd had KDXs? Front springs on those were pretty light & responded well to some stiffer springs (mind you my one was a 91, but the later ones apparently too).

Dead right, the fork springs on the KDX were light, but then when the rider is around the 50 - 55 kg mark they are about right, whacked in a softer spring at the back and longer dog bones and all was good, bike came with gold valves fitted in the front and it works well set up like this its regular rider.

Pumba
22nd March 2010, 18:42
Hmmm, interesting, I was woundering where that Aprilia Frame from trade me ended up (I presume it is the same one that went up for sale recently)

Henk
22nd March 2010, 19:49
Saw it in the back of a ute on Sunday, pretty. Shame the sprocket etc is all on the wrong side.

Kickaha
22nd March 2010, 20:37
Saw it in the back of a ute on Sunday, pretty. Shame the sprocket etc is all on the wrong side.

Thats not hard to fix, you just turn the wheel around and fab new caliper mounts

Kickaha
22nd March 2010, 20:38
Saw it in the back of a ute on Sunday, pretty. Shame the sprocket etc is all on the wrong side.

Thats not hard to fix, you just turn the wheel around and fab new caliper mounts

Henk
22nd March 2010, 20:53
Thats not hard to fix, you just turn the wheel around and fab new caliper mounts

And drill a hole in the swingarm for the chain to run through?

Ned Kelly
23rd March 2010, 06:54
Hmmm, interesting, I was woundering where that Aprilia Frame from trade me ended up (I presume it is the same one that went up for sale recently)

Yip that was the one Pumba. Another small project for the Winter.

TZ350
23rd March 2010, 06:58
Chambers has made a scale drawing of the FZR swing arm and sprocket showing maximum travel and the frame mounting points so he can design some engine plates and get the frame, engine, sprocket and swing arm relationship sorted properly.

Ned Kelly
23rd March 2010, 07:00
And drill a hole in the swingarm for the chain to run through?

Not as easy as turning the wheel around and drilling holes. The swing arm is a piece of work.
The plan is to use an Aprilia engine, well at least the bottom end. This way we get a six speed gear box and the drive on the right side anyway. Work on using a RG400 cylinder and new chamber. 100cc water cooled six speed is the end result. Sounds easy. How long will it take.???

jasonu
23rd March 2010, 12:54
Not as easy as turning the wheel around and drilling holes. The swing arm is a piece of work.
The plan is to use an Aprilia engine, well at least the bottom end. This way we get a six speed gear box and the drive on the right side anyway. Work on using a RG400 cylinder and new chamber. 100cc water cooled six speed is the end result. Sounds easy. How long will it take.???

I've got a 95 RS125 (honda) swingarm I would sell you if you are interested. The chain is on the left (correct?) side so you won't be forced into using the Aprilia bottom end. It needs some welding and then machining where the rear wheel came loose and caused some damage around the axel area.
PM me if you are interested.
Jason

TZ350
23rd March 2010, 17:00
Its all a puzzell, three FZR shocks, rockers and swingarms and every thing is different.......

F5 Dave
23rd March 2010, 17:04
Well it's good to see Yamaha obviously were doing some intensive R&D race development on the FZR250 hence all the changes. Probably find the FZR250SP RR R RRR had the adjustable pivot height required for one of the setups.


. . . .either that or some contractor was off loading some longer shocks cheap enough to make it worth changing the linkages.

SS90
25th March 2010, 21:41
Teezee, can we please see a copy of your dyno run.

You built this up for weeks, claimed "it worked", then nothing.

gatch
25th March 2010, 21:51
HEY I have a question regarding cut springs, if making the end of the spring perfectly flat is not your idea of fun. Would a turned bit of ally, with a thread cut in that was the same pitch as the springs coils be feasible ?

I ask because I'm probably going to be cutting some springs and can't be fucked dicking around, finishing the ends, when I could use the same threaded bit of ally after every trial cut..

Catch my drift ?

TZ350
26th March 2010, 08:00
Teezee, can we please see a copy of your dyno run.

After your posts last week on the Team ESE thread, I don’t think so.


.... we only hear from Teezee (and his halfwit inbred delinquents)…….


Is that better?... this thread was dying a death...now we can go back to the "old School" shit talking!

TZ350
26th March 2010, 08:08
HEY I have a question regarding cut springs, if making the end of the spring perfectly flat is not your idea of fun. Would a turned bit of ally, with a thread cut in that was the same pitch as the springs coils be feasible ?

I ask because I'm probably going to be cutting some springs and can't be fucked dicking around, finishing the ends, when I could use the same threaded bit of ally after every trial cut. Catch my drift ?

Looks like a really good idea, two things,

I think the length of spring wound onto the alloy plug would be inactive and have to be counted as a cutoff piece and the full length of the plug would have to be counted as preload spacer.

But it looks like a good idea, we might try it ourselves.

SS90
26th March 2010, 08:20
After your posts last week on the Team ESE thread, I don’t think so.

Oh come on Teezee, let's all just move on.

plenty of people are interested in seeing what the curve looked like, open discussion brings rewards.

jasonu
26th March 2010, 13:04
HEY I have a question regarding cut springs, if making the end of the spring perfectly flat is not your idea of fun. Would a turned bit of ally, with a thread cut in that was the same pitch as the springs coils be feasible ?

I ask because I'm probably going to be cutting some springs and can't be fucked dicking around, finishing the ends, when I could use the same threaded bit of ally after every trial cut..

Catch my drift ?
Sounds like way more trouble than giving the cut end a quick lash with a disk grinder...

F5 Dave
26th March 2010, 14:20
Well you need to heat & bend the top coil sort of flat before hitting it with the grinder, but you don't want to temper the metal & getting it flat & equal length to the other side is a knack, but not too hard. Meat axes do not apply.

jasonu
26th March 2010, 15:27
----------------------------------

gatch
26th March 2010, 16:03
Sounds like way more trouble than giving the cut end a quick lash with a disk grinder...

Rubbish. I think this would be much better. Besides, we engineers like to take the hard road..


Well you need to heat & bend the top coil sort of flat before hitting it with the grinder, but you don't want to temper the metal & getting it flat & equal length to the other side is a knack, but not too hard. Meat axes do not apply.

Yep, I don't have a gas plant at home.. Also I think when you are heating the spring, the heat soak may take the temper from the spring for a few more mm than what you want..

Mudflaps
26th March 2010, 18:11
So I just read this post from page 130 to the end. I can't believe how much I've learnt and understood. Thanks

I don't know if I'll ever be able to contribute in any fashion, but keep explaining stuff as you have been cause it's great to read.

gatch
26th March 2010, 19:29
Looks like a really good idea, two things,

I think the length of spring wound onto the alloy plug would be inactive and have to be counted as a cutoff piece and the full length of the plug would have to be counted as preload spacer.

But it looks like a good idea, we might try it ourselves.

Grouse, you can try it out for me :D

I figure you could use a radius tool that is about the same diameter as the spring wire if you have one handy, or grind up a piece of assab, or a chipped cobalt slot drill. Anything really..

I reckon 1 complete coil wound on would be more than sufficient to hold it steady ?

speedpro
26th March 2010, 21:07
I think you'll find all this talk of cutting springs is a waste as stock FZR springs are about right. I've set mine up by mixing and matching, trimmed the spacer, set oil levels and it's sweet enough for me. I've probably ridden one bike that's better but there isn't much in it. There's enough compression damping with the emulator preload wound up yet it's compliant over the worst ripples at Mt Wgtn but still has about 5-10mm travel left.

Couple of things I have done that seem OK - the rear preload is on minimum and the front has been dropped down the forks by the thickness of the handlebar clamps. Turns OK at Mt Welly but is still stable at Taupo.

gatch
26th March 2010, 22:46
I think you'll find all this talk of cutting springs is a waste as stock FZR springs are about right. I've set mine up by mixing and matching, trimmed the spacer, set oil levels and it's sweet enough for me. I've probably ridden one bike that's better but there isn't much in it. There's enough compression damping with the emulator preload wound up yet it's compliant over the worst ripples at Mt Wgtn but still has about 5-10mm travel left.

Couple of things I have done that seem OK - the rear preload is on minimum and the front has been dropped down the forks by the thickness of the handlebar clamps. Turns OK at Mt Welly but is still stable at Taupo.

Wish I could say the same for the spada fork springs. They are progressive rate, and softer than a bag of warm marshmallows.. Cut cut cut. If that doesn't work I'm buying new..

TZ350
27th March 2010, 07:36
Page 140 links collection

Links from the last ten pages, other link collections can be found on pages 80, 90, 100, 110, 120, 130

KartWeb Tech Articles
www.kartweb.com/TechArt/2Stroke/chapter1.doc
www.kartweb.com/TechArt/2Stroke/chapter2.doc
www.kartweb.com/TechArt/2Stroke/chapter3.doc
http://www.kartweb.com/TechArt/2Stroke/chapter1-2-3.swf
http://www.kartweb.com/TechArt/2Stroke/2_stroke_technology.htm

Suspension Stuff
Tony Foal on motorcycle chassis and suspension:- http://www.tonyfoale.com/Articles/index.htm
Motorcycle Chassis Design and Construction and Other Technical Topics:- http://www.eurospares.com/frame.htm
A Progressive spring is not the same as a Dual-Rate Spring. http://www.worksperformance.com/html/multirate_desc.html

Talks about Harley’s but the ideas apply to any bike:- http://www.calsci.com/motorcycleinfo/Suspension.html

1 - Front compression
This is when you want your front compression to control the "nose down" effects of braking so it turns in to corner properly
2 - Front rebound
You have let go of brakes, adjust front rebound so that the front forks extend at a controlled rate allowing you to keep your line.
3 - Rear Compression
You want the rear end to squat a bit as you apply the power.
Make sure that the rear rebound setting keeps the rear wheel in contact with the road.
http://www.gostar-racing.com/information/motorcycle_suspension_set-up.htm

How do you do change the stock springs, spring rate?
How do you do change the stock springs! Spring rate? YOU CUT THEM SHORTER! But not without calculating how much! to get from .72 kg/mm to 0.9 kg/mm the calculation is rather strait forward surprisingly! Just figure out the percentages!
0.9 minus .72 divided that by .72 = 24% holy moly!!!
You need to cut off 24% of the coils to get a 0.9 spring rate? Or you could just settle for 0.8 kg/mm or 10% cut off!
From:- http://www.vfrdiscussion.com/forum/index.php/topic/28721-calculatingmeasuring-fork-spring-rates/

I just knew it was going to get complicated, from YSSUA the suspension people:-
http://www.yssusa.com/suspension_problems.html

SS90
27th March 2010, 07:48
Don't get distracted Teezee, where is the dyno run of your "plenum that works"

SS90
27th March 2010, 07:54
Post your dyno run, and I will never post on your precious ESE thread ever again.

