ESE's works engine tuner

[dtenney]

Very good system Wayne!
Testing at 40° gives 1-1,5 HP more than the 53° we used at Aprilia.
That is what we saw when testing from 90° to 40° with 5° intervals.
Why more than 50° on track was preferred by Mr Witteveen I don't know.....
I think he was afraid of 'cold seizures'
He considered a piston clearance of 0,04mm as VERY important.
But when I tried 0,06mm the engine gave more power!
I did this without telling anyone, as it was seen as pure heresy at Aprilia…..
Of course, after only one training session, piston clearance was 0,10-0,12mm.
So they kept changing pistons….

Shoud the cylinder and head both be cooled to the same temp? Assuming one has access to an unlimited supply of water, would it be beneficial to have separate cooling for the cylinder and the head?

[katinas]

The customer hecitate few months, now it is the last iteration. CNC machining would start next week. Thanks for interesting patents!

Hi, from my testing with suction directly to transfers ports on conventional engine, I noticed that power drops with very wide suction duration ( too high piston skirt edge, like in your schematic ). And this effects feels without blocking crankcase space.
Maybe, would be better start with longer skirt ( say, half of exhaust side skirt length ) and then shortening step by step.

[jbiplane]

Maybe, would be better start with longer skirt ( say, half of exhaust side skirt length ) and then shortening step by step.

Thanks for advice Katinas. Easy to follow it! I making big parts for pistons need order correct material like AA2018 AA2218 AA2618
Or may be for CNC mill without forging there is better materials...

BTW want to ask comunity for advice how correctly port Yamaha BWS100 and Suzuki ad 110? May be discussed somethere...

[Pavel Myslik]

I could remove fan and cowling but cylinder head fins
Are to small for this move. Did another thing, as original bike spins around 6000 rpm, I cut every second fin on the fan. Heard from malossi scooter mechanic that every 5000 rpm fan takes around 1 hp.

Michael, on that track that very day we had some in-face excessive wind, when racing centrifugal clutch class. Than you shape yourself as a hedgehog..
Wind issues are more or less clear, but some theoretical/ideal gearing for given track I was wondering somebody has.

I am always setting my gearing so the engine will be overreved in the fastest point of the track or a couple meters before. This is usually at the end of the longest straight. I am racing little 50cc bike with 3 speed gearbox and using the 2nd gear for most of the corners so then I check that in the slowest corner the rpm don't drop from the "powerband" and acceleration from the corner suffers. Then it is simply a compromise.
I have found out that changing the sprocket on the engine by 1 tooth makes too much of a difference so I have a set of rear wheel sprockets which differs only by 1 tooth. When I have final ratio for the qualification I then use 1 tooth bigger = "slower" sprocket for the race because you might be forced to ride at defensive line or somebody will be blocking you and your corner speed will drop and so the rpm. Engine can handle the overrev if you will have clear track ahead.
Setting the ratio litlle longer and using the tow of a faster rider might be a good strategy too but I think this depends on the speed you are racing at. In my case top speed is little over 80 kph.

[Frits Overmars]

the DEA KZ125 from our friend Andrea degli Esposti. He's also the only one until now with a balance shaft in that type of engine.

Hi Frits, interesting whether the whole cooling liquid enters the cylinder from 'under exhaust' side on this engine.

Yes, all coolant enters the DEA cylinder under the exhaust; there is no other water connection anywhere on the cylinder.

Looks, that Honda used small cooling hole through narrow EX divider on late Aoyama cylinder and maybe last NSR 500.

Yes, that is correct Katinas. I have some better images at home, but I'm not at home. Maybe just as well, because I'm not supposed to have those images .

Setting the ratio little longer and using the tow of a faster rider might be a good strategy too...

That reminds me of a similar remark by a Garelli rider: "Maybe we should gear it one tooth faster; that could be helpful in slipstreaming".
To which Jan Thiel simply replied: "Who do you want to slipstream?" (the Garellis were unbeatable for six years in a row).

[Michael Moore]

To which Jan Thiel simply replied: "Who do you want to slipstream?" (the Garellis were unbeatable for six years in a row).

For many of us the answer to that would be "all those faster people who keep passing me throughout the race".

The needs of a top rider on a top bike may not be quite the same as a mid-pack rider on a mid-pack bike, but I can't say for sure since I've never been a top rider on a top bike.



cheers,
Michael

[wobbly]

Coolant temp is a complex combination of factors and depends alot on how much good technology is being used.
Way back I used a twin route water system on Champ winning Jetski engines.
The block was kept at 40* and the head was kept at 80* , this gave the best power but was very "on the edge " all the time re deto.
But this was before I understood the relative importance of what should be cold , what should be hot , and why.
Running the head hot , was conforming to the idea that the reduced temp delta would keep more energy within the combustion process , thus expanding the gas more and pushing down harder on the piston.
But Jan showed us the way forward , by allowing water close to the plug threads , keeping the sparkplug body cool , and thus reducing deto sensitivity.
The next step was doing the same thing with the squishband area - over cooling this area keeps the boundary layer surrounding the end gases cooler , again keeping deto at bay.
TM's head surrounds the chamber itself with a large mass of " insulator " material as part of the cover.
They even have an air gap , to keep the chamber area even hotter.
It is possible to combine both philosophy's , that is keeping the chamber surface itself hotter , but over cooling the plug threads and the squish area to retard deto sensitivity.
But that is a secret im keeping for now.
I have a pic of an interim solution , i will find it and post.

