I am helping a friend rebuild an engine and a question arose re the front cam bushing. Both the ID and OD are good, but the hole for the set screw is slightly enlarged and, being an early style cam, there is excessive play front and back when the lobe is aligned with the notch. About .030" movement in all. Since the fit is good otherwise, I was thinking about using Chaffin's shim pack to eliminate the movement. Either that or replace the bushing entirely. I know from past experience the new bushings aren't much, but things may have changed. I'd like to hear from those who have recently purchased a front bushing including the name of the supplier, and those who have had experience with the shim pack. Pros and cons.
Even when I place a washer behind the cam shoulder I still have .013 front and back movement when the lobe is in the notch.
Can you J-B weld in a bushing to make the hole the correct size and location?
The JB Weld wouldn't help the play that occurs when the lobe is in the notch. If it worked, which a question considering the closeness of the bushing OD to the hole in the block, it would only remedy the play occurring from the enlarged set screw hole, that is the play that is due to the bushing itself moving back and forth.
I do use JB Weld in other bushing situations but you have to turn down the OD so there is plenty of room to give the stuff the space to set up. Also you have to be concerned about removal. It takes a good deal of heat to break it down, not a real good thing for a bushing in the block. I have used it to float the rear cam bearing for alignment, but its never going to be removed, at least not in my lifetime.
Thanks for the interest.
I installed the shim kit in front of my cam gear and it seems to be working fine. You may need to machine the brass washer to adjust the thickness in your car. I also cleaned up the casting on the inside of the gear cover to make a for a good running surface. Don't forget to apply some grease between the transmission washers before you button it up.
Good Luck
The new cam bearings I last bought were slightly overlength on purpose and had to be lapped down to fit. Makes for a good set up.
Richard, be careful if you order your new bearing from Chaffin's, I've been waiting since November last year for the one I ordered, with plenty of emails and a few (international) phone calls to prompt things. They did finally send one a few months ago, but the halves were not a pair. I sent it back (my cost, international freight) and I'm still waiting (and they have answered an email to confirm they have recieved it back). Sorry to hijack your thread, but your post has prompted me to put it out there. Always had the best service up until now. Regretfully posted, Bede.
Rich, if you have slop in your lock bolt, make sure the hole is round in your cam bearing, and take the lock bolt and use a fine tip, and run some brass on it as the lock part is pointed down a little bit, so the brass will not get in the threads, and then cut it down to a nice slip fit in the cam bearing hole, with No play, and no binding. We do that with all our Front, and center cam bearing lock bolts.
The brass thrust on between the cam , and cover, while may be not necessary, I like them, and would use one on my engine, if I ever have time to build one.
Herm