ESE's works engine tuner

[richban]

Anyone that runs a 9 in a racebike is a complete Wally - the NSR250 road bike runs this heat range, does this indicate something ?
Honda RS125 ended up with 10.5 as whenever they got tuned to the edge the plug would overheat and sag the piston centre, does this indicate something ?
All this is helped by cooling the plug thread effectively, but nothing will save you if running a 9 on purpose - SToP IT. NoW.

I have been told. They are never going in the bike again. As usual poor attention to detail hurts the poor we bike.

[husaberg]

Anyone that runs a 9 in a racebike is a complete Wally - the NSR250 road bike runs this heat range, does this indicate something ?
Honda RS125 ended up with 10.5 as whenever they got tuned to the edge the plug would overheat and sag the piston centre, does this indicate something ?
All this is helped by cooling the plug thread effectively, but nothing will save you if running a 9 on purpose - SToP IT. NoW.

So for the V twin with the front wheel near the head is this the ones he needs?

NGK R5300A-105


Or is it these ones
R7282-105

[Neal]

So for the V twin with the front wheel near the head is this the ones he needs?

NGK R5300A-105


Or is it these ones
R7282-105

Either one will work with the correct plug cap . I used the 7282 with no problems

[peewee]

smitty i think my next purchase will be a small 3 in 1 mill, lathe, drill press. that should be good enough to machine heads and other small projects. i simply just dont have the available space for full sized independant machines. im very excited to be able to weld most anything now , right in my garage.

anyone tried one of the ck micro tig torches for very tight spaces ? that might be whats needs for getting inside of transfer ducts. everything else can probly be done with the standard size torch

[husaberg]

Straight intakes for those using cr125 Honda RS reeds.

I think these are 36mm but I don't know much about Mircolights.
Or bing Carbs. But it seems the carb od 49.5mm

JBM Industries has created tooling for this carburetor socket boot for MZ engines.
The material is TSR compound. It is designed to fit the popular BING 54 carburetors used in LSA
aircraft with MZ 202 engine. These parts use a rubber covered steel plate with 6mm mounting
holes. Rubber cover is .070 thick, so no gasket is required. 52 X 72mm hole locations.
These rubber boots are found on the engine or cylinder inlet manifold on MZ 202 ultralight
or light sport LS power units. These rubber carburetor sockets have the locking rib and internal
size for the Bing model 54 carburetor used on ultra-light or micro-light aircraft. This boot is used
for heat and vibration isolation. This part is NOT made by the original manufacturer, but is made
in the USA and designed to fit. It may fit other models and engines.

MZ 202 Engine Carburetor Socket Boot for Bing model 54 carb.
Designed for 6mm bolts 72 mm by 52 mm centers. 37 mm overall height.
http://jbmindustries.com/MZ_Socket_Boot.html
http://www.ebay.ca/itm/MZ202-to-BING...4ddedf&vxp=mtr


This is the NF4 and NX4 intakes
http://www.risingsuncycles.com/image...s/botmveiw.jpg


This place also does Carb Diaprams
http://jbmindustries.com/Dimensions.html
Plus a lot of other manifolds.
http://jbmindustries.com/RubberFlange.html
http://jbmindustries.com/HOLDERS.html

Either one will work with the correct plug cap . I used the 7282 with no problems

Cheers

[Sketchy_Racer]

I am also running the NSR300 and am having the same issue with the piston crown sagging even though i've got the wanky NGK 10.5 race plugs in.

I had a lot of teething issues on its first track outing, with one being the stock cylinder heads I machined out cracked and let all it's water into the cylinder so I thought I better do it properly and machined up a 2 piece head loosely based off the VHM products. I'm going to do the insert a little different this time though and modify it so I can get some more water around the spark plug as the VHM style seem to have the thickest wall section at the spark plug.

[speedpro]

With all this talk of carb mounting flanges it just occurred to me - why don't we use 4T style mounts? Typically only 2 bolts but that works on 4Ts, and often we have an adaptor somewhere in the whole carb/reedblock/engine assembly so why not have one screwed to the reed block and then the carb mount to the adaptor? Mostly nice and straight. For a "real" race bike it would add undesirable length but as an option for us it would seem OK.

[Sketchy_Racer]

So the question has been asked about piston rings, 1 vs 2.

I remember reading a post from Frits (Im sure it was him!) that made comment about the extra ring just adding more friction to the job and not succeeding in removing heat from the piston or have I got this all wrong? Anyone know how to find the post?? Husa Help!!

Cheers,

Sketchy

[husaberg]

So the question has been asked about piston rings, 1 vs 2.

I remember reading a post from Frits (Im sure it was him!) that made comment about the extra ring just adding more friction to the job and not succeeding in removing heat from the piston or have I got this all wrong? Anyone know how to find the post?? Husa Help!!

Cheers,

Sketchy

Attachment 309064Attachment 309065Attachment 309066Attachment 309067
A couple of head designs. The finned one is from the current benchmark in superkart engines. DEA & the other with the passages about the plug may be a Thijs Hessels design.
Frits the DEA head seems to go against what has been described for performance, however this engine is extremely powerful. Given your friendship & confidential nature with Andrea I hope it wouldn't be asking to much to have you explain how / why this style is employed within the DEA inline engines.
Thanks in advance

Or two. Front and side views of a double-finned insert and cover: Attachment 309036

You won't. You can't.

Seeing as Frits said it you could click on his name and then click view forum posts.
Or you could use those same words in a forum search top right.
Or I will find it in a minute.

It seems I just can not let go of the thought of the rings dissipating heat from the piston. Thus - two rings should dissipate more heat than one ring. At the same time, I've got the impression the ability of the heat dissipation from the rings might be overrated.


I've had a std head machined down as much as possible (0,5mm), but this only brought down the squish band from the usual 1,8/1,9mm to 1,3mm. The VHM heads are said to dissipate heat much better than the stock 122 heads. Maybe I should get a VHM head for domed piston and machine it to the desired specification. Thanks.

Young, definitely. Velkommen, ung mann.

I can't let go of the thought that a ring rubbing against a cylinder bore generates heat .

hello. 1 ring! there is no need for a second ring. good 1 ring pistons with the ring peg at "18 o clock" position (so you can widen the b ports) are easy available for this engine.

i dont know why but i doubt this vhm heads a little bit. i think it would be better to not use a flat piston and have a stock head machined to desired specification.

Hi, I'm a 48 year old (Or, is it young?) Norwegian. I've been lurking around this thread for some time now. I'm currently in the process of building a tuned Rotax 122 engine. The bike will be used mostly for fun on road and track days. My only concern is getting as much power as possible from the engine.

The cylinder has been reworked by a known UK tuner. To go with this I've got a VHM head for use with flat top piston. And a good selection of different reeds, carbs, std and custom exhausts, different ignition CDI's, etc.

I just can't make up my mind if I should go for a 1 or 2 ring piston. It seems to me both have their pros and cons and I would appreciate very much any advice. For now, I'm thinking 1 ring is the best.

Thank you.

With all this talk of carb mounting flanges it just occurred to me - why don't we use 4T style mounts? Typically only 2 bolts but that works on 4Ts, and often we have an adaptor somewhere in the whole carb/reedblock/engine assembly so why not have one screwed to the reed block and then the carb mount to the adaptor? Mostly nice and straight. For a "real" race bike it would add undesirable length but as an option for us it would seem OK.

Like this?

[Sketchy_Racer]

Thanks Husa,

I did search his posts in this thread but alas I couldn't find that post! Or I glossed over it. Turns out Frits has 33 pages of awesome information in this thread, brilliant!

So to clarify the consensus is that 2 rings add heat? The response was a little bit cryptic haha

Cheers,

Sketchy

[husaberg]

Thanks Husa,

I did search his posts in this thread but alas I couldn't find that post! Or I glossed over it. Turns out Frits has 33 pages of awesome information in this thread, brilliant!

So to clarify the consensus is that 2 rings add heat? The response was a little bit cryptic haha

Cheers,

Sketchy

My take was Two rings adds friction, friction equals heat and two stroke rings transfer bugger all heat to the bore anyway.
I recall there was a Seatle Smity question as well I didn't see it in the search though.

[Sketchy_Racer]

The most powerfull 125 known to man quite happily got rid of the heat generated thru a single ring.
There have been cases of huge overbored ie oversquare cylinders that had piston heat trouble and twin rings
did help in this particular scenario, but that was a special case where the real issue was lurking elsewhere and the rings just
ameliorated the symptoms.

Well this sort of sums it up. Although the NSR300s are over square, so it might be a case where having the extra ring might help "ameliorate" the problems of our over heating pistons?

[Sketchy_Racer]

My take was Two rings adds friction, friction equals heat and two stroke rings transfer bugger all heat to the bore anyway.
I recall there was a Seatle Smity question as well I didn't see it in the search though.

Yes, that's how I read it, and I suppose the bloody rings aren't touching the cylinder walls for quite a lot of the time given that there are a lot of holes in the side of it!

[husaberg]

Yes, that's how I read it, and I suppose the bloody rings aren't touching the cylinder walls for quite a lot of the time given that there are a lot of holes in the side of it!

Yeah Bell did tests on the dyno (I think it was on a YZ80) it gained under 9000 from better sealing and lost out over that. seeing as they likely don't spend much time under 9000 it would be pointless.
From memory the bore wears faster as well with two rings but on a road bike the two sealing surfaces offer a longer service life. (Not an issue on a competition engine)
Wob has mentioned that Dykes rings wear the bore faster and cost high rpm power.
The dykes rings were the answer until thin piston ring technology caught up, But I think they still have a place on Blown engines as they seal better.

Maybe Frits or Wob could tell us if the higher the ring is the more power it makes, until (I guess) it gets too hot due to its location it fails or does too high a ring location eventually lead to detonation?

The ring on the RSW look to be only about 0.6-.8mm thick at a guess.
Here is a few KTM and Aprilia piston pics

[Frits Overmars]

Maybe Frits or Wob could tell us if the higher the ring is the more power it makes, until (I guess) it gets too hot due to its location it fails or does too high a ring location eventually lead to detonation?
The ring on the RSW look to be only about 0.6-.8mm thick at a guess.

From memory the RSW and RSA rings were 0.7 mm thick.
The higher the ring, the more power. The limit is not the ring temperature but the piston top land temperature, because the cross sectional area through which heat is transported from the top land to the bulk of the piston, becomes too small. Then the alu weakens and the ring will hammer the ring groove out of shape, causing leakage.
In the RSW and RSA this did not cause detonation, just loss of power.