That's got to be the offer of the century.

Henk
27th March 2010, 08:08
SS90. You've made your point, it's starting to get annoying now. Some of us try to follow this thread for the technical stuff and the bitch fight is an uneccesary distraction.

SS90
27th March 2010, 08:27
SS90. You've made your point, it's starting to get annoying now. Some of us try to follow this thread for the technical stuff and the bitch fight is an uneccesary distraction.

Yes, Henk, and when the technical stuff is wrong, what then?

I am annoyed as well, I'm trying to expand my knowledge.

The personal attacks are always coning from his kids (others too get abused in other threads), it's not necessary, and childish.

For me the subject of this thread is more than "just a game", I don't go advertising who I am so I can make money on return to NZ.

I only question things I don't see as correct, and give advise that helps.

What is wrong with that?

Anyway, as you where.

TZ350
27th March 2010, 09:32
.... we only hear from Teezee (and his halfwit inbred delinquents)…….


Is that better?... this thread was dying a death...now we can go back to the "old School" shit talking!


The personal attacks are always coming from his kids........:crybaby:.......

????..................

SS90
27th March 2010, 09:48
Got that dyno run yet?

I don't want to ridicule, I could have done that when you puffed out a megre 15PS because you where way to over advanced and rich, and you spent 2 months thinking you had so much power it was over heating...... but I'm too nice to mention that.

I am genuinely interested in the shape of the curve, as well as what it sounded like (you mentioned Blarrrs) (sp )

TZ350
27th March 2010, 10:08
I don't want to ridicule............


.... we only hear from Teezee (and his halfwit inbred delinquents)…….


Is that better?... this thread was dying a death...now we can go back to the "old School" shit talking!


The personal attacks are always coming from his kids........:crybaby:.......

Is it jealousy that drives SS............

SS90
27th March 2010, 10:19
found that dyno run?

Bren_chch
27th March 2010, 10:23
I dont think anyone else cares about the dyno run. chasing your tail?

TZ350
27th March 2010, 10:25
found that dyno run?

This is fun.........its like making your pet dog beg for a treat.......woff...woff

SS90
27th March 2010, 10:31
:scooter::scooter::scooter:

TZ350
27th March 2010, 10:37
:scooter::scooter::scooter:

Wrong again, Team ESE is five bikes................

SS90
27th March 2010, 10:42
Wrong again, Team ESE is five bikes................

Oh yes, that's right.
:third::third::third::third::third:

TZ350
27th March 2010, 11:14
Oh yes, that's right.
:third::third::third::third::third:

Yes we have scored a few third place trophies.........:D..........and pleased as punch we are too.

jasonu
27th March 2010, 12:47
I dont think anyone else cares about the dyno run. chasing your tail?

I'd like to see it.

Bren_chch
27th March 2010, 12:51
well you would wouldnt you. there aint one to see... lol

Buckets4Me
27th March 2010, 17:51
Wrong again, Team ESE is five bikes................

thats SIX (getting forgetfull)

4 f4 and 2 f5 come on you'r getting bad again
and what happend to the spares (red and yellow) 7,8
and then there is the other rg50 thats half together
and the aprillia thats to good to bucket race 9,10

so whats this with only 5 bikes ???????

TZ350
27th March 2010, 17:57
Below they talk about the overly wide inlet and how improving the transfers allows a smaller inlet/exhaust port and also how Japanese bikes are on the money.

From:- http://drunkmunkey6969.googlepages.com/ts1cylinderporting

Pic 1. Inlet port on the all out race cylinder is colossal in comparison to the stage 2 cylinder on the left. This will lead to awesome all out performance....but due to the decreased life of the piston and rings, its not the kind of thing you'd do 12,000 miles worth of touring on!

Pic 2. On the left, these transfers really help to increase the power dramatically, but without the wear problems associated with oversized inlet and exhaust ports. Which is why so many jap bikes have fantastic transfer port set ups these days.

Some of those old Team ESE posts are worth a re-visit.

Buckets4Me
27th March 2010, 18:00
well you would wouldnt you. there aint one to see... lol

there is but I dont think it's been shown (more fun that way and it realy pisses SS90 off) 22 hp out of an air cooled 100 :)

was run at Taupo ( last to nearly first in the first 3-4 corners ) till it threw the rider on the ground
thats why we are now working on the suspention

bucketracer
27th March 2010, 18:03
thats SIX (getting forgetfull)

4 f4 and 2 f5 come on you'r getting bad again
and what happend to the spares (red and yellow) 7,8
and then there is the other rg50 thats half together
and the aprillia thats to good to bucket race 9,10

so whats this with only 5 bikes ???????

TeeZee has only got five fingers on one hand to count with.......:bleh:

bucketracer
27th March 2010, 18:06
there is but I dont think it's been shown (more fun that way and it realy pisses SS90 off) 22 hp out of an air cooled 100 :)

was run at Taupo ( last to nearly first in the first 3-4 corners ) till it threw the rider on the ground
thats why we are now working on the suspention

Yes, it binned Chambers then tossed Avilon a bit later in the same corner.

Buckets4Me
27th March 2010, 18:30
TeeZee has only got five fingers on one hand to count with.......:bleh:

he will have to use the other hand and take his shoes off shortly

Bren_chch
27th March 2010, 18:38
Yes, it binned Chambers then tossed Avilon a bit later in the same corner.

We heard it seized :)

bucketracer
27th March 2010, 18:38
..........more fun that way and it realy pisses SS90 off...........


Don't get distracted Teezee, where is the dyno run of your "plenum that works"


I'm not going to hand feed you .....…. If I did, where is the fun in that :devil2:...……. At this point I am going to dissapoint every one.......

TeeZee’s not going to hand feed you SS...……. If he did, where is the fun in that...:laugh:

Buckets4Me
27th March 2010, 18:40
We heard it seized :)

when where what it ran all day Avalon rode after the restart and finished (was around third on the first lap from the back of the field but didn't like how it bucked and swayed in corners so drifted back further)
Avalon just refused to ride it again after that race



you will have to come up next year and see for yourself

Buckets4Me
27th March 2010, 18:46
while I respect that many people would have a real intertest in this "Kiwi guy in Germany" at this stage I am not willing to do that.

However, I will "help the boys back home"

HA HA HA real interest my ass

stop making me laugh it hurts to much

CookMySock
27th March 2010, 18:55
I don't want to ridicule, I could have done that when you puffed out a megre 15PS because you where way to over advanced and rich, and you spent 2 months thinking you had so much power it was over heating......Snort, LMAO!!!

Steve

Squiggles
27th March 2010, 19:00
I dont think anyone else cares about the dyno run. chasing your tail?

I do... followed this thread for so long i'll feel ripped without it :cry:

Bren_chch
27th March 2010, 19:05
i dont think there is a dyno run on chart :D

TZ350
27th March 2010, 19:16
We heard it seized :)

No, Avilon fell and the race was re-started, on the restart she went from last to very close to the front in the first lap but drifted back as she battled with the bikes handling.

Thats when we knew for sure we were never going to be able to do it with the Suzuki GP chassis.....

TZ350
27th March 2010, 19:19
i dont think there is a dyno run on chart :D

Correct........John Conners dyno is not equipped to print graphs.......

Picture is of Bucket4me warming NedKellys bike up on Johns home Dyno.

Bren_chch
27th March 2010, 19:22
oh the specifics! ;)

TZ350
27th March 2010, 19:34
oh the specifics! ;)

Only because you and Squiggles have asked. I thought it was only that twit SS90 that was interested.

I can say that it didn't blow up and its first dyno test session, if not spectacular was at least encouraging.

Its the first cut and I would have liked to have completed some more development........

A lot of our recent work was inspired by some sensible and constructive posts earlier from Sonic_V they are worth another look….……


There has been a lot of kart classes over the years that have used restrictive carbs. They all use the venturi principle plus the intake tract length tends to be longer than when a non restrictive carb is used.

As for venturi in your intake, I would suggest a taper from the choke of the carb out to 30mm should be adequate, keeping included angle below 14degrees as has been mentioned elsewere. I suspect that once the intake is flowing better, that you will be able to close the disc valve earlier. This is the area that needs looking at………………


0.00017 is spot on for an engine were you require a good spread of power. Basically, you have a 25hp exhaust port there. (for an air cooled engine) The fact that you are five short indicates that your problems are elsewere. Pulling the engine speed down via a longer exhaust system is likely to find some of this power plus your intake work should find most of the rest. I have found it possible to make excellent power with exh time/area as low as 0.00016 plus a nice spread of power.

This is from memory, and remember Johns dyno only graphs rwhp against road speed so rpm has to be calculated.

The original engine with a std 24mm carb and an inlet duration of 225deg made 19+rwhp at 11,250 rpm.

The same engine was fitted with a barrel that has enlarged transfers and a reduced exhaust duration as suggested by SS90 and a 24mm venturi carb as suggested by Sonic_V which was fitted conventionally on the side, it made 21+rwhp at 9,500rpm. It ran best on a 130 main jet and was a strong runner at Taupo.

Same engine, same carb same 225deg inlet duration but with the plenum chamber, it was frighteningly fast up the drive on Taupo gearing but suffered badly from a flat spot below the power band at about 4-5k rpm.

Sonic_V in one of his early posts had suggested an inlet closing point of 60deg ATDC, for a duration of 205deg.

Same plenum engine, same carb but with 205deg inlet duration it still suffered from a lesser but significant flat spot below the power band at about 4-5k rpm.

Reducing the closing point to 45 then 35 degrees ATDC for a duration of 180 reduced the flat spot but it still made the bike unrideable in competition.

