ESE's works engine tuner

[F5 Dave]

Interesting article. Gets hard to decipher when they are talking about customer TZs & OW race bikes though.

[F5 Dave]

ok we are getting waay off subject but I'm learning some history. . .

[from webpage]
The mighty TZ 750

In 1972 . . . .blah blah etc etc.. .
standard. Interestingly, Yamaha claimed the bike had the potential to produce almost 140bhp with TZ350 cylinders fitted.{DT edit;as opposed to it's standard barrels}


Technically, though very similar to the TZ350 motor-wise, it differed in a few crucial areas, these being:

1. The head's squish band was reduced from the 350's 2.0mm to 1mm and it's combustion chamber was made a little deeper so as to keep the compression ratio to 7.3:1.

2. The exhaust port was lowered 1.5mm and four petal reed valves added to help control the influx of fuel mixture from the 34mm Mikuni carbs and to help "tame" the power delivery of this awesome machine , along with an additional fifth transfer port, "inlet" port if you like.


- - - - - -
ok so the premise (and popular story) I was under that the 700s were fitted with TZ350 barrels. That isn't actually true. The TZs were piston ported & the TZs were Reed from the beginning.


So yes those barrels SS posted are entirely likely to be TZ250 as suggested (but could equally be 500).

[SS90]

Hmmm, lots to catch up on here, but did you manage to find out what year they would likely be?

I was punting on early eighties, but now I'm not so sure!

[TZ350]

.

If they are TZ250's my guess is they will be between 74 to 82. And as I remember it the first factory TZ500's had piston ports and later reeds with power valves, the later production 500 racers came out with reeds and power valves as std.

The first TZ700's for production reasons had a piston and barrel made to the same dimensions as TZ350's but with reed's. Then they went to bigger pistons and their own new barrels to be true 750's.

Many TZ750 motors and early 700's were fitted with TZ250 barrels and run as 500's in side cars. I have also seen a TZ750 fitted with one 350 barrel and one 250 barrel to qualify for the 600cc postclassic junior class until the rules were changed to limit bigger 2-strokes to 2 cylinders.

I have also worked on the engine of a speedway car that had special home made crankcase plates and four TZ750 barrels and modified RD cases and cranks. This car went like a cut cat. It had a habit of breaking conrods but did not visible slow down untill it had let go at least three rods. The rods would wrap themselvs around the bigend pin. It could go out, break a rod or two and continue competitivly in a race and finish.

.

[F5 Dave]

Hmmm, lots to catch up on here, but did you manage to find out what year they would likely be?


Well I've proved I'm no expert on the matter, but I did stumble across this in the Tips page of the same site/

1. Barrels:
F or G model 350 barrels are best, i.e. 6 port. They are easier to ride.


that was 79 & 80 so not those years is at least certain.

I may become more educated when I get to that chapter as the site seems a bit of a mishmash of info, I'd trust the book as more well researched.

[TZ350]

.

The last of the 350 barrels were 6 port but SS90's pictures are of 250 barrels. You can tell they are 250's by the thicker cylinder spigot. I am not sure if 250's were ever 6 port, but the last of the conventional twins, the "G" I think had a really wide inlet port and an appetite for pistons and also an odd bore size, slightly bigger. It was possible to mix up the new style pistons and old cylinders then they would seize, it caught a few people out. http://www.tz350.net/tz250page.htm portmap for the TZ250 from 1976 to 1984.

.

[TZ350]

I am working on making a copy of the "Darcy" pipe.

Lots of info on pipes at the bottom of the page for the RG500 which could be suitable for a GP125 as there are a lot similaritys between the RG500 and GP125 rotary valve engine.
http://homepage.mac.com/rg500delta/deltaphasetwo/Frames/pipe_design.html

How to go about a graphical analysis of the wave action in the pipe your designing
http://homepage.mac.com/rg500delta/deltaphasetwo/Frames/pipe_design.html#Graphical_pipe_analysis

Plots of various pipes
http://homepage.mac.com/rg500delta/deltaphasetwo/linked%20files/pipes/Delta%20Pipe%20designs.pdf

Spec sheet of the Darcy pipe.
http://homepage.mac.com/rg500delta/deltaphasetwo/linked%20files/pipes/DarcyPipeSpec.txt

Dyno runs. http://homepage.mac.com/rg500delta/deltaphasetwo/images/pipes/darcy%20test1.jpg

Chambers, NedKelly and myself with Thomas's help, are working flatout building new pipes, engines with better breathing, diffuser carburettors and tweeking the suspension of our GP's for Taupo. Its just amazing how long it takes to do the simplist things. For the last three months we have been staying back after work most nights and some Saturdays and are still running out of time.

.

[koba]

I am working on making a copy of the "Darcy" pipe.

Lots of info on pipes at the bottom of the page for the RG500 which could be suitable for a GP125 as there are a lot similaritys between the RG500 and GP125 rotary valve engine.

My MB100 runs a right rear RG500 Pipe. (I think) It goes good, Having a guess at what to do I was going to add a wee bit in the belly section to bring the revs down a wee bit but I may have another plan now.

I drew it up and overlayed it on a drawing of the RM125C Pipe as provided in A. Graham Bells book and it was VERY similar except the RM had about 18.75mm more in the belly section...

[TZ350]

.

Motor number two with reduced crankcase volume, opened up transfers, bigger inlet tract, race style forged piston, RGV250 rod kit, KX80 ignition, 24mm diffuser carb and the good old faithful copper head.

Pic-01 engine number two.
Pic-02 24mm diffuser carb
Pic-03 piston with the transfer widened and a small boost port in the back
Pic-04 cases with the bigger inlet tract and opened up transfers
Pic-05 KX80 ignition, fixed point, hope to change this for a suitable retarding unit later
Pic-06 opened up the transfers with the port roofs Devconed to a higher angle on the front transfers and flat at the back

I have tried to incorporate all those ideas put forward by SS90, F5_Dave, Speedpro, Sonic_V, K14, Buckets4me, Bucketracer, Sully60 and others recently. I am hoping for the same power, but at lower rev's with a wider power band. Looking forward to getting it on a dyno soon.

Now to start assembling the RG50 engine.

.

[TZ350]

.

Thanks Sonic_V I have just realized that there is a very interesting source of technical info on Kart engines. Its the homogolation tech sheets from the

"COMMISSION INTERNATIONAL DE KARTING - FIA"

Here's one that has chamber dimensions and drawings of the ports for the engine in the first picture.

http://www.ak-racing-shop.de/ak-racing/Handel/Vortex/Homologationen/VORTEX%2030-M-09.pdf

.

[bucketracer]

.

Handy crank angle to piston position calculator

http://www.torqsoft.net/piston-position.html

.

[bucketracer]

.

Ok here is one for you TeeZee

The 125cc Parilla Sudam engine is an amazing engine package. This engine built as an open with dual carbs and stroked crank is capable of a reliable 55+ horsepower.

http://buller.net/cat--125cc-Parilla-Sudam-Engine--eng_sudam.html

.

[TZ350]

.

The 125cc Parilla Sudam engine is built as an open with dual carbs and stroked crank capable of a reliable 55+ horsepower.

http://buller.net/cat--125cc-Parilla-Sudam-Engine--eng_sudam.html

.

Thanks for the tip. I looked the engine up. Bored+Stroked = 130+cc and running on methanol = 55+Hp at the crank.

From what I can make out the standard 125 version on pump fuel is in the low/mid 30's for Hp.

Very encouraging though, because it means that air cooled 125's can make much more Hp than I thought.

People had been telling me the thermal limit of an air cooled engine on petrol is in the high 20's well it looks like we can go to 30's OK.

Very exciting............BIG rwhp here we come.. :woohoo: .. FXR's.....get a :spanking: and :cry: while GP125's come :first:.

I already have the copper cylinder head and barrel cooling to do the job and am getting the retarding ignition thing worked out.

Plus some other ideas like bronze clutch plates and a gear box oil cooler so I can really cane it coming out of the corners.

By following Sonic_V's tips we have been able to greatly increase the air flow through the regulation 24mm carb.

So it might be possible to make a F4 GP125 with a mid 20's rwhp setup for long tracks, too late for the Taupo TRRS this Xmas but maybe for next time.

Next year looks interesting already, the promised land beckons.

.

[Yow Ling]

Well Im going to hang my hopes on this thing next season




By following Sonic_V's tips we have been able to greatly increase the air flow through the regulation 24mm carb.

.

We have found a similar thing by fitting a 34mm carb !

[Henk]

Well Im going to hang my hopes on this thing next season



We have found a similar thing by fitting a 34mm carb !

So the answer to ultimate performace is to get a carefully calibrated ruler and hope nobody notices?

[Skunk]

Thanks for the tip. I looked the engine up. Bored+Stroked = 130+cc and running on methanol = 55+Hp at the crank.

From what I can make out the standard 125 version on pump fuel is in the low/mid 30's for Hp.

Very encouraging though, bSo it might be possible to make a F4 GP125 with a mid 20's rwhp setup for long tracks, too late for the Taupo TRRS this Xmas but maybe for next time.

Next year looks interesting already, the promised land beckons.

.
Kaitoke is ready for you to do testing! ;)
I'd be interested in seeing how you go improving the airflow though the 24mm. I'm not into the engine building as I like building the bike itself.

[F5 Dave]

. . .
Plus some other ideas like bronze clutch plates and a gear box oil cooler so I can really cane it coming out of the corners.
. . .

Sorry? What is wrong with the clutch? Suzuki plates take some real beating as demonstrated by my long suffering RG50 clutch. No bike gets more of a clutch hammering to be sure. While adjusting the lever I did get some suspicion of slip at Kiatoke up the hill last week. But I had the lever with minimal adjustment at the time so maybe not. Oh well I had some new plates in the spares for some reason (I run TS125 plates). measured difference after heck maybe 6-7 year of extreme abuse; 0.1mm difference. Word. :eek5:

[jasonu]

That’s very interesting, could the difference between the RS pipe stopping dead on your bike and it reving on, on an RS125 be the retarding ignition that the RS uses? do you have any dyno graphs or dimensions of the pipes you could post?

.

I'll do my best. However, it was built 10 years ago, I now live in the States and the graphs etc are at my mates place in Titirangi. But I will try.[/QUOTE]

Here are the dyno graphs for my RG 400 barrel KE125 bottom end bucket. I had to go over them with a pen because my emailed copies are very faded and hard to see. However, they are accurate.
This motor was built 11 years ago. I got 2nd in the Ohakea GP behind Morley Sherriffs (I still don't know how he kept that pile of shit going...) and in front of Jimmy Steadman. It ran at a Manfield national where F5Dave got a ride and at a Taupo (old track) meet in F3 where it was good and fast as we had corrected a high compression cockup. That is when development stopped and we are sure (read we know) it will give more.

[jasonu]

Some pix of the 2 pipes. The RS pipe is a 1991 with a hand made header. The last pic has the TZ500 pipe fitted. Never mind the fat bastard in the background, it is the only pic I have that shows that pipe.

[Buckets4Me]

Sorry? What is wrong with the clutch? Suzuki plates take some real beating as demonstrated by my long suffering RG50 clutch. No bike gets more of a clutch hammering to be sure. While adjusting the lever I did get some suspicion of slip at Kiatoke up the hill last week. But I had the lever with minimal adjustment at the time so maybe not. Oh well I had some new plates in the spares for some reason (I run TS125 plates). measured difference after heck maybe 6-7 year of extreme abuse; 0.1mm difference. Word. :eek5:

I think you will find that TZ350 also abuses the clutch much like you do :gob:
just he has a slightly bigger bore stroke to help out with munching those fiber things apart ( I saw a clutch basket fly apart on his tz350 and he still beat everyone off the start line):woohoo:
I do believe that he hasn't put more than one NEW clutch in his bucket. And it's still good (at the moment)

[speedpro]

I do believe that F5s RG50 clutch has never been fully engaged with the engine running and in gear, ever! Since he's owned it anyway.

[Buckets4Me]

I do believe that F5s RG50 clutch has never been fully engaged with the engine running and in gear, ever! Since he's owned it anyway.

that i could belive

[TZ350]

.

My bikes engine is dragging twice the weight of F5's with maybe twice the HP, the clutch does suffer.

the crankcase's run about 100 degrees C or a little more even though I have improved the thermal barrier between them and the barrel

I have not burnt the clutch friction material right off the clutch plates yet

but the inner steels turn blue the oil smells burnt and the friction plates become cooked hard during a hectic days racing

if you think about it there are a few benifits to running with cooler oil.............. ;)

.

[TZ350]

Some pix of the 2 pipes. The RS pipe is a 1991 with a hand made header. The last pic has the TZ500 pipe fitted. Never mind the fat bastard in the background, it is the only pic I have that shows that pipe.

Thanks for the pics and dyno graphs, interesting little peak on the TZ graph, nice wide power band too, I wasn't expecting that from a mid 20's rwhp 100.

Do you recall any of the engine details like the inlet closing point?

.

[jasonu]

Thanks for the pics and dyno graphs, interesting little peak on the TZ graph, nice wide power band too, I wasn't expecting that from a mid 20's rwhp 100.

Do you recall any of the engine details like the inlet closing point?

.

