Groove in rear cam bearing on 66-67 396 engines

[retengw31]

Hoping someone here is familiar with this one, good friend just finished up his 40 Chev Street Rod from the gound up. He rebuilt the 66 396 engine with a Crane Cam, everything came out fine, runs great. Except when he was cleaning up some paperwork, he came across a thing in the cam box that said if you use that cam on a 1966 or 1967 396, the rear cam bearing needed to be grooved on the camshaft before you put it in. He checked the old removed cam and sure enough it was grooved.

He's worried he has to tear down the whole front end of the car to pull the cam on this, and that's no easy task. It's a typical loaded street rod with A/C, rack and pinion steering, etc. and the entire front end will have to come off.

Anyone familiar with this? Is it really necessary to machine this groove in a new cam? Never heard of a big company selling a product like this that would require machine shop work prior to installation.

Anyone know why a newer 396 wouldn't need this groove? Appreciate all hints.

Thanks,

Dave

[Seattle Sam]

The groove supplies oil to the lifter galleys, Its needed on early blocks that do not have a grooved camshaft journal.

From the Bill Mitchell web site ..



Also on a stock 454, this shows the two holes in the rear camshaft journal that feed both the lifter galleys. Therefore, oil must pass by both the rear main bearing and the rear cam bearing before finding its way to the lifters. Also, this groove is not present in an early 396 block, which is why a grooved cam is needed in that application to ensure oil feed to the lifters.

[BBIGG BLOCK 396]

It does need the groove in it for the early model engines.I went through this and my machinist had told me he did it.I thought I was going to have to pull the engine and take it back but he told me I was covered.If the groove is not installed it will gauld so I am told from lack of oil on that cam bearing!If you did not put the groove in it you need to pull it out and do it or it will cost you in the long run!

Bobby Dodson

[retengw31]

Thanks, I think he was hoping it was no big deal, but this is a no excuse car, so apart it'll come. Appreciate the quick response and especially the pics and explanation.

[Kim_Howie]

It will have no oil pressure from the lifter to the rockers. Been there.

[Chevy454]

Been in that same boat before...put it all together, and was priming the oil system, but one side never would take...got the specs for the groove, and Mo ended up putting the cam on a lathe...

[Kim_Howie]

I did it with a hand held grinder worked fine. I was 20 at the time. You never forget mistakes.

[retengw31]

He started taking it back apart yesterday. Sad after being down to a body and rolling chassis for 2 years and all that was left was the seats and door panels.

Good advice, though. Thanks again.