Horsepower boost for 302

[jimd5447]

I have a 1989 302 EFI which I purchased and installed. It has aluminum heads. supposedly forged pistons, 70mm throttle body and a f303 cam.
The idle is a little rough, but it runs fairly strong. On a dyno it showed 238hp at wheels. i think it was well built, but may be a little tired or needs more help than I can offer. Question???
What is the best way to revitalize this 302..maybe get another 50-75hp.. or should I just go with a new Crate Engine..Carb or EFI.. Looking for the best bang for my buck.
Thanks,
Jim D

[powerhouse]

were all the cylinders firing? a combo like that should put out 275-300hp at the wheels.What does it have for an intake and heads? I would do a leakdown test and make sure there are no major problems. If that is ok I would assume your tune is way off, Or your current parts are very mismatched.If you can give me a detailed list of the engine parts I can give you a good idea of what you need to do to reach your goals.

[MJN]

Jim

What intake are you running? A stock '89 intake will significantly restrict your HP potential. Also the stock 58mm MAF sensor won't help much either. Post a few more details on your set up if you can.

[nc1mike]

Jim, a stock 5.0 makes about 188-195hp at the rear wheels. So your'e about 50hp on the plus side. I am no fuel injection expert, however i do know that they are sensitive to fuel pressure and ign. timing. When you say it idles a little rough, many times this is a bad state of tune rather than a lumpy cam. Fuel pressure regulators go bad or are not set correctly and cost a lot of hp. Almost all the 5.0 I know of make good hp to the day they die, and thats with almost 200k miles. I'm not fan of replacing engines w/ crate motors just because...I say scope the engine and repair if needed. Then tune to the max.. there may be another 30+ hp lurking inside. Just waiting for the fuel ratio and ignition timing to be corrected..research and testing is a lot cheaper than a crate engine.
Best of luck
Michael S.

[jimd5447]

Well thanks Guys! Here is some more info.. It has Edelbrock Performer Heads, I know this for sure because I can see them..`also a F303 cam, 24lb injectors and a 70mm throttle..which I do not have the knowledge to verify.. and a Cobra efi manifold.

[powerhouse]

through a standard tranny that should easily make 275 at the wheels. The factory stock engines I build with stock cams,unported gt40 p heads and cobra intakes make 290-300 at the wheels, with peak power around 5300.
Do a leakdown test. If that looks good, get it tuned and you should reach your goals.
good luck Andrew

[jimd5447]

Thanks Andrew ...but what is leak down test?

[powerhouse]

Aleakdown test is putting pressurized air into the cyl. with the valves closed. Aleakdown tester is a tool with 2 pressure gauges on it. one reads the line pressure and the other records the pressure that the cylinder will maintain. most use 100psi as the setting point. A good leakdown test will be under 5%. any more than that and you are loosing power. Make sure to do the test with the engine at operating temp. Most parts stores sell the leakdown tester. they usually go for $60-$100

[Tims 88GT]

huh that does not sound right with my mods i make about 240 to the tires, what is your timing and fuel pressure?