The TZ500 pipe graph was the last run of the night and it never went back on the dyno so we are positive we can tune the 'peak' part of the curve to something better.
I don't recall any port timing numbers but when I built it I used A. Graham Bells 2 Stroke Tuners Guide as a starting point and went from there. The actual number will be close to what you find in the book and I do remember it is a fairly mild number. The good thing with the disk valve motor is if you do cock it up, you can simply bolt on another disk and try again. I know people say that book is old hat but it is still relavent to a lot of buckets as they are generally old hat motors.

[B.Crump]

a little off what you guys are talking about could somone point me to a thred that will tell me how much better a water cooled head is and what pump to use etc (tf125) cheers :done:

[Buckets4Me]

a little off what you guys are talking about could somone point me to a thred that will tell me how much better a water cooled head is and what pump to use etc (tf125) cheers :done:

this thread would be a good start

20hp from a watercooled 100
20hp from an aircooled 125 with 24mm carb :jerry:

you think that the advantages of watercooling are there ???
or keap it simple stupid (KISS) ??

[speedpro]

definite advantage

[SS90]

Unquestionable advantage.

The most obvious is that the cylinder compresson ratios you are able to run are increased dramatically (reducing the likelyhood of detonation), as well as a more cosistant power throughout the entire race (i.e less likely to "power fade")

and perhaps the most important is, in a high spec engine a more consistant temperature reduces the likelyhood of siezures as well.....

So, I would say A water cooled two stroke head brings increased reliabilty and power.

Could someone please over complicate that for us?<_<

[speedpro]

Been there, done that, gonna do it again. It makes a huge difference. On a TS you really need to limit the compression to about 14.7:1. If you water cool the head you should be able to go to 15.2:1. Perks things up nicely but it gets touchy on jetting and timing at that compression. You will need 100 octane and something like a YZ80 ignition. With the standard ignition you will end up with a hole in the piston if you can get it to run. Again - been there done that.

[TZ350]

The TZ500 pipe graph was the last run of the night and it never went back on the dyno so we are positive we can tune the 'peak' part of the curve to something better.
I don't recall any port timing numbers but when I built it I used A. Graham Bells 2 Stroke Tuners Guide as a starting point and went from there. The actual number will be close to what you find in the book and I do remember it is a fairly mild number. The good thing with the disk valve motor is if you do cock it up, you can simply bolt on another disk and try again. I know people say that book is old hat but it is still relavent to a lot of buckets as they are generally old hat motors.

When modeling my engine on MOTA I would often get a peak like that and the area in front of the peak could be filled in by delaying the inlet closing point.

I know MOTA is not a real mota but it did sugest a direction to look in.

Std inlet timing was 145/55 and modified was 145/85 and as a comparison my TZ was 90/90

.

[TZ350]

.



So, I would say A water cooled two stroke head brings increased reliability and power. Unquestionable advantage.


I have to agree


Could someone please over complicate that for us?<_<

and not wanting to disappoint,

I have to point out that an air cooled head is much more efficient at shedding heat than a water cooled one....:laugh:....yes its true!!

So why are high power race engines water cooled? :scratch: now that's something to think about.....

And how is the majority of the heat transmitted from the cylinder head to the water?...:)... and hint, it's not by conduction

.

[TZ350]

a little off what you guys are talking about could someone point me to a thread that will tell me how much better a water cooled head is and what pump to use etc (tf125) cheers :done:

BTW in F4 you can't run water cooling on a 125 but can on a 100.

If I was running a water cooled head for extra power I would also seriously look at water cooling the crankcase's too.

I have been looking at a lot of high power kart engines and notice that some water cool the crank cases.

There are lots of places like the cavity's around the TF's front engine mounts you could run water through.

.

[F5 Dave]

Don't lose any sleep, look at what he is running the TS in. Not a bike.

[Buckets4Me]

Don't lose any sleep, look at what he is running the TS in. Not a bike.

he still needs top workout how to get HP out of it before worring about watercooling the head

otherwise he may as well just buy an rs125 engine and go for both BIG HP and bling bling with the watercooled head

ps I know where there is a good rs engine for sale :clap:

[bucketracer]

ps I know where there is a good rs engine for sale :clap:

Me too, but TeeZee has fitted the carb from it onto a GP engine and I think he is looking at doing something with the ignition too.

[bucketracer]

So why are high power race engines water cooled? :scratch: now that's something to think about.....


OK. I'll chance my arm here.

Its because cooling "efficiency" and "effectiveness" are not the same thing.

A British sniper is "efficient" while a patrol of gum chewing American soldiers blazing away with their automatic weapons is "effective".

It all depends on the result you want.

Internal Combustion Engine Heat Transfer Outline....http://www.engr.colostate.edu/~allan/heat_trans/page1/page1.html

OK TZ if the heat in a water cooled head is not transferred from the cylinder head surface by conduction, how does it get transmitted into the water?

[TZ350]

Internal Combustion Engine Heat Transfer Outline....http://www.engr.colostate.edu/~allan/heat_trans/page1/page1.html

OK TZ if the heat in a water cooled head is not transferred from the cylinder head surface by conduction, how does it get transmitted into the water?

By forced convection and micro bubbles........:bash:

Check it out here:- http://www.liquidcooledairpower.com/lc-ridofheat.shtml

.

[TZ350]

.

Had a few test runs up the drive on the new bike.

Much to my relief the diffuser carb idea seems to work ok,

It has 230 degrees inlet duration and still idles well.

Inlet opens 145 BTDC and closes 85 ATDC, Ex opens 83 ATDC 73% bore width and Transfers open 116 ATDC, Honda RS125 chamber.

On Taupo gearing I can even drive off from a near standstill just on the throttle and without using the clutch.

Can't tell if there is the same or any more/less power but it drives well.

Possibley get it to the dyno Wednesday to dial it in and check the shape of the torque curve.

.

[sonic_v]

tz - You have so many changes compared to your present setup was wondering if your rm125 based exhaust will fit on this engine so that at least you get a back to back on the exhaust systems. Failing that if you had a 15mm spacer for the front of the rs system it would be interesting to see the results.

[TZ350]

.


tz - You have so many changes compared to your present setup .

Yes its a big roll of the dice, but I have kept my RM based pipe and engine intact so I can go back to it if I have too.

Thanks to your help, the big advance on the new engine could be the much improved 24mm carburettor.

The new 24mm diffuser carb flows 50% better than the old 24mm GP125 carb as measured by our manometer and industrial vacuum cleaner test rig.

.

[TZ350]

wondering if your rm125 based exhaust will fit on this engine so that at least you get a back to back on the exhaust systems. it would be interesting to see the results.

Good idea, if there is time I will try the old RM spec pipe for a comparison.

.

[gav]

.

My bikes engine is dragging twice the weight of F5's with maybe twice the HP, the clutch does suffer.

the crankcase's run about 100 degrees C or a little more even though I have improved the thermal barrier between them and the barrel

I have not burnt the clutch friction material right off the clutch plates yet

but the inner steels turn blue the oil smells burnt and the friction plates become cooked hard during a hectic days racing

if you think about it there are a few benifits to running with cooler oil.............. ;)

.

So what gearbox oil are you running? Is Motul Transoil still the preferred choice?

[B.Crump]

Thanks guys i have jennings and gram bell tuning books i get a bit of power fade due to low speed im only doing 64km top due to the track we use so water cooling will be my next move i tryed to get a ts125 barrel but could only find a crap one does ony one know of one for sale?

[Buckets4Me]

So what gearbox oil are you running? Is Motul Transoil still the preferred choice?

auto trans fluid if I rember right the red stuff :niceone:

[koba]

Thanks guys i have jennings and gram bell tuning books i get a bit of power fade due to low speed im only doing 64km top due to the track we use so water cooling will be my next move i tryed to get a ts125 barrel but could only find a crap one does ony one know of one for sale?

Bell touches on ducting and the like for aircooled go karts.

[B.Crump]

iv only got as far as blue printing the motor in the book i might skip ahead and take a look at it cheers

[TZ350]

.
Dynode a couple of the team bikes yesterday. We had a laser temperature gun to see if we could get some idea of the average exhaust temperature.

Blair lists the average exhaust temp and BMEP for a road bike as something like 360 degrees C – 5 bar BMEP, enduro 500 – 8 bar, motorcross 600 – 9 to 10 bar and GP racer 650 – 11+ bar.

From this I expected that the more power the hotter the exhaust, but we had one bike with an exhaust temp less than 300 that made 2hp more than a bike with a 560 degree exhaust.

On the bike with the 560 deg exhaust, thinking we had it tuned wrong we advanced the ignition 3 deg. The ex temp dropped and so did the power. Same with the main jet, bigger jet cooler exhaust and less power so it looks like we had it right first time.

My guess is that the engine with the hotter exhaust develops a higher BMEP but at much lower revs than the higher hp engine. Unfortunately the dyno could not pickup the engine rpm so we don’t know for sure. Interesting though.

High BMEP is everything, but it looks like a high BMEP (hot exhaust) at low rev's can equal less HP than a lower BMEP (cooler pipe) at much higher revs.

Hope to get back to the dyno tommorow
.

[koba]

.
High BMEP is everything, but it looks like a high BMEP (hot exhaust) at low rev's can equal less HP than a lower BMEP (cooler pipe) at much higher revs.

Hope to get back to the dyno tommorow
.

Do you know which one would win in a drag race? (maybe a short one for buckets)

[sonic_v]

.
Dynode a couple of the team bikes yesterday. We had a laser temperature gun to see if we could get some idea of the average exhaust temperature.

Blair lists the average exhaust temp and BMEP for a road bike as something like 360 degrees C – 5 bar BMEP, enduro 500 – 8 bar, motorcross 600 – 9 to 10 bar and GP racer 650 – 11+ bar.

From this I expected that the more power the hotter the exhaust, but we had one bike with an exhaust temp less than 300 that made 2hp more than a bike with a 560 degree exhaust.

On the bike with the 560 deg exhaust, thinking we had it tuned wrong we advanced the ignition 3 deg. The ex temp dropped and so did the power. Same with the main jet, bigger jet cooler exhaust and less power so it looks like we had it right first time.

My guess is that the engine with the hotter exhaust develops a higher BMEP but at much lower revs than the higher hp engine. Unfortunately the dyno could not pickup the engine rpm so we don’t know for sure. Interesting though.

High BMEP is everything, but it looks like a high BMEP (hot exhaust) at low rev's can equal less HP than a lower BMEP (cooler pipe) at much higher revs.

Hope to get back to the dyno tommorow
.

I would suggest try the midsection of the pipe. Not sure what it will be like with a laser temp gun as I normally use type k thermocouples inserted into the exhaust system. However, the temperature difference between engines in the midsection is much smaller compared to front of pipe.

Exhaust gas is not a great method of comparing engines anyway as one engine might make its power with a low delivery ratio and a high trapping efficiency and another will make its power with a high delivery ratio and a low trapping efficiency. The two engines might be making the same bmep at the same revs but will have a different exhaust gas temp. However, as a means of checking fuelling and ignition timing on an engine that you have some experience of it can provide a useful guide.

[F5 Dave]

of my very limited understanding is that temp can vary a heap & should only be used as a baseline. Measurements on EGTs are typically done at 4-6" from piston face.

the bike is then set up best it will go & measured. If it is then run at a track & the temp is lower than baseline tuning is preferable. Too cold will be rich.

. . . Or it could be lean, but the difference is it will likely get hot, then cool down as the heat energy moves from the pipe into the piston. So you have to watch for the temp change to get an indication.

Fitted an EGT this week so aim to get on dyno on sunday.

[TZ350]

.
At the BOB today Avalon made one of the Team Bikes (NedKellys) look good, gaining a second place in a support race and setting the second fastest PB time in the BOB race itself before retiring with a broken engine mount.

The thing I like most about buckets is all the great people you meet.
.

[Kickaha]

Fitted an EGT this week so aim to get on dyno on sunday.


When I raced Karts guys were going away from EGT as they reckoned quite often by the time you'd noticed your engine was already toast

They were all swapping to Det counters

[TZ350]

When I raced Karts guys were going away from EGT as they reckoned quite often by the time you'd noticed your engine was already toast

They were all swapping to Det counters

Hi Kickaha, my interest in exhaust gas temperatures gathered while running the bike on a dyno, is so I can design a more effective pipe.

I can understand what you mean about monitoring the EGT while racing but I don't know anything about using a Det Counter, probably time for me to learn, have you used one yourself?

.

[TZ350]

I would suggest try the midsection of the pipe. Not sure what it will be like with a laser temp gun as I normally use type k thermocouples inserted into the exhaust system. However, the temperature difference between engines in the midsection is much smaller compared to front of pipe.

Exhaust gas is not a great method of comparing engines anyway as one engine might make its power with a low delivery ratio and a high trapping efficiency and another will make its power with a high delivery ratio and a low trapping efficiency. The two engines might be making the same bmep at the same revs but will have a different exhaust gas temp. However, as a means of checking fueling and ignition timing on an engine that you have some experience of it can provide a useful guide.

By using a laser temperature gun on the dyno I had hoped to get an idea of the average exhaust gas temperature. It was not that easy as the temperatures along the pipe varied greatly, they also varied between runs and no doubt were hotter inside the pipe than on the outside.

On the dyno yesterday I measured the midsection temperatures as 160 deg C on my bike and 180 deg C on another ESE bike that’s making another 1.5 RWHP than mine.

Interestingly the best runs were often cooler than other rich/lean or over advanced/retarded runs. Generally the first pull in a run was cooler than the second and the third pull in a run was hottest. And as the power went up the final "best run" midsection temp was down compared to other lesser runs.

