ESE's works engine tuner

[wobbly]

The basic rule is that you cant have a radiator thats too big.
But running Methanol will basically turn an air cooled motor into an efficient an engine, as a normal watercooled.
This basically means that the aircooled wont go off due to thermal overload like it will do naturally on petrol.
But running a watercooled on meth means it will be hard initially to get any temp into the water, so my advise is to use a small rad but plumb it with a bypass
thermostat.
This will naturally reduce the water cooling effect early in the passes, but when the temp starts to rise it will then use the water to do its job.

[bjorn.clauw.1]

That sounds a lot like a water brake. My first dyno was a Heenan & Froude water brake. In its original form it was totally unsuitable for two-stroke development.
The torque curve of the engines was much steeper than the brake's torque curve so either the engine torque was lower than the brake's and the engine would stall,
or the engine torque was higher than the brake's and the revs would shoot right up to the engine's maximum rpm.
I more or less solved that by doubling the brake's revs and tripling the water pressure in the system. But the high pressure led to the next problem: the hoses that connected the brake body to the feed pump, tried to straighten themselves, exerting an unknown amount of extra torque on the brake body and hence on the scales (no load cells in those days).

Another consideration: building an inertia dyno is always simpler and cheaper than building a braked dyno and an inertia dyno is much more useful for competition engine development because you can choose the gearing such that the rate of engine acceleration on the dyno equals that of the same engine on the race track.
This way the all-important temperature rise of the exhaust pipe will match the real circumstances; that is impossible to achieve with a brake.
And before someone tells you it can be done with a step-test: no it can't. A step-test requires a brake with a sophisticated controller and all it can do is register a certain rpm and a certain torque value, and then let the engine accelerate to the next rpm-step in a pre-set amount of time. If the engine happens to pass through a torque dip, the controller will ease off some braking in order to get to that next rpm within the pre-set time.
Reality is not so kind: if an engine on the track goes through a torque dip, the rate of acceleration will drop, it will take more time to get through the dip, and sometimes carburation behaves so bad that the engine won't climb out of the dip at all. An inertia dyno will relentlessly reveal this; a brake won't.

Tanks for the input Frits and Wobbly. Will put my hydraulic brake + load cell in storage. There has gone some work in modifying and machining the hydraulic pump but this does not compare to the amount of work that still had to be done on electronics. So thank you both for the extra 2 months I saved by not pursuing this.

I have a burnt out electric 3 phase motor 22kw 900rpm. Digging through some datasheets the inertia af the rotor is 11.4kg/m2. In the ballpark of others systems I found. Will give this a try instead.

[bjorn.clauw.1]

Not really sure where to start. Wob and Frits have seen most of it, and it seems the TSW thread has been viewed.

Hi Makr. I was wondering if you still use a slipfit to install your liner? You o ring the 'levels' of your cilinder so water, ports and crankcase are seperated but is there a barrier between the transfer ports and the exhaust ports? (In other words, could the exhaust blow (/creep) around the liner to where the transfers enter the outside of the liner?

[Frits Overmars]

this is a methanol drag racing bike remember. to reduce weight ive seen some guys use just a very small rectangle aluminum tank, so water can still be pumped through the cylinders and head but there is no fins or tubes on the tank, basically just a rectangle alloy box.

If you don't cool the water it's a different situation. The more water you carry, the slower it will heat up and the longer it will take before your engine power collapses.

do you have any rule of thumb for radiator size ?

Yes: bigger!

I have a burnt out electric 3 phase motor 22kw 900rpm. Digging through some datasheets the inertia af the rotor is 11.4kg/m2. In the ballpark of others systems I found. Will give this a try instead.

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: FLYWHEEL.zip It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

[bjorn.clauw.1]

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

You may want to play a little with this program: FLYWHEEL.zip It has attained the age of majority so I'm not sure if it will run on your computer. Just let me know.

Forgot to mention the overspeed (safe max speed) is 2400 rpm. Will do some numbercrunching this evening. Let you know what I come up with.
(Offtopic: had a rotor that exploded once, hydro electric setup with screw of archimedes. Fault in electric braking circuit and motor 120kw revved to about 8000rpm.
It was the gearbox thar failed first (20:1) but motor followed shortly after. They had quitte a bit of work repairing the walls/ceiling afterwards.

Makes you wonder what the flywheel would take with him when your engine seizes during the max rev part of the run on. (One way clutch would not hurt here)

[adegnes]

That must be a beast of a motor. 11,4 kgm² (no slash between the kg and the m²) is a lot! It equals a massive steel flywheel with 440 mm diameter and 400 mm width. It would certainly be enough for a decent inertia dyno, but I'm a bit worried about the revs. 900 rpm is not a lot and that rotor won't be made of steel, so in order to prevent it from exploding centrifugally you may have to use a fairly big reduction from crankshaft rpm to rotor rpm. And alas, that increases the inertia requirement.