[wobbly]

Here is pic of partial solution for the TM cylinder.
Cold water is squirted back over the transfer tops, with only small holes under the Exhaust duct cooling that with flow direct from the case below.

[husaberg]

Yes, all coolant enters the DEA cylinder under the exhaust; there is no other water connection anywhere on the cylinder.


Yes, that is correct Katinas. I have some better images at home, but I'm not at home. Maybe just as well, because I'm not supposed to have those images .

That reminds me of a similar remark by a Garelli rider: "Maybe we should gear it one tooth faster; that could be helpful in slipstreaming".
To which Jan Thiel simply replied: "Who do you want to slipstream?" (the Garellis were unbeatable for six years in a row).

I think he got that from his Aprilia inspired version

You mention the Honda from memory either the NSR250 road bike or the NSR125 had it flowing below the EX port but the racers didn't

edit i think its both but the water feeds into the crankcase of the 250 and the side of the cylinder on the 125 but that could be fixed

Kennys Roberts designers got it right.

[wobbly]

No, King Kennys boys ( Sinclair et al ) simply copied what Yamaha were doing at the time in GP - even the transfer ducts were carbon copies.
From my testing the best solution is cold water in over the boost port, flowing forward over the transfer tops.
Then the Ex duct cooled from below with small holes , the two flows meeting above the Exhaust duct and into the head.
Old Honda NF4 cylinders had the rear inlet , but no case cooling , so didnt have a separate duct flow.

[husaberg]

No, King Kennys boys ( Sinclair et al ) simply copied what Yamaha were doing at the time in GP - even the transfer ducts were carbon copies.
From my testing the best solution is cold water in over the boost port, flowing forward over the transfer tops.
Then the Ex duct cooled from below with small holes , the two flows meeting above the Exhaust duct and into the head.
Old Honda NF4 cylinders had the rear inlet , but no case cooling , so didnt have a separate duct flow.

I think the NSR250 has the holes at the rear but the NSR125 has none.

The 250 ones have the holes though i think are blind recesses to the crankcase, but without access to a few i am only guessing and relying on memory


the early RS's i think just followed the old CR design like this one they caried over from 84-87 on the cylinder reed and 88 on the case reed which is what i think the NF4 is

Too be honest with you they likely did it this way as a production consideration as it saved a few mm of Rubber pipe.
It might also be the same reason the NSR125 goes to the front as that's where the water pump is mounted on them.


The later RS125 NX4 though has the plug in the front i guess left over from Machining or might hint at road bike or multi use origins of the moulds.
it could be a core print but i doubt it.


Kenny crew basically put Yamaha pipes and port spec into the RGV for JNR it had no more hp which upset Suzuki no end as they couldn't see the point until they showed them it lapped much much faster. that story came from Willing.

I hate rear axle driven water pumps. While you are on the starting grid, revving the engine, waiting for the flag to drop, there is no water circulation at all!
Kart engine manufacturers know that too, of course. They supply engines for amateur drivers with an engine-driven pump. So it is al the more surprising that their six-speed competition engines have no pump - with one exception: the DEA KZ125 from our friend Andrea degli Esposti. He's also the only one until now with a balance shaft in that type of engine.
Attachment 340579 Attachment 340580


.

Oddly Vortex do them for the non gearbox karts but not the gearbox class i even thought one of their old ones had them at one stage.
http://www.vortex-engines.com/download/fiche_ROK_GP.pdf

As does the Rotax max

[F5 Dave]

Just been out road testing my 500 in scorching wellington weather (anything over 20 degrees).

You don't know you are born. I have very compromised radiator area.

[F5 Dave]

For giggles;


I had huge bad surging on the 500 test ride last week.

So this weekend id try figure out the 500
Plugged it in to the laptop and revved it. Quickshifter goes Yes No Yes No. Ahhh.

[Frits Overmars]

... either the NSR250 road bike or the NSR125 had it flowing below the EX port but the racers didn't.......The later RS125 NX4 though has the plug in the front i guess left over from Machining or might hint at road bike or multi use origins of the moulds.

The cylinder on the left is not from an RS125 NX4 but from an NF4 that was still strongly based on the CR125 MX-engine, with a hose feed from the pump to the side of the cylinder.
Its successor, the NX4 cylinder, got its water from below, under the exhaust, through internal channels cast in the crankcases, as did all subsequent Honda racers.

I'm still trying to get used to you guys talking about Honda NSR street models. I don't think we ever got any NSR street bikes over here. To me, NSR is the designation for a 250cc or 500cc Honda works racer (there never was an NSR125, only A-kits for a few selected riders and B-kits for riders with more money than talent).
The Honda production racers were called RS.
The cooling channel through the exhaust bridge was exclusively reserved for the late-model NSR cylinders.

[katinas]

The cylinder on the left is not from an RS125 NX4 but from an early-model NF4 that was still strongly based on the CR125 MX-engine, with a hose feed from the pump to the side of the cylinder.

Interesting, on CR 125 mx cylinders, Honda used coolant intake over C transfer over very long period ( and first RS125/250 ND roadracers ), from first 1980 water cooled type to 2004.
On "Final Cut" cylinders from 2005 to 2007 they used under the exhaust flow from crankcase.