Increasing the inlet tract length inside the plenum by 35mm cured the flat spot and it was rideable on the track at Mt Wellington in the wet.

Now Dyno Time….

21+rwhp at 9,500 rpm from the conventional engine with 225 deg inlet duration Sonic_V venture carb SS90 barrel, Honda RS125 chamber and 130 main jet.

20+rwhp at 8,500 rpm from the same engine fitted with the plenum and 180deg inlet duration and it ran best on a 185 main jet.

Interestingly the plenum engine made much more hp below the power band, about 4-5hp every where and this extra low down grunt probably accounts for the wheel spin when giving it some big throttle during testing at Mt Welly.

Testing stopped when we realised that there may be a lubrication problem as most of the pre-mix oil was being left behind in the plenum. To do any more development I will have to build an auto lube motor to go with the plenum.

As the BMEP for 20rwhp at 8,500 is a whole lot better than for 21 at 9,500, it will be interesting to see where the plenum idea goes with more inlet duration and barrel/chamber mods as suggested by Sonic_V for max power at 10,500.

Team ESE are building some new chassis and I have taken the plenum off old Blue to use in the new bike.

So there you have it, encouraging but not spectacular….. "yet"………

Gentelmen do you want to place your bets?

SS90
27th March 2010, 22:51
Interesting.

The unusually large mainjet phenominon I have noticed when you "over carb" an engine.

For example.

Say you have a 125cc engine that produces 26PS with a 28mm carb, and a 138 mainjet, the same engine may well produce the same (peak) power (with flatspots in the midrange...some call it "resonance hole") using a (as an example 36mm carb), but requiring a 185 mainjet.

The same power (or less, or what ever) with a bigger carb, and massive mainjet?

That doesn't make sense at all.

Think about it at full throttle a 138 mainjet flows xxx liters per minute, a 185 significantly more.

No way that 185 mainjet is actually flowing what it can, therefore, why does the carb/engine combo require it, just run run somewhere close to cleanly?

In my experience, it comes down to signal strength.

In situations such as this, you can swap jets as much as you like, but there are resonance issues causing the problem, and big jets just mask it, not remedy it.

TZ350
28th March 2010, 06:20
.

I have noticed this about you before, you obsess about things, it’s a bit disturbing.

Forget the blars, forget the main jet, all this has been covered before.


Unlike other motors where at resonance the air bounces back and forth in the inlet tract at least three times, picking up fuel each time it passes the jet,

I think the air flow through the plenum carb is all one way, so it has to pick up all its fuel in one go on the way in, hence the bigger jet.

There is clearly an intake tract resonance issue here. The resonance issue is with the 34mm tract from the motor into the plenum.


The blars were cured by changing the length of the inlet tract inside the plenum.

The larger jet is required because the air flow is all one way into the plenum.

There is now no problem with the blars and no stand off in front of the carb at any rev's.

You have seen the video……


Dad was out on a job so we had a bit of fun at lunch time, probably get our arses kicked later for fu..king around at work.

In the first moments of the clip you can see how easy it is to start from cold, and that there is no blow back from the carb.
The Magic Vacuum Cleaner 01 http://www.youtube.com/watch?v=YxiEo8cgopg

Warming it up before a bit of a blurt up the drive.
The Magic Vacuum Cleaner 02 http://www.youtube.com/watch?v=p4ef-WUO1Qs

You now have the dyno report and any more work on the plenum will have to wait until we have an auto lube motor and a good chassis to put it in.

Engines are not our main focus at the moment.

Now if you actually know, any tricks about converting an FZR250 chassis and suspension into a realy good bucket your input would be more welcome.

Otherwise we will have to ignore you as a time waster and mock you in the talk shit thread.......

Bert
28th March 2010, 07:18
Sounds like you have made some good progress.
Are you going to re-instate the orginal autolube? or build something better?

TZ350
28th March 2010, 07:27
Sounds like you have made some good progress.
Are you going to re-instate the orginal autolube? or build something better?

Yes, I am pretty happy with things.

When we made the current no lube motor all the unnecessary internals were discarded and the end of the jackshaft cut off. Bugger don't you just hate that.

We will have to start again and we plan on using a dual line pump from a GT125 and running the oil to the l/h main brg so it can be picked up and feed directly to the bigend like the old style RM125 did. The other line will go to the barrel and oil the piston directly under the exhaust port like on a RGV250.

Henk
28th March 2010, 07:28
Why does everybody rip the autolube of as a matter of course?

Downsides of autolube
1. extra weight
2. exra possible point of catastrophic failure is the pump lets go

Upsides

Running premix you have to run the mix for full load so if it needs 40:1 at max revs thats what you use, however at idle you might only need 100:1 (trials bike autolube systems idle at about this) and the extra oil at the lower volumes and velocities can fall out of suspension loading up the engine, hence the rev the crap out of it before tackling anything that requires immediate engine responce behaviour that you see in trials.

I would have thought that a well sorted autolube system was better.
Please correct me if I'm dead wrong on this.

fi5hy
28th March 2010, 07:35
, hence the rev the crap out of it before tackling anything that requires immediate engine responce behaviour that you see in trials.



I thought that was to get the flywheel spinning fast to get the inertia needed to flick the bike forward.

TZ350
28th March 2010, 07:37
Why does everybody rip the autolube of as a matter of course?

I am not sure either, must have been a good idea at sometime, maybe I was a fashion victim...........

Buckets4Me
28th March 2010, 07:50
Why does everybody rip the autolube of as a matter of course?


BLING you can put a nice polished ally plate over the hole = 10 points in bling

also force of habit and who wants 3 premix bikes and 1 auto lube one

maths
3 premix + 1 auto lube = 2 tins of petrol (and a big mess if I use the rong tin)

Henk
28th March 2010, 07:58
4 autolube bikes = one tin of petrol and you can chuck whats left in the van for the drive home.

Used to have 3 different blends here, 40:1 for KDX, 50:1 for TM and 4 stroke for EXC, yes it was a huge pain and now I have more petrol cans than you can shake a stick at.

the unfinished (and probably never to be completed) MB50 F5 project was going to run autolube for this very reason.

bucketracer
28th March 2010, 09:37
I am not sure either, must have been a good idea at sometime, maybe I was a fashion victim...........

This little beauty uses Auto Lube....

Bert
28th March 2010, 10:06
Well isn't that a work of art..
Nice multiple point injection.
Got to love yamahas.

Yow Ling
28th March 2010, 17:58
in the pics it called "little nipper" is that cos its always nipping up ?

bucketracer
28th March 2010, 18:06
More Oil means more power according to this article by Gordon Gennings:- http://www.bridgestonemotorcycle.com/documents/oilpremix6.pdf

bucketracer
28th March 2010, 18:07
in the pics it called "little nipper" is that cos its always nipping up ?

..............:laugh:.......got me...

F5 Dave
29th March 2010, 11:28
oh ohh, I used to keep my old posts so I could cut & paste when I hung out in dirt forums with challenged am-ercans. Saved me extra typing. So from the Best of Dave part 3:


<link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cdavid%5CLOCALS%7E1%5CTemp%5Cmsoh tml1%5C01%5Cclip_filelist.xml"><!--><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><style> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; text-align:justify; mso-pagination:widow-orphan; font-size:11.0pt; mso-bidi-font-size:10.0pt; font-family:Arial; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-NZ;} p.MsoPlainText, li.MsoPlainText, div.MsoPlainText {margin:0cm; margin-bottom:.0001pt; text-align:justify; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Courier New"; mso-fareast-font-family:"Times New Roman"; mso-bidi-font-family:"Times New Roman"; mso-ansi-language:EN-NZ;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style><!--[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"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> [I]"Oil injection has the advantage that when you run out of gas in the middle of nowhere you can blag some straight petrol from the local farmer.<o></o>
<o></o>
Many people slag off oil injection which works just fine in zillions of road bikes everywhere. These old world closed minded people cannot accept the risk that the oil pump mechanism will continue to meter oil reliably into your precious engine.<o></o>
<o></o>
When I discovered (just in time) that my oil level of my old DT200 was not going down I became one of these people.<o></o>
<o></o>
[I]We meet on Tuesday nights."<o></o><o></o><o></o>

F5 Dave
29th March 2010, 11:38
4 autolube bikes = one tin of petrol and you can chuck whats left in the van for the drive home.

Used to have 3 different blends here, 40:1 for KDX, 50:1 for TM and 4 stroke for EXC, yes it was a huge pain and now I have more petrol cans than you can shake a stick at.

the unfinished (and probably never to be completed) MB50 F5 project was going to run autolube for this very reason.

So you give less oil to the Italian bike than the Japanese one?!??:confused:

Why not just jet them all for 40:1?

That said I run more oil in my 50 as it does a million revs & less on my Trials bike as it doesn't & spends a lot of time chugging.

Henk
29th March 2010, 16:05
TM used to load up and then hit even more like a hammer running 40:1. Not that big a deal really since we were riding lots at that stage and the gas never got a chance to go off.

TZ350
29th March 2010, 17:38
.

Thomas showing off the template he has just made for the FZR-GP125 conversion.

We will get two sets of these water cut in thicker plate.

Buddha#81
29th March 2010, 18:16
now thats a smoko room you can be proud of.......almost mancavish

Bert
29th March 2010, 19:02
...
....... just made for the FZR-GP125 conversion.


Given the RVG250 barrell sitting on the table it is more like a FZR-GP/RGV125 conversion; looks like you guys must have some great trouble shooting conversations at smoko!!

Bert
29th March 2010, 19:02
...
....... just made for the FZR-GP125 conversion.


Given the RVG250 barrell sitting on the table it is more like a FZR-GP/RGV125 conversion; looks like you guys must have some great trouble shooting conversations at smoko!!

bucketracer
29th March 2010, 20:13
Given the RVG250 barrell sitting on the table it is more like a FZR-GP/RGV125 conversion; looks like you guys must have some great trouble shooting conversations at smoko!!

HaHa, TeeZee you must check before posting to see what secrets are lurking in the background.......:laugh:

Whats the new bucket engine your building Burt?

speedpro
29th March 2010, 21:09
I see the trophy shop has had a sale as well . . . .

TZ350
29th March 2010, 21:39
I see the trophy shop has had a sale as well . . . .

