502 Mag MPI cam specs
03-08-2005, 07:04 PM
#1
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502 Mag MPI cam specs
Does anybody know what the cam specs are for a stock 502 Mag MPI cam . It is a 2000 Gen 6 and I believe it is also a roller cam. I am asking because I need to buy Valve springs and retainers for the Edelbrock heads I am installing on this motor. I am keeping the cam stock for now. In case you are wondering why, can you say "Whipplecharged" 
Below is a pic of one of my motors.
Below is a pic of one of my motors.
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03-08-2005, 07:32 PM
#2
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Re: 502 Mag MPI cam specs
From the GM Performance parts catalog:
Gen VI 454&502 HO
valve spring kit #12495514
valve spring cap and seal kit #12360872
valve stem key #3947880
I just bought the stuff for my rebuild...
About $150...
Good Luck
Gen VI 454&502 HO
valve spring kit #12495514
valve spring cap and seal kit #12360872
valve stem key #3947880
I just bought the stuff for my rebuild...
About $150...
Good Luck
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Patrick
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03-09-2005, 11:08 AM
#3
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Re: 502 Mag MPI cam specs
BW - I have the specs in a book at home. I'm at work right now. If you haven't had a reply by time I get home, I will look them up and post.
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Jay
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03-09-2005, 12:00 PM
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Re: 502 Mag MPI cam specs
Originally Posted by Pat McPherson
From the GM Performance parts catalog:
Gen VI 454&502 HO
valve spring kit #12495514
valve spring cap and seal kit #12360872
valve stem key #3947880
I just bought the stuff for my rebuild...
About $150...
Good Luck
Gen VI 454&502 HO
valve spring kit #12495514
valve spring cap and seal kit #12360872
valve stem key #3947880
I just bought the stuff for my rebuild...
About $150...
Good Luck
Are you running hyd flat tappet or hyd roller. If you are running a roller you better re-think that spring choice. Sure those are fine for a car that the engine is going to see 2000 to 2800 rpm all day long driving with a few 5500 rpm shifts but they will not last in a marine application. You need to shoot for a minimum of 130# seat pressure at installed height.
Chris
03-10-2005, 05:34 PM
#5
MarineKinetics
Platinum Member
Re: 502 Mag MPI cam specs
Bigwavz,
Cam specs for 502 MPI:
288*/288* seat
224*/224* @.050"
.483"/.483" valve
115.5* LSA
109* ICL
122* ECL
The spring kit Pat mentioned is:
1.487"
110# @ 1.88" installed
261 # nose
316# rate
Bob
Cam specs for 502 MPI:
288*/288* seat
224*/224* @.050"
.483"/.483" valve
115.5* LSA
109* ICL
122* ECL
The spring kit Pat mentioned is:
1.487"
110# @ 1.88" installed
261 # nose
316# rate
Bob
03-10-2005, 06:53 PM
#6
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Re: 502 Mag MPI cam specs
Originally Posted by cstraub
Pat,
Are you running hyd flat tappet or hyd roller. If you are running a roller you better re-think that spring choice. Sure those are fine for a car that the engine is going to see 2000 to 2800 rpm all day long driving with a few 5500 rpm shifts but they will not last in a marine application. You need to shoot for a minimum of 130# seat pressure at installed height.
Chris
Are you running hyd flat tappet or hyd roller. If you are running a roller you better re-think that spring choice. Sure those are fine for a car that the engine is going to see 2000 to 2800 rpm all day long driving with a few 5500 rpm shifts but they will not last in a marine application. You need to shoot for a minimum of 130# seat pressure at installed height.
Chris
Those are the springs that came in the engine stock.
The stock cam is going back in my engine so I don't know why a new set of stock springs wouldn't work?
The last set lasted 480+hours...
The stock roller cam is vary mild...
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Patrick
Patrick
Last edited by Pat McPherson; 03-11-2005 at 07:26 AM.
03-10-2005, 07:50 PM
#8
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Thread Starter
Re: 502 Mag MPI cam specs
Thanks Bob
It appears to be a smaller cam than I figured on. I might have to go a little bigger
It appears to be a smaller cam than I figured on. I might have to go a little bigger
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03-10-2005, 08:33 PM
#9
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Re: 502 Mag MPI cam specs
Originally Posted by cstraub
Pat,
I wouldn't be that lucky. How much shim did they take after the seat were ground?
Chris
I wouldn't be that lucky. How much shim did they take after the seat were ground?
Chris
There is a shim/washer under the springs, but I don't know how thick...
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Patrick
Patrick
03-11-2005, 07:24 AM
#10
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Re: 502 Mag MPI cam specs
Originally Posted by Bigwavz
Thanks Bob
It appears to be a smaller cam than I figured on. I might have to go a little bigger
It appears to be a smaller cam than I figured on. I might have to go a little bigger
So what cam is the logical upgrade for a 454 or 502 MPI roller cam engine?
Personally my budget would not alow for all of the after-market goodies required for larger cam. Not to mention the ECM calibration issue.
Bob (rmbuilder) is there a little larger cam that could be used with the stock GM stuff and would not require ECM recalibration?
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Patrick
Patrick