Another difficulty is this dyno only graphs RWHP against road speed so I have to work backwards to find RPM. From the RWHP + Estimated Transmission Losses and RPM I have been able to estimate the BMEP at 120 psi or 8.3bar and this suggests an average exhaust pipe temperature of 500 deg C.

The estimated crank HP at 10,000 rpm, 8.3bar BMEP and 500deg C accord well with Blairs pipe formulas and allow me to re-evaluate the porting to better suit the RS pipe.

The RS's exhaust timing won't work properly for the GP even though we are using an RS pipe as the GP engine does not have the same trapping efficiency or exhaust port time area and average exhaust gas temperature as the RS125.

I now know there is little point in using the same exhaust timing as the RS on the GP, and I have to work out a new one to suit the new motor/pipe combination.

In back to back runs with the new RS pipe and the old RM one it was found that they both made the same power at much the same RPM but the RS pipe gave much more useful over rev and now that we have the carb thing sorted I am keen to develop this GP-motor/RS-pipe combo further as I think it has real potential.

After the good showing by Avalon at the BOB Team ESE are very much looking forward to Taupo.

.

[ajturbo]

.
At the BOB today Avalon made one of the Team Bikes (NedKellys) look good, gaining a second place in a support race and setting the second fastest PB time in the BOB race itself before retiring with a broken engine mount.

The thing I like most about buckets is all the great people you meet.
.
you stupid man...... Avalon makes ANY bike look good!!!
especial if she is standing next to it.....and even better when she is riding it....

[TZ350]

you stupid man...... Avalon makes ANY bike look good!!!
especial if she is standing next to it.....and even better when she is riding it....

Sooo True......:laugh:

[sonic_v]

Those temperatures for your midsection are well below what the actual midsection gas temperatures are likely to be - typically 400 degC plus.

Not surprised that cooler temps are associated with your better runs as that particular rs pipe has a tuned length that is far too short for your exhaust port time area / exhaust duration setup - 814 mm on the rs. If you get a chance try the 15mm spacer I had suggested in a previous post. Just out of interest, what sort of ignition timing worked best.

I would also give some thought to trying a milder closing point on your disc valve - 85 degrees is typical of gp aprilias. On homebru discvalve racers a milder timing can be better all round. Try 75 deg atdc.

[Kickaha]

but I don't know anything about using a Det Counter, probably time for me to learn, have you used one yourself?


Haven't used one myself as they were a pricey bit of kit, K14 had one on his RS125 so he would be able to tell you about them

[TZ350]

Not surprised that cooler temps are associated with your better runs as that particular rs pipe has a tuned length that is far too short for your exhaust port time area / exhaust duration setup - 814 mm on the rs.

I will put a degree wheel on the crank and measure the ignition timing, my guess is that its about 14deg BTDC fixed. Retarding it with the RS pipe did not seem to improve the over-rev past peak power like I expected, previously it had done so on the RM pipe but the RS pipe has plenty as it is.

One of the Team ESE bikes is running an inlet that closes at 76deg ATDC and an Ex that opens 80deg ATDC with 70% bore width, trans open 114 ATDC and an RM spec pipe for 20RWHP, it runs quite well and is relatively easy to ride.

I measured the tuned length from the piston face on the GP with the RS pipe to the end of the convergent cone at 825mm, the exhaust tract on the air cooled barrel is 55mm. I think this is a little longer than the RS cylinder but could be wrong as its hard to measure the chamber accurately.

Like you suggest I will make up a series of spacers to try. All my modeling with Blair’s formulas suggests the pipe could be longer, like up to 900mm TL with different scenarios.

Looking at Blair’s formulas and using what I think the BMEP currently is (8 bar) I have come up with a new plan to try with the RS pipe.

From what I have measured, the RS125 transfers open 116 and Exhaust 86 Deg ATDC

My plan is to modify the GP125 transfers to open 114 and Exhaust 81 Deg ATDC 75% bore width for peak power at 11,000 rpm using the RS pipe.

Sure a longer duration means a longer pipe but a lower average ex gas temp like we are getting in the GP calls for a shorter pipe.

Using Blairs formulas and my estimated BMEP but at a higher rpm the above arrangement evens out producing higher HP than my current 20.

Anyway that’s the plan, and I would like 24 RWHP (26 at the crank) for Xmas. I can see your spacer idea being very useful.

I notice that in the top of the RS125 cylinder exhaust port, it is heavily angled down at the port window, is this a good idea?

.

[F5 Dave]

Well I had another fairly depressing day at the dyno. Despite the rebuild I was 1hp down & at narrowed spread & increased revs. Odd. Did the EGT probe effect the pipe? Would have been useful if I'd taken the bung with me but sadly forgot.

Also I kept throwing mains at it as in all gear runs it was falling off at the upper gears. It liked it & I'd gone from a 130 to a 142 before it went a smidge too far.

Maybe it has an airleak. I'll do a pressure leakdown test.

So how long has it been like this is also a question? maybe I was running the last GP like this as I never retested it after that rebuild & I've run the bike so infrequently after my crash.

Best look under the seat, maybe it's there.


So what did I learn from, the EGT? Hmm I need more time on it. it reacts very swiftly. Thinking back it was kinda queer as it was getting hotter with every gear. OK it was falling off power as slightly lean. But this should have shown the temp get hot & then cooler. But this didn't happen.

[TZ350]

.

Was 20 rwhp at 11,250 RPM now 21.5 RWHP at 9,000 rpm BMEP 8.5Bar, SS90 was sure right about unmasking the transfers and Sonic-V’s tips on diffuser carbs sure have made a difference.

But from the numbers my RS pipe at a TL of 825mm is short way to short as Blair suggests a TL of 1045mm for this scenario.

At 11,500 rpm the pipe will be the right TL and if I can get the same or better BMEP then I can expect a handy increase in RWHP.

Going for the max………

.

[sonic_v]

.

Was 20 rwhp at 11,250 RPM now 21.5 RWHP at 9,000 rpm BMEP 8.5Bar, SS90 was sure right about unmasking the transfers and Sonic-V’s tips on diffuser carbs sure have made a difference.

But from the numbers my RS pipe at a TL of 825mm is short way to short as Blair suggests a TL of 1045mm for this scenario.

At 11,500 rpm the pipe will be the right TL and if I can get the same or better BMEP then I can expect a handy increase in RWHP.

Going for the max………

.

Nice to see things moving the right direction!

Any chance of showing either a torque or bmep curve?

[TZ350]

Well I had another fairly depressing day at the dyno. Despite the rebuild I was 1hp down & at narrowed spread & increased revs.

I have had them too, and if the results aren't depresing then they are more often than not just confusing.

I am making another cylinder to better match the pipe, fingers crossed that it works.

.

[TZ350]

Any chance of showing either a torque or bmep curve?

Will have to go to a different dyno for that, probably not before Xmas. :no: every thing is insane around hear at the moment.

[speedpro]

Nice numbers, especially at those rpm. I got to find at least another couple. How did you measure the rpm?

[TZ350]

How did you measure the rpm?

Worked backwards from the road speed and wheel rolling diameter. So not totaly sure about the rpm but expect it's in the ball park.

.

[TZ350]

Just out of interest, what sort of ignition timing worked best.

Thomas has just put a degree wheel on it and it works out at 16 deg or 1mm BTDC.

.

[sonic_v]

Will have to go to a different dyno for that, probably not before Xmas. :no: every thing is insane around hear at the moment.

If you are handy with spreadsheets you could pick a few points of your power/speed curve and create a chart.

[SS90]

All this talk of EGT's is quite interesting.

Kiakaha mentioned that most Kartsporters don't use them anymore, and instead use det sensors, which is interesting.

Personally I use both a Det sensor and an EGT, combined with a cylinder head temp sensor.

All the sensors have a data logging capability, which I believe is what is really needed.

I also don't really use them too much on the Dyno, as too many variables come into play on the track (atmospheric pressure for one), but when I try drastically new things on an existing engine I certainly do, simply for comparisons with previous runs on the same engine.

Interesting that you found the best power for a fixed ignition was 16 deg Teezee, when dealing with a fixed ignition, I have found that is pretty much the same.

Now is the time to make your programmable ignition!
What I notice F5dave has mentioned is that he found the temperature to be to variable to make a measurement, and I guess that would be true unless you had a data logging capability so that you could concentrate on maximum's rather than fluctuating numbers that confuse the issue.

2 years ago I went to the effort of finding Maximums (well, for air cooled two stroke small frame Vespa's that is), and I was quite surprised.

In summary of that, I found that the best power was achieved when the Maximum temp was 460 deg, and disaster was achieved at 610 deg (3 times):crazy:

However, I run lower cylinder head compression ratios and a different cylinder head design than Teezee, so th enumbers would be different than Teezee would expect.

I feel it was worth it, as it suggested that settig an engine up to run high EGT's was detrimental, not only in power, but obviously also in reliability.

I always champion the idea of "to finish first, first you must finish", and my experience suggests that a larger safety margin is best for all.

There are heaps of data logging equipment available, and the best place to look is Kartsport....... you can buy an "all in one" unit (EGT,DET, and CHT) for a surprisingly acceptable amount.

I brought mine second hand for €250 and have used in trouble free for over 2 years.

[TZ350]

Hi SS, interesting post. thanks for your ideas on the safe exhaust temperatures. Yes data logging would be very useful, we will go there in the new year.

We now have a programmable ignition but have run out of time to properly fit it and get it set-up before Taupo so that will have to wait until the new year too. Flat out just trying to get the bike to run decently as it is.

One of our 20rwhp bikes went pretty well at the BOB until an engine mount broke, I have been told that it had the legs on the CBR150 and all the FXR's which is pretty satisfying as top speed is all about overcoming air resistance with hp and aerodynamics and very little to do with weight although the light weight RS chasis would certinly have helped coming out of the corners.

As we are now developing a new generation of 20+rwhp engines, next year looks very interesting. Thanks for your help.

.

[TZ350]

If you are handy with spreadsheets you could pick a few points of your power/speed curve and create a chart.

Good idea, I am planing on getting back to John Conners dyno on Friday and will bring a hp/road speed graph home with me and see if I can convert it like you suggest.

.

[TZ350]

These are the specs of Avalons Team ESE's BOB Suzuki GP125 20 rwhp engine:

Skim the barrel 1.5mm and “o” ring it, no head gasket, thin alloy spacer plate under the barrel and Suzuki RG250 pipe modified to RM125 specs, KX80 ignition. Raise the exhaust to open 83 deg ATDC, and widen to 70% of the bore, cut 30 deg from the closing point of the rotary disk, so inlet opens 145 BTDC and closes 85 ATDC. Champher the inlet side of the crank at 45 deg to aid inlet flow. Set the mj about 102.5 105 107.5 and ignition timing, 26-28 BTDC using a dyno. A link to Bells book and the RM pipe specs can be found on page 100 of this thread.

Cheep easy effective mods that most anybody can do and get 20 rwhp.
.

[koba]

These are the specs of Avalons Team ESE's BOB Suzuki GP125 20 rwhp engine:

Skim the barrel 1.5mm and “o” ring it, no head gasket, thin alloy spacer plate under the barrel and Suzuki RG250 pipe modified to RM125 specs, KX80 ignition. Raise the exhaust to open 83 deg ATDC, and widen to 70% of the bore, cut 30 deg from the closing point of the rotary disk, so inlet opens 145 BTDC and closes 85 ATDC. Champher the inlet side of the crank at 45 deg to aid inlet flow. Set the mj about 102.5 105 107.5 and ignition timing, 26-28 BTDC using a dyno. A link to Bells book and the RM pipe specs can be found on page 100 of this thread.

Cheep easy effective mods that most anybody can do and get 20 rwhp.
.


Should go good with Avalon on it!

[gav]

One of our 20rwhp bikes went pretty well at the BOB until an engine mount broke, I have been told that it had the legs on the CBR150 and all the FXR's which is pretty satisfying as top speed is all about overcoming air resistance with hp and aerodynamics and very little to do with weight although the light weight RS chasis would certinly have helped coming out of the corners.
.
Funny that, can't recall the bike ever being in front of the CBR150?
Oh, and that CBR150 won a 150 Streetstock race too! :cool: And a standard FXR ran inside the top 10 of the 150SS too.

I think the secret is having super fast lightweight riders. :2thumbsup

[gav]

These are the specs of Avalons Team ESE's BOB Suzuki GP125 20 rwhp engine:

Skim the barrel 1.5mm and “o” ring it, no head gasket, thin alloy spacer plate under the barrel and Suzuki RG250 pipe modified to RM125 specs, KX80 ignition. Raise the exhaust to open 83 deg ATDC, and widen to 70% of the bore, cut 30 deg from the closing point of the rotary disk, so inlet opens 145 BTDC and closes 85 ATDC. Champher the inlet side of the crank at 45 deg to aid inlet flow. Set the mj about 102.5 105 107.5 and ignition timing, 26-28 BTDC using a dyno. A link to Bells book and the RM pipe specs can be found on page 100 of this thread.

Cheep easy effective mods that most anybody can do and get 20 rwhp.
.

And what carb would you suggest using?

[TZ350]

Funny that, can't recall the bike ever being in front of the CBR150?

