327 Cam Bearings

[Martin M.]

I have just been told that the cam bearings, and possibly the cam, are unique to the '62-'63 engines. Is this so, and how???

Thanks, Marty

[Joe R.]

Re: 327 Cam Bearings

Marty,

All 327's have the same bearings but the cams are different for different Horsepower engines.

JR

[Martin M.]

Re: 327 Cam Bearings

Joe, that's what I thought, and I do respect your opinion. My engine builder is assembling a 340hp engine that is original to a car I have here. He was unable to get oil pressure with his tool. He consulted a lot of people, who I have no idea, and said that an old-timer, his term, told him that the cam bearings for '62-'63 are different than later 327 engines. This was news to me, but I am an amateur at this? He was told by this EXPERT that almost noone knows this.

Marty

[Joe L.]

Re: 327 Cam Bearings

Joe, that's what I thought, and I do respect your opinion. My engine builder is assembling a 340hp engine that is original to a car I have here. He was unable to get oil pressure with his tool. He consulted a lot of people, who I have no idea, and said that an old-timer, his term, told him that the cam bearings for '62-'63 are different than later 327 engines. This was news to me, but I am an amateur at this? He was told by this EXPERT that almost noone knows this.

Marty

Marty------

There was a difference if you go back to 1955 versus 62-63. But, there was nothing unique about 62-63.

By the way, I HIGHLY recommend the use of Durabond cam bearings over any others, including GM.

[Joe R.]

Re: 327 Cam Bearings

Joe, that's what I thought, and I do respect your opinion. My engine builder is assembling a 340hp engine that is original to a car I have here. He was unable to get oil pressure with his tool. He consulted a lot of people, who I have no idea, and said that an old-timer, his term, told him that the cam bearings for '62-'63 are different than later 327 engines. This was news to me, but I am an amateur at this? He was told by this EXPERT that almost noone knows this.

Marty

Marty,

All 327 small journals were the same for main and cam bearings. Sometime in 1968 GM went to a large journal crank. Maybe that's what he is talking about. Should not have any influence on him building your 327!
Find another engine builder.

JR

[Bob J.]

Re: 327 Cam Bearings

I have just been told that the cam bearings, and possibly the cam, are unique to the '62-'63 engines. Is this so, and how???

Thanks, Marty

Marty,
I remember the REAR cam bearing changes after 1963. Only years 1955-63 use a rear cam bearing stamped #5.
I looked it up. A 55-63 rear is 3723587 and a 64 up rear is 3723585 (which is a #2 position cam bearing).
I went through this about 3 years ago rebuilding a 63.
Bob Jorjorian

[Joe L.]

Re: 327 Cam Bearings

Marty,
I remember the REAR cam bearing changes after 1963. Only years 1955-63 use a rear cam bearing stamped #5.
I looked it up. A 55-63 rear is 3723587 and a 64 up rear is 3723585 (which is a #2 position cam bearing).
I went through this about 3 years ago rebuilding a 63.
Bob Jorjorian

Bob------


Yes. However, I don't think that difference would have any effect on the ability to circulate oil using the distributor oiling tool.

[Joe R.]

Re: 327 Cam Bearings

Bob,

Joe L. is right and there is no difference in the blocks. The rear cam bearing is dependent on the holes in the block to distribute oil to the rest of the engine. IF you install the wrong cam bearing in the rear you won't have any oil pressure.
Looks like you have he same mechanic as Marty. Did you send your motor all the way to Nevada?

JR

PS. This issue comes up all time with 396 and early 427 engines.

[Bob J.]

Re: 327 Cam Bearings

Joe Ray,
I don't know why GM listed them as different but they did. +
The later ones may work just fine but as expensive as rebuilds are I just wanted to point out that GM did list a different rear cam bearing for 55-63.
No need to ship blocks to Neveda........plenty of local talent close by.
Bob Jorjorian

[Wayne L.]

Re: 327 Cam Bearings

Some of the tools just turn the oil pump, and do not seal well enough to get oil up to the top of the engine. Also, most drills used to power the tools do not turn fast enough to build up oil pressure.
Wayne

[Steve D.]

Re: 327 Cam Bearings

Marty

I recently replaced an oil pump and could not get more than about 15 psi to register on the gauge when I spun it with the tool. I talked to George Richmond at Melling (their you-tube guy) and he said no worries on the pressure reading as long as you can see that oil has been circulated up the push rods.

Steve

[Joe L.]

Re: 327 Cam Bearings

Marty

I recently replaced an oil pump and could not get more than about 15 psi to register on the gauge when I spun it with the tool. I talked to George Richmond at Melling (their you-tube guy) and he said no worries on the pressure reading as long as you can see that oil has been circulated up the push rods.

Steve

Steve------


He's exactly correct. There's absolutely no need to achieve running oil pressure on a prime. In fact, as you've found, it's pretty hard, if not impossible, to do.

[Joe L.]

Re: 327 Cam Bearings

All-------

Attached are photos of an NOS GM #3723587 camshaft bearing. This bearing was, indeed, cataloged as the rear camshaft bearing for 1955-63 Corvette engines. You will note that it is wider than most small block cam bearings and it has the 2 side-by-side oiling holes. While it was cataloged for 1955-63, this bearing is only necessary for 1955-56. It can be used on 57-63 and, in fact, could be used on even later small blocks for the rear cam bearing. But, it's only necessary for 55-56. Why GM carried this bearing for 57-63 is somewhat of a mystery to me. The only thing I can surmise is that to simplify things and considering the necessity of using this bearing for 1955-56, they decided to just use this bearing to SERVICE the rear bearing position of all 1955-63. They could actually have done so after 1963 but, apparently, they decided to end it at that point.

What it essentially boils down to is that one can use an incorrect rear cam bearing for 1955-56 blocks but one can't use an incorrect rear cam bearing for 1957+. By the way, the narrower 64+ rear camshaft bearing can be used on 55-56 blocks IF it is modified by widening the oil hole.

[Martin M.]

Cam Bearings Update

My man using advice from a lot of people, pulled the cam and changed the cam bearings TWICE with still no oil pressure. Getting frustrated, he pulled the oil pump, a new one, and disassembled it. He found the relief valve, or something, stuck open. A new oil pump solved the problem. Engine is to be delivered tomorrow.

Goody, goody. Now all I have to do is install it into the car.

Thanks for all your advice. I sure learned something.

Marty