ESE's works engine tuner

[wobbly]

Re Vegas - here is some cut and paste from a report on the result I did.


We were top 3 fastest thru all the sessions, but the engine guy for the team we race for didnt tighten the new sparkplug prior to qualifying.
Of course it wound almost all the way out and our pace dropped by 3/10s, enough only for 6th.
In the first heat we were up to 4th pulling in the top 3 easily within 2 laps when the 3rd place missed a gear mid bend under big pressure and spun
right in our karts path - DNF.
Means we went into the final from 12 on the grid, got to 5th place and ran out of time - track position is everything when only a few 1/10ths cover the top 5 pace.

I took the deto gauge off the dyno and ran the 0-5V output into the Pi datalogger, and was very surprised to find that after leaning down enough to get hits, that the only place
it deto'ed was the acceleration phase after 2nd, 3rd, 4th gearchanges, when dropping back to near peak power after overeving to 12200.
The 5th to 6th change stayed above peak power and didnt deto at all down into the shute.
So I fitted the new header with the deto button installed and the gearchange deto dissapeared completely.
That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress.
This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate doesnt allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off
the ski jump at the closing Ex port.
This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.
We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.

[steamroller]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

[diesel pig]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

Wiseco say you can use there standard 2-stroke ring in any bore excrept chrome bores.

[husaberg]

Can anybody tell me is there a difference between a piston ring used on cast iron to a piston ring used on nickesell. Or are they both made of the same material? Thanks

Hard and soft are needed to get along. Otherwise they wear each other out in a short space of time
If the bore is hard then the ring surface needs to be soft and visa versa. That's my understanding of it.

[mr bucketracer]

Hard and soft are needed to get along. Otherwise they wear each other out in a short space of time
If the bore is hard then the ring surface needs to be soft and visa versa. That's my understanding of it.

+1 but do know cast iron on cast iron is fine to , but race engines of today? , i know my ktm125 duke had some hard cast iron sleve ?or something close.

[F5 Dave]

Well certainly soft on soft will wear like two bits of cheese rubbed together.

[husaberg]

+1 but do know cast iron on cast iron is fine to , but race engines of today? , i know my ktm125 duke had some hard cast iron sleve ?or something close.

unplated sleeves are generally cast iron. Akunar sell blanks at very reasonable prices. The rings from memory are generally ductile iron or steel. Most modern rings have a coating of some sort. The old stuff was a brittle cast iron for old low powered stuff

[ken seeber]

Virtually every performance ring you see is chrome plated on its rubbing outer surface. Chrome doesn't like being rubbed up with chrome whereas cast iron doesn't mind a rub with cast iron. So, chrome rings are ok against cast iron and Nikasil: cast iron rings are ok against cast iron or chrome bores (typically string trimmers, small Comer kart engines etc). Usually Dykes rings are cast iron so they can be used in cast iron linered kart engines ....dunno where else you might see them these days.

[Lightbulb]

Re Vegas - here is some cut and paste from a report on the result I did.

So I fitted the new header with the deto button installed and the gearchange deto dissapeared completely.
That allowed another 3 jets leaner before it started again.

Get this - the egt at that level was 1390* F with no sign of deto or piston heat stress.
This is due to the fuel octane being too high for the com, and the fact that the SKUSA advance restrictor plate doesnt allow us to add enough static timing to create more power - only pipe heat.

I think I have worked the logic of the deto button - it creates turbulence in the top 1/2 of the duct, allowing the smooth flow along the floor to return easily up the duct and be aimed upward off
the ski jump at the closing Ex port.
This came from finding that having the floor of the oval/round transition spigot co linear with the duct floor, and all of the transition angle in the roof made best power.

So here is the jetting chart prior to adding the new header, based on safe deto level, not egt as I would usually use.
The Lambda ( in the muffler ) showed the kart was fastest at 13.8 :1 ( and it hardly varied anywhere within the usable power band ), going leaner or richer was slower on track.
We tested both VP C12 ( 108 octane ) and VP98, the 98 being both faster and easier to tune to the edge.

Hey Wayne, Do you think this deto thing could work in the 2.5 cc pipe engine ? How do you attache the mushroom to the inside of the header ?
Can you send me some specs to scale one to try please ?
Thanks Neil
PS, it is only cheating if the rules say you can't do something, but make a work around that if caught is against the rules. When the rules do not specify something, then it must be legal.

[mr bucketracer]

Virtually every performance ring you see is chrome plated on its rubbing outer surface. Chrome doesn't like being rubbed up with chrome whereas cast iron doesn't mind a rub with cast iron. So, chrome rings are ok against cast iron and Nikasil: cast iron rings are ok against cast iron or chrome bores (typically string trimmers, small Comer kart engines etc). Usually Dykes rings are cast iron so they can be used in cast iron linered kart engines ....dunno where else you might see them these days.

so a honda rs125 piston ring is fine with a cast iron sleave as you say ? ...thanks

[F5 Dave]

I can tell you a Kawasaki ring for electrofusion bore will wear a cast bore to the next size in one meeting.

[wobbly]

The original deto mushrooms were installed about 50mm down into the pipe header, but in the SKUSA Honda we cant touch the spec pipe.
Whereas the spigot is open except for the overall length.
I was a bit surprised that moving the thing closer to the piston still worked so well, no power loss on the dyno, but I didnt have lean enough jets
during testing to get deto happening.

As the area where the mushroom was installed was less than out in the header I simply scaled it down.
But as I said I was surprised to find that the piston killing deto only occurred after dropping back to around peak power from gearchanges, and that
the change into 6th ( with minimal rev drop ) didnt deto at all in the overev.

It would work just as well in model engines if you are getting deto that eats away the piston in the squishband, but as I see it you are running for
the longest period way into overev, not sitting on peak Hp during flight - so it may not have any useful effect.

The end of the mushroom is step threaded, and this screws into a hole with a chamfer on the outer surface where the pipe sleeve seals.
After installing it I sat it in the press and using a 90* pointed mandrel on centre, expanded the flat threaded end into the spigot chamfer.
I would have preferred to have a small boss within the spigot, but this involved way too much extra CNC time with difficult programming and special tooling.

[Lightbulb]

On an 11.4mm header pipe, does a 4.2mm diameter mushroom 0.7mm thick sound right on an oval at 2mmx1.2 holding it, the whole insert being 5.2mm high ?
Neil

[ken seeber]

I can tell you a Kawasaki ring for electrofusion bore will wear a cast bore to the next size in one meeting.

Dave, I can't answer this one directly. When I was at Orbital we had a couple of 3 cyl 1.2 litre engine plated by Kawasaki. Call it electrofusion or WESC (Wire Explosion Spray Coating). We just used regular chromed rings, so can't answer the reverse.

It is a really neat process. Wires, successively of molybdenum and high carbon steel (piano wire) of around dia 1.5 mm, were tensioned along the cylinder centreline, and given 20 kV or so. The steel particles would hit the cylinder or the previous coat, cooling instantly to become pure martensite, a very hard form of steel. This was effectively embedded in a background matrix of the moly, which acted as a from of lubricant. No chemicals, but all I remember was the impressive bang, despite the cylinder being encased in some sort of sound proof container. This was back in late 80s, so all I can really remember was the bang. Nothing wrong with that.

[jonny quest]

Wobbly, any Ryger engines in Vegas?