WTF!!!!!! someone has nicked all the :third::third::third::third::third: place trophies???????????

Buckets4Me
29th March 2010, 21:39
I see the trophy shop has had a sale as well . . . .

notice the TRRS muggs in the dish drying rack ??
I cant see them on the window sill ?

SS90
29th March 2010, 22:11
WTF!!!!!! someone has nicked all the :third::third::third::third::third: place trophies???????????

Oh, yes?

What other trophies are there?

Most creatively worded/doctored post of a dyno run perhaps?

Reeks of "Pay no attention to the man behind the screen"

If you can't print out a graph, or some sort of hard data (spread sheet is normal if the software lacks the ability to graph) how does the computer relay the data from the run....smoke signals?, semaphore, perhaps a bingo roller?

F5 Dave
30th March 2010, 08:28
You might want to run some bigger screws for those plates, don't think M4s will cut it.

Bert
30th March 2010, 08:36
HaHa, TeeZee you must check before posting to see what secrets are lurking in the background.......:laugh:

Whats the new bucket engine your building Burt?

Another dirty two stroke, to mount in my fxr frame...
lets just say its been done before, its got water cooling and I'm not going to over port it; and hopefully it will stay together longer than my current (15 year old) TF100 scud....
As I'm sick of rebuilding motors and would like to concentrate on learning to ride again.

richban
30th March 2010, 11:55
(....more power to make up for my lack of skills)


Hey thats my plan! Was working well till Taupo.

TZ350
31st March 2010, 16:02
.

Snapped BucketRacer working on his engine, its taken him hours to make the adapter plate and cut out the transfers.

Another sneek photo of Bucket and another of Thomas posting something on Kiwi.

Bert
31st March 2010, 22:02
.

Snapped BucketRacer working on his engine, its taken him hours to make the adapter plate and cut out the transfers.

I hope that was done on his lunch break... looks like a stimulating work atmosphere.
nice, beats the hell out of looking at numbers all day.

SS90
31st March 2010, 22:53
.

Snapped BucketRacer working on his engine, its taken him hours to make the adapter plate and cut out the transfers.

Another sneek photo of Bucket and another of Thomas posting something on Kiwi.

Oh my god, Bucketracer is a child!

If I had known earlier, I would have ignored him from day 1.

Is he getting his first razor next Christmas?

Yow Ling
1st April 2010, 05:22
Oh my god, Bucketracer is a child!

If I had known earlier, I would have ignored him from day 1.

Is he getting his first razor next Christmas?

And you act like a child , is there some point you are trying to make?

Bert
1st April 2010, 06:39
Oh my god, Bucketracer is a child!

If I had known earlier, I would have ignored him from day 1.

Is he getting his first razor next Christmas?

At lease they are shearing their highs and lows of their bucket build (and supplied a lot of useful information along the way), bugger all others are.
some of their ideas are out there; but if no one tried different shit we would still be living in caves.

Boody Hell SS90, be constructive (which you have been in the past) or piss off.



I would suggest that this great thread being slightly tarred with increasing amounts of bullshit.
ouch, my first ever RedRep in five years of KB; I must have got out of bed on the "not PC side" today

SS90
1st April 2010, 06:54
Fine, then let's all drop the bullshit, and get back to constructive posts.

I am happy to do that.

TZ350
1st April 2010, 07:36
.

Instead of hanging around us, start your own thread. If anyone is interested, they will go there.

SS90
1st April 2010, 07:41
.

Instead of hanging around us, start your own thread. If anyone is interested, they will go there.

I tried that Teezee, and your sons ruined it.....don't you remember?

TZ350
1st April 2010, 15:49
.
The 11mm mounting points were bored out and sleeved back to 10mm and the holes checked for alignment.

Marking out the RD125 engine mounts.

And check fitting them in Chambers FZR frame.

As the sprocket is smaller than the swing arm pivot it needs to be well forward for chain clearance. There will be tensioner/guide rollers fitted.

Carburation is a single 38/24mm venture carb made from an RS125 carb feeding into a split manifold.

Bert
1st April 2010, 17:20
.
Carburation is a single 38/24mm venture carb made from an RS125 carb feeding into a split manifold.

Are you going to re-configure the crank and have a big bang motor? :yes:

any thoughts on the potential for turbulence using the split manifold, are you going to get enough velocity through the intake (venture to reed face) that the fuel stays linearly atomised?

Are you also going to be cunning and also use a linked boost port off the top of the reed block ???? so much potential here.... why hasn't this been done before (or at lease written about?)

sorry of all the questions, I seems to be a lot more to this cunning plan than what's been let out thus far.

Buckets4Me
1st April 2010, 18:31
Are you going to re-configure the crank and have a big bang motor? :yes:

he will probably try. Please dont incorage him
(it's already a big bang motor ( remember the poll about weather it would go bang or work))


any thoughts on the potential for turbulence using the split manifold, are you going to get enough velocity through the intake (venture to reed face) that the fuel stays linearly atomised?

?
(would be a big yes as he has taken the reads out and throwen them away (well actualy it never had reads it a rotary valve engine))


Are you also going to be cunning and also use a linked boost port off the top of the reed block ???? so much potential here.... why hasn't this been done before (or at lease written about?)


again dont incorage him


sorry of all the questions, I seems to be a lot more to this cunning plan than what's been let out thus far.

maby maby not :)


here I go running my mouth off bewfore I have read and thought about the other post's (much like SS90)
I now see that it's an yamaha rd125 not a suzuki gp125

bucketracer
1st April 2010, 18:33
seems to be a lot more to this cunning plan than what's been let out thus far.

Hi Bert, plenty of options for sure, but I don't know what all their plans are, but I do know Chambers is thinking of using some very nice Mini Motard wheels he has, that are 2-3 kg each lighter than the original FZR ones.

Bert
1st April 2010, 19:54
1.it's already a big bang motor ( remember the poll about weather it would go bang or work)
2.would be a big yes as he has taken the reads out and throwen them away (well actualy it never had reads it a rotary valve engine)
3.NO
4.maby maby not :)

I'm sorry, But it looked strangly like a Yamaha RD125 sitting in the FZR frame, with new engine mounts being made....? my mistake, looks like they miss spelt suzuki with a y?


mini motard rims, nice idea; I've been trying to find some of those for ages...

back to the RD, why not mount two RG50 barrels on it (apparently they can be bored out a bit)
I know its been done before but it would be nice to see another one out there.

bucketracer
1st April 2010, 20:11
.

SS90, good news, we have dug up your old 2-Stroke Tuning thread.


I tried that Teezee, and your sons ruined it.....don't you remember?


Sshhhhhhh Bucketracer....the grownups are talking!


............before the local fools start replying..........


Teezeetreefiddy "old boy", once again...........


can you give me an example of my abuse, I can certainly show you many examples of yours including much childishness.

Yep ssK9 that's just like you, blame every one else for the crap you find yourself in.

although there was some shit talk and you got your arse kicked, honestly no one killed it but yourself.

And as the talk shit thread is the proper place for talking shit,

Dad has told us to leave you alone on your thread unless you involve us or indulge in negative posts.

So no excuses now, you have a clear field, so lets see if you can reserect the 2-stroke tuning thread and show us how truly interesting you are.....................

.................or if you really are a negative have nothing and need to cling to Team ESE for people to notice you...............:mellow:

SS90
1st April 2010, 21:41
Are you going to re-configure the crank and have a big bang motor? :yes:

any thoughts on the potential for turbulence using the split manifold, are you going to get enough velocity through the intake (venture to reed face) that the fuel stays linearly atomised?

Are you also going to be cunning and also use a linked boost port off the top of the reed block ???? so much potential here.... why hasn't this been done before (or at lease written about?)

sorry of all the questions, I seems to be a lot more to this cunning plan than what's been let out thus far.

Yes, these are good points. Does someone know if these are 360 or 180 cranks?

TZ350
1st April 2010, 22:18
back to the RD, why not mount two RG50 barrels on it (apparently they can be bored out a bit)
I know its been done before but it would be nice to see another one out there.

Watch for a Suzuki GT125 twin with RG50 barrels, possibly latter in the year.

Some of the GT125's had crankcase reeds like the RG50.

Bert, what sort of engine are you building?

SS90
1st April 2010, 22:36
Watch for a Suzuki GT125 twin with RG50 barrels, possibly latter in the year.

Some of the GT125's had crankcase reeds like the RG50.



I think that was the X5, (1982 model?) from memory they would do something like 130KPH standard.

speedpro
1st April 2010, 22:47
Pete Sale did a Suzuki(?) 125 twin years ago. The memory is fuzzy but pretty sure it had 2 carbs, reeds added and two motocross ignitions, one driven by a toothed belt. It was only around for a year I think. Trouble with any of those twins is the gearbox ratios. There was a 125 twin made more recently here in Auckland. we had the 24mm carb rule by then so the guy used copper water pipe Ts to mount a single carb feeding both cylinders. It worked OK but was limited by lack of development.

speedpro
1st April 2010, 22:55
The motor in that chassis looks to be mounted a long way forward with a big distance between the sprocket and swingarm pivot and those mounting plates look like steel in that light.

That RGV(?) cylinder being fitted to the GP bottom end looks like a familiar project. I fitted an RGV cylinder to a converted full crankcase reed TS125 bottom end. The biggest bitch was sorting a waterpump. I fully endorse electric pumps now. Every single person I know who has ever converted a bucket to water cooling says the same thing.

TZ350
1st April 2010, 23:12
The biggest bitch was sorting a waterpump. I fully endorse electric pumps now. Every single person I know who has ever converted a bucket to water cooling says the same thing.

Yep this is where we expect to go. And I remember what you said about the transfers on the RGV250 cylinder of yours.

TZ350
2nd April 2010, 18:27
.

One look at Fi5hys Bucket and you can see the empathise on handling and modest easy to ride power is all you need for a winner.

