Need more power!

[chipperb]

Have fresh 302 HO with single Holly double pumper and AFR 165cc heads. Ws plenty of power, now want moe: question: would addind second four barrel, hoter cam and alum rocker arms give me sig more power? TY cb

[Barnsnake]

If you want "significantly" more power without a major loss of drivability, you need more displacement. You could stroke the 302, or move to a stroked 351. The latter option would require new (or significantly modified) headers. There's certainly more power potential in a 392, 408, or 427 Windsor than any 302-based motor. The torque increase also helps the drivability.
Pushing the 302 to anywhere near those power levels would likely make it unpleasant to drive anywhere but a racetrack.

[lovehamr]

I think a supercharger would do nicley in that application. Paxton, Vortec, Weiand, Eaton; all are possibilities and could boost your power by 40% with relative ease.

Steve

[blykins]

Working with such a small displacement limits you on what you can achieve, but it also limits you on streetability as you start playing with parts. You can add more head, a larger cam, etc., but street manners and low end power slowly go down the drain.

I would follow the suggestions of Barn and Love.....either increase the displacement or throw a blower on it. I don't like forced induction myself, so I would vote for a stroker kit.

[wtm442]

Originally Posted by lovehamr

I think a supercharger would do nicley in that application. Paxton, Vortec, Weiand, Eaton; all are possibilities and could boost your power by 40% with relative ease.

Steve

or maybe a turbo or nitrous.

[Excaliber]

I'd run a super charger, much easier than dealing with a turbo and far less complex. HOWEVER, I wouldn't blow it if it didn't have forged pistons and a compression ratio that would be reasonable with a blower.

Typically 302's do not come with forged pistons, making a blower a bit risky.

[lovehamr]

There are literally thousands of otherwise untouched blown 5.0 liter mustangs running around with no ill effects. All you have to do is keep the boost to a reasonable level and use good gas. My daily driver Tacoma (also my tow rig) is equipped with the TRD/Eaton supercharger with no other changes. That truck has pulled my Mustang through the Blue Ridges twice and back and forth halfway across the country. Now with 150K on the engine/supercharger combo it still uses no oil between 5Kmi oil changes. The point is; to get that “major increase in power” without a loss of drivability then the displacement will have to go up (i.e. new motor) OR he can keep the one that he has and boost it. Anything else (i.e. big cam etc.) would boost the power and kill drivability. Plus the installation of a centrifugal supercharger is a weekend’s work at most, much easier that a rebuild or even a cam swap. Now all that doesn’t mean that Ex is not right in that forged pistons would much better, but I don’t consider it a deal breaker because what ever you do to increase power will increase stress on the pistons, not just supercharging.

Steve

[bobcowan]

Second carb: Oddly enough, most dual quad set ups for 302's actually lose power; especially at the low end. The only one I saw that actually made power was the Summit Racing kit. And it wasn't a huge amount of power, either.

Alum rocker arms: That will make the valve train lighter, but won't provide a significant power increase. If you increase the ratio, you can gain a small amount of power.

New Cam: Now this is where you can pick up a lot of power. What do you have now? You can use a pretty healthy cam without losing drivability and mileage, especially with 165 heads; which are perfect for a mild 302. Even with a moderatly large cam, your intake velocity will still be high. Go to the Comp Cams web site and read the descriptions and maybe pick a better cam.

Blower: Probably the best bang for the buck. You can easily pick up a 35-40% increase with 2-3 days work. But they can be tricky to tune. Lots of engine have been destroyed with a poor tune. So make sure you have a dyno shop that can tune this well. That will be expensive, but worth every penny.

[Excaliber]

Blower tuning, that was really my point. Without forged pistons there's little room for error. Octane to low, timing to advanced, lugging the engine under boost, anything that might lead to premature detonation is bad news. Get it right, right away.

Electronic fuel injection and computer control usually incorporate a knock sensor and can immediatly reduce the timing when needed, saving the motor (pistons). With a carb and a typical MSD type ignition, your on your own.

[jdean]

Stroke it. Cheap way to add 50 HP.....and more importantly lots more torque for driveability.

[chipperb]

Thank You all!

This engine is in my newly completed GT40 replica:

351: won't fit with out lots of mods

blower: a real possibility IF it will fit,

Cam: yep: was a Car Craft article on a 302 with 165 heads and a nice cam:

stroked: maybe in the future.

Another question: how about a solid linkage for the carb secondaries vs present vac operated secondaries. c

[ENTDOC]

the second linkage will make little difference I suspect. Putting a blower in a 40 may be tough. What kind of transaxle are you running? That will make a difference in how much power you can handle.

[lovehamr]

Originally Posted by chipperb

Another question: how about a solid linkage for the carb secondaries vs present vac operated secondaries. c

#1. And I'm only answering like this because of the way the question is worded; No! Do not try to put a solid linkage where the vac. secondarys are now. W/O the extra accelerator pump it would fall flat on its face any time you opened it up.

#2. If you meant go with a double pumper type carb; I have to ask why? If the carbs are similar in size then your net gain would be negligible. It might jump off the line slightly quicker but then that’s not what most people do with GT40s. If you go with a larger carb just make sure it matches the rest of your combo or drivability problems could be the name of the game. Its worth considering as well that your engine will be more well mannered with a larger carb if it has vacuum secondarys because they won’t open until the engine needs them.

Steve