LOBE 2 20-21

[twinshocker]

I´sorry to sound so hart Beat , but i predict this will be your next DNF with a damage of a couple of hundred Stutz to your wallet !!
Don´t get me wrong , i would be very happy i i am wrong !

A plain bearing is always better in this place , they do it only on twostrokes where they have ne decent oil supply !

[Mark Cook]

Not as much fun for Beat, but a PES version would still be working

And cheaper by now I expect.

Mark

[beat]

A plain bearing is always better in this place ,

Don´t get me wrong , i would be very happy i i am wrong !

I will try to find this out.....

Not as much fun for Beat,

this is why !

[kommando]

Needle rollers in place of bushes is to cope with high revs, in a small end its a rocking motion and small end wear is rare in a relatively low revving single. A solution in search of a rare problem is mis-directed resources.

[beat]

hi kommando

I got teached once ( it is a wheile since and it is maybe wrong ) as a roller bearing is having much less friction and is producing by far less heat in compare to a plain bearing, - mainly if it is under heavy load.

by all this three „ sizers“ we got last season, the plain bearing of the piston pin was involfed by showing overheating colores
and once it was twisting the bush in the smalend.

maybe this is a result of the non alingment of the piston to the barrel bore, but in my eyes it not wrong to have a needle bearing in place.
and about the lubrication , - the roller bearing is much easier to handling, less oil needed, less cooling needed.

beat

[Mark Cook]

How is the piston going to loose heat, now it can't pass it to the connecting rod Beat?

[minetymenace]

....by the additional oil spray Beat has added perhaps Mark?

[kommando]

....by the additional oil spray Beat has added perhaps Mark?

Which is not currently working if the gudgeon pin is being coloured by overheating. It will be worse with a needle roller not better. Beat using an oxygen sensor to tune the carb would also mean he is running a leaner more efficient combustion which will lead to more heat up top.

[beat]

The oil spray is what I do count on it about cooling.
the A/F mixture is nicely on the rich side by 12.3 to 13.4 range, - AND THIS BY OVERLOD TROTTLE POSITION !
means it is running cooler than a street legal engine wich is serving the exhaust gas restrictions.

But I stil ask myself what kind of bearing is used in other modern 4stroke racing engines?

anyone got a Idea ore a drawing ?

beat

[Mark Cook]

Your very long stroke engine has nothing to do with modern racing engines Beat.
I think you require more material in the skirt of the piston, also a larger pin diameter.
Some engines I have seen have plated small end eyes, but that is also to do with weight.

Mark

[beat]

plated smal end eye. ??

means plain bearing but no extra bushing inside ??

beat

[Mark Cook]

The small end eye is hardened I believe, then plated to act as a bearing.

Mark,

[beat]

thanks mark