Thread: How much to take off of Edelbrock fe heads

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I currently have 9.0 to 1 compression with edelbrock alum heads on my 30 over 390 in a 63 gal conv. How much has to be taken off to achieve 11:00 to 1 compression? Recommendations regarding a 3 angle valve job, porting? Thanks, ling102.

First I would cc the heads pistons measure the deck and gaskets to calculate the proper compression ( use the calculator at RSC just google compression calculator) then you can vary the results to see what amount you need to loose to increase compression. However head and block shaving can only go so far before you affect intake manifold sealing. 11 to 1 is a bit high for any street car 9.5 is usually max for cheep pump gas 10 plu is premium and retarded timing. I believe though you need to change pistons to achieve that much change( domed with valve reliefs) Head porting is tricky usually you want to only increase the top and bottom of the port for volicty air flow wider tends to increase volume but slows the air down at slow rpms.
plus be carefull how much you remove, water flows around the ports. match as close as you can to the gaskets and in only about 1/2 in or so adn then just smooth out the ports. valve wise just get the heads built if they are not already ( hard seats , guides, valves,) I know its expensive but in the long run its worth it.

ace


Acepatt

ling, you're starting with one of the heaviest cars that was ever produced by a manufacturer. You could bolt two 390's in the car and it still wouldn't be fast. What is your goal with the car?

Originally Posted by techinspector1

ling, you're starting with one of the heaviest cars that was ever produced by a manufacturer. You could bolt two 390's in the car and it still wouldn't be fast. What is your goal with the car?

i had a 64 conv with the stock 4bbl 289 all original and that thing was fast when you got it rollin, it was just slow off the line

With a big ol' boat like that, you don't want really high compression. It takes too much throttle to keep her moving, getting it into "pinging" too much. Much like a pickup truck, too much CR makes it a dog to drive.

yup.... 9.0:1 would be a good ratio, rear gear should be a 3.73-4.10 for a good streetdriver, you cant expect too much top speed out of those rear gears, but in a boat going to fast gets scary, the frontend likes to float too much

Plans have changed. The motor is out of the car after a bad soft plug was revealed. The block is at the machine shop as I write this. I will let you all know the outcome as I know it. Also, yes I know it is a barge! I had the occation to ride in a 390 1963 Galaxie in 1966. Incredible!! Rubber in 3 of 4 gears. That is what I am trying to improve upon. Hopefully 4 for 4. I know I could go to a 460 with the right parts. However, I am partial to FE's. OLD SCHOOL!!!!!!!! Thanks again.........

goodluck with the machinist.... i like FEs as well... i'd put one in my mustang, but i'd have to do a lot of cutting to make it fit..... plus i dont think i'd be able to find an FE bellhousing to fit my t-56

i read a article about getting 410hp out of a 390 with not a lot of work.

There was a good article in street rodder mag several yrs ago about building f/e's. About them being slow, in the area I live in there is a 63 box top that does 4'wheel stands, and runs in the 8s in the 1/4 mile. crites has a excellent article about using t-bird disc on the ft. I had a 521 /460 eng in one, easy swap.