Were you riding or lap scoring? I have only heard reports about the race from the pit crew myself, a super light/fast rider is certainly the biger part of it, for certain sure it couldn't/wouldn't have happened if I was riding.

.

[TZ350]

And what carb would you suggest using?

38mm Keihin Flatslide like in Pic-01 and Pic-02 :msn-wink:

The 24mm Keihin diffuser carb in Pic-03 may be the way of the future, we will know more after Taupo.

The above specs of Avalons engine are all the mods done to a std GP125 to get 20 rwhp, she was running the std GP125 carb.

.

[gav]

Were you riding or lap scoring? I have only heard reports about the race from the pit crew myself, a super light/fast rider is certainly the biger part of it, for certain sure it couldn't/wouldn't have happened if I was riding.

.
I was riding, when ever the CBR150 lapped me Avalon wasn't far behind, but the gap was getting slowly bigger. Shame she had problems, she was flying for sure!

[TZ350]

.

On a good day, I am a bit of a mid-fielder myself, and have seen some great racing action from there that I am sure you don't get to see from the side lines.

.

[TZ350]

.


Well I had another fairly depressing day at the dyno.

Dave I know your pain, Picture 01 and 02 are of my new piston. I was running the new engine set-up on the dyno trying different pipes. I just couldn’t tune it for any more power and when I pulled the barrel of I found these seizure marks.

Could it be that the 1.0 thou clearance measured at the bottom of the skirt was to tight.

Or were they the result of over advancing the ignition or too much retard, we moved the ignition both ways to find the limits.

Or the couple of times we forgot to turn the cooling fans on before doing a run and I saw 200 degc on the barrel and 160 on the head.

Or may be the diffuser carb leans out too much at the top end, although I think it goes rich but without an EGA who knows?

During one series of runs there was brown soot blowing out the exhaust. I have seen that before on some road cars under heavy acceleration, so what is that brown stuff? it's not rust!

Or a cold seizure, where the engine is run under load before its properly warmed up and the piston expands faster than the barrel.

And then there is the exhaust gas temperatures, I have measured every thing from 250 to 600 at different parts of the pipe.

I have no idea when it happened only that it lost power at some stage while I was swapping pipes and fiddling with the tuning and couldn’t get all the power back.

.

[F5 Dave]

one thou clearance on an air cooled barrel?!?? I run 2 thou on aircooled & I wouldn't run 1 thou on anything, even my 50.

[TZ350]

I had been reading up on piston clearances and how Yamaha selected their clearance according to the power output of the engine and that they ran air cooled tighter than water cooled because the air cooled cylinders expanded more than water cooled ones so the air cooled piston needed less initial clearance.

I filed the high spots off, I guess my piston has more than a thou clerance now. :) any way its all back together with a new copy of a Darcy pipe from post 1507 page 101 and it runs ok, reputedly 170 rwhp on a RG500, hopefull get back to Johns dyno again tommorow, 24+ rwhp at 10500 would be Ok.

.

[speedpro]

i assembled the last motor with .0015" clearance, more or less. I did spend a whole day creeping round the kart track running it in. Seems good as gold now and has only wear marks and no scuffs when pulled down. I agree with Dave, .001" is a bit tight. I know what I'm doing Friday night . . . . .

[bucketracer]

.

I know what I'm doing Friday night . . . .

.

"Friday Night Drags"............don't tell me, your going to get all dressed up again..............like you and Dad did last week......:laugh:

.

[Buckets4Me]

Funny that, can't recall the bike ever being in front of the CBR150?
Oh, and that CBR150 won a 150 Streetstock race too! :cool: And a standard FXR ran inside the top 10 of the 150SS too.

I think the secret is having super fast lightweight riders. :2thumbsup

all the E.S.E bikes have run in the top 10 of the ss150's at taupo
so thats no surprise about the fxr (even an rg50 can do it) :lol: :buggerd:
and I dont think any of them had super light riders 80+ kg (sorry dad)
apart from maby mine with Keith on it

[sonic_v]

CO meter is a handy tool for this type of work. The cheap type as sold by motor factors is not up to the job though. You require one that uses the ndir (non-dispersive infrared) method.

[sonic_v]

I had been reading up on piston clearances and how Yamaha selected their clearance according to the power output of the engine and that they ran air cooled tighter than water cooled because the air cooled cylinders expanded more than water cooled ones so the air cooled piston needed less initial clearance.

I filed the high spots off, I guess my piston has more than a thou clerance now. :) any way its all back together with a new copy of a Darcy pipe from post 1507 page 101 and it runs ok, reputedly 170 rwhp on a RG500, hopefull get back to Johns dyno again tommorow, 24+ rwhp at 10500 would be Ok.

.

The peak power shown at the dyno curves link from above show a peak power of 128 bhp or is this not the Darcy pipe?

http://homepage.mac.com/rg500delta/deltaphasetwo/images/pipes/darcy%20test1.jpg

[ajturbo]

These are the specs of Avalons Team ESE's BOB Suzuki GP125 20 rwhp engine:

Skim the barrel 1.5mm and “o” ring it, no head gasket, thin alloy spacer plate under the barrel and Suzuki RG250 pipe modified to RM125 specs, KX80 ignition. Raise the exhaust to open 83 deg ATDC, and widen to 70% of the bore, cut 30 deg from the closing point of the rotary disk, so inlet opens 145 BTDC and closes 85 ATDC. Champher the inlet side of the crank at 45 deg to aid inlet flow. Set the mj about 102.5 105 107.5 and ignition timing, 26-28 BTDC using a dyno. A link to Bells book and the RM pipe specs can be found on page 100 of this thread.

Cheep easy effective mods that most anybody can do and get 20 rwhp.
.

this wouldn't help me would it
.. as i have a spare GT125 twin engine... .....

would anyone notice if i put both in a frame???:buggerd:

[ajturbo]

a serious question here...

the positioning of the front brake caliper...

on my GT it is on the left fork, BEHIND the fork

i have just seen a photo of one with it on the RIGHT, therefore in FRONT of the fork

question::::

which is better????

[F5 Dave]

Theoretically behind, but with one small caliper & small forks & wheels it probably doesn't matter a squat.

[TZ350]

The peak power shown at the dyno curves link from above show a peak power of 128 bhp or is this not the Darcy pipe?

http://homepage.mac.com/rg500delta/deltaphasetwo/images/pipes/darcy%20test1.jpg

Yes I think the black line is the Darcy pipe, but 128 bhp? I thought it was more like 170 SAE Hp measured at the back wheel, I know there is many different coloured horses, what with SAE, Metric, Brake, Hp Etc., have I missed something?

I have not given up on the RS pipe, I think it has real potential but need more time to make some spacers like you sugested and I was thinking of a sliding mid section too for testing on the dyno.

.

[sonic_v]

Yes I think the black line is the Darcy pipe, but 128 bhp? I thought it was more like 170 SAE Hp measured at the back wheel, I know there is many different coloured horses, what with SAE, Metric, Brake, Hp Etc., have I missed something?

I have not given up on the RS pipe, I think it has real potential but need more time to make some spacers like you sugested and I was thinking of a sliding mid section too for testing on the dyno.

.

Black line is torque - 66 ft-lbs

[gav]

170 rwhp? From an RG500? Not even the full factory GP bikes were making that were they?

[TZ350]

Black line is torque - 66 ft-lbs

Ok so the lower three traces are rwhp, at 170 I did have my hopes up for at least a low 20's rwhp pipe for my bike.

I am expecting to get to the dyno this afternoon, it will be interesting to see how the Darcy pipe goes.

.

[sonic_v]

Ok so the lower three traces are rwhp, at 170 I did have my hopes up for at least a low 20's rwhp pipe for my bike.

I am expecting to get to the dyno this afternoon, it will be interesting to see how the Darcy pipe goes.

.

Your bike is well capable of 24/25 bhp. It is all in the pipe!!

On a positive note, the rg500 is giving about 32bhp per cylinder at 10500 revs/min. As this is the sort of revs you want to peak at, you are able to take a significant drop in torque and still make 25 bhp.

PS I think that you should investigate an earlier closing point for the disc valve at some stage! 85 is quite extreme and as your intake now flows better than before it should in theory require a milder closing point

[TZ350]

I think that you should investigate an earlier closing point for the disc valve at some stage! 85 is quite extreme and as your intake now flows better than before it should in theory require a milder closing point

Yes plan to do this, will try a series of them, but interestingly the 85 doesn't spit back and it drives (up the drive) on the throtle quite well.


Your bike is well capable of 24/25 bhp. It is all in the pipe!!

On a positive note, the rg500 is giving about 32bhp per cylinder at 10500 revs/min. As this is the sort of revs you want to peak at, you are able to take a significant drop in torque and still make 25 bhp.

Thats encouraging, I think I should be able to get mid 20's rwhp out of the GP125 too. I chose to make a copy of the Darcy pipe as it was developed on an engine similar to mine and proven in dyno test comparisons with other well known after market pipes.

.

[ajturbo]

170 rwhp? From an RG500? Not even the full factory GP bikes were making that were they?
my buell (XB ) does....:whistle:

[ajturbo]

Theoretically behind, but with one small caliper & small forks & wheels it probably doesn't matter a squat.
thanks... didn't think it would make too much difference.. just a question...

[speedpro]

There's news to be shared but for some reason Rob's not sharing. Cully may enlighten us as long as we promise not to accuse him of showing off.

[Buckets4Me]

is this good or bad :(
even I havent heard yet
sounds like the 100 is the fastest E.S.E bike around

[TZ350]

There's news to be shared but for some reason Rob's not sharing. Cully may enlighten us as long as we promise not to accuse him of showing off.

Yesssssss.....Ok....choke....cough....splutter.... . Cullys bike has more power than mine and looks better on the dyno graphs.

.

[TZ350]

is this good or bad :(
even I havent heard yet
sounds like the 100 is the fastest E.S.E bike around

Testing with the Darcy pipe, best results, max power (21 rwhp) at 9,000rpm mid section temp 80deg C, cylinder temp 90 and head 60.

Optimized the jetting and tried retarding the ignition, and got more heat less power, advancing the ignition, same result, more heat less power.

It beats me how my new engine which has more port/time/area than the old one, and with the same RM pipe as my previous 11,000rpm engine now makes slightly more max power but at only 9,000rpm.

I have tried pipes optimized for 10,11 and 12,000rpm on it but it always made much the same 21 rwhp at about 9,000 rpm, with the high power/rpm RS pipe being the best.

Although the new motor is making a little more power than before, its as if, just as its getting well into its stride something chokes its potential, the suspects are the transfers or the exhaust port.

The good thing is in back to back comparisons with others the diffuser carb worked best.

The plan is to reduce the inlet closing point, make some spacers for the RS pipe and re-measure the port/time/areas, make some changes and hopefully back to the dyno next week.

.

[Chambers]

I'm not going to crow as time has been the problem with TZ and once we get a handle on whats going on I'll be expecting 26 rwhp my 100 was done as a comparision of Open Carb 100 as aposed to restricted 125. Watch this space!

[Buckets4Me]

so for a years work you have gone from 14 hp and third at the Taupo gp
to 21hp and who knows where at the gp this year

so a 50% increase in HP this year :buggerd:
and Rick may have to watch out. No :zzzz: on the start line this year

[Chambers]

Hopefully no dickhead will be in my grid position this year and I manage to finish the race this time, its not fun sitting on the infield watching.

[TZ350]

.

Another interesting clue was the carb with the power jet. As the motor started getting onto the pipe you could see the petrol drawn up the clear plastic tube to the power jet. Then as the motor was still pulling hard and sounding ok, you could see the petrol in the power jet tube pulsing at maybe 3-5hz quite slow but marked. Then as the motor topped out the petrol retreated from the power jet, so at over rev the vacuum at the bell mouth must have fallen right away.

So over 9,000 odd rpm I think that induction is being blocked by some sort of wave action, or the clash of two waves that is stopping the motor from revving on and making real power. With the pipes, the motor should have revved higher but something is getting out of step, I suspect the power peak being seen is from the combination of a second order and a primary resonant peak and the motor and pipe have not fallen into step together properly on matching primary resonant peaks of their own.

But what to change?

.

[bucketracer]

Hopefully no dickhead will be in my grid position this year

There is always a slow as, dickhead that pushes to the front and nabs someones allocated grid position. When the flag drops I expect most front rower's can always start faster than a dickhead and it must be tempting to give them a shoulder barge on the way past......;)

[bucketracer]

Two Stroke Tuners Hand-Book http://www.datafan.com/TunersHandbook/2-strokefiltered.html

[sonic_v]

.

Another interesting clue was the carb with the power jet. As the motor started getting onto the pipe you could see the petrol drawn up the clear plastic tube to the power jet. Then as the motor was still pulling hard and sounding ok, you could see the petrol in the power jet tube pulsing at maybe 3-5hz quite slow but marked. Then as the motor topped out the petrol retreated from the power jet, so at over rev the vacuum at the bell mouth must have fallen right away.

So over 9,000 odd rpm I think that induction is being blocked by some sort of wave action, or the clash of two waves that is stopping the motor from revving on and making real power. With the pipes, the motor should have revved higher but something is getting out of step, I suspect the power peak being seen is from the combination of a second order and a primary resonant peak and the motor and pipe have not fallen into step together properly on matching primary resonant peaks of their own.

But what to change?

.

