Thread: Your opinion on a 502 build please.

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I am upgrading the tried and true 427 big block in my ’72 Nova. Just picked up a zz502 short block. I wish to retain the short block as-is with the exception of the cam, and want to go with a larger roller. A cam that I’m considering is an Edelbrock is as follows:
#2264

ENGINE: 500+ (1991 & Later Gen V & Gen VI)
RPM RANGE: 1500-6500

Duration at 0.006" Lift: Intake: 308° Exhaust: 315°
Duration at 0.050" Lift: Intake: 248° Exhaust: 256°
Lift at Cam: Intake: .371" Exhaust: .381"
Lift at Valve: Intake: .632" Exhaust: .648"
Timing at 0.050" lift: Open Close
Intake: 14.5° BTDC 53.5° ABDC
Exhaust: 62.5° BBDC 13.5° ATDC
Centerlines: Intake Centerline - 109.5° Exhaust Centerline - 114.5°
Lobe Separation: 112°

I have a 1050 Dominator I’ll be using with an Edelbrock Victor manifold.

What I’m hoping to get is advise on is the heads for this engine. I’ll need a small-ish combustion chamber to get the desired 9.5/1 to 10/1 ratio I desire. Approximately 110cc chambers I’m thinking. The ZZ502 head gasket is .040. Is there a thinner one available? My big question concerning the heads is intake runner volume. Some heads I’d looked at were Edelbrock’s Victor Jr. 24° Rectangle Port or the E-CNC 355 - Rectangular Port. The Victor Jr. comes in at 300cc intake runners where the CNC 355’s are bigger at 340-ish.

I’ve listed Edelbrock stuff but this is just where I’ve started looking so would consider other manufacturers as well.

The car will weigh approximately 3400lbs. It’s got a turbo 400, 3500-stall converter. Rear end is a 4:11 geared 12 bolt with 28” tall tires. The car will see very short trips on the street very occasionally, and may make a pass every now and then at Pacific Raceways as well. I want these street trips to be an exercise in throttle control, with more HP than the tires can handle just a blip of the throttle away!

Thanks!

I think you'll need at least 12.5:1 static compression ratio to run that cam. All the good heads seem to be cast in 119cc chamber size, so it will take a pretty healthy lump on the piston crown to get you where you need to be. A 41cc dome should get you in the ballpark.

Most aluminum head manufacturers will recommend a certain composition gasket for use with their heads to prevent Brinelling. These gaskets will be in the neighborhood of 0.040".

I am totally dismayed at the advertising gimmicks of some manufacturers. In this episode, Edelbrock claims this cam makes power 1500 to 6500. BULL HOCKEY. Camshafts have a range of 3000 rpms in general and some may be effective in a 3500 rpm range. To say that this cam is effective in a 5000 rpm range is just not professional in my opinion. They're just trying to be everything to everybody. I'm seeing the cam as effective 3000 to 6500 at best and more like 3300 to 6300 if you want to get realistic.

i had my hands in more then one 502 .the deal is much like tech said the pistons are a je piston with a very small dome so you have to watch your ccs of your new heads i would not look at a head bigger then 310to320 .that cam is wild i know i use a cam a hair bit smaller in my street 496 s and its got some hair on it .if you bore this 502 out to 4.500 you can run a shelf piston that you can get some CR with and a solid roller with some 320 runner heads and it will run very good built some. or step down on the cam and use the zz502 head thats what the piston was built for. we run the 355 cnc heads on 540and some 565 that head on a low cr will not work very good less you have a blower or turbo pushing air threw it head needs 750+ lift to shine and you will need some CR to make the cam and heads work. OH most all felpro race head gaskets will work with ALUM heads i used them all .. gasket for the mark 5 and 6 are not the same. older mark 4 gaskets or heads will not seal up on the mark 5/6 deck..... your can use the fel pro f1047 4.540 bore and there others makers but that gasket works fine

I had a talk with a great tech at Comp Cams, Justin. I described the project and he recommended going with large ovals such as the heads that came with a ZZ502. GM performance p/n 12363391,
valves 2.19/1.88, 110cc semi-open chambers with a intake such as a Victor 454-O/4500. The cam he suggested was a #01-424-8,
242/248 @50 Duration, 545/560 lift. What do you think?

with so many 900-1000 cfm carbs available I would stay away from a dominator 4500 for the street

The reason for the 1050 is I already have a nice one that is set up and dialed in for street use.

Originally Posted by vetski179

I had a talk with a great tech at Comp Cams, Justin. I described the project and he recommended going with large ovals such as the heads that came with a ZZ502. GM performance p/n 12363391,
valves 2.19/1.88, 110cc semi-open chambers with a intake such as a Victor 454-O/4500. The cam he suggested was a #01-424-8,
242/248 @50 Duration, 545/560 lift. What do you think?

I believe them are similar to Edelbrock's RPM heads. That's what I've read anyway. I'd go with a set of AFR heads. They can mill them to reduce chamber volume if needed.