NOID
2nd April 2010, 18:48
mmmmmmmmmmmmmmmmmmmm Fi5hy's bike ... i likey likey

Buckets4Me
2nd April 2010, 18:53
I fully endorse electric pumps now.

sounds good but I think we should wire it up to a run switch (pump is running when ignition is on)

otherwise I will forget to turn it on :) garanteed

TZ350
2nd April 2010, 18:58
sounds good but I think we should wire it up to a run switch (pump is running when ignition is on)

otherwise I will forget to turn it on :) garanteed

I was thinking of a thermosiphon set up supplemented with an electric pump activated by a thermal switch on the head thats wired in series with the engine Run switch like you suggested.

Kickaha
2nd April 2010, 19:05
I was thinking of a thermosiphon set up supplemented with an electric pump activated by a thermal switch on the head thats wired in series with the engine Run switch.

Davies Craig have all you need (http://www.daviescraig.com.au/Electric_Water_Pumps-content.aspx), Diesel Pig used one of these on a Bucket he built, he tried thermosyphon and it didn't work well enough

TZ350
2nd April 2010, 19:11
.

I was looking at an Aprilia 125 cylinder today and was struck by how much effort they went to to cool the exhaust port tract.

Looks like the water enters under the exhaust port and flows up and around it slowly through some restriction holes so it gets plenty of time to take heat from the exhaust stub.

I have always thought cooling around this area is important and it looks like Aprilia does too……….

TZ350
2nd April 2010, 19:18
Davies Craig have all you need (http://www.daviescraig.com.au/Electric_Water_Pumps-content.aspx), Diesel Pig used one of these on a Bucket he built, he tried thermosyphon and it didn't work well enough

Thanks Kickaha for the link and tip on Diessl Pigs experiance with thermosyphon.......

Buckets4Me
2nd April 2010, 19:56
http://www.daviescraig.com.au/Electric_Water_Pumps-ELECTRIC_BOOSTER_PUMP_12V_SHORT___PART_No__9002-details.aspx
could you leave the charging system on the bike to run the pump ???

and at $132 it's not a bad price (ausie dollars)

Technical Specifications
Motor 12V Brushless
Operating Voltage 9V DC to 15V DC
Maximum Current 1.3 Amps
Flowrate @ 10 kpa 15 L/min. (4 US gal/min)
Operating Temperature -40 to 120 DegC
Pump Design Recirculating Centrifugal
Motor Life 15000 hours at 80 DegC
Pump Weight 245 grams (0.54 lb)
Pump Material Nylon 66, 30% Glass Filled
Burst Pressure 250 Kpa (36psi) Min.
Fits Hose Sizes 19mm (3/4 ins)

Davies, Craig Pty Ltd
77 Taras Ave.
Altona North VIC 3025 Australia
Tel: +61 (0)3 9369 1234, Fax: +61 (0)3 9369 3456
Email: dcfans@daviescraig.com.au
Web: www.daviescraig.com.au


hows that for a free plug

TZ350
2nd April 2010, 20:27
.

Thanks for posting that, I was at a loss before wondering what to do for a pump.

The new ignitions we have require 12v from a battery and a pickup trigger on the flywheel.

I am thinking of rewinding the old HV charging coils on our KX80 ignitions for 12v so as to have a charging system to run the water pump and re charge the battery for the programmable CDI ignition.

koba
2nd April 2010, 21:30
.

I was looking at an Aprilia 125 cylinder today and was struck by how much effort they went to to cool the exhaust port tract.

Looks like the water enters under the exhaust port and flows up and around it slowly through some restriction holes so it gets plenty of time to take heat from the exhaust stub.

I have always thought cooling around this area is important and it looks like Aprilia does too……….

RG150s have a water passage running though the exhaust bridge, I thought that was worth taking note of.

TZ350
2nd April 2010, 21:46
RG150s have a water passage running though the exhaust bridge.

Thanks, I didn't know that.....

TZ350
4th April 2010, 15:36
The motor in that chassis looks to be mounted a long way forward with a big distance between the sprocket and swingarm pivot and those mounting plates look like steel in that light.

Yes, steel engine plates this time, we are still smarting from having an engine mount break at the BOB.

The original FZR250 sprocket was 17 teeth, the new bucket sprockets are smaller in diameter at 12-13-14 teeth.

As well as putting more weight on the front wheel, the motor has been moved forward so the smaller sprockets don't drag the chain over the swingarm pivot. And with the rider aboard we are looking for a 50/50 weight bias.

The chain run was checked at the extreme ends of suspension travel and the chain now just clears the swing arm when its in any position. Any chain tension problems will be delt with using a chain tensioner like on MX bikes.

And its all been hand done in the Bucket Racer tradition. A big hats-off to Chambers for sorting all this out and making the engine plates using only very basic tools.

Bert
5th April 2010, 08:07
RG150s have a water passage running though the exhaust bridge, I thought that was worth taking note of.

As does my yamaha, RGV and KTMs (to a point, depended on design), I would think that it is mostly to do with the power values and making some attempt to reduce thermal expansion on the barrel casings and the potential for binding the power values up...?

2 cents worth

SS90
5th April 2010, 09:43
As does my yamaha, RGV and KTMs (to a point, depended on design), I would think that it is mostly to do with the power values and making some attempt to reduce thermal expansion on the barrel casings and the potential for binding the power values up...?

2 cents worth

They primarily cool the bridge to stop it expanding (particularly when warming the engine up from cold), If the bridge heats up too fast, it expands into the cylinder, and can actually seize an engine (termed a "cold seize") as the heat cannot travel from a thin piece of aluminium (or in the case of a RG150, steel liner, which is actually more prone to cold seizures than an all aluminium cylinder) to the rest of the cylinder fast enough, and it simply expands.

There are other methods of achieving a similar result, the most common is to drill two 2mm holes on the exhaust side of the piston skirt that line up with the bridge.... the air/oil/fuel mix under the piston will travel through these small holes, and assist in keeping the bridge cooler, you can also relieve the bridge back slightly (particularly if it is a cast iron liner), as, afterall, the bridge is only there to stop the ring protruding into the exhaust port (if the exhaust port width is wider than 72% of the bore that is), and it is quite acceptable for it to be a few thou away from the piston skirt to allow for expansion....the practice of thinning the bride out to increase port area is normally the biggest cause of this type of problem.

In a water cooled performance two stroke, cooling the bridge is not a silly idea. Particularly if you widen the exhaust port alot,(or even if th efactory has them quite wide) which increases localised heating of the exhaust side of the piston crown (as well as the bridge).

Bert
5th April 2010, 19:59
That makes sence, hadn't though of that at time of typing...

anyway though that some might find these pages useful, when it comes to sizes/product numbers of conrods and bearings etc.

http://www.kevinbreedonracing.co.uk/products_conrods.asp

F5 Dave
5th April 2010, 21:42
.
. . .
Carburation is a single 38/24mm venture carb made from an RS125 carb feeding into a split manifold.
Eh? so you are running a 38mm carb that sleeves down to 24 & then feeds both cylinders?


& Mike, Pete's twin was a T90 so could run 2 carbs of any size (before 125 rule anyway). Steel cylinders limited development as did 5 speed gbox. Pretty sure he still had it last time I was past his shop (but that was a few years back now & he was clearing out stuff).

TZ350
5th April 2010, 23:05
.

I think Chambers is going with a conventional 24 first, then when the bugs in the rest of the new bike are ironed out he might try the 38/24.

But yes, 38/24 feeding both cylinders. We have been successful with a 28/24 combo on the GP125 and now have a 38/24 that shows real promise on the flow rig.

One of the problems I can see, is low signal strength at the main jet. Our 28/24 run conventualy uses a 130 main. Keihin 38’s on 125 MX’s run 180-190 mains std.

So I expect that on a 38/24, the main will need to be even bigger. Because of the reduced signal from lower airflow passing through the 38mm metering section at full throttle due to the more restrictive 24mm venturi section of the carb down stream.

My guess is 200+ for the main on our 125's using a 38/24 venturi carb...................

Also we figure, if you can't drop a 24mm ball brg through a carb with a circular throat then the cross sectional throat area is equivalent to or less than a carb of 24mm and so satisfies the 125 2-Stroke carb rule.

The beauty of the 38/24 combo seems to be that the airflow in the 38 section gets straightened up before entering the 24mm venturi allowing a higher flow rate in the venturi area.

The details and pictures are in earlier posts. From memory, if the venturi is 60-70% of the pipe (carb) diameter then there is a 94-98% pressure recovery (air flow) down stream for Reynolds (gas velocity) numbers less than 0.5.

So you can see that its possible to make a 38/24mm combo carb that flows like a conventional 34mm. But wether it works on the track we wont know untill we get one of the new bikes going.

Remember you heard about this idea of 38/24 and 28/24 carbs from Team ESE first..............

TZ350
10th April 2010, 10:57
Its 4-Stroke but useful for getting an idea of how things behave in an inlet tract..

“Relationship of Intake Port to Torque Peak

For a given intake port design, the cross-sectional area of the runner affects the location of an engine's torque peak in the RPM band. The runner length and shape is also very important, but the cross-sectional area will be the strongest determining factor.

Also, keep in mind that peak torque and peak horsepower do not occur at the same rpm and that when you shift it is always better to fall back to a region of maximum torque instead of trying to "climb the mountain" to get back to your next redline shift point.

We cannot emphasise enough that you must view the engine as a complete system and not concentrate on only one aspect of it.”

From:- http://www.rbracing-rsr.com/runnertorquecalc.html

You need to know this to be able to use the calculator,

One Sqr In = 6.45 Sqr Cm and one Cub In = 16.39 CC.

Runner length calculator:- http://www.bgsoflex.com/cgi-bin/intakeln.cgi?length=7

Runner length/area comparitor:- http://www.speedwaybids.com/calcs/intakerunnerlength.html

Metric:- http://www.exx.se/techinfo/runners/runners.html

Plenums:- http://www.team-integra.net/sections/articles/showArticle.asp?ArticleID=471

Halve the calculated rpm or inlet runner length to relate it to a 2-Stroke, and double the 2-Strokes rpm when entering data.

The inlet runner length is measured from the port window to the top of the carb's bellmouth.

They are not the Bible, or tell you everything, but these can give you a feel for what sort of changes affect things and by how much.

TZ350
10th April 2010, 18:31
.

Chambers has been able to successfully convert his spoked wheels to tubeless like these Talon ones are.

Using silicon glue for the spokes and wide tape for the center section of the rim. Tapes tried were fiber reinforced packing tape, rubber electrical tape, and wide rim tapes.

