OK, I have a 69 302 I got from the junk yard...but it came out of a 84 mustang. I beleive it was a remanufactured engine. Anyways, I'm getting closer to having it rebuilt. What I want is to have a 302 that has good power but it doesn't have to be a torque monster...I'm going for the sound, the lopey idle. BUT...The numbers on the heads say that they are TRUCK HEADS...with 69cc chambers. With the speed pro flat top pistons I am going to be using, There website says that with a 69cc head I will only have a little more than 8.1 compression. I have been looking at Crane cams and can't find a cam that would give me a mild to rougher type idle unless it is like 8.5 or higher compression. I'm not planning on racing the truck or anything like that...just a hot rod type vehicle thats sounds good and when completed I would like do drive alot. Does anybody have any recommendations on cams that would give me a noticeable idle and would run ok with that low compression. Or will I be stuck going with a regular stock like cam

PS: I do not know much about compression...for instance, If I did put a performance cam in the engine with 8.1 or so compression while the performance cam needs 9.0 or higher compression...would I have to run racing gas for it to idle?
Can some one enlighten me about compression too?

 

You can shave the head or the block to up the compression a little bit. Your engine builder should be able to help you figure out how much and where to shave.

Or you can go with different heads - depends on your budget.

Also, with a lopey cam like you're talking about, it's not going to have good torque down low. If you want the sound, you can get close with the right exhaust.

 

I would think nearly any other small block heads would be better than the ones you have there reed1951. E7TE's are relatively cheap and abundant, and they should be quite a bit better than the heads you have, with their colossal 69cc combustion chambers.

 

But can the E7TE's heads fit directly onto the older block? I have herd they are different some how and you have to drill holes or something for them to work but I don't know much info about it. I'm curious about putting on E7TE's...i have some in the garage. Actually they are E5TE's but they are practically the same, They are truck heads from an 87 5.0 pickup. Is there anything you have to do special when putting newer E7 heads on older engines?

 

Typically, with a quality rebuild, the deck of the block will be checked for flatness, and milled if required. Also, with a quality machining, the decks will be brought to the same distance from the crankshaft centerline, maintaining equal compression in all cylinders, assuming the combustion chambers in the heads are all of equal volume. The same applies to the heads. They should be checked for cracks, and warpage or flatness. In a major overhal, the heads should be gone over thoroughly anyway, especially if you're going with a high performance cam. Cam companies spend a lot of money doing research to find the optimum spring to compliment the cam. Sometimes, this requires additional machining to allow the use of the proper springs. Failure to use the proper springs can result in valvetrain failure, usually as a result of not enough spring pressure, causing the valve to "float" on opening, or "bounce" on closing. I highly recommend buying a total package of lifters, springs, retainers, etc. from the same company you get your cam from. Rebuilt heads are probably the best way to go in your situation, using your old heads as your "core". Plus, you should be able to find a set with the chamber volume you want, once you settle on the comp. ratio. Don't be afraid to talk to your machinist. Read everything you can get your hands on about comp. ratios and camshaft function. Trying to explain just a small portion of either would take all night. Go to Comp Cams' website tech section. The Edelbrock catalog has a lot of tech in it, along with formulas to figure c/r, horsepower, gearing,etc. Google Ford Racing. Isky Cams has a great tech section. Small rant- don't believe everything you read in the supposed "hot rod" magazines-rant off. For professional advice, go to the source- usually the manufacturer.
Just remember- the camshaft is the "heart" of your engine, and the heads are the "lungs". They have to work together well, or you're wasting time and money.



Pete

 

No way around it. You are going to have to match the compression with the cam you want to run. If you don't, you have a complete dog. I would recommend that you save your money and get a good set of aftermarket heads. Iron heads are fine for the street and relatively cheap compared to modified production heads. Remember, there is never enough money and time to do it right, but plenty of money and time to do it over. Been there, done that.

 

Thanks guys