I have seen a similar affect on reed valved engines. On a 80cc motocross engine tuned for roadracing that produces 25bhp at 13000 revs/min using a 30mm carb, fitting of a 32mm carb resulted in a violent drop in power at 12,000 revs/min. Violent enough to almost launch me over the handlebars. Everything pointed to some sort of resonance effect in the carb floatbowl. I tried different things to counteract it such as varying the length of plastic tube going to the float bowl vents, plus drilling of the vent apertures but to no avail.

Any chance you could show the power curve even if against road speed? I am particularly interested to see if you actually have a double hump to your curve which would indicate some sort of recovery.

Certainly at this moment in time, everything points to your inlet as you have tried so many exhausts and have seen this problem with them all. Just maybe earlier closing of disc valve might help you.

[sonic_v]

It beats me how my new engine which has more port/time/area than the old one, and with the same RM pipe as my previous 11,000rpm engine now makes slightly more max power but at only 9,000rpm.

I have tried pipes optimized for 10,11 and 12,000rpm on it but it always made much the same 21 rwhp at about 9,000 rpm, with the high power/rpm RS pipe being the best.

Although the new motor is making a little more power than before, its as if, just as its getting well into its stride something chokes its potential, the suspects are the transfers or the exhaust port.

The plan is to reduce the inlet closing point, make some spacers for the RS pipe and re-measure the port/time/areas, make some changes and hopefully back to the dyno next week.

.

It is neither your exhaust port or transfers. That exhaust port is good for 26 bhp. Going for even more time area is likely to send you backwards. This is an inlet problem. Any chance you are running your float bowl dry? Could you modify your previous carb to work as a diffuser?

[TZ350]

.

Sonic_V thanks for your ideas, saved me from screwing up the exhaustport.

Unfortunately I don’t have a graph, I had some saved to a memory stick, but can’t open them on my home computer, computers!!!!!!

I intend changing the inlet closing point to 75, first thing and will take a 65 with me on my next trip to the dyno.

I tried two distinct styles of diffuser carb, I could make something with a clear tube so I can keep an eye on whats happening in the float bowl and I will also try the original carb on my next dyno trip.

Taupo is a week away, so I am quickly running out of time, just have to be philosophical I guess and enjoy the day as is.

.

[TZ350]

Two Stroke Tuners Hand-Book http://www.datafan.com/TunersHandbook/2-strokefiltered.html

Cheeky bugger :girlfight: minime just for that, you can go out and mowe the lawns.

.

[TZ350]

With my so called diffuser carburetors the idea was to move the 24mm high velocity area away from the disruptive metering area around the slide.

As I understand it, a carburetors size is measured at its smallest point, traditionally the choke is at the metering point as this gives the strongest signal to the jets but it doesn’t have to be. Carbs with throttle plates like on older cars have the air flow control and metering areas in different places, motorcycles traditionally use a system where air flow control and metering are done together in the same place.

The way I see it there is no rule about what a carb should look like. The only requirement of a carburetor is that it controls the air flow and meters fuel and in the case of F4 125 2-strokes that it has a choke no bigger than 24mm. If someone else sees the rules differently now's a good time to let me know so I don't make a complete ass of myself.

Pic-01 has the 24mm choke well clear of the disruptive area of the slide and flows 50% more than the original 24mm carb and is the one I have been using. It was made by permanently inserting a 24mm choke into a 28mm Keihin flatslide.

Pic-02 is a 24mm OKO (Keihin copy) flatslide carb that has been taper bored so that only a small area in the bell mouth is 24mm and the disruptive metering area is larger, this carb flowed about 30% more than the original 24 on our test rig.

.

[sonic_v]

Pic-02 is a 24mm OKO (Keihin copy) flatslide carb that has been taper bored so that only a small area in the bell mouth is 24mm and the disruptive metering area is larger, this carb flowed about 30% more than the original 24 on our test rig.

.

Was any dyno testing done with this carb and if so what was the result?

[TZ350]

Was any dyno testing done with this carb and if so what was the result?

No, the bulk of testing was done with carb-01 the 02 carb had the power jet, at first the jetting was not good and when we had mostly dialed it in, we could see it mimicked the shape of the first carb's power curve, maybe slightly lower but with all the same problems.

.

[TZ350]

Here are pictures of the actual carbs themselves.

Pic-01 and 02 the 28mm Keihin with a permanently fitted 24mm choke.

Pic-03 and 04 The taper bored power jetted OKO (Keihin Copy) 24mm at the bell mouth 28mm at the engine side.

I think this inventiveness is in the spirit of buckets but if anyone thinks its not within the rules and can explain why please tell me now before I hit the track at Taupo.

.

[TZ350]

.

Ok...just re-checked everything and the numbers are:-

Ignition timing 16 deg BTDC
Ex opens 86 deg ATDC 73% bore width
Transfers open 116.5 deg ATDC
Inlet opens 145 deg BTDC and closes 85 deg ATDC
Inlet port at the valve is 30mm dia equivalent.

Nothing totaly out of kilter there, its all as was planed but its now thought that the inlet timing is wrong. I didn't realy know what size equivelent to use for the inlet port, 24mm carb choke, 28 or even 30 at the port window when calculating the port/time/area.

I will change the rotary valve closing point from wild to something mild. A quick re-calc of the port/time/area required for 9000 rpm and 28mm dia equ and settle on an inlet timing of 145/60 and thats handy as its also a disk I allready have.

As it had the most over-run I am going to refit the RS pipe and try a 50mm spacer in the header. When I get back to the dyno I will take a series of spacers from 15mm to 100mm to try.

.

[TZ350]

.

Chambers has just come back from Mt Welly and he looks very pleased with himself, his bike must be going well.

.

[Pumba]

.

Chambers has just come back from Mt Welly and he looks very pleased with himself, his bike must be going well.

.

Yes he may have a smile but anyone and everyone else at the track today (especially those of us going to Taupo) have got far from a smile.

[speedpro]

.

Chambers has just come back from Mt Welly and he looks very pleased with himself, his bike must be going well.

.

It was quick in the straights but there was a couple of younger guys who were really pitching it in on the corners - #66 for instance. Good day watching as well as riding. It'll be a hard one to beat at Torpo I'd say

[B.Crump]

he still needs top workout how to get HP out of it before worring about watercooling the head

otherwise he may as well just buy an rs125 engine and go for both BIG HP and bling bling with the watercooled head

ps I know where there is a good rs engine for sale :clap:

How much for that enigne? just curious as i dont have a lot of spear time to mod the tf125. iv got the port sizes off a ts125 so im gonna copy them and see how that goes (when i geet round to it) :blink:

[TZ350]

How much for that enigne? just curious as i dont have a lot of spear time to mod the tf125.

Team ESE have shared all their information to make it easier for someone getting started with their own Suzuki GP engine and hopefully encourage others to use a 2-stroke to give those pesky 4-smokers a run for their money.

Its the best we can do. We don't have a lot of spare time either. Good luck with your project.

.

[TZ350]

.

Chambers rode one of the CB125T's at Mt Welly last weekend and was impressed at how easy they are to ride fast, very predictable but boring he said. Team ESE are starting to get enough killer hp and now power delivery and handling will be what they need to work on next year.

Speedpro is allready getting a good handle on power and handling with his bike, Team ESE will be playing catch up next year.

But Chambers GP100 at 22 rwhp is making 2 more hp than the bike Avalon rode in the BOB. :woohoo: He is very much looking forward to Taupo and this time I don't think the bike will break an engine mount.

At Taupo there is going to be some stiff competition in the drag race from the start to the first corner, my money is on a Team ESE GP125 getting there first.

.

[Buddha#81]

.

At Taupo there is going to be some stiff competition in the drag race from the start to the first corner, my money is on a Team ESE GP125 getting there first.

.


My money is on a skinny wee punk on a MB/RS from down our way to win that..........:scooter:

[F5 Dave]

um, I like Diesel, but I'm going to have to say I assume that with that description :Oops:someone else is riding his bike?

[jasonu]

.

Chambers rode one of the CB125T's at Mt Welly last weekend and was impressed at how easy they are to ride fast, very predictable but boring he said. Team ESE are starting to get enough killer hp and now power delivery and handling will be what they need to work on next year.

Speedpro is allready getting a good handle on power and handling with his bike, Team ESE will be playing catch up next year.

But Chambers GP100 at 22 rwhp is making 2 more hp than the bike Avalon rode in the BOB. :woohoo: He is very much looking forward to Taupo and this time I don't think the bike will break an engine mount.

At Taupo there is going to be some stiff competition in the drag race from the start to the first corner, my money is on a Team ESE GP125 getting there first.

.

Shame it has only got 5 gears...

[F5 Dave]

The next big thing for ESE:innocent:

[jasonu]

The next big thing for ESE:innocent:

I like it!!!

[TZ350]

With those gears and the RS chasis we are saving lots of weight.........so now we can eat more xmas lunch :laugh:

I hear that towards the end of her run at the BOB Avalon was having trouble with her gears because of the broken engine mount and she was having to bend down and change them by hand and was still keeping up, I think the CBR was possibly a lucky winner.

.

[Buckets4Me]

Shame it has only got 5 gears...

I have enough trouble remembering witch gear I'm in anyway why would I want more ?????????

and at 21hp @9500 why would it need more gears :scooter:

[Buckets4Me]

The next big thing for ESE:innocent:

thats only rated to 1 hp (human power)

[gav]

um, I like Diesel, but I'm going to have to say I assume that with that description :Oops:someone else is riding his bike?
Its another one, MB/RS's are pretty common down here. :Oops:
Oh by the way, buckets are racing at round one of the Nationals down here .... :woohoo:

[Buckets4Me]

Oh by the way, buckets are racing at round one of the Nationals down here .... :woohoo:

:wari::scooter::wari::scooter::wari::scooter:

[Kickaha]

um, I like Diesel, but I'm going to have to say I assume that with that description :Oops:someone else is riding his bike?

He's talking about a totally different bike and rider

[F5 Dave]

Ahh you mean DC? Back on board. Or another one? Sheesh mine will be a classic racer by the time I finish it & I'm pretty sure I started first.


Well I did the dyno thing & found all my lost horsepower on the 50 (was in the glovebox).

It appears the EGT probe was in a bit too far & really screwed things up. I'll not bother with it at Taupo & experiment when I have more time.

[TZ350]

A collection of the better links from the last few pages, more on pages 80 90 & 100

Two Stroke Tuners Hand-Book http://www.datafan.com/TunersHandbook/2-strokefiltered.html

GP125 18+ rwhp: skim the barrel 1.5mm and “o” ring it, thin alloy Spacer plate under the barrel and Suzuki RG250 pipe. Ex opens 86 deg ATDC and Trans opens 114 ATDC, std head , inlet timing 145/55 and carb mj 95.

The specs of Avalons Team ESE's BOB Suzuki GP125 20 rwhp engine:
Skim the barrel 1.5mm and “o” ring it, no head gasket, thin alloy spacer plate under the barrel and Suzuki RG250 pipe modified to RM125 specs, KX80 ignition. Raise the exhaust to open 83 deg ATDC, and widen to 70% of the bore, cut 30 deg from the closing point of the rotary disk, so inlet opens 145 BTDC and closes 85 ATDC. Champher the inlet side of the crank at 45 deg to aid inlet flow. Set the mj about 102.5 105 107.5 and ignition timing, 26-28 BTDC using a dyno. A link to Bells book and the RM pipe specs can be found on page 100 of this thread.

Cheep easy effective mods that most anybody can do and get 20 rwhp.

Internal Combustion Engine Heat Transfer Outline....http://www.engr.colostate.edu/~allan/heat_trans/page1/page1.html

Forced convection and micro bubbles........
Check it out here:- http://www.liquidcooledairpower.com/lc-ridofheat.shtml

http://www.tz350.net/tz250page.htm portmap for the TZ250 from 1976 to 1984.

24mm carb for 30+ hp go-cart engines
Carb-01 http://www.out2win.com/catalog/images/ibeal5.jpg
Carb-02 http://www.out2win.com/catalog/ibea.html
Carb-03 http://www.j3competition.com/downloads/technical/L6_Homologation.pdf

Expansion Chamber Design According to Blair:-
http://members.bellatlantic.net/~vze2p5sj/modelengines/expcham.htm

.

[TZ350]

Well I did the dyno thing & found all my lost horsepower on the 50 (was in the glovebox).
.



I will think of a better place to hide your extra hp next time. :bleh:

.

[jasonu]

I have enough trouble remembering witch gear I'm in anyway why would I want more ?????????

and at 21hp @9500 why would it need more gears :scooter:

5 gears and max hp at only 9500, you might run out of puff. Hope you have plenty of over rev.

[bucketracer]

5 gears and max hp at only 9500, you might run out of puff. Hope you have plenty of over rev.

Not to sure about TZ's, but Chambers and NedKellys have plenty of zing and Buckets4me has allways been a good performer and Avalon will have her own RS/GP.

[jasonu]

Not to sure about TZ's, but Chambers and NedKellys have plenty of zing and Buckets4me has allways been a good performer and Avalon will have her own RS/GP.

Good luck at the GP. I am looking forward to the pix and hopefully vids.