The problem area was the welded part where the rim is joined, this area needed to be carefully cleaned up on the inside to get an air tight seal with the tyre.

On some rims the welded area can be ground down to far by the factory leaving a flat spot, this could be built up with devcon and shaped to match the rest of the rim.

koba
10th April 2010, 21:48
.

Chambers has been able to successfully convert his spoked wheels to tubeless like these Talon ones are.

Using silicon glue for the spokes and wide tape for the center section of the rim. Tapes tried were fiber reinforced packing tape, rubber electrical tape, and wide rim tapes.

The problem area was the welded part where the rim is joined, this area needed to be carefully cleaned up on the inside to get an air tight seal with the tyre.

On some rims the welded area can be ground down to far by the factory leaving a flat spot, this could be built up with devcon and shaped to match the rest of the rim.

Why? <tenlittlecharchars>

TZ350
10th April 2010, 23:35
Why? <tenlittlecharchars>

So he can run GP125 slicks tubeless.

All the slicks we have seen are ribbed inside and although talkum powder helps, these ribs eventually wear through a tube puncturing it.

We have suffered more DNF's through flat tyres than anything else.

Henk
11th April 2010, 07:59
At a guess, because spoked wheels have a habit of wearing holes in the tubes, especially over long races.

bucketracer
11th April 2010, 12:15
Its 4-Stroke but useful for getting an idea of how things behave in an inlet tract......

Some video clips of reversion for those who are interested in such things………..sick bastards…

http://video.google.com/videoplay?docid=-7393939630149644203&q=V10+Engine#docid=-2158273019926133763

http://video.google.com/videoplay?docid=-7393939630149644203&q=V10+Engine#

Pic-01 particles in the reversion cone
Pic-02 Air flow Velocity

Brian d marge
12th April 2010, 01:34
Pic-01 particles in the reversion cone
Pic-02 Air flow Velocity

I have been using that program , and have that pdf that those JPEGs come from
I can model a basic room and get the air flow in that room but those inlets ,,,I am trying ,,
there are three things I would like to do
1. solid shaped in differing airflows
2, Oil through orifices
3. Air flow at differing velocities in Differing containers ( read air-boxes and inlets)

The program is OpenFoam

if you know anyone using I would love to open a dialogue !

Stephen

ps those Engines sounded fantastic !!

jasonu
12th April 2010, 05:41
Sounds like a lot of effort to run dodgey wheels. Sooner or later they will fail. (sooner is my guess)

F5 Dave
12th April 2010, 09:39
Woe & betide if you need to replace any spokes. That said my Trials bike has been running like this for a decade & it avoids any silly oddball spokes in a lip rim like on my Beta.

The other advantage is the 400g a tube weighs (front from memory) at the largest circumference of the wheel.

However I would still be careful to inspect the rim shape at the lip interface. if the tyre was to creep, slip or deform that would be uncool if deflation occurred. We often run quite low pressures.

Buckets4Me
12th April 2010, 19:34
Woe & betide if you need to replace any spokes. That said my Trials bike has been running like this for a decade & it avoids any silly oddball spokes in a lip rim like on my Beta.

The other advantage is the 400g a tube weighs (front from memory) at the largest circumference of the wheel.

However I would still be careful to inspect the rim shape at the lip interface. if the tyre was to creep, slip or deform that would be uncool if deflation occurred. We often run quite low pressures.


agin all very well and good

but these guys have all gone bald pulling there hair out time and time again with flat tires because of the tubes

and they like to fix things there way ( they use to replace the tubes every year)

Kickaha
12th April 2010, 19:48
but these guys have all gone bald pulling there hair out time and time again with flat tires because of the tubes


I've run tubes in 125 slicks on two different bikes which did 4 seasons between them with not a single puncture

Buckets4Me
12th April 2010, 20:03
I've run tubes in 125 slicks on two different bikes which did 4 seasons between them with not a single puncture

ye ye and next you will say you put telcon powder on the as well :)

Kickaha
12th April 2010, 21:11
ye ye and next you will say you put telcon powder on the as well :)

Tyre talc, yes I did, stupid to fit any tube without it, there's a few others that have run tubes in them down here without any problems

TZ350
12th April 2010, 21:53
I've run tubes in 125 slicks on two different bikes which did 4 seasons between them with not a single puncture

Good to hear someone has had a good run with tubes in slicks.

We haven’t had such a good run, we run 18 psi F & R and if the day is realy cold 16-17 psi. the cart track is also pretty demanding cornering wise.

Its a a tight circuit with low tyre pressures the norm here at Mt Welly, we change the tubes before the two hour each year and sometimes again before Taupo.

What pressures do you run?

Kickaha
12th April 2010, 21:58
What pressures do you run?

I haven't ever run less than 26, less flex with a higher pressure so less likely for the problems you are having to occur

TZ350
12th April 2010, 22:06
I haven't ever run less than 26, less flex with a higher pressure so less likely for the problems you are having to occur

Yes 26 is about what the manufacturer recommends, but wouldn’t work for us, we would be on our backsides in no time.

We need the low pressure so the tyres flex and heat up and work properly on the short cart tracks.

But the extra tyre flexing eats into our tubes quite quickly.

Bert
13th April 2010, 07:14
A Little bit off topic, but a while ago (maybe 18 months or so), i read an article on tube/tubeless (lack of a the correct name) systems for MX / enduro bikes (I'm still trying to find it).

summary of what it was:
a smaller inner tube (more like a mountain bike tube in size but a whole lot thinker) that sat and sealed the spokes nipples and rim base, with a second inlet that passed through into the cavity between the smaller tube and the tyre; when inflated (40-60psi i think) the tube sealed everything up. then you just put in the required air pressure as you would a tubeless tyre.
the main function of this system was (as far as I can recall):
1. to reduce the wear on the tube from the steel belts, by producing a air cavity between them.
2. if a tyre did get punctured it would hopefully only let the air out of the cavity and you might be able to get home on a slightly deflated tyre sitting on the inflated inner tube.. not ideal, but if your in the back of nowhere it might save your tyre...

anyway, I just wander if this kind of solution might be worth investigating, especially if your filled the air cavity with nitrogen to stabilise the temperature and expansion rates.

Another option is to put a cut inner tube around the actual inner tube thus increasing / supplying an extra layer to reduce wear on the actual inflated tube. I've done this before when my old mx tyres had / were a bit sharp on the inside. basically spot glued it together; but I'm sure others will say this is a stupid idea, but it seemed to work for a while so i could save up for new tyres...

F5 Dave
13th April 2010, 09:15
Buy some decent tubes, ones that don't say Kings or Chen Sheung on the box. Don't use tubes that have sat out of the box in sunlight.

But yeah tubeless is much better.

Kickaha
13th April 2010, 17:34
Buy some decent tubes, ones that don't say Kings or Chen Sheung on the box.

Made in Japan are noramlly good quality although if I can get them I like Michelin

bucketracer
16th April 2010, 22:21
.

From :- http://justkdx.dirtrider.net/printcarbtuning.html

No jet acts independently of the others but rather they work together to deliver gasoline to the engine.
They do however target specific throttle openings and have the most effect in that area. See below.

The air screw is most effective between idle through 1/8 throttle.

The pilot (slow) jet is most effective between 1/8 through 1/4 throttle.

The slide valve is most effective between 1/8 through 1/2 throttle

The jet needle is most effective between 1/4 through 3/4 throttle.

The main jet is most effective between 3/4 through wide-open throttle.

.................................................. .................................................. ........

Not talked about much, but as Team ESE found out, the height the needle jet stands up in the carb throat has a very big effect on mixture strength or atomization around the eighth to half throttle position, shorter is weaker and a too short a one accidentally fitted to one of the GPs caused no end of trouble with a major flat spot and the bike was really un rideable regardless of what other jetting changes were made.

TZ350
17th April 2010, 09:12
.

Pic 1.... http://www.psep.biz/store/mikuni_needle_jet.htm

Something worth knowing about Mikuni needle and main jets:- http://www.ozebook.com/compendium/t500_files/mikuni.pdf

TZ350
17th April 2010, 09:41
.

DON'T OPEN THAT THROTTLE WHEN USING THE CHOKE!

Air flowing into the starting carburetor makes fuel come out of the bowl to join the airflow, and this is caused by the high vacuum, or suction, because you are cranking the engine. The piston is moving up and down gasping for air, but it can't get very much, so vacuum is high.

What makes high vacuum behind the throttle slide, is the fact that you are cranking the engine with the THROTTLE SLIDE CLOSED. Leave the throttle completely closed until the engine starts. If you can't resist opening the throttle with a spastic reaction every time your kicking foot moves down, try putting your right thumb in your mouth.

If you insist on opening the throttle, the vacuum behind it disappears and the starting carb will not work. Most of the hard starting of Mikuni-equipped bikes is caused by this right-hand syndrome.

and other good advice from here:- http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=265950

TZ350
17th April 2010, 09:49
.

From:- http://www.iwt.com.au/mikunicarb.htm

The slide valve affects carburetion between 1/8 thru 1/2 throttle. It especially affects it between 1/8 and 1/4 and has a lesser affect up to 1/2. The slides come in various sizes and the size is determined by how much is cutaway from the backside of it, fig 3. The larger the cutaway, the leaner the mixture (since more air is allowed through it) and the smaller the cutaway, the richer the mixture will be. Throttle valves have numbers on them that explains how much the cutaway is. If there is a 3 stamped into the slide, it has a 3.0mm cutaway, while a 1 will have a 1.0mm cutaway (which will be richer than a 3).

F5 Dave
19th April 2010, 10:00
.. . . If you can't resist opening the throttle with a spastic reaction every time your kicking foot moves down, try putting your right thumb in your mouth. . .


:blink: Kicking foot? Why are you kicking the poor bike? Just let the clutch out as you push it along.

You can tell that was written in the 70s (let me guess Super Hunky?) that sort of terminology would have the lawyers running for cover these days.

TZ350
19th April 2010, 18:39
Sunday at Mt Welly. points day, It was a totally fun day with lots of laughs for Team ESE.

Chambers got to wave the Green and Checkered Flags and I managed a stint or two at the flag marshals stations. Very few incidents and none in my quadrant, so didn’t have to flap the yellow flag at all.

Conditions were near perfect and the racing was very fast, with NedKelly trying out his GPS lap and data logger, recording PB times and thoroughly enjoying himself.

Henk commented how much faster everyone seemed to be. I guess it’s the ready availability of good second hand slicks and the numbers of FXR’s on the track. There is no doubt about it; the FXR is the business for Bucket racing at Mt Welly and the bike to beat.

Buckets4me borrowed Ned’s bike for the “B” grade and got a flying start taking the lead from the second row going around the sweeper and still holding first position after a couple of laps...:woohoo:.......we were all going wild and cheering.......

Then as the race of his life was unfolding, inexplicably in front of the pits and everyone watching he swerved off the track, pulling a sharp right at mach 9 into the infield. His ride had developed a mind of its own.

When he came to a stop we could see the back wheel was flopping all about. :o Someone hadn't done up the swing arm bolt properly and it was half out giving Team ESE its first real DNF. But when Buckets had finished his little rain dance :crazy: he managed to see the funny side of it all.........

Due to a last minute race order change for F5, Buckets had to rush to grid up for the next race and was a bit flustered. But he started well and got caught up in a brave, race long tussle with one of the shining lights in F5. Then half way round the last lap he ran out of petrol.......Soooooo Classic.........:laugh:

Buckets in his rush to get to the grid had forgotten to fuel up his 50..........

But he pushed in for a fourth, it seems Buckets4me never gives up, or stops smiling…..…:D

A great day and fun for all…….perfect…….:sunny:

Buckets4Me
19th April 2010, 21:14
Then as the race of his life was unfolding, inexplicably in front of the pits and everyone watching he swerved off the track, pulling a sharp right at mach 9 into the infield. His ride had developed a mind of its own.

When he came to a stop we could see the back wheel was flopping all about. :o Someone had not done up the swing arm bolt properly and it was half out giving Team ESE our first real DNF. When Buckets had finished his little rain dance :crazy: he managed to see the funny side of it all.........



I'm still laughing and swearing about it now :)
tiped the bike into the infield corner and coming out I touched the peg on the ground (little bit of a fright but nothing realy) Next thing I know the bike has spat me into the grass and I'm trying to get back to the track without smashing into anything coming arount the track . Next corner was ok same with the one after, then right infrount of the pits I thought someone had hit me as the back of the bike came around spitting me back into the grass. Gave it some gass and got a good snake on with the wheel spinning in the grass, thought something was a bit up and looked behind me to see the bike had rear wheel stearing. parked the bike on the infield and decided to have a proper GP rant and rave at the bike.

all in all it was a great day and i had only gone out to run the 50 up and see if it was still ok after the TRRS anyway so to get such a good start and have a few realy good laps (would have been my 3rd win every and 20 points) I came home with a 3rd and 4th DNF and last or near enough to it (was buggered from pushing the 50) all good fun

thems the highs and lows of racing

Yow Ling
20th April 2010, 06:36
Sounds like a dress rehersal for the next BOB !

The devil is in the details

Buckets4Me
20th April 2010, 06:41
Sounds like a dress rehersal for the next BOB !

The devil is in the details

yep and now we have the details sorted :) watch out !!

Sketchy_Racer
20th April 2010, 20:58
To the Two Stroke genius's

I was wondering if anyone would be able to enlighten me briefly the effect of reducing my crankcase volume? What sort of changes to engine characteristic could I expect from it?

Also, what effect will increasing my intake duration?

Cheers,

-Sketchy

Sketchy_Racer
20th April 2010, 20:58
To the Two Stroke genius's

I was wondering if anyone would be able to enlighten me briefly the effect of reducing my crankcase volume? What sort of changes to engine characteristic could I expect from it?

Also, what effect will increasing my intake duration?

Cheers,

-Sketchy

speedpro
20th April 2010, 21:56
There's been a bit of discussion about crankcase volume and compression. My view, as explained to me by Wobbly, is that the crankcase is just somewhere to store fuel and air before the transfers open and it is sucked out. The fact the mixture is trapped in the crankcase and partially compressed by the descending piston helps move it a bit as well.

If the volume is large then the crankcase pressure will drop at a lower rate and therefore flow will continue at a greater rate up the transfers after that initial burst.

With a lower volume there will be a greater rate of flow up the transfers due to crankcase compression initially but as the volume is lower the crankcase pressure will fall faster restricting transfer flow later in the cycle.

The higher crankcase volume motor relies on the pipe resonance more to achieve good transfer flow and may hit a bit harder coming on the pipe. However potentially it could work better over a greater rpm range.

Plenty of theories on this . . . . .

speedpro
20th April 2010, 22:00
Duration will have all sorts of effects depending on where it is now and what you are trying to achieve. It is fairly well documented and proven that there are optimal "time/area" values you should be aiming for. Depending on use and which port you are talking about there is a proven range that is best.

bucketracer
20th April 2010, 23:12
To the Two Stroke genius's

I was wondering if anyone would be able to enlighten me briefly the effect of reducing my crankcase volume? What sort of changes to engine characteristic could I expect from it?

Also, what effect will increasing my intake duration?

Cheers,

-Sketchy

Page 80 of this thread has a collection of links where you can download Bells and Jennings books on 2-Stroke Tuning.

"briefly" its easy to find out for yourself, and the relevant chapters of Jennings and Bells books are a good place to start..........

Another useful link collection is on page 90 and there are more interesting collections on pages 100, 110,120 etc

TZ350
21st April 2010, 09:05
I was wondering if anyone would be able to enlighten me on the effect of reducing my crankcase volume? What sort of changes to engine characteristic could I expect from it? Also, what effect will increasing my intake duration?

Speedpros posts 2225 and 2226 are worth reading and like Bucketracer said, if you want to find out more, there is plenty of links to other interesting items to read on pages 80-90-100-110-120-130 and 140.

Yow Ling
21st April 2010, 13:43
Could always pm SS90 hehe

TZ350
21st April 2010, 16:02
NedKelly having fun last Sunday at Mt Welly.........

SS90
21st April 2010, 17:01
Could always pm SS90 hehe

Sure, why not, plenty of people do.

SS90
21st April 2010, 17:18
To the Two Stroke genius's

I was wondering if anyone would be able to enlighten me briefly the effect of reducing my crankcase volume? What sort of changes to engine characteristic could I expect from it?

Also, what effect will increasing my intake duration?

Cheers,

-Sketchy

There is plenty of mis-information available on the net, and some of the written material available in books can be a little misleading as well (in the sense that no one really gives finite values).

When you say "reducing" your crankcase volume, I assume you mean that you want to increase the primary compression ratio. Is that correct?

If that is the case, your results will vary depending on your expansion chamber design.



The first thing to do is work out what you have already.

There is plenty of information (one of my first posts) that indicates that the maximum value for a primary compression ratio is 1.5:1, and this is considered to be true by most tuners.

However, with such a ratio, you would need to have an expansion chamber design that has the second baffle with a shorter, sharper taper (much like you would expect too see on something like a mid eighties Japanese two stroke).

The effect of such a primary compression ratio and pipe combo would be slightly more peak power, but at the cost of range (simply put a "narrow power band"

My work (following up on others) suggests that a minimum primary compression ratio would be something like 1.33:1, but to get any advantage form this set up, you would need an expansion chamber with a second baffle that has a taper that is long and slow.

This can be difficult, as such baffle tapers can (and do) cause resonance "holes" just before they "come on the pipe", but this (mostly) be avoided.

Like I say, the first thing is to find out what you have, and chamber design is critical in getting the rewards.

1.5:1 is the maximum (any more and the work required by the engine to pull the piston down will negate any gains from the higher primary compression "a pumping loss")

1.33:1 is the minimum, (losing crankcase scavenging efficiency) That said, I remember asking around and being told that KTM used below 1.33:1 (something like 1.25:1) on one of their 125GP machines, but I suspect that their infinite choices for gear ratios give them the skope to be able to "tune out" the disadvantages of such a set up.

The attachment on the left is with a primary compression ratio of 1.42:1, the right, considerably more, from memory about 1.55:1.

The set up on the right struggled to pull top gear, and required lower primary gearing to be useable, even though it made more power.

The expansion chamber used in this series of tests remained unchanged (short, sharp baffle angle), and I found the lower the primary compression , the longer and more gradual the baffle taper was required.

With the right exhaust and primary compression ratios this cylinder put out 23PS.

F5 Dave
23rd April 2010, 11:41
<link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Cdavid%5CLOCALS%7E1%5CTemp%5Cmsoh tml1%5C01%5Cclip_filelist.xml"><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><style> <!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-NZ;} @page Section1 {size:612.0pt 792.0pt; margin:72.0pt 90.0pt 72.0pt 90.0pt; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> </style><!--[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"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> <o></o>He’s quite right it is about the ‘package’. <o></o>
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For a starting point Duration: if you are talking about your H100 (my old) engine; the reed on back of crankcase is connected fairly enthusiastically around the transfers so is potentially open 360 degrees, but of course the reeds don’t allow that (unless they are broken). Inlet duration totally reed dependant.<o></o>
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As for primary com SS is talking some pretty low numbers for KTM, that surprises me but it might be a compromise that suits disc valve engines with the right pipes (maybe of which they couldn’t use in the past due to transfer design).
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Interestingly just yesterday I was reading about the RG500s (privateer race ones not road) development cycle. At one point in part due to handling woes they figured that a heavier bike would give the chassis more grief so to aid handling lighter weight was to be pursued at all costs, with the added advantage that it helps acceleration. They redeveloped the engine with tiny crankcases, smaller flywheels etc. They then found that the engine was somewhat lesser of a performer as the compression ratio was too low. At least in the author’s opinion.<o></o>





My work (following up on others) suggests that a minimum primary compression ratio would be something like 1.33:1, but to get any advantage form this set up, you would need an expansion chamber with a second baffle that has a taper that is long and slow.

