I found some dirt cheap non-PI heads. I need to know if 99+ mustang GT cams/springs/valves will work on these heads, and if it will be expensive to have them milled down a little to bump compression.

Also, how much material should be taken off the heads?

Thanks! And I'll be contacting you about a tune for the heads when it gets closer to the time!

-Flea

 

Flea,

Don't touch the heads. Your CR will go up to around 10.5:1 just by using the PI heads. The CC volume is 49 cc on the PI heads and 52 on the non PI heads. Either you do them of have a shop inspect them.
Make sure they are not cracked and the mating surface is flat. Nothing sucks more than to have parts installed and they fail.

JMC

 

I wouldn't touch them, if the were PI, but unfortunately, they're not. So I just wanna know how much I can take off and get around 9.5-10:1 c/r.

-Flea

 

Hi Flea,

Good to see you again!

For details about cylinder heads, you'll need to call us - that really isn't applicable to the Computer Chips section.

Exactly how much you need to shave the older heads to get the compression up to 10:1 will depend somewhat on which head gasket you use - I'd talk with your machine shop that is going to do the work about that.

The '99 & up Mustang cams are significantly higher lift at .505/.534, so even the PI head truck owners have used those cams to upgrade their PI heads.

Keep in mind that when you do raise the compression the engine should be re-tuned to make sure you don't detonate, and you'll always need to run premium gas from then on as well (even on the factory program), due to the increased cylinder pressure. Since they are the non-PI units, you'll probably also want to have them work on the swirl fin in the combustion chamber that's right next to the intake valve to unshroud it & help it breathe better. (Thats just one of numerous improvements that were made on the PI heads, a much smaller swirl fin.)

Good luck!

 

Thanks, Mike! I figured that it's out of place, but I wanted to get your take on it, as you're kinda the authority on modular motors and tuning, etc.

It'll be a couple months project, as I'll be upgrading injectors (may as well; this should push me past the working range of the 19# units), and I want to have room to grow. Also, I'd have to do things in steps, as I'm a little short on cash to do this all in one fell swoop. Just curious, though... I've got the Flip-Chip, and was wondering if you could tune it for an every-day 92 octane and an agressive/Saturday night 92 or 100 octane tune?

I'll be calling you sometime soon to go over this in more detail. Glad you're feeling better, and thanks for the nice Christmas card.

-Flea