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What is the best way to increase the performance of a 302, right now what i have is a MerCruiser 302 that was just pulled out of a racing truck. It has dished pistons, 85 ho heads, double roller timing chain, Edelbrock Perfromer 289 Intake, mild performance cam (not sure exactly what it has exactly) and a Holley 650 cfm Double Pumper. What is the best way to squeeze some more power outa this small block?
Stroking, nitrous (forged pistons) forced induction (turbo or supercharging) which means pistons (dished) again, a good ignition system, and a more radical cam come to mind. I found some REALLY good deals on stroker parts cheap. If you're interested, PM me and I'll hook you up.-Pete
Taller intake such as an Edelbrock RPM Air gap, higher lift camshaft, ignition system, underdrive pullies, high volume fuel pump, flat top pistons, high performance clutch, or a shift kit for a auto, there are many different things you can do on a budget. And last but not least, a heavy right foot! email me if you have any questions..... Jordan
Taller intake such as an Edelbrock RPM Air gap, higher lift camshaft, ignition system, underdrive pullies, high volume fuel pump, flat top pistons, high performance clutch,
Not to be critical, but I don't agree with these suggestions,
-Already has an intake - doesn't need one
-Already has cam - doesn't need one
-Stock ignition acceptable at this point
-underdrive pullies are worthless - poor bang for buck - hardly improve anything
-current fuel supply has room to go
-flat top pistons require complete teardown
-doesn't need clutch at this point - stocker is fine
Have you got a full exhaust for this engine?
Find out what cam you have in that.
I'd say you can't do much else without opening a can of worms. Swapping heads will probably be your next move. But the head you choose should be the final choice considering it's cost and it's need to match the intake, cam, and exhaust. I wouldn't go put a big head on that engine w/o swapping everything else...
Last edited by MustangGT221; Jan 27, 2006 at 12:42 AM.
302's came with non roller timing chains and flat tops back then right? Someone has been in this engine and added a double roller timing chain and dished pistons and also put 85 HO heads on. I'm running 3rd cylinder back dump headers with a exhaust system that came with it. Isthere any way to see what the cam is with it in the engine?
Find out from whoever did the work - or you'd have to measure it with a dial indicator and degree wheel.
The 85' heads are nothing special - there are several aftermarket heads that will seriously out flow those. That's why I am saying that heads are probably the next move in line - but swapping heads will also probably mean that you'd want to also change the intake or work the intake over, and do more upgrades with it.
So you're better off just leaving it alone until you're ready to completely re-do it to the way you want it vs in pieces. That goes for any engine work - much easier to do it all at once. You can't easily modify things over time unless it's just sitting in your garage.
Last edited by MustangGT221; Jan 27, 2006 at 03:27 PM.
Tried to get ahold of the builder but the guy i bought it from said the guy that built it went to SouthDakota, so i guess i'll have to use the degree wheel. Jeff said it sounded like a mild performace cam, kinda like a hotrod.....
Well, mild or not it doesn't tell ya anything. All it means is that it could be a little more aggressive than stock. A marine engine is intended for low RPM (4000 or less) use with a lot of torque so the cam is going to follow suit. The cam you have could be who knows what.
Someone mentioned looking for a #, i'll just have to borrow a degree wheel or just say $@#$@# it and just put er back together the way it was and call it good.
A stock cam may have a number on it - not sure if yours would - but the specs wouldn't be printed in it. They come on the cam card when you purchase it.
Do you just have the cam in hand or is it in the block? If in hand you may be able to bring it to an engine shop and have them tell you what it is - or use the degree wheel and dial indicator for if it's in the block. You setup the degree wheel, and turn the engine over with the dial indicator measuring it, it's a precise process. Should be able to find some tech articles on the web as to how to do it - or in an engine building book.
Good engine builders always check the cam specs when building an engine to make sure they got the right cam and it didn't get switched in shipment.