Carrera intake on 83 3.0 - intake/head port matching?
 

I'm considering an EFI installation on my 83 3.0L engine utilizing the Carrera intake and megasquirt.

I read through the archive and some people mentioned port matching the intake to the head - it's 41mm for Carrera intake and 34mm for 83 SC heads, if I recall correctly. Also, there seem to be an issue with injector groove which has to be enlarged on the SC head.

Are these modifications absolutely necessary? I plan on doing a rebuild within a couