ESE's works engine tuner

[kel]

My air cooled 125 finally fell victim to over heating last weekend
The aim now is to reduce as much heat as possible from getting to the motor and to increase the motors ability to shed heat.
The cylinder and head have been sand blasted and now need coating. Has anyone tried Boron Nitride? Is there a source in NZ that's cheaper than the $235 a tin stuff from evolution motorsports
Stopping the heat from the exhaust soaking into the motor would seem to make sense. Exhaust wrap is cheap, is there a reason no one seems to use it (corrosion issues aside)? What about ceramic coating of the exhaust has anyone tried this on 2 strokes? Is the extra cost over wrap warranted?
Cheers

[Yow Ling]

My air cooled 125 finally fell victim to over heating last weekend
The aim now is to reduce as much heat as possible from getting to the motor and to increase the motors ability to shed heat.
The cylinder and head have been sand blasted and now need coating. Has anyone tried Boron Nitride? Is there a source in NZ that's cheaper than the $235 a tin stuff from evolution motorsports
Stopping the heat from the exhaust soaking into the motor would seem to make sense. Exhaust wrap is cheap, is there a reason no one seems to use it (corrosion issues aside)? What about ceramic coating of the exhaust has anyone tried this on 2 strokes? Is the extra cost over wrap warranted?
Cheers

Why not put a 100cc water cooled cylinder on it, like Frits suggests

[wobbly]

Coating the inside of the exhaust port with ceramic to reduce head soak into the cylinder material worked a treat on the Britten V1000, to stop boiling on the start grid.
As would have doing the same to the pipes interior, that would have increased the scavenging wave energy.
But coating the duct and or then wrapping/coating the header is way bad in a 2T.
The overscavenged air/fuel mix sitting near the piston that gets shoved back into the cylinder by the return wave, becomes over heated by the hotter surrounding surfaces
and this then heats up the combustion mix - where it instantly creates deto.
Been there, done that, no free lunch.

[ken seeber]

I worked for quite some time at a company called Orbital Engine Company in Perth WA. In the early days of the development of a 3 cyl 1200 cc DI two stroke engine, we decided that the engine, which for simplicity reasons had to incorporate exh valves operating on a single axis parallel to the crank, therefore necessarily the cylinder scavenge axis had to be normal to engine longitudunal axis. This is unlike the skewed scavenge axis which is quite common on multicylinder outboard engines. The skewing allowed the transfer passages to "nest" in to each other allowing the cylinder spacing to be minimised.

In our case, we developed a compact transfer port layout that had 100 mm bore centres with an 84 bore. To compare its performance with other 400 cc engines (of the day 100 years ago) we set up a Suzuki PE400 engine in one of our test cells. We made some trial cylinders with our scavenging system (the X porting system we called it), these being able to fit on to the PE400 lower half and this allowed us to directly compare the watercooled X system with the air cooled PE400 cylinder and head.

Getting back to the story, it became clear, as expected, that the air cooled engine very quickly lost its performance as it warmed up. This fact is also well known, particularly in go kart engine circles where air cooling it still used for certain classes (eg Yamaha KT100J and KT100S). Compared to a bike with a gearbox and a half decent exhaust, these have a low specific output, say 18 hp for 100 cc.

So, how to combat this? Firstly we blasted it with strong air flows and this helped, but the best was was to put some micro irrigation jets in front of the barrel and head. The latent heat of vaporization of the water did the rest, quickly bringing the performance up to that of a cold engine.

Getting back to the issue of Kel's cooked 125 air cooled engine, I can offer the following uptions:
1. Carry a small tank of water on the bike with this spraying or dribbling over the motor
2. If you perspire enough, have a catch arrangement inside your race suit and run this via a hose to the engine
3. For karting, I have often wondered if a small "leak" incorporated into the pressure side of the Walbro pumper carb (which is usually in front of the engine on piston ported inlet engines) might be beneficial to allow fuel to flow/trickle over the engine and evaporate. Some tech dudes might see some safety issues with this one however.
4. Back to the racesuit. You could also drink lots of water before your race and, in conjunction with a good controllable diuretic and a hose connected to your good self, perhaps cool the engine that way. Might smell a tad though.


Thanks Ken Strike Products

[koba]

Getting back to the issue of Kel's cooked 125 air cooled engine, I can offer the following uptions:
1. Carry a small tank of water on the bike with this spraying or dribbling over the motor
2. If you perspire enough, have a catch arrangement inside your race suit and run this via a hose to the engine
3. For karting, I have often wondered if a small "leak" incorporated into the pressure side of the Walbro pumper carb (which is usually in front of the engine on piston ported inlet engines) might be beneficial to allow fuel to flow/trickle over the engine and evaporate. Some tech dudes might see some safety issues with this one however.
4. Back to the racesuit. You could also drink lots of water before your race and, in conjunction with a good controllable diuretic and a hose connected to your good self, perhaps cool the engine that way. Might smell a tad though.

