want to put a 10-71 on my 502 motor.
10-24-2012, 05:21 PM
#1
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want to put a 10-71 on my 502 motor.
Ok, here is my plans. I want to put blower on my 850 carbed 502 (which is in the boat now) for next summer. While/until I can convert my 540 drag motor to a blower motor and upgrade my lower unit. Got few questions. I don't plan on any more(MAX) than 8 lbs boost on the 502. Its got 9-9.5 comp. now with AFR 320 alum heads.
Questions
#1.....I've already have 2 850 holley double pump carbs, can I make them work (since I already have them)even though the formulas say that a couple of 750 0r 800's would be better suited?
#2......its got a 500 hp camshaft. Do I need to swap out for a blower cam?
#3..... the heads on drag motor are Pro one 355 CNC ported, should I put those on the 502 motor? Will the bigger heads help or hurt an over-carbed motor? And what about the torque? Are those heads too big for mild 502?
P.S. This will be just a weekend fun run boat(502) with few hrs. put on it. And won't be ran hard until I can afford to swap out the Bravo1
Questions
#1.....I've already have 2 850 holley double pump carbs, can I make them work (since I already have them)even though the formulas say that a couple of 750 0r 800's would be better suited?
#2......its got a 500 hp camshaft. Do I need to swap out for a blower cam?
#3..... the heads on drag motor are Pro one 355 CNC ported, should I put those on the 502 motor? Will the bigger heads help or hurt an over-carbed motor? And what about the torque? Are those heads too big for mild 502?
P.S. This will be just a weekend fun run boat(502) with few hrs. put on it. And won't be ran hard until I can afford to swap out the Bravo1
10-25-2012, 04:48 PM
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The short block is suppose to be a zz502 create w/ a 500hp cam and the 320 heads. Im not sure what cc the heads are. I haven't pulled the motor yet to find out whats in it for sure. I just bought boat and motor in Aug. I have seen extra thick head gaskets, any idea how much compression I can kill w/ those?
10-25-2012, 05:04 PM
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The ZZ502 was 9.6:1 with the 110CC chamber heads. If your using the GM Rect port Iron heads, they are around 119cc. That combo will get you down around 9:1. With a slightly thicker head gasket, you can probably knock off another .2. But, you really need to measure the quench area, and cc a chamber to be sure. If the piston's in the hole .020, you dont want to run a .066 thou headgasket, and have .086 quench height. I'd keep it around .040- .060 on a supercharged deal, and around .035-.050 on a N/A.
10-25-2012, 05:11 PM
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The ZZ502 was 9.6:1 with the 110CC chamber heads. If your using the GM Rect port Iron heads, they are around 119cc. That combo will get you down around 9:1. With a slightly thicker head gasket, you can probably knock off another .2. But, you really need to measure the quench area, and cc a chamber to be sure. If the piston's in the hole .020, you dont want to run a .066 thou headgasket, and have .086 quench height. I'd keep it around .040- .060 on a supercharged deal, and around .035-.050 on a N/A.
10-25-2012, 06:34 PM
#10
