View Full Version : Looking for original factory camshaft from a '72 472/500


The Ape Man
04-05-06, 09:57 PM
After hearing (on this board) that the '72 and maybe a few other year 472 or 500 engines had a camshaft that is different from other years, I've decided to try to find out for sure. Every aftermarket source except 1 performance oriented vendor shows the '68-'77 engines replacement camshaft as being the same exact part number. I have been told that this is incorrect and that the exact GM camshaft number shown in Motors manuals may indeed be incorrect. To be 100% honest, I thought this was another bench racer story at first. Thinking a little about my mis-spent youth, I recall tearing down my 1971 472 searching for the reason why it didn't run nearly as well as my 1972 472 which I had a couple of years earlier. My first Cadillac was a '72 CDV. Second was a '71. The '71 seemed to be a dog compared to the '72. Checking distributor curves and carbonator jetting yielded no reason. I finally pulled out the 472 and dropped in a recent (at the time) 425 which became available at a local junkyard at a get rid of the evidence now price. That 425 moved the car almost as well as the 472 so this added to my search for an answer.
'71 was the year that GM reduced engine compression. I'm thinking that Generous Motors may have decided to do something about the performance drop experienced by owners of the new lower compression 1971 472.
These cams held up much better than other brands of the day. The light valve spring pressures combined with billet machining made for a cam that lasted a LONG time. So anyone who might be replacing a usable cam out of a 1972 472 or 500 who is interested in recovering a few bux please send me a private message. I might be interested in a wiped out cam for research purposes also.

davesdeville
04-06-06, 07:24 PM
If nobody over here can get you one try over at cadillacpower dotcom.

I have a 72 472 on my porch but I'm still debating whether or not to run an aftermarket cam when I transplant it into my 74 LTD Country Squire...

Night Wolf
04-06-06, 10:17 PM
The MTS #5 is an "updated" version of the '72 472/500 cam....

The Ape Man
04-07-06, 04:25 AM
The MTS #5 is an "updated" version of the '72 472/500 cam....

That sounds like it could be a plan B. Thanks.

DaveSmed
04-08-06, 01:03 AM
I just so happen to have a 1972 Motor manual on my desk.

Lift:
V8-472 1968-71
Intake Lift: .440
Exhaust Lift: .454

V8-472 1972
Intake Lift: .490
Exhaust Lift: .490

Timing (Intake opens before TDC):

V8-472 1968-70: 18 deg
V8-472 1971: 38 deg
V8-472 1972: 34 deg

Kind of interesting. Looks like the valve timing adjustment in 71 wasn't enough to compensate for the compression loss, so they added some lift.

The Ape Man
04-08-06, 10:07 AM
Kind of interesting. Looks like the valve timing adjustment in 71 wasn't enough to compensate for the compression loss, so they added some lift.

Yet Motor's Parts And Time Guide shows only one part number camshaft and timing gear pieces for 1968 to 1977 Cadillac manufactured engines. Same goes for TRW and various other rebuild parts sources.

I agree with your idea that the engine was changed in order to get a little more power back after the reduction in compression.

Fleet
04-16-06, 08:51 PM
That's very interesting. I've always wanted to know the cam specs of the '71 and '72 Cadillacs (and '73-'76).
I'm really surprised that the lift was more for '72. Both are really up there, though. In the muscle car engine range, in fact.

Now I see why those car magazines said that the 273-2 bbl Mopar engine was very mildly tuned... the lift for those was only .397 intake and .403 exhaust.