Haha, interesting post, welcome along.

I'm managing to keep up reasonably well on an Aircooled engine with 18hp.
Perhaps that is because it gets pissed all over when it comes to dyno numbers?!

[pete376403]

(snip interestingstuff) Getting back to the issue of Kel's cooked 125 air cooled engine, I can offer the following uptions:
1. Carry a small tank of water on the bike with this spraying or dribbling over the motor
2. If you perspire enough, have a catch arrangement inside your race suit and run this via a hose to the engine
3. For karting, I have often wondered if a small "leak" incorporated into the pressure side of the Walbro pumper carb (which is usually in front of the engine on piston ported inlet engines) might be beneficial to allow fuel to flow/trickle over the engine and evaporate. Some tech dudes might see some safety issues with this one however.
4. Back to the racesuit. You could also drink lots of water before your race and, in conjunction with a good controllable diuretic and a hose connected to your good self, perhaps cool the engine that way. Might smell a tad though.


Thanks Ken Strike Products

Would this not be considered watercooling and so be illegal for that capacity? How is water cooling defined in the rules?

[koba]

Would this not be considered watercooling and so be illegal for that capacity? How is water cooling defined in the rules?

Number one would certainly be out, but I think he may have been taking the piss...

Rules:

Solo motorcycles shall have two engine capacity classes:

F4
2 stroke 55-100cc
2 stroke 55-125cc air cooled
4 stroke 55-150cc

F5
2 stroke 0-50cc
4 stroke 0-100cc air cooled



The maximum capacity for rebored engines shall be:

F4
2 stroke 55-100cc - 104cc
2 stroke 55-125cc air cooled - 130.5cc
4 stroke 55-150cc – 158.09cc

F5
2 stroke 0-50cc - 53cc
4 stroke 0-100cc - 104cc

[koba]

What if I have a 54cc Two-stroke?

[speedpro]

I worked for quite some time at a company called Orbital Engine Company in Perth WA.

I applied for a job there in '87-'88. Didn't get it but had a good look around the factory. Very very interesting. The original Orbital engine was sitting on top of some lockers or something like that, tossed in a corner sort of thing.

[pete376403]

The water spray idea is good, the other three are obviously facetious.

Tyrell used water spray cooled brakes in F1 years ago (although the real reason was weight. Cars were allowed to be refilled with fluids prior to post-race weighing. Dumping a lot of water during the race gave them a weight advantage)

But - what defines water cooling? If water spray is illegal then can an air-cooled bike race in the rain?

[koba]

The water spray idea is good, the other three are obviously facetious.

Tyrell used water spray cooled brakes in F1 years ago (although the real reason was weight. Cars were allowed to be refilled with fluids prior to post-race weighing. Dumping a lot of water during the race gave them a weight advantage)

But - what defines water cooling? If water spray is illegal then can an air-cooled bike race in the rain?

The rules say "air cooled" so it has to be that, I'd interpret any intentional effort to cool with anything other than air as cheating.
Internal Fuel cooling effect has to be excepted on common sense grounds.

Rain is just a 'bonus' lots of power when you least need it!

[F5 Dave]

Hey Ken, good to have you on board. Any other stories of the like would be welcome.

[F5 Dave]

Coating the inside of the exhaust port with ceramic to reduce head soak into the cylinder material worked a treat on the Britten V1000, to stop boiling on the start grid.
As would have doing the same to the pipes interior, that would have increased the scavenging wave energy.
But coating the duct and or then wrapping/coating the header is way bad in a 2T.
The overscavenged air/fuel mix sitting near the piston that gets shoved back into the cylinder by the return wave, becomes over heated by the hotter surrounding surfaces
and this then heats up the combustion mix - where it instantly creates deto.
Been there, done that, no free lunch.

Sadly so have I and I didn't learn the first time. Actually the wrap didn't make much of a diff on my 50 bar 200rpm, and when I HPC coated the pipe it was about the same.

on my RZ/CPI496 (I was keen on a nice pipe finish for a road bike, worked ok on my 750SP) - it raised the revs about 900 so I got them stripped which brought it back down to calculated. Big vs small cylinders behave differently it seems. Never again.

[husaberg]

Hey Ken, good to have you on board. Any other stories of the like would be welcome.

And some 50mm ish pistons with low gudgeon heights wouldn't hurt Mr Strike.......
What would be the minimum order we would need to come up with?

[F5 Dave]

Oh! That's who it is. 51mm KT100S would be peachy. Maybe with a 15 or 16mm pin while I'm dreaming.