ESE's works engine tuner

[peewee]

Keys don't hold on stuff, the taper does...... if it came off the nut was loose and or the taper was shagged. keys are only the locating device on flywheels.
lap it on, nut up tight, they stay there....... I learnt that lesson after I lost my flywheel a couple of times

think of all the rubes that buy mx bikes. if there was no key they wouldnt a clue where to put the flywheel

[WilDun]

just grind them with abrasive valve paste if they are not a perfect fit.

I have seen some guys just putting coarse paste on the tapers and tightening them up - and it did seem to work! - animals?

[husaberg]

Question for the learned
If one was to be so silly as to do a air cooled 125 cylinder
Should the fins in the area of the outside of the transfers passages only attach to the transfers or to the rest of the cylinder as well?
I only ask as I note on nearly all water cooled cylinders the transfer have no outer water jacket.

[Flettner]

My 350 has fins all the way up from the crankcase.

[pete376403]

Is that one of those split-singles I read about?

[Frits Overmars]

If one was to be so silly as to do a air cooled 125 cylinder...

If one was to be so silly as to do an air cooled cylinder of any capacity...
A friend of mine is that silly. Well, almost; he is competing in a class were stock frame and engine, stock intake system and stock cooling type are compulsory.

Should the fins in the area of the outside of the transfers passages only attach to the transfers or to the rest of the cylinder as well? I only ask as I note on nearly all water cooled cylinders the transfer have no outer water jacket.

The outside of an air cooled cylinder gets so much hotter than a watercooler that you should put fins everywhere. And not just on the cylinder. This friend of mine added cooling fins under the engine, to the clutch cover, to the ignition cover, and even the last get surprisingly hot. O, and he won the championship.

[husaberg]

If one was to be so silly as to do an air cooled cylinder of any capacity...
A friend of mine is that silly. Well, almost; he is competing in a class were stock frame and engine, stock intake system and stock cooling type are compulsory.The outside of an air cooled cylinder gets so much hotter than a watercooler that you should put fins everywhere. And not just on the cylinder. This friend of mine added cooling fins under the engine, to the clutch cover, to the ignition cover, and even the last get surprisingly hot. O, and he won the championship.

Thanks Frits and Neil, So if I concede that the Germans know a little bit about air cooling.
Would this be the way to go.............

Or should I follow the route of the chainsaw and or scooter.
I ask about the chainsaw because they spend their life at max revs.

[Yow Ling]

Thanks Frits and Neil, So if I concede that the Germans know a little bit about air cooling.
Would this be the way to go.............

Or should I follow the route of the chainsaw and or scooter.
I ask about the chainsaw because they spend their life at max revs.

Just bite the bullet and get a RG bottom end,

[Flettner]

Is that one of those split-singles I read about?

Ha Ha very good.

[WilDun]

Thanks Frits and Neil, So if I concede that the Germans know a little bit about air cooling.
Would this be the way to go.............

Or should I follow the route of the chainsaw and or scooter.
I ask about the chainsaw because they spend their life at max revs.

This aircooling stuff is getting ridiculous - nearly as ridiculous as 14 speed gearboxes to compensate for the narrow power bands in the sixties!
Wouldn't it just be much easier for everyone to get together, change the rules and make aircooling illegal?

[F5 Dave]

The first Rotax tandemtwin engines (I received the first two in December 1980) had long tapers on the crankshafts and in the large primary coupling gears. In addition Rotax seemed to have used the strongest Loctite available on those tapers. In trying to get the gears off their tapers I broke two pulley pullers, without joy. I had to heat the gears to such an extent that I had to bin the oil seals afterwards.
One of the many mistakes in those first tandemtwins was that the oil seals ran not on the crankshafts, but on bushes on the gears. This allowed air to leak through the key slots in the tapers, causing all kinds of nasties.
Lessons learned: never use Loctite on tapers if you ever plan to take them apart again; just grind them with abrasive valve paste if they are not a perfect fit. And look for air leaks in even the most improbable places.

Maybe loctite master gasket rather than threadlock would be the go. Ya know that might explain a mates past issues with his 1980 256. Been reliable as last 20 years (in his spare bedroom).

Fine valve grinding paste is the go. I've had some coming on 30 years. Not like I'm going to be lapping any valves.

[Ocean1]

Thanks Frits and Neil, So if I concede that the Germans know a little bit about air cooling.

Mr Volkswagen knew more than is usually recognised.

Having read something of his work I'm surprised we haven't seen a lot more of ducted fan cooling in buckets...

[husaberg]

yeah I think the chainsaws and the scooters are onto it re the aircooling tech

[jasonu]

Wouldn't it just be much easier for everyone to get together, change the rules and make aircooling illegal?

If you are referring to Buckets then definitely not. Part of the attraction and beauty of the class are the different types and configuration of motors that fit within the rules and the lengths some builders go to to be competitive.

[Ocean1]

yeah I think the chainsaws and the scooters are onto it re the aircooling tech

One of the issues with fans is the problem with power going up exponentially with rev's. You don't need that much increase in airflow so the fan drive represents a loss up around max HP rev's.

The trick is to involve a torque limiting feature in the fan drive. Like a V belt that begins to slip over a certain torque.