This can be difficult, as such baffle tapers can (and do) cause resonance "holes" just before they "come on the pipe", but this (mostly) be avoided.
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On this bike when I originally had it I designed a pipe (the hideous looking one) for supercross power, hard hitting, figured it was the right thing for kart tracks. It had a very steep baffle & I got quite a dip before peak power. Being that this was a fun bike I wasn't about to change the pipe & instead investigated the boost bottle which is why there was an adjustable one fitted. This largely diminished the dip to level so I left it like that. A band aid for sure but it was more for the experiment, that old chassis wasn't right for more power.
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SS90
23rd April 2010, 20:20
I will admit too, I once got carried away with baffle tapers (this is quite an old run, but I learned alot from this chamber) I managed to get 24PS and 19NM with this set up, ( I was experimenting with several things with this series of runs,and it was not just the baffle I changed to get the power that high),but that hole at 5500 required a lower primary gear ratio to be able to be rideable with 4 gears.

I always considered using a boost bottle set up like the Suzuki RGV150 (simply a large diameter rubber hose running the length of the frame), but small changes in baffle angle and the correct primary compression ratio (oh, and stiffer top reeds, for obvious reasons) was the answer in the end.

Long slow baffles are great for that nice wide flat peak power, (as long as the engine is designed to work with such a baffle), but, as you can see, there are limits....

The best advise I can give is to make your chamber be able to have a "clip joint" header, so you can test a few different baffle angles before finishing the pipe.

TZ350
25th April 2010, 00:16
Diagrams of various bellmouths and their effect on air flow..........

4-Stroke but still an Interesting read on inlet and exhaust tuning http://bmwmotorcycletech.info/InExTuning.htm

bucketracer
25th April 2010, 19:30
Prof Blair on the design of an intake bell mouth:- http://www.profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf

Pic-01 I know its not buckets but you have to admire it:- http://www.billzilla.org/pearce.htm

Pic-02 "you can improve the flow into those by fitting a flat plate just behind the trumpet bell and rounding off the bell so that it smoothly blends into the flat plate. The reason is that most of the air comes in the trumpet from the sides on the induction stroke rather than in line from the front as you'd expect, so if the airflow has to pass over sharp lip of the trumpet it will generate turbulence. If it has a nice, smooth bump to go over then little turbulence will be generated" from:- http://www.billzilla.org/engineintro.htm#Inlet

Pic-03 Designing an elliptical inlet bell mouth, Prof Blair found that an elliptical inlet bell mouth to be best.

TZ350
25th April 2010, 20:33
Page 150 links collection


Page 80 of this thread has a collection of links where you can download Bells and Jennings books on 2-Stroke Tuning.........

Its easy to find out a lot about tuning strokers for yourself, and the relevant chapters of Jennings and Bells books are a good place to start..........Page 80, 90, 100 etc have more link collections

Motorcycle carburetion is fairly complex, but a basic understanding of the parts and theory involved will go a long way to simplify the processes:- http://justkdx.dirtrider.net/printcarbtuning.html

From Bucketracer…..No jet acts independently of the others but rather they work together to deliver gasoline to the engine. They do however target specific throttle openings and have the most effect in that area. http://justkdx.dirtrider.net/printcarbtuning.html

Something worth knowing about Mikuni needle and main jets:- http://www.ozebook.com/compendium/t500_files/mikuni.pdf

Mikuni Jetting parts:- http://www.psep.biz/store/mikuni_needle_jet.htm

Most of the hard starting of Mikuni-equipped bikes is caused by this right-hand syndrome.
and other good advice from here:- http://dirtbike.off-road.com/dirtbike/article/articleDetail.jsp?id=265950

Ian Williams tuning, the home of “MOTA” software and a place in Aus you can purchase carb parts.
http://www.iwt.com.au/mikunicarb.htm#

From Buckets4me…… Electric water pumps:- http://www.daviescraig.com.au/Electric_Water_Pumps-ELECTRIC_BOOSTER_PUMP_12V_SHORT___PART_No__9002-details.aspx

From Bert… some might find these pages useful, when it comes to sizes/product numbers of conrods and bearings etc. http://www.kevinbreedonracing.co.uk/products_conrods.asp

We cannot emphasise enough that you must view the engine as a complete system and not concentrate on only one aspect of it.”

From:- http://www.rbracing-rsr.com/runnertorquecalc.html
You need to know this to be able to use the calculator,
One Sqr In = 6.45 Sqr Cm and one Cub In = 16.39 CC.
Runner length calculator:- http://www.bgsoflex.com/cgi-bin/intakeln.cgi?length=7
Runner length/area comparitor:- http://www.speedwaybids.com/calcs/in...nerlength.html
Metric:- http://www.exx.se/techinfo/runners/runners.html
Plenums:- http://www.team-integra.net/sections/articles/showArticle.asp?ArticleID=471

Reversion Some video clips of reversion for those who are interested in such things………..sick bastards…
http://video.google.com/videoplay?docid=-7393939630149644203&q=V10+Engine#docid=-2158273019926133763

http://video.google.com/videoplay?docid=-7393939630149644203&q=V10+Engine#

KartWeb Tech Articles
www.kartweb.com/TechArt/2Stroke/chapter1.doc
www.kartweb.com/TechArt/2Stroke/chapter2.doc
www.kartweb.com/TechArt/2Stroke/chapter3.doc
http://www.kartweb.com/TechArt/2Stroke/chapter1-2-3.swf
http://www.kartweb.com/TechArt/2Stroke/2_stroke_technology.htm

The inlet port on the all out race cylinder is colossal in comparison to the stage 2 cylinder on the left. This will lead to awesome all out performance.... http://sites.google.com/site/drunkmunkey6969/ts1cylinderporting

4-Stroke but still an interesting read about inlet/exhaust tuning http://bmwmotorcycletech.info/InExTuning.htm


Speedpros posts 2225 and 2226 are worth reading and like Bucketracer said, if you want to find out more, there is plenty of links to other interesting items to read on pages 80-90-100-110-120-130 and 140.

Some of those old Team ESE posts with pictures are worth a re-visit. To find the good ones, use the “Thread Tools / Thread Images” tabs near the top of the page…….

TZ350
27th April 2010, 10:47
Building the new Team ESE FZR/GP bikes is like wading through treacle. It just takes forever to get anywhere. We generally only get an hour or so after work and every thing takes so long that the days just melt away.

Pic-01 the FZR-GP lowered to the bottom of its suspension travel to check ground clearance.

Pic-02 The start of the front brkt.

Pic-03 The suspension brackets get in the way of the expansion chamber. We will have to make new pipes that come further forward.

Pic-04 Showing the increased area of the ported rotary valve inlet.

Pic-05 That pesky plenum chamber, that I am looking forward to getting back to developing some more. At the moment all that can be said is, that the bike runs with it and is rideable. When the new motor is built I am hoping to run a true back to back comparison with the conventional carb and plenum setup. The new motor and bike should be ready in a month or so, fingers crossed.

Team ESE is Sooooo looking forward to the next TRRS.

TZ350
27th April 2010, 10:50
Photos from the Taupo 09 TRRS
I am not sure where these came from, if they are yours and would like me to add your name please PM me.


Pic-01 Rolling out from the dummy grid.
Pic-02 The Start
Pic-03 The First Corner
Pic-04 Climbing the Hill
Pic-05 NedKelly
Pic-06 Avalon on Chambers Bike

F5 Dave
27th April 2010, 16:23
3. Surely you would hack that pipe (?) mount off the frame (to the right of the linkage) & route the pipe up there hanging the pipe off the peg bracket perhaps? Depends how long your dwell is & with low revving you may be stuck,

or you could be tricky with the band saw & curve it to the left then right possibly behind the linkage, looks like there is stacks of room. Like my 500 (which is pretty tight probably with a smaller chassis).

Pumba
27th April 2010, 18:07
Dave have you taken that chunk out of the swing arm in your second phiti or is that a factory feature? Just curious thats all.

bucketracer
27th April 2010, 20:23
.


............ looks like there is stacks of room...............

Not as much room on TeeZee's bike as it looks. Scraped some photos of Speedpros #6 thread to show that, and his very clever solution to the problem.

speedpro
27th April 2010, 20:24
Pic-03 The suspension brackets get in the way of the expansion chamber. We will have to make new pipes that come further forward.

I could have told you about that little problem. That's one of the reasons I built a new pipe from scratch rather than continuing to use my old one with a few cuts. There's a bit of work weaving the pipe around or taking it forward and then back so that the fatter bit is forward of the linkage. If you have the pipe out the side at all it will scrape as the bikes handle so good you will be leaning it over further than the old one and then the pipe bangs down.

speedpro
27th April 2010, 20:31
Damn . . . . .

My new one exits out the back like nearly everybody else. I reconfigured the layout of the little bits of cone so it did a more forward curve. It's not ideal but it hasn't scraped yet. Maybe someone a bit keener could get it to scrape.

F5 Dave
28th April 2010, 10:51
Dave have you taken that chunk out of the swing arm in your second phiti or is that a factory feature? Just curious thats all.
P model RGV250 VJ22 factory fitted. They went to this after the banana arm as it was a bit bendy & heavy

TZ350
3rd May 2010, 17:46
NedKelly fits his new programmable Igntech ignition.

Pic-01 the ignition unit, it runs from a battery and only needs a trigger coil on the flywheel.
Pic-02 using a DTI to find TDC and the max advance point.
Pic-03 marking TDC and the max advance point on the flywheel.
Pic-04 uncomfortable test ride without the seat but it fired up and ran ok.

TZ350
3rd May 2010, 17:53
Chambers, checking out the fit of his new GP100 down-pipe with the FZR lowered to the bottom of its suspension travel. The last time we had his 100 on the dyno with the up-pipe(same design), it made 22.5 RWHP. The last photo shows there is no part of the chamber sticking out to drag on the ground.

mud in ur eyes
7th May 2010, 17:54
Chinese CDI unit............

I sorry, I can't remember who was looking for a Chinese CDI wiring diagram so have posted it here. I expect the pin-out is much the same for all of them.

Thomas

TZ350
9th May 2010, 15:16
Now boys and girls, this is a real plenum chamber blow up........ https://mail.google.com/mail/#search/Joe+Mead/127b782cc1bc27c1

schrodingers cat
9th May 2010, 15:43
Kart tuner certainly optimise within a tight set of regulations. If the gloves came off they would do things differently. Interesting to follow the generic basics but I wouldn't be copying an apple to build an orage