[Buckets4Me]

5 gears and max hp at only 9500, you might run out of puff. Hope you have plenty of over rev.

thats what the box of sprokets are for :2thumbsup

pitty we didn't send any down with Ned Kelly's bike for the BOB

it's your bike Dave will be riding is it
the tz kwaka 100cc ???

going to be a good fast year this time

[B.Crump]

will you guys be racing on the new race track in tauranga ? (when its finshed) at the all terrain park from what i hear its going to be a nice track

all so when water cooling a head do i strip all the paint off first or leave it on? all so can i cut a bit of the fins away ? any one know were some pic's are?

[Yow Ling]

will you guys be racing on the new race track in tauranga ? (when its finshed) at the all terrain park from what i hear its going to be a nice track

all so when water cooling a head do i strip all the paint off first or leave it on? all so can i cut a bit of the fins away ? any one know were some pic's are?

You are decades away from needing water cooling, get it ported and going fast first, watercooling wont make it fast. the questions you are asking show you probably out of your depth

[F5 Dave]

will you guys be racing on the new race track in tauranga ? (when its finshed) at the all terrain park from what i hear its going to be a nice track

Yeah that's where we have all our next meetings planned. ESE may have to do some long travel suspension work & consider grooving those slicks a little deeper.:stupid::

[bucketracer]

when water cooling a head do i strip all the paint off first or leave it on? all so can i cut a bit of the fins away ? any one know were some pic's are?

Unless your restricted to 125cc if you need more power, simply fit a larger engine, plenty of older air cooled engines come up on trademe like GS400's etc.

[Buckets4Me]

Yeah that's where we have all our next meetings planned. ESE may have to do some long travel suspension work & consider grooving those slicks a little deeper.:stupid::

TZ350's bike had knobley tires on it when first brought
could fit them again :2thumbsup

[jasonu]

thats what the box of sprokets are for :2thumbsup

pitty we didn't send any down with Ned Kelly's bike for the BOB

it's your bike Dave will be riding is it
the tz kwaka 100cc ???

going to be a good fast year this time

Yes, but it hasn't been riden in anger for 12 years. Hopefully it will hold up.

[TZ350]

Yes, but it hasn't been riden in anger for 12 years. Hopefully it will hold up.

Great to see your bike is going to be out there.

There are certainly going to be some interesting bikes this year.

This is Chambers 22 rwhp 100 with 32mm flatslide RGV carb.

.

[TZ350]

.

NedKellys 20 rwhp bike being fettled after its trip to the BOB. Avalon will have one of her own but with a standard GP125 15 rwhp engine, we had to give ourselves some sort of advantage.

.

[TZ350]

.

TeeZees GP125 21 rwhp @ 9,000 rpm, not to sure how this one will go. Looking forward to getting back to the dyno after Taupo so I can properly try out Sonic_Vs ideas on rotary valves and header spacers.

Pictures 2 and 3 show the ducting for cooling the head, we want 26 - 28 rwhp from this engine next year.

.

[jasonu]

.

TeeZees GP125 21 rwhp @ 9,000 rpm, not to sure how this one will go. Looking forward to getting back to the dyno after Taupo so I can properly try out Sonic_Vs ideas on rotary valves and header spacers.

Pictures 2 and 3 show the ducting for cooling the head, we want 26 - 28 rwhp from this engine next year.

.

Nice pix mate. I like the RS chasis bike in the 2nd set. The first one looks a bit porky. Do you know the weights of them all? Mine weighs 75kg wet.
Not sure if a 24mm carb will allow 26-28hp... If you get it, it will be a handful with that spindly frame and swingarm. Good luck though.

[TZ350]

Nice pix mate. I like the RS chasis bike in the 2nd set. The first one looks a bit porky. Do you know the weights of them all? Mine weighs 75kg wet.
Not sure if a 24mm carb will allow 26-28hp... If you get it, it will be a handful with that spindly frame and swingarm. Good luck though.

Do you think I could get it with a 28? my 24mm diffuser carb flows as well as a 28 racing Keihin as measured on our test rig.

The last of the air cooled Honda MT125R's were in the high 20's and they had a backbone frame like ours and they only had a cable operated disk brake on the front and...yes... 26+ hp I think the GP's will be a bit of a handfull.

MT125R parts list http://www.cmsnl.com/honda-mt125r-roadracer-us_model1086/partslist/

From memory the GP's are in the low 90's and the RS is in the 70's about 20kg difference.

Looking forward to seeing your bike at Taupo.

Pic's are of a Honda MT125R

.

[jasonu]

Do you think I could get it with a 28? my 24mm diffuser carb flows as well as a 28 racing Keihin as measured on our test rig.

From memory the GP's are in the low 90's and the RS is in the 70's about 20kg difference.

Looking forward to seeing your bike at Taupo.

.

Mine runs a 28mm RG400 flat slide that has been 'D' bored, actual is about 31mm. We tried a 34 round slide, it made the response flat with no more HP. We wanted to try a 'D' bored 32 flat slide but I left the country for overseas sex and beer.

[F5 Dave]

. . . but I left the country for overseas sex and beer.

And probably more of that horrible green Chartreuse:mad:

[TZ350]

.

Team ESE are very much looking forward to that first corner crush after the start flag and the argy bargy that goes with it before the run up the hill where we clear off and (hopefully) leave the field behind....:2thumbsup

.

[jasonu]

And probably more of that horrible green Chartreuse:mad:

Na mate, that stuff is nasty. Last time I drank it I made a real c*%T of myself in public, puked on my mates bed and pissed in his wardrobe.
Never again!!!

[F5 Dave]

last time I drank that some prick was buying it for me the night before racing at Ohakune street cct, insisting I drink it or be labeled a homo, felt well de-tuned the next day. . . . however we couldn't race anything other than hungover in those days so no change to original plan.

[richban]

last time I drank that some prick was buying it for me the night before racing at Ohakune street cct, insisting I drink it or be labeled a homo, felt well de-tuned the next day. . . . however we couldn't race anything other than hungover in those days so no change to original plan.

Got half a bottle with your name on it.

[jasonu]

last time I drank that some prick was buying it for me the night before racing at Ohakune street cct, insisting I drink it or be labeled a homo, felt well de-tuned the next day. . . . however we couldn't race anything other than hungover in those days so no change to original plan.

WHAT A MEMORY! That had to be at least 11 years ago. I think that was the 1st outing for my 100. I had effed up the comp ratio and had trouble with the head sealing. It had the stock TZR rear end with a stuffed shock I paid top $s to Jebbie Bruin to fix. It started leaking while unloading from the trailer. Jimmy and Ken Steadman were there too I think. DD knocked me off around the sweeper in the back end of the track OUCH!
Who was the prick and were you labeled a homo anyway???

[F5 Dave]

Quite likely I was, - I think it was in retaliation for buying Shooters when up in Auckers for some misc night out when you got a bit messy.

yeah I think I have a pic of your bike then. I suffered a similar fate one year (so many trips there not sure if same) when my forks burst a leak when I tried to blank off the antidive (need to cut a channel).

A few years later when they ran the GP there Greenie past me down the straight in a prelim race & promptly dived under my front wheel. Never found out who paid him, but that is dedication to the cause.

Off thread topic a bit? Ah heck it didn't get to 111 pages by staying on topic.

[TZ350]

First pic is another of the Team ESE bikes, Buckets4Me's RS/GP125. This bike has been the most reliable and probably ride-able of the Teams bikes.

B4Me and John Conner ringing a bit more out of the Team bikes and the last pic is Chambers 50.

.

[B.Crump]

You are decades away from needing water cooling, get it ported and going fast first, watercooling wont make it fast. the questions you are asking show you probably out of your depth

i only go 64km on the straght due to it being short and being geared down so not a lot of air going past the fins. i notice a bit of power fade so i was hopeing that water cooling would help with that but you are right i am just starting out. im porting it out at the mo using g bell tuning book cheers for the info :)

[bucketracer]

i only go 64km on the straght due to it being short and being geared down so not a lot of air going past the fins. i notice a bit of power fade so i was hopeing that water cooling would help with that but you are right i am just starting out. im porting it out at the mo using g bell tuning book cheers for the info :)

Interestingly at 30k you get quite good cooling and need to go 120k to double the cooling effect. All this air speed and cooling effect was covered earlier in this thread. It turns out that 15-45k is a very effective air speed, slow enough for the air to pickup its fill of heat and fast enough to clear the hot air from the fins, if your engine is suffering heat fade you might benefit from fitting some air ducting.

And if you really need water cooling you could just fit a thermal switch to the head and squirt water over the fins from a windscreen washer bottle when the motor gets hot.

Have you gone to any trouble to read much of this thread?
.

[jasonu]

[.

And if you really need water cooling you could just fit a thermal switch to the head and squirt water over the fins from a windscreen washer bottle when the motor gets hot.


.[/QUOTE]

Don't you think this might pose a scrutineering issue, squirting h2o onto a race track? Maybe you could rig it to squirt sideways when someone trys to pass you...

[TZ350]

It would be interesting to see some of the other bikes heading to Taupo, any one got pictures of their bike and can post them?.

.

[Yow Ling]

Heres mine, its on its way to Taupo, DC is taking it as a spare incase trouble happens with his MB

[Skunk]

Mines loaded in the trailer now, Heading to Cemetery Circuit first then Taupo.
No photo sorry - but this pic is similar but very little of that frame (or tank, clipons etc) still remains...

[diesel pig]

This is my machine when it was a bit cleaner.

[TZ350]

.

Wow......there are some great bits of kit coming to Taupo this year.....I am impressed....I am looking forward to catching up with everyone.

[bucketracer]

.

Some of the Auckland talent that could be heading for Taupo.......

.

[Henk]

And an untalented Aucklander coming down.

[Monkeynz]

And an untalented Aucklander coming down.

You don't look slow and bald in this pic Henk. :2thumbsup

[Henk]

Still slow and bald. I just like climbing all over the bike like a monkey, the mirror ball helmet is so that innocent women and children don't run screaming to the hills when they first catch sight of my shiny head.
This thread seems to have gone a little off topic but I suspect most of the FXR diesels are going to be left lookng a little bit silly by the hot 2 strokes over the coming days.

[Yow Ling]

but I suspect most of the FXR diesels are going to be left lookng a little bit silly by the hot 2 strokes over the coming days.


Dont forget the story of the turtle and the hare, came true at the BOB !

[gav]

And also some hot two strokes coming from South Island too! :headbang:
Good luck to all the mainlanders making the trip!! :banana:

[ajturbo]

don't forget about the fly in the ointment .....
the might GT...
with the worst rider you have ever tried to over take....

[TZ350]

.

After a years work its interesting to see what other people have done and photos of their bikes.

Yes anything can happen, there are a lot of really good riders on FXR's and Diesil Pigs RS/MB looks the business.

Jasonu's bike looks good and Nigal Duff, is a quick rider on a quick bike, and then there is the potential of ajturbo's mighty GT......

.

[Henk]

Hmmm got an MB50 project in the garage that I never really got started on. Might be time to resurect it so I can run two classes. That said I'm supremely fit and completely knackerd after riding the diesel alone so the plan may be a little ill advised.

[TZ350]

Hmmm got an MB50 project in the garage that I never really got started on. Might be time to resurect it so I can run two classes.

Get your 50 going Henk, I am building one too, just didn't get it finished in time for Taupo. I have riden Buckets4me's one, 50's are a load of fun.

.

[TZ350]

.

More of the Auckland Talent.........

.

[TZ350]

.

Another quick GP125..................not one of ours but very quick and could quite easily pull it off at Taupo..........

.

[bucketracer]

I suspect most of the FXR diesels are going to be left lookng a little bit silly by the hot 2 strokes over the coming days.

The 2-strokes are looking good and they have tried hard to win previously but haven't been able too yet, so maybe/maybe not.

Sensible money would be on this FXR.

.

[SS90]

The 2-strokes are looking good and they have tried hard to win previously but haven't been able too yet, so maybe/maybe not.


.

Then something is seriously seriously wrong!:oi-grr:

[Buckets4Me]

Sensible money would be on this FXR.

.

only is a Squid dosent knock him off again :Playnice: (money well spent rick)

[Buckets4Me]

Then something is seriously seriously wrong!:oi-grr:

14 hp wrong now an extra 50%

[TZ350]

Then something is seriously seriously wrong!:oi-grr:

Hi SS90 thanks for your help during the year, a phat 21 rwhp at 9,000 rpm, instead of a peaky 20 at 11,250, points the way to where we need to go with development next year. I have some ideas on how to overcome the restriction imposed by a 24mm carb so next year looks good.

I hope to do you and all the others who helped me during the year proud at Taupo.

.

[jasonu]

Is Nigel D. going to show up?

[Henk]

His name is on the entry list

http://www.roadracespectacular.4t.com/TAUPO%20SPECTACULAR%20PROGRAM.xls

Link doesn't work for some reason but you can get to it from

http://www.roadracespectacular.4t.com

[ajturbo]

there are only 3 of us here in wellington running 50's... that is when Dave gets better.... but his is so fast he races with the big boys....

[Henk]

There are a few F5 bikes in auckland. I'd be either running it as a non competitive laugh in a 2nd class or sending my wife out on it. If I ever get it finished. Shouldn't be hard. I just dragged it out of the corner of the shed where it has been languishing and all it really needs is the pegs and conrols sorted out. Hardest thing will be figuring out a way to hook up a back brake. Other than that everything I need is pretty much there in the boxes of bits from bikes I used to own and the bits I chopped of the FXR. Only thing I can see that I will have to find somewhere is a front master cylinder.
This is not going to be a threat to the likes of the Diproses but might be good for a giggle and could also be a low stress intro to racing for people that don't want to head into a feild of 20 plus bikes first time out.

