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I could tell you a basic recipe that I helped a friend/oso member with .
Stock brand new GM 502 shortblock assembly. Engine Quest 320cc heads (stock no porting). Isky valve springs, Ferrea Super Alloy valves, johnson hyd roller lifters, 242/250 112 LSA custom comp cam with .630 lift , Merlin single plane brass lined intake, 850 Quick fuel marine carb. This was a budget build platform to replace the worn out 502 mags, run on 87 octane. (8.7:1 static compression). Engines were dynoed in full marine trim, all accessories and wet marine exhaust 34* timing. They made 570hp and 550ft lbs. With some dyno headers, and no accessories , prob would have made 600ish. Nothing fancy, just basic build with all new parts, with main goal of reliability. |
Originally Posted by MILD THUNDER
(Post 4602072)
I could tell you a basic recipe that I helped a friend/oso member with .
Stock brand new GM 502 shortblock assembly. Engine Quest 320cc heads (stock no porting). Isky valve springs, Ferrea Super Alloy valves, johnson hyd roller lifters, 242/250 112 LSA custom comp cam with .630 lift , Merlin single plane brass lined intake, 850 Quick fuel marine carb. This was a budget build platform to replace the worn out 502 mags, run on 87 octane. (8.7:1 static compression). Engines were dynoed in full marine trim, all accessories and wet marine exhaust 34* timing. They made 570hp and 550ft lbs. With some dyno headers, and no accessories , prob would have made 600ish. Nothing fancy, just basic build with all new parts, with main goal of reliability. |
Originally Posted by Fitchpowerboat
(Post 4602076)
How high did those motors turn seems like the duration if measured at .050 would be suited for some Rpm but I am by no means a cam expert. Either way very good numbers for such a mild build
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Originally Posted by justintocars
(Post 4602045)
What is a reasonable time frame for springs? I know it is dependent on cam lift to an extent, but with what I have I cant go to radical anyway.
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Tanks everyone for the info.
Originally Posted by MILD THUNDER
(Post 4602072)
I could tell you a basic recipe that I helped a friend/oso member with .
Stock brand new GM 502 shortblock assembly. Engine Quest 320cc heads (stock no porting). Isky valve springs, Ferrea Super Alloy valves, johnson hyd roller lifters, 242/250 112 LSA custom comp cam with .630 lift , Merlin single plane brass lined intake, 850 Quick fuel marine carb. This was a budget build platform to replace the worn out 502 mags, run on 87 octane. (8.7:1 static compression). Engines were dynoed in full marine trim, all accessories and wet marine exhaust 34* timing. They made 570hp and 550ft lbs. With some dyno headers, and no accessories , prob would have made 600ish. Nothing fancy, just basic build with all new parts, with main goal of reliability.
Originally Posted by Griff
(Post 4602106)
With a 731 cam and some good Isky springs, probably 300 hrs.
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you may be able to have a cam ground like the 731 w/ mid .500" lifts and then the springs should g 4-500hrs.
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Originally Posted by justintocars
(Post 4602149)
That sounds good, is the power usable at that rpm? Im just asking because I dont know... . Like sutphen said, you could go with a cam with less lift, like in the 550-575 range, and some isky tool room series springs. That should get you into the 500 hour range before needing to touch it. |
On a motor like this if you reduce lift do yo give up all the horsepower and torque, or does it just move the power down the rpm range?
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