Compression Ratio Question

I've been looking for info on compression ratios versus head material and octane ratings.

I've found a 351 that was recently rebuilt stock and I've also found two sets of GT40P heads that I like.

Does anyone know what kind of compression ratio I can run with the iron heads and 93 octane fuel? Reason I ask is there are two sets of heads available, one set has been milled 0.030" and the other set is still stock. I think the milled heads will give a comp ratio of about 10:1 while the stock heads will give about 9.50:1.

I have a Griffin aluminum radiator and a Taurus electric fan for cooling. I'll be running a Weiand Stealth dual plane intake for now with a 650 Holley. Also, long tube headers I think, not sure, haven't looked too deeply into 351/Fox headers yet.

Any info or knowledge is appreciated.

Don

In my (un)expert opinion, I don't think that 10:1 compression ratio is too bad for 93 octane. You'll have to be careful with the mixture and timing, but it should be doable.

Good luck finding the long tube headers that will fit both a 351, and a GT-40P.

Tell me more about your fan setup, please. What year Taurus? How did you mount the fan? How many amps does it draw? How are you controlling it? Have any pics?

Later,
Mike.

[quote="Aug"]In my (un)expert opinion, I don't think that 10:1 compression ratio is too bad for 93 octane. You'll have to be careful with the mixture and timing, but it should be doable.

I agree.

The one I bought is from a 94 Taurus. It's a 2 speed. The key is the dimensions from what I read. It's exactly the right size to fit my radiator between the tanks and top to bottom 17x22x5.

I'm just now wiring it up and haven't run it yet! I bought it in the fall but the motor is out of the car now and so it's untested - other than applying 12 volts to be sure it spools up. It came with a wiring diagram for the two speeds for cars without electronics. I'll try scanning it in and posting later this week.

So, short story shorter, still a work in process!

As I get it installed I'll post info and pics though.

Don

10-1 is about the limit on iron heads. you could go a little higher with aluminum. btw, mac makes longtubes for your setup.