[TZ350]

.

Actually my RG50 is more complete than it looks. I have ported and rebored the cylinder and done most of the other engine work, made the chamber, clipons, rearsets and have a 28mm flat-slide for it. To make the TZR wheels fit they were milled back to the brgs and the front and back wheels fitted with a 15mm spacer on one side.

I am going to get right into it when I get back from Taupo and expect to have it all up and running for the start of the season. I think that riding in F5 might be more fun than getting tangled up in the crowded fields of F4. I am just sorry I didn't get it finished for Taupo, but might get to ride Chambers F5 in the GP.

I look forward to lining up on the F5 grid with you next season.

.

[ajturbo]

just one thing... IF luke turns up... (IF) you guys will be wondering who the fuck is he???

[SS90]

.

Another quick GP125..................not one of ours but very quick and could quite easily pull it off at Taupo..........

.

Is that an RG150 expansion chamber fitted to that GP powered FXR?

If it is quicker than your bikes, do you think there might be something in that?

[TZ350]

Is that an RG150 expansion chamber fitted to that GP powered FXR?

Yes...RG150 chamber, good spotting.

The rider is certainly quicker than me, the bike is fast but is it quicker than mine? not so sure about that..............will find out soon.....

.

[gav]

The 2-strokes are looking good and they have tried hard to win previously but haven't been able too yet, so maybe/maybe not.
.
Im kinda hoping that a two stroke does win it, #17 though, representing the Mainland :yes: . If nothing else check out the finish on that bike, it would make HRC proud to turn out a bike as well prepared as his. He cleaned up the bucket class at Greymouth Street Races, including the hot Aussie CBR150 and Joe :gob:
He's used to racing on a full size circuit too.
He should go well! :yes:

[Buddha#81]

Im kinda hoping that a two stroke does win it, #17 though, representing the Mainland :yes: . If nothing else check out the finish on that bike, it would make HRC proud to turn out a bike as well prepared as his. He cleaned up the bucket class at Greymouth Street Races, including the hot Aussie CBR150 and Joe :gob:
He's used to racing on a full size circuit too.
He should go well! :yes:

Pity the owners a wanker ;)

[jasonu]

Is the F4GP at Taupo today or tomorrow?

[B.Crump]

[QUOTE=bucketracer;1129583939]Interestingly at 30k you get quite good cooling and need to go 120k to double the cooling effect. All this air speed and cooling effect was covered earlier in this thread. It turns out that 15-45k is a very effective air speed, slow enough for the air to pickup its fill of heat and fast enough to clear the hot air from the fins, if your engine is suffering heat fade you might benefit from fitting some air ducting.

And if you really need water cooling you could just fit a thermal switch to the head and squirt water over the fins from a windscreen washer bottle when the motor gets hot.

Have you gone to any trouble to read much of this thread?


I have started and am not gona ask any more Q's untill i have caught up otherways im just gona piss somone off lol i am copying and pasting all the bits that have spec's etc

[Yow Ling]

OK so how the ESE racers going at Taupo?
Any Diesels in the top 10?
How did the mainlanders go?

Any more broken engine mounts?

That should cover it.:msn-wink:

[Ned Kelly]

OK so how the ESE racers going at Taupo?
Any Diesels in the top 10?
How did the mainlanders go?

Any more broken engine mounts?

That should cover it.:msn-wink:

Well it turned out to be a long weekend for a few of the ESE team. Saturday 2nd Practise session. Chambers had just started to really get his GP100 going well when he took a spill at the end of the back staright into the main start. He high sided the bike and was unfortunately hit by a trailing bike. He was Ko'ed for a while. He was not looking well when the ESE guys all stopped trackside to help him. Thankfully paramedics arrived pretty quickly. He was pretty shacken and had a pretty impressive bruise on his rear.
His engine certainly had real speed. Chambers was not racing for the rest of the weekend so Avalon jumped on his bike.
She ran it in the F4GP. She really made that bike sing. Unfortunately she also took a spill which did not help. She got back on but the race was run for her and she ended the GP around 12th

TZ350 had a few problems wth performance and decided to change his engine on Saturday. This was the engin he had run last year but it just did not want to perform and the weekend became a bit of a downer for him.

Buckets4me ran pretty well and he made some big gains in his running from last year. He did well and I am sure he would be happy with his results.

I (Ned Kelly) had not a bad weekend. I qualified 8th in the F4GP. Qualifing time 1:30.33. This was a huge improvement on last year.
I was pretty sure the bike was going to perform pretty well. Avalon had found all the problems with the bike which we made sure were well and truely repaired before Taupo. I had a real poor start and ended up mid feild before working my way back through the feild to finish 10th
I was pretty happy as my best laptime was 1:29.52. 5sec better than last years best lap.
Had a DNS in the second race gear leaver linkage came loose on the warmup lap and had no option to pull into the pits.
Final race finish 11 but was right on the tail of the 8,9,10 bikes. Had a good weekend and really enjoyed the weekend. We have work to do to catch the real flyers but at least we are making improvements.

Have a great New Year All.

Ned Kelly

[Kickaha]

How did the mainlanders go?


Very well I heard, maybe the NI bikes aren't as fast as they'd like to think:whistle:

[ajturbo]

just one thing... IF luke turns up... (IF) you guys will be wondering who the fuck is he???
well he turned up .... but didn't race..... the poofter

[Buckets4Me]

Very well I heard, maybe the NI bikes aren't as fast as they'd like to think:whistle:

The E.S.E bikes are fast enough just look at the BOB :2thumbsup
pitty the skill is lacking
next year will see us all back again :cool:

[Kickaha]

The E.S.E bikes are fast enough just look at the BOB :2thumbsup

remind me where they finished again? :whistle:

[Buckets4Me]

remind me where they finished again? :whistle:

it, only one (not 4)was second for a good portion of it :buggerd:(how many fxr didn't finish)


:2thumbsup

[TZ350]

OK so how the ESE racers going at Taupo?
Any Diesels in the top 10?
:msn-wink:

From the official results and as I remember it.

In the two F4/F5 all in races Nathanial Diprose rode a 50 into 5th (BT 1:32:35) and 7th (BT 1:30:79) respectively, and there were at least 10 Diesels behind him. :girlfight:

The fast guys were:-

Andrew Adlam FXR150 Wellington 1st in the GP (BT 1:27:48) ? and 2nd in the two F4/F5 combined races.

Darryl Cotton Honda RS/MB100 CHCH 2nd in the GP (BT 1:27:39) 1st and 1st in the two F4/F5 combined races.

Neil Batchelor MB100 Rangiera 3rd in th GP (BT 1:27:94) 2nd and 3rd in the two F4/F5 combined races.

Other fast runners were:-

Gavin Veltmeyer FXR150 Auck 4th in the GP (BT 1:28:76) 3rd and 4th in the two F4/F5 combined races.

Richard Ford FXR150 Auck 5th in the GP (BT 1:28:88) 4th and 6th in the two F4/F5 combined races.

Tim Frazer FXR150 Auck 6th in the GP (BT 1:28:89) 6th and 5th in the two F4/F5 combined races.

And the best time recorded by a Team ESE bike was NedKelly on his RS/GP125 at 1:29:52

The worst moment was when Chambers high sided of his bike in practice, knocked himself out and was hit by another bike that could not avoid him. Chambers recovered pretty quickly and now has a big bruse on his bum, there are pictures some where.

The best moment was watching Avalon on Chambers bike start from the back of the GP grid and cut her way to near the front in one lap. On the second lap her race was cut short when she fell at the same spot as Chambers had, she re-mounted and sensibly rode a more reserved race for a finish, 12th I think.

Chambers GP100 sure had the leggs needed but getting the old GP frame to handle well enough to run at the front might be a bridge to far.

.

[koba]

Had a DNS in the second race gear leaver linkage came loose on the warmup lap and had no option to pull into the pits.


My heart sank for you as I was right next to you and saw you falter, looked down and saw your lever hanging. :shit:

Shit luck man!

Maybe it was the RS 125 bits, perhaps you should sell me yor bike cheap :blip:


(I was #157 on the green FXR with a number plate)

[TZ350]

Im kinda hoping that a two stroke does win it, #17 though, representing the Mainland :yes: .

Diesel_Pig :second: in the GP and a :first: and another :first: in the F4 races.

.

[TZ350]

.

Pic of Chambers bum, after he fell at Taupo, and was hit by a following bike....:buggerd:

so now you know.......this is what happens when you cop an FXR up the arse.......:laugh:

.

[Kickaha]

Diesel_Pig :second: in the GP and a :first: and another :first: in the F4 races.

.

You're getting him mixed up with DC (Darryl Cotton)


.

Pic of Chambers bum, after he fell at Taupo, and was hit by a following bike....:buggerd:

so now you know.......this is what happens when you take an FXR up the arse.......:laugh:

.

Interesting bruising and pretty much a carbon copy of what happened to me when I tossed the bucket away 3 weeks ago, my ended up about twice that size after 4-5 days then disappeared over the 4-5 days after that, but 3 weeks later is still swollen and tender

[Kickaha]

Darryl Cotton Honda RS/MB100 CHCH 2nd in the GP (BT 1:27:39) 1st and 1st in the two F4/F5 combined races.

Neil Batchelor MB100 Rangiera 3rd in th GP (BT 1:27:94) 2nd and 3rd in the two F4/F5 combined races.



Next year we better send the fast guys up:whistle:

[TZ350]

.

I personally enjoyed the weekends racing and meeting up with old friends and some new ones from KiwiBiker. :D


Very well I heard, maybe the NI bikes aren't as fast as they'd like to think:whistle:

Andrew Adlams FXR150 is certainly a very fast bike and he rides it like a demon. Darryl Cotton and Neil Batchelor both from the mainland and running MB100 engines have very fast 2-Strokes. It was great to see these guys riding; and their aggressive cornering was breath taking.

I think the ESE engines are approaching this level, certainly Chambers is, but I don’t see myself riding at the front with these guys, NedKelly probably could next year and Chambers if he can get his bikes handling sorted, the sharp end has become very competitive. I think I will content myself with just taking part, enjoying the day and developing engines with Thomas’s help.

At Taupo, I had a series of small self inflicted problems :argh: that held me back but I enjoyed being there and now feel confident we are on the right track with our engine development and diffuser carb ideas. Next year is looking very interesting.

.

[bucketracer]

Interesting bruising and pretty much a carbon copy of what happened to me when I tossed the bucket away 3 weeks ago, my ended up about twice that size after 4-5 days then disappeared over the 4-5 days after that, but 3 weeks later is still swollen and tender

We saw the photos and were much impressed.

.

[koba]

.
Andrew Adlams FXR150 is certainly a very fast bike and he rides it like a demon.

I think it was alot to do with how damn fast he rides, the bike isn't stock but it isn't really heavily wanked either.

#45, Richard Ban had an even faster FXR, he is the one who crashed out on turn four of the GP. His bike is a bit of a rocket!

[Kickaha]

.
Darryl Cotton and Neil Batchelor both from the mainland and running MB100 engines have very fast 2-Strokes. It was great to see these guys riding; and their aggressive cornering was breath taking.

There would be at least another 3-4 guys down here that would easily run at their pace or faster, I wonder if the fact we normally run on tracks similar to size in Taupo helps them get up to speed faster when they get there

[koba]

There would be at least another 3-4 guys down here that would easily run at their pace or faster, I wonder if the fact we normally run on tracks similar to size in Taupo helps them get up to speed faster when they get there

Yep, and the bikes will be built for that kind of racing, here power isn't really that much of a big deal.

[Buckets4Me]

There would be at least another 3-4 guys down here that would easily run at their pace or faster, I wonder if the fact we normally run on tracks similar to size in Taupo helps them get up to speed faster when they get there

well they had better make the trip next year then hadn't they :banana:
untill then I'm still going to remember that they where behind Avalon :Playnice:

lol :2thumbsup and she has a whole year to get her bike up and running

[Kickaha]

untill then I'm still going to remember that they where behind Avalon :Playnice:


Where did they finish overall compared to her? :bleh:

[TZ350]

There would be at least another 3-4 guys down here that would easily run at their pace or faster, I wonder if the fact we normally run on tracks similar to size in Taupo helps them get up to speed faster when they get there

I am sure that running on longer tracks gives them a different focus to us at Mt Wellington, but I think the Team ESE engines are starting to get there as good all rounders and I expect we will be able to develop them further this year.

.

[Buckets4Me]

Where did they finish overall compared to her? :bleh:

didn't even start the trrs :buggerd: :girlfight:

so way behind :whistle:

[TZ350]

There would be at least another 3-4 guys down here that would easily run at their pace or faster.

Thats Good......Team ESE don't want it too easy when we come south.........:whistle:....

.

[TZ350]

.

Where did they finish overall compared to her? :bleh:

Ok...you got us..........but there is next year ...;)............and we plan on being there...

.

[ajturbo]

the mighty GT (stock ) did ok with an old man riding it...

[TZ350]

the mighty GT (stock ) did ok with an old man riding it...

You looked good Aj,.....but this old man got passed in one practice session by a girl peddling a Honda XL100 F5 bike.........:weep:

.

[koba]

You looked good Aj,.....but this old man got passed in one practice session by a girl peddling a Honda XL100 F5 bike.........:weep:

.

Didn't everyone?

[TZ350]

.

Just before Taupo there was a bit of talk about wether Buckets could be as fast as Street Stocks.

I see from the results that there are quite a number of Buckets that based on their times could have run at the front of SS.

Results from Taupo.. http://www.marktime.co.nz/results/091228-SRA.HTML

.

[gav]

There would be at least another 3-4 guys down here that would easily run at their pace or faster, I wonder if the fact we normally run on tracks similar to size in Taupo helps them get up to speed faster when they get there

He's not joking either! Check the results from the Bears Winter series
http://www.bmrc.co.nz/Points/2009%20points.php
Neil Batchelor ran that same MB/RS combo and finished the series outside the top 5.
Darryl didnt race the winter series but did race a modified FXR in the MotoFX class.

Also seems a shame that the GP title was decided over a 5 lap race? GP races are usually alot longer than that.

[Yow Ling]

Also seems a shame that the GP title was decided over a 5 lap race? GP races are usually alot longer than that.

True, but up north they seem to have reliability issues.

[Buckets4Me]

True, but up north they seem to have reliability issues.

I seem to remember there was more than one DNF at the BOB :bleh:

[Buckets4Me]

Also seems a shame that the GP title was decided over a 5 lap race? GP races are usually alot longer than that.

the GP was longer but some plonker failed to stay on his bike
so they started again

[Skunk]

I thought the points were averaged from the 9 laps?

Either way the race was far too short to be a GP - it should have been 40 mins at least (25 laps +/-).

[Kickaha]

I thought the points were averaged from the 9 laps?

Either way the race was far too short to be a GP - it should have been 40 mins at least (25 laps +/-).

Good point, I thought the GP has a minimum distance?

[Buckets4Me]

I'm sure it was longer last year
but I dont think they had the time this year with the 3 hour race on the first day :pinch:
and not having a third day to play with
if there is any complaints I'm sure someone els will be happy to hold the gp at another time and date
just dont winge if it's back in auckland

[SS90]

Good point, I thought the GP has a minimum distance?
You mean A motorcycle GP in general, or a bucket GP?

With-out going to the effort of checking, I am pretty sure that a GP is around 45mins to an hour.

Basically the amount of time you can run a 125cc engine for on a tank of gas.

[gav]

I'm sure it was longer last year
but I dont think they had the time this year with the 3 hour race on the first day :pinch:
and not having a third day to play with
if there is any complaints I'm sure someone els will be happy to hold the gp at another time and date
just dont winge if it's back in auckland

We can always hold it in Christchurch if you like? Maybe BOB could be the GP race? Or a GP race could be held alongside BOB? Might not be too many bikes left running after both though? I thought 40-45 mins was the norm for a GP race (buckets included)

[richban]

the GP was longer but some plonker failed to stay on his bike
so they started again

Sorry about that. Believe me I would have rather stayed on.

[Buckets4Me]

We can always hold it in Christchurch if you like? Maybe BOB could be the GP race? Or a GP race could be held alongside BOB? Might not be too many bikes left running after both though? I thought 40-45 mins was the norm for a GP race (buckets included)

and the point of my remark was
ARE YOU GOING TO DO ALL THE WORK TO ORGANISE IT ???

or are you going to bitch and moan about how it was done
I have watched the gp every year since I started racing and havent seen to many people run the thing
just JC and nor the guys at the TRRS (good on them makes a change from the Mt Wellington track)

[Yow Ling]

I'm sure someone els will be happy to hold the gp at another time and date
just dont winge if it's back in auckland

We have the BOB every year, if we say in August 2010 "Its F4 GP time" does that make it the GP ?, would Auckland come down for it?
Buckets are strong both sides of the ditch, its just a really long way to go. maybe we should run F4 GP in the north one year , then the south the next , that way we cant complain that we never have the chance to be GP winner

[Skunk]

Don't turn this into a GP bitch thread.
I'm fine with the way it was run - because it was run. I don't care where it is run, how long it is or anything else. If it's worth going to, and I can afford it, I'll be there. :)

[Buckets4Me]

Don't turn this into a GP bitch thread.
I'm fine with the way it was run - because it was run. I don't care where it is run, how long it is or anything else. If it's worth going to, and I can afford it, I'll be there. :)

thats what I'm saying they in the MAIN LAND can go to the effort of running a gp if they want and I'm sure some of the north island crew mill try and make it down ( I know I would try)
but first they have to organise it (not just call it a gp)
I'm still looking foward to the BOB when I get a chance to go down :yes:
and I think Taupo is the most central place for the GP

and If some one had a BOB at Hampton downs :scooter: I'd be there
( because I didn't have to do anything but turn up. Nothing happens unless you make it or support it when it dose)

well done to everyone at the TRRS no complaints about the length of races from me (I got to race where I wouldn't have otherwise)

so GAV get organising (and I will get saving)

I like the idear of north one year and south the next (again get organising book it in I'm not coming down the month before TRRS sorry)

[Kendog]

and I think Taupo is the most central place for the GP
Taupo isn't very central for those down in the SI.

[TZ350]

.

Now that Taupo is done and dusted.

I have been looking at ways of improving the induction system on my GP to maximise the air flow through the restriction of the 24mm carburettor insert.

Looking at resonance in air columns:- http://hyperphysics.phy-astr.gsu.edu/Hbase/hframe.html

And the design of air box’s for modern 4-Strokes:-

Resonant Airboxes: Theory and Applications:- http://motorcycleinfo.calsci.com/Airboxes.html

resonant rpm = 4775 sqrt( 116.5 A / VL ) (single cylinder 4-stroke)
resonant rpm = 9550 sqrt( 116.5 A / VL ) (V-twin 4-stroke)
resonant rpm = 19100 sqrt( 116.5 A / VL ) (4 cylinder 4-stroke)

Two of the formulas can be used for 2-Strokes

resonant rpm = 9550 sqrt( 116.5 A / VL ) (single cylinder 2-stroke)
resonant rpm = 19100 sqrt( 116.5 A / VL ) (twin cylinder 2-stroke)

Where the A=area of the inlet tube is in cm2, V = volume in cc’s, L=length of the inlet tube in cm’s.

The theroy is that the maximum volume of air will flow through the 24mm carburettor when it is in resonance with the plenum.

Using the formula for single cylinder 2-strokes I find that with a plenum of 1000cc and an inlet tract diameter of 24mm the inlet tract only needs to be varied 3-6mm approximately to shift the resonant point from 8,500 rpm to 12,000.

If I can arrange it so the motor draws directly from the plenum through a short 34mm inlet duct. And make a variable length 24mm carb that stays in resonance with the plenum as the rev's vary then the motor will be drawing directly from a high-pressure source (the plenum) through an unrestricted 34mm inlet.

Hopefully this should be much like having a 34mm carb on the motor. I have already started making the parts.

A resonant air box (plenum) is also something that the 4-stroke boys could make to increase their hp and extend the power band of their motors.

.

[F5 Dave]

So did you ever find out why the No1 motor wasn't shifting properly?

[TZ350]

So did you ever find out why the No1 motor wasn't shifting properly?

Hi Dave, No, I have not properly investigated it yet but think I may have been a bit hasty in changing it out for last years engine. That night when I thought about it I realised it was jumping out of gears randomly on up shifts but not out of first or down shifts which suggests the gear linkage may not have been adjusted properly for a full throw up-shifting.

Pity as the new engine felt real good and pulled and throttled well. I was encouraged as the special diffuser carb idea seemed to work ok and the motor made good power and drove well on the track.

But I had no time to test ride it before hand. I guess that’s what you get for rushing to finish a job and taking an untried bike to Taupo. Also it was the first time I had been on a bike for a while and I was struggling a bit but all in all I enjoyed my two days at the TRRS.

The plenum chamber idea is something that I had wanted to try at Taupo but ran out of time. Now I can rework the whole engine and try some new ideas, like the plenum chamber, programable ignition, water injection, oil cooling, cold air box and spend some time on the dyno getting the pipe right.

There is a lot to do before next year.

.

[TZ350]

I am still finding my way around the new system and can't upload images ???????

Why????????

[gav]

thats what I'm saying they in the MAIN LAND can go to the effort of running a gp if they want and I'm sure some of the north island crew mill try and make it down ( I know I would try)
but first they have to organise it (not just call it a gp)
I'm still looking foward to the BOB when I get a chance to go down :yes:
and I think Taupo is the most central place for the GP

and If some one had a BOB at Hampton downs :scooter: I'd be there
( because I didn't have to do anything but turn up. Nothing happens unless you make it or support it when it dose)

well done to everyone at the TRRS no complaints about the length of races from me (I got to race where I wouldn't have otherwise)

so GAV get organising (and I will get saving)

I like the idear of north one year and south the next (again get organising book it in I'm not coming down the month before TRRS sorry)

Well, didnt mean to ruffle any feathers. I had thought that a GP title was suppose to be run over a certain length, but see now that it was suppose to be a 10 lapper. Couldnt actually find any rules that state it has to be a certain length, so maybe just a tradition?
I've been on the committee for BOB down here, and I believe this year we are tyring to do something a bit special, hopefully over a weekend with racing at both Ruapuna and Levels, both tracks are awesome on a bucket.
Think the Welly mob enjoyed it down here, when they made the trip and we enjoyed them being here. Hopefully we can get you Aucklanders down here too. Sorry but Taupo at xmas time is a bit pricey to get too for most down here I think.

[richban]

.

Now that Taupo is done and dusted.

I have been looking at ways of improving the induction system on my GP to maximise the air flow through the restriction of the 24mm carburettor insert.

Looking at resonance in air columns:- http://hyperphysics.phy-astr.gsu.edu/Hbase/hframe.html

And the design of air box’s for modern 4-Strokes:-

Resonant Airboxes: Theory and Applications:- http://motorcycleinfo.calsci.com/Airboxes.html

resonant rpm = 4775 sqrt( 116.5 A / VL ) (single cylinder 4-stroke)
resonant rpm = 9550 sqrt( 116.5 A / VL ) (V-twin 4-stroke)
resonant rpm = 19100 sqrt( 116.5 A / VL ) (4 cylinder 4-stroke)

Two of the formulas can be used for 2-Strokes

resonant rpm = 9550 sqrt( 116.5 A / VL ) (single cylinder 2-stroke)
resonant rpm = 19100 sqrt( 116.5 A / VL ) (twin cylinder 2-stroke)

Where the A=area of the inlet tube is in cm2, V = volume in cc’s, L=length of the inlet tube in cm’s.

The theroy is that the maximum volume of air will flow through the 24mm carburettor when it is in resonance with the plenum.

Using the formula for single cylinder 2-strokes I find that with a plenum of 1000cc and an inlet tract diameter of 24mm the inlet tract only needs to be varied 3-6mm approximately to shift the resonant point from 8,500 rpm to 12,000.

If I can arrange it so the motor draws directly from the plenum through a short 34mm inlet duct. And make a variable length 24mm carb that stays in resonance with the plenum as the rev's vary then the motor will be drawing directly from a high-pressure source (the plenum) through an unrestricted 34mm inlet.

Hopefully this should be much like having a 34mm carb on the motor. I have already started making the parts.

A resonant air box (plenum) is also something that the 4-stroke boys could make to increase their hp and extend the power band of their motors.

.

I have looked at this in the past. I can't remember what bike it was but it had a flap inside the air box that increased and decreased the volume on throttle position (quite nifty). When I fitted a make shift air box to my bike everything started to come together. I am working on 2 exhausts at the mo. When they are built I will be making some air boxes to try with each pipe. I reckon there are big gains to be made.

[Buckets4Me]

Well, didnt mean to ruffle any feathers. I had thought that a GP title was suppose to be run over a certain length, but see now that it was suppose to be a 10 lapper. Couldnt actually find any rules that state it has to be a certain length, so maybe just a tradition?
I've been on the committee for BOB down here, and I believe this year we are tyring to do something a bit special, hopefully over a weekend with racing at both Ruapuna and Levels, both tracks are awesome on a bucket.
Think the Welly mob enjoyed it down here, when they made the trip and we enjoyed them being here. Hopefully we can get you Aucklanders down here too. Sorry but Taupo at xmas time is a bit pricey to get too for most down here I think.
didn't ruffle any feathers here :)
na its just all the talk about how it should be this and that and something compleatly different
but the truth of the matter is that if it wasnt 5 laps or 10 laps we just would not have had a GP this year at all
who els was ready to run it ?????
The team at the TRRS had only 2 days to fit in an awfull lot of racing (3 days last year much better)
and need I remind you that buckets where not the only bikes there
the 3 hour was much more important than us (but only just)
so we can count ourselfs lucky that we got 10 laps and not just another half hour arount MtWellington like every other year

ps we would have made more of an effort to get to bob this year but at 2 weeks before TRRS good luck :)

Sorry but Taupo at xmas time is a bit pricey to get too for most down here I think.
snap same problem dam this long thin country (we did get A bike there )

[jasonu]

What about trying to combine with the Classics mob for the next GP. Invite the 150SS as well. Say a 2 day meet at Taupo. They have less classes and generally shorter races (those old guys on old bikes don't like the marathon length races) so more chance for a decent amount of laps for a national GP title race. If you keep trying to combine with the big bikes F1 F2 etc the buckets will always be bottom of the totum pole. No disrespect intended to the organisers of the Taupo meet, I know Chris always does his best to please all.