ESE's works engine tuner

[SwePatrick]

Yes,, that may be why he keeps engine up top as a bad habit.

Very often this happens.

[Vannik]

Inertia dyno testing, motor shows horsepower gains on the bottom end lower mid range.

On the track the dyno gains aren't felt by the rider.

Why is this?

Maybe:

1. Pipe and engine was not at the correct temperature when dyno run was started; or
2. Acceleration rate on dyno is too fast showing the effect of a longer pipe because the pipe temperature does not heat up fast enough: or
3. ???

[jonny quest]

Maybe:

1. Pipe and engine was not at the correct temperature when dyno run was started; or
2. Acceleration rate on dyno is too fast showing the effect of a longer pipe because the pipe temperature does not heat up fast enough: or
3. ???

Very valid answers/questions. I didn't mention this in my original question...which now will change answers dramatically.

This particular question of mine is on a 4 stroke, with pretty consistent testing on my part.

I have an idea as to why this is the case to my original question, but I didn't want to skew the replies as of yet

[Frits Overmars]

Maybe:
1. Pipe and engine was not at the correct temperature when dyno run was started; or
2. Acceleration rate on dyno is too fast showing the effect of a longer pipe because the pipe temperature does not heat up fast enough: or
3. ???

#2 is a common cause. On low-inertia dynos it may be necessary to make a dyno run in top gear if you want to mimic track behaviour in third or fourth gear.

Rider complains it doesn't have enough bottom end power

Wimps! What those riders need is a ride on a twelve-speed Kreider or a fourteen-speed Suzuki.
OK, we've outgrown the times of 7-rpm power bands, but that's no excuse not to use your gearbox.
What has struck me in the course of the last half century: the best riders complain the least
(could of course also be because they have the best engineers on their side, right Jan? )

[jonny quest]

I surely didn't put enough information in my original, nor second post regarding my question.

My power spread question regards an MX bike.

Riders want Enduro low end, Road Race top end. It truly isn't feasible to shift when you need too, or are supposed to on a MX track. Clutches are abused in almost every corner keeping revs up. If you happen to run out of gear on the lip of a jump... it's not pretty.

[F5 Dave]

Maybe:

1. Pipe and engine was not at the correct temperature when dyno run was started; or
2. Acceleration rate on dyno is too fast showing the effect of a longer pipe because the pipe temperature does not heat up fast enough: or
3. ???

An all-gears run was always important on inertia dyno testing.

[lodgernz]

50 CC AM6 2 stroke with turbo which set the land speed record of 233 KPH /144 MPH .

[Peljhan]

Didn't Frits once enlighten us, that actual record engine was not this one, but "standard" with methanol and nitro?
I am wondering, what happened with Dutch attempt Green Tulip?

http://www.groene-tulp.nl/cms/
https://www.flickr.com/photos/teamhe...57641769130104

Random question.. What would be good material to make cylinder studs? Which heat treatment? I know Frits would say Dilavar, but I think that is out of reach for me.

[Flettner]

Didn't Frits once enlighten us, that actual record engine was not this one, but "standard" with methanol and nitro?
I am wondering, what happened with Dutch attempt Green Tulip?

http://www.groene-tulp.nl/cms/
https://www.flickr.com/photos/teamhe...57641769130104

Random question.. What would be good material to make cylinder studs? Which heat treatment? I know Frits would say Dilavar, but I think that is out of reach for me.

I would just use 4140 or 4340.

[Frits Overmars]

Didn't Frits once enlighten us, that actual record engine was not this one, but "standard" with methanol and nitro?
I am wondering, what happened with Dutch attempt Green Tulip?
http://www.groene-tulp.nl/cms/
https://www.flickr.com/photos/teamhe...57641769130104.

Some myths are very persistent. The many pictures of the Buddfab turbo-Minarelli-50 are well known; pictures of the engine actually used in the Buddfab record machine are as rare as hen's teeth but they do show that the turbo was left at home in favor of a nitrous oxide (not nitromethane) injection system, below.


What happened to the Green Tulip? It's Bonneville participation got drowned in rain and I haven't heard anything about it since. I would have visited its rider, my friend Aalt Toersen (shown below in his office) if it hadn't been for this damned Covid that makes traveling almost impossible.

[KKT]

Eric Noyes writes that the 2008 144mph record run was done with the turbocharger fitted:

http://www.landracing.com/forum/index.php?topic=18228.0 (there are two pages to read)

[TZ350]

.
Posted for those like my self who are following 2Stroke Stuffing's adventures with his supercharged engine. https://youtu.be/47sf_5IQeMI



I have been pretty quiet my self lately re-building a 250cc pre 72 Post Classic racer with its rotary valve Kawasaki engine. Flettner has given me a lot of help with this. Also someone else, the DoldGuy donated the carburetor and also helped me a lot with getting the DynoJet dyno working again.

There is nothing to special about this engine. It follows the current conventional single exhaust, 5 transfer two stroke tuning ideas. And the timing and pipe design was developed using EngMod2T software. It will run on a petrol/acetone/methanol mix. Methanol for cooling. Acetone to stabalise the Methanol against pre ignition. Petrol to adjust the engine's running temperature.

I am working on finalising the pipe design now and expect, because the engine will be Methanol cooled the pipe will be noticable shorter than a straight petrol pipe because the average pipe temperature will be much lower. I am not entirly sure about this so if anyone has experiance with this any tips would be welcome.



This is not my bike but gives a bit of an idea of what they looked like back in the 70's.

[Grumph]

I can observe that a 250 gearbox kart I helped with - on a Meth/Tolulene/acetone mix - won a few Nationals using the stock MX pipe dimensions.
Never bothered to develop a pipe specifically for that fuel.

From my experience with Methanol in 4T's, the exhaust temps are not that much cooler.

[teriks]

.
I am working on finalising the pipe design now and expect, because the engine will be Methanol cooled the pipe will be noticable shorter than a straight petrol pipe because the average pipe temperature will be much lower. I am not entirly sure about this so if anyone has experiance with this any tips would be welcome.

Not that I would draw much of a conclusion from it for your engine, but I see pipe temperatures not too far from Wobbly's gasoline numbers on my tiny stuff running 80% Methanol, 20% Castor oil (as per the class rules).

[SwePatrick]

My kawasaki methanol 212cc engine always performed best when around 430c exhaust temp, probe was three pistondiams down in header.