cam cover gaskets

[46CHF]

building a knuck motor and right hand case is 112-404 with a g-9 date code believe it was a 61 cube engine as I had to machine scraper to accept 8 1/2 inch wheels. Between where the lifter blocks bolt in there is a oil return hole that the lobe at the top of the cam cover would cover the problem is all the the cam cover gaskets I have the hole is much lower and the gasket does not fully cover the return hole on the case.. What to do???

[billpedalino]

This is an important issue as I suspect that I have this issue and if so, it may have casued me a whole lot of unnecessary time and effort. I am experiencing a problem that I believe is directly related to this precise problem- I may be wrong, but I hope not.

My motor is a new rebuild with only a few minutes running time and I'm having a problem returning oil from the rocker boxes to the cam case breather valve. The oil fills the cups and pushrod tubes, leaks through the valve guides and is burned during combustion, as well as leaking out and causing a total mess. This is most often casued by a vacuum loss betwen the cam case breather valve and the oil return tubes in the rocker boxes/valve cups. After trying everything else, including a complete head disassembly and the necessary re-cutting of the (New) valve seats, the problem is still there - and I'm really itching to ride this machine and break it in duiring the cooler weather!

I'm not an inexperienced motor builder and have done scores of knucklehead motors over the last 40 years. I always try to be very meticulous in my motor work and I've never had this problem on one of my motors before. However, what I did not do is check the cam cover gasket against the vacuum hole position in the case when I replaced the cam cover - and I admit that this was NOT meticulous on my part. I am hoping this oversight will be the source of the vacuum-break.

It seems that the gasket manufacturers now use the 1963-1965 cam cover gasket with the overhead oil feed passage hole and rely on the cover-to-case seal on the earlier panhead and knucklehead covers to afford the necessary seal. I remember some older gaskets to not have this hole punched and the 1963-1965 gasket sets having modified gaskets. I used a new James gasket set, with James being a high quality gasket - but again, I didn't check.

I did check a few older loose paper cam cover gaskets thaty I have (yes, I do still like paper gaskets when properly prepared) against another knuckle right case and the hole position was indeed off, albiet, I did not re-hydrate and swell the older gaskets.

After the above long-winded diatribe, my suggestion is that you pay close attention when sealing this orifice against the cam cover and gasket or it may cause you much grief. The hole that you see in the face of the case was placed there for the purpose of connecting the lifter block drain passages and can (and probably should) be blocked off just below the gasket surface. While I've never done this before, If my problem is due to a vacuum leak at this location, I will most likely tap-in a countersunk screw to insure the correct seak, regardless of the gasket used. I do suggest that a high-quality gasket be used (and checked), as you already did, as well. Ordering a properly cut gasket will avoid a lot of disappointment when starting the bike that first time.

I will remove the cam cover again over the next couple of days and report back. Until then and as always, I welcome all input from other respected motor builders concerning this problem.

[Rubone]

Read this thread on the caimag site...
http://www.caimag.com/forum/showthre...blem-on-the-41

[Steve Little]

2 or 3 years ago I bought a new pack of 10 cam cover gaskets from one of our local wholesalers. They are the green James Gaskets and the description on the pack said something like "Covers all Knuckleheads and Panheads" from such and such a date to ?... I can't give the exact description of year as I am away from home, but I still have some gaskets in that pack.
I was building a knucklehead engine at the time and had the engine laying with the cam chest facing up. I was setting the shim tolerances in the cam chest and noticed that when I removed the cam cover after checking the tolerances and the gasket was lying on the gasket surface and the screw holes were nicely positioned but the vacuume hole was only half covered by the gasket.
I thought it must have been a defective gasket and tried another. They were all the same and for a few minutes I thought the gaskets had shrunk while sitting in my toolbox. But common sense finally took over and I rang the wholesaler.
I started out by describing that I had bought some cam cover gaskets a couple of years ago and I was building a Knuckle eng... that's as far as I got in the conversation.
The guy cut me off and said ...Yeah I know!! ...We took that up James a year ago. I'll send you down a new pack that only suits Knuckle engines.

James make good gaskets but something went astray on either the labeling or the person who was in charge of identifying gaskets for packing... That is only my guess.

[billpedalino]

I just received some James cam cover gaskets (from Ted) and upon matching them up with another right case, they appear to fit correctly and fully surround the hole in question. I will replace my gasket this weekend. However, I'm thinking that I'm still going to install the plug.