Rebuilding a 67 427-435

[Clem Z.]

Re: Rebuilding a 67 427-435

you only need the cam thrust button with a roller cam because the lobes are not tapered ground.

[Domenic T.]

Re: Rebuilding a 67 427-435

Dom:

Did the wear occur with a cam gear while using the steel shim or was the steel shim used to make up for the wear from a steel gear on the iron block. Did the steel shim prevent further wear? Was it necessary to bond the shim to the block for it to protect the block?

Patrick,

The wear was not from an aluminum gear but from a aftermarket gear set using no chain, and yes I did secure it to the block.

As far as furthur wear, I am sure the problem is solved because I have a double roller and chain set now.

Clem was first to post the problem and he may have seen more than I but I was skeptical and used a steel washer and fastened it with 2 flat head screws and locktite.

If you don't have wear I wouldn't worry about it , just use the double roller cam gear and it should work fine.

Someone used a all gear setup on mine and the button must have been pushing to tight on the cam gear and wore the block.

You are not going to use the all gear set up (without a chain) and will be OK.

DOM

[Joe L.]

Re: Rebuilding a 67 427-435

Patrick,

The wear was not from an aluminum gear but from a aftermarket gear set using no chain, and yes I did secure it to the block.

As far as furthur wear, I am sure the problem is solved because I have a double roller and chain set now.

Clem was first to post the problem and he may have seen more than I but I was skeptical and used a steel washer and fastened it with 2 flat head screws and locktite.

If you don't have wear I wouldn't worry about it , just use the double roller cam gear and it should work fine.

Someone used a all gear setup on mine and the button must have been pushing to tight on the cam gear and wore the block.

You are not going to use the all gear set up (without a chain) and will be OK.

DOM

DOM------

Did your cam gear drive set-up use dual idler gears between the cam gear and the crank gear? Without it, the cam will turn in reverse rotation relative to the chain drive.

[Domenic T.]

Re: Rebuilding a 67 427-435

DOM------

Did your cam gear drive set-up use dual idler gears between the cam gear and the crank gear? Without it, the cam will turn in reverse rotation relative to the chain drive.

Yes it did have the extra gear but The promlem was in the adjustment on the aluminum timing cover that puts pressure on the cam.

DOM

[Patrick B.]

Re: Rebuilding a 67 427-435

Thanks for the advice from the commenters to my thread. I may be trying to solve a problem that doesn't exist, but I have seen a number of 427 blocks with worn cam gear thrust surfaces and it caused me to worry about the compatability between the iron block and aftermarket steel or iron gears.

I took Joe's advice and got a Cloyes 9-3110A Tru Roller set and a simple 9-220B bronze wear plate to replace the nice but needlessly complex thrust bearing included in the set. The bonze plate was a nice close fit but I put a few drops of red Lock-Tite on it anyway. I also found a simple nylon cam button (Comp Cams 202) to assure that the wear plate cannot become dislodged during backfiring or any other event. I have attached a picture of these parts for those not familiar with them.

I have attached another picture as a warning to those rebuilding 65 and 66 Corvette big blocks that use the windage tray studs with female threads for tray attachment bolts. Throw those studs away and use the current production studs with male threads for tray attachment! The picture below shows the current type stud on the right (which I believe was used in 1967 up), and two of the 65-66 type studs that broke when I attempted to torque them on a 66 engine some years ago. Also back in the day, I had a friend with a 65 396 that dropped a valve under warrantee and received a new short block and one head . The dealer reused the Corvette oil pan and windage tray setup, and one of these 65-66 style studs cracked causing the main bearing to fail. Even the 4 bolt caps don't work with only 3 bolts. This time the dealer installed a complete iron head LS-7 for an upcharge, and I bought the wounded but very low mileage 396 short block and discovered the cracked stud. This is one of the reasons a lot of Big Block Corvettes lost their original motors, and that many of the blocks one gets for restorations have one sleeve.

[Mike M.]

Re: Rebuilding a 67 427-435

an excellant and informative thread. thanks guys.mike