The rotor in my dyno is a feeble 2.17kgm2, 317mm diameter, also from an old ac motor (ABB). Seems to work fine up to at least 60whp, it's spinning uncomfortably fast when selecting a high enough gearing to get good runs with that kind of power though... I've touched 4000rpm! Nothing I would encourage anyone to duplicate.

[Frits Overmars]

Makes you wonder what the flywheel would take with him when your engine seizes during the max rev part of the run on. (One way clutch would not hurt here)

If you're lucky the chain will snap without hitting you on the back; a bit less lucky and the engine will be ground to smithereens. If the chain and the engine can withstand all the violence, the flywheel may turn the whole test bench over and over. You don't want to be in the same time zone when that happens.

Warning! this may also happen when you just brake too hard after a successfull dyno run. Therefore it's wise to put a spring and an end stop under the dyno brake pedal. Another nice solution is to operate the brake caliper with compressed air instead of hydraulic pressure. The air pressure can than be regulated thus that there is no risk of overbraking.

[wobbly]

In my opinion you must run an intermediate shaft ( like a kart axle behind the engine ) that has an overun clutch
that then drives to the flywheel.
You can make a very easy/small/cheap overun clutch from the ones they use on a tractor PTO shaft, for when driving mowers etc.
If they dont use one the mower inertia is so great, it keeps driving the tractor forward with no engine power.
Having said that I have never seized an engine on my dynos in 30 years.
If you watch the power curve,or egt, or deto level on screen as the run up progresses, you can see if something is seriously wrong.
But just seems comfortable to me that when you are doing a run up, you can shut down the engine instantly at any time,and then brake the flywheel
independently ( slowly or fast, it makes no odds ).
I have several different sprockets permanently fixed onto the axle shaft that can be moved into line for any engine.
An 80 tooth 100cc kart one and 428/520/525 ones for 125 and 250/400 kart/bike engines.

[AndreasL]

Hmm, a lot of people "active" in this thread right now.

Might it be the news that the Ryger engine has passed homologation that drives people here...

Congratulations Harry!

[wobbly]

The Ryger may have been passed but the homologation papers are still not posted on the CIK site.

[Makr]

those look like mikunis ? im looking for some carbs around 40mm that will still function halfway normal while slanted forward at a fairly steep angle. i was thinking of lectrons unless theres something better thats readily available . do you have any advice on this ?

44 mm round slide Mikunis. These would be 15 degrees from parallel. They work fine. I have very little experience performance tuning anything else. I seem to be able to tune the round slide so as adventurous as I am in some areas there are some I try to keep consistent.

That is an interesting setup how you cool the case. I'm working on the same idea on my RZ with taking a smaller amount of water coming from the pump leading through the case and than back to the radiator... Have you already run the engine with that case cooling, did you found significant gains?
Juergen

I have no idea if there are any gains because this is a completely new engine. I run all of the coolant through the base and then up through the port in the center that goes up through the intake manifold and into the cylinder. I will plumb it different next time to just go straight into the cylinder. Frits pointed out it was heating up the intake after I had it all done. Doh!

Hi Makr. I was wondering if you still use a slipfit to install your liner? You o ring the 'levels' of your cilinder so water, ports and crankcase are seperated but is there a barrier between the transfer ports and the exhaust ports? (In other words, could the exhaust blow (/creep) around the liner to where the transfers enter the outside of the liner?

Yes it is a snug slip fit. Yes it absolutely can leak and probably does. I see it as a small compromise.




I welded a plate onto the top of the case to accept the much larger transfers. It pulled itself apart several times before I had to fix it for good.

Plus it was a leaky mess anyway.


I cut off the front of another case and machined a piece to replace it.









This is a picture of the setup part but you get the idea.




I haven't pulled it apart since.

[wobbly]

If you want to tip carbs up steep then Lectrons are the go.
They flow way more air than any round slide, are easy to tune and are period legal for Pre 82 Post Classic if thats important, and were used by King Kenny
on TZ750/500 in the early 70s..
As long as you keep the powerjets reasonably small ( 60 ) the fuel curve is much better than any normal carb where the fuel circuits and air correction
overlap, that cause dips and bumps in the A/F readings.

[husaberg]

In my opinion you must run an intermediate shaft ( like a kart axle behind the engine ) that has an overun clutch
that then drives to the flywheel.
You can make a very easy/small/cheap overun clutch from the ones they use on a tractor PTO shaft, for when driving mowers etc.
If they dont use one the mower inertia is so great, it keeps driving the tractor forward with no engine power.
.

Pretty much any tractor made after 1960 now is non live drive, but anyone who has driven a mower on a fergie will know the but clenching that occurs when the mower starts and continues to drive the tractor even though the clutch is pressed in.
Many a fence has been driven through when this occurs.
I am suprised how easy it is to still get the over running clutch it might pay to buy a few, because they will stop making them someday.

[Flettner]

I cut off the front of another case and machined a piece to replace it.

Didn't you say you had to use the original cases? Is there some percetage rule?

[adegnes]

Didn't you say you had to use the original cases? Is there some percetage rule?

Small repairs are allowed