Con rod sml end bushing

[Stan]

I have a brass bushing in the small end (top) of the connecting rod, as I understand it, the 6/1's with the heavy flywheels have them.  There is also a hole in the top of the connecting rod approx. 1/4" in diameter, and a corresponding hole in the brass bushing.  The obvious reason is to supply splashed oil to the wrist pin.  However, when I looked at it just prior to assembly, the brash bushing had rotated to the point where the oiling hole didn't line up with the hole in the connecting rod to the degree that 3/4 of the hole was blocked.  I was able to gently pry the brash bushing back around so the hole lined up with distressingly little pressure.  The wrist pin slides in to the brass bushing with the appropriate amount of friction, indicating a proper fit so there appears to be little wear up there.

My question is this.  If this brass bushing will rotate in the housing with a little pressure on my part, what is stopping it from rotating when the engine is operating?  Should I be worried and try and secure the bushing in place somehow?
Stan

[dieselgman]

Maybe someone with much machining experience on the CS models can add some detail here. I know from engines in general and Lister air-cooled designs in specific; the small-end bushing is a heavy interference fit. It is very tight in the conrod and cannot rotate even under much stress. The new bushings we install are pressed in and then machined to size. I am thinking your bushing probably needs to be renewed (and machined back to proper size).

Best Regards,

Gary
diesel-electric.us

[Geno]

Gary's right, it should be a tight fit.

Thanks, Geno

[hotater]

Stan--

That bushing can easily be saved, if the internal fit to the wristpin is still right, by knurling the outside.  The bushing is strung on an expanding arbor and knurled enough to give a tight press fit.

A good alternative is a Loc-Tite product designed for loose bushings in mind.  Check the auto parts stores.

[Stan]

OK guys.....I talked to a machinist in town and he swears by Permatex bearing mount for worn parts  http://www.devcon.com/techinfo/BEARING%20MOUNT%20FOR%20RELAXED%20FITS.pdf

He wasn't too thrilled to work on Penelope's con rod and said he uses this stuff all the time.  I am a little concerned by the 250 degree C temp limit though, I would imagine the bottom of the piston would get that hot at least.

I guess if I go for a new bushing I'll have to look around to see if I can find someone willing to press fit it for me.
Stan

[hotater]

stan--

The hottest I've recorded on thebottom of the piston is 295F--146C.   THat's the kind of goop I was talking about.

[Stan]

That's good data to have, Thanks  it'll make my decision easier.
Stan

[listerdiesel]

I have a brass bushing in the small end (top) of the connecting rod, as I understand it, the 6/1's with the heavy flywheels have them. 

They all have the bush, Stan, it's a standard fitting.

My question is this.  If this brass bushing will rotate in the housing with a little pressure on my part, what is stopping it from rotating when the engine is operating?  Should I be worried and try and secure the bushing in place somehow?
Stan

You could solder the bush outer face and press it in, that has worked for me before, but a new bush would be better.

I don't think I have any new CS small end bushes, but I do have new CE/CD bushes. I'll check them later and see what the differences are if any and post back here.

We are a bit busy with the factory move so may be a 'bit' later :-))

Peter

[Stan]

Thanks Peter, Troy says he has one in stock and can get it to me.  Thanks for the advice, I had decided to rrrreplace (as the scottish sargeant major said to the druggist).
Stan

[Stan]

Thanks Peter, please forgive my confusion on this but what is part #574-10320.  My 1970 manual plate 5 "crankshaft connecting rod piston and cylinder" shows this as the "bushing" on the small end of the connecting rod with the notation "*This bearing is also used on 6/1 engines fitted with heavy flywheels eg: Electric generating sets".

I'm confused.
Stan

[rcavictim]

OK guys.....I talked to a machinist in town and he swears by Permatex bearing mount for worn parts  http://www.devcon.com/techinfo/BEARING%20MOUNT%20FOR%20RELAXED%20FITS.pdf

Stan

Bearing Mounts for Relaxed Fits.

Isn`t relaxed fit an oxymoron?  I don`t think I can remember ever being relaxed while having a fit dammit! 

[Stan]

How would you remember?
Stan

[Dail R H]

   Isn't anything made by Permatex classified as "stick shit",and therefore not suitable for use in a Lister?

[listerdiesel]

Thanks Peter, please forgive my confusion on this but what is part #574-10320.  My 1970 manual plate 5 "crankshaft connecting rod piston and cylinder" shows this as the "bushing" on the small end of the connecting rod with the notation "*This bearing is also used on 6/1 engines fitted with heavy flywheels eg: Electric generating sets".

I'm confused.
Stan

ALL Lister CS engines had a small end bush of some description, there was a change to sizes when the crankshaft went from 1-3/4" to 2" diameter and there was a corresponding gudgeon pin size change as well, but these are early on in the life of the engines. There was also a change from 2-1/4" big end to 2-1/2" big end.

Your parts book is quoting a very late part number and I suggest that it is a revised bushing for the higher output 8/1 engine that was also used on the SOM engines.

My Book 103 parts section doesn't list that number at all, the number quoted is 008-04007/001,  and this book covers the 8/1 and 16/2 engines. This book is dated 1983.

I'll try and find out what the differences were. The older bush part number was 5-1/D7A. The 3-1 engine was different again..... 208/19 and the 1-3/4" crankshaft conrod had a small-end bush # 5-1/D7.

Peter

[MikeyT]

   Isn't anything made by Permatex classified as "stick shit",and therefore not suitable for use in a Lister?

Yes!

This loose bushing is almost certainly a result of this engine not being properly fastened to the geometrically correct minimum 2.5 tons of rigid mass.