Rocker covers that eat gaskets

[flatside]

I seem to have bought aftermarked rocker covers that once were steak knives ?
The new heads have been on for just over 12 months, and for the second time, the engine has to come out.
The rear rocker cover edge (where it sits on the gasket) is a bit on the thin side at the rear L/H corner, causing it to eventually chew thru the gasket and spew oil out.
Is this quality control (or the lack of it ) common with aftermarket covers ?
They were bought from J&P.
Tiny

[steve_wood]

Rocker covers - gotta love em.

You'll find lots of info on this in the knowledge base, but here's the quick summary:

- Rocker cover gasket surfaces have to be perfectly flat to ensure a good seal and the repop units are NEVER flat.

- Even with a flat gasket surface, you need to make sure that surface includes the areas towards the insides of the holes. If there isn't any metal there, the oil will leak out through the screw hole. See attached.

Not sure why the edge of the cover would be destroying the gasket to the point where it would leak. It might cut away the portion that isn't under the cover, but it shouldn't be harming the portion that IS under the cover. Your leak might be caused by something else.

Is it possible that the cover screws are just coming loose from vibration? Stupid question but did you use lock tight?

Is it possible that you've been tightening the screws to the point where the cover has warped and no longer seats properly with the gasket?

What kind of gasket from J&P? I've heard that the James gaskets are good. Accurate Engineering makes a really good gasket ($30 per pair) but those are only available at the Accurate Engineering website.

I'm sure lots of folks in this forum will have lots more useful comments and suggestions... read on!!

steve

[flatside]

Thanks for the reply Steve,
The gaskest are the thick cork ones, and I didnt use loctite, and yes, the screws need the occasional snug up, but always a little at a time, and all the same tightness (not over tight).
I'll have a better look when I pull the cover off again (winter approaches here).
I did have a clearance problem 1st time 'tween the rear head and the frame seat post, which I fixed, thinking the constant growth of the cylinder and head when hot, then the movement back downwards when cold was the cause of the gasket failure No1 (it was actually split/cut right thru)
Jezz, think what the modern HD riders are missing out on,,they don't even have oil in 'em ? do they?, how else could they remain oil stail free?
Tiny

[Cotten]

If you don't use fat gaskets, the screws won't come loose.

...Cotten

[fourthgear]

Is your clearance problem with the rear head , why you say you have to pull the motor to replace cover gaskets ? You should be able to just pull the heads to replace them. They only need to clear the cylinder fire ring to come off( the thick cork gaskets my have some thing to do with clearance ).

The advice in the above posts are right on . I have went to the James rubber type gasket for my 65 , but I don't have a problem with my other Pan with the regular gasket ( not cork ) as said above its all got to be flat .Some things not flush to be cutting/pinching the gasket up.

[flatside]

Thanks for all the tips.
The reason for engine removal lies in the frame I made, to stop temptation from making me build a stroker engine, I limited the clearance 'tween the rocker covers, and the frame (it hugs both heads).
The frame was built while the engine had its stock shovel heads , now the clearance with the STD Pan heads is .020"
Tiny

[redinthehead]

Guys,
Not sure if I should have started another thread. What would you recommend for cleaning aluminum rocker covers? they look pretty good finish wise I just want to try and lift some of the grime that is sitting there. Mild soap and a soft scrub brush seems to be to obvious. Any help would be great.

Red

[steve_wood]

Define clean !!

Soap and water will work, but it won't do anything about the dullness from corrosion. The only way to get rid of that is abrasives, although i heard that soda blasting gives a nice matt finish similar to a fresh casting. But then again, I don't know if the original aluminum rocker covers were cast or pressed and polished plate.

On my XLCH I sanded all the major aluminum parts all the way up to 1000 grit (wet) and then wheel buffed them with red jewellers rouge. They came out very shiny. Not the stock look, but very sharp. Wonder what AMCA would think about that.....

steve

[Cotten]

Blasting a polished surface with peanut or walnut hulls will give a satin finish, but a trained eye can still discern the difference from anodizing.

...Cotten

[Guest]

Hi Cotten,
I was thinking that these covers where anodized so I didn't want to polish them. Some one told me that aluminum rockers were polished. Is that true?
what years did they anodize rocker covers??

Red

[Cotten]

Red!

To the best of my knowledge so far... All years of aluminum pan rocker covers were anodized.

Polishing is just one of many, many steps involved to give used covers a pleasing appearance,.. to those who can be pleased.

An AMCA judge who cannot find anything else wrong is obligated to point them out. It's his duty.


....Cotten

[redinthehead]

Hi Cotten,
That is funny. I was talking to a guy on the phone that owns an antique Cycles parts supply and he told me they were all polished. I just let him talk because I wasn't 100% sure that they were anodized. He told me that they get that look from sitting around and not being cared for. Me thinks I was being missled!!!

Red

p.s. hopefully I can post some pictures and see what you all think later today.

[steve_wood]

What would we do without the internet? Check this out: A home kit for annodizing:

http://www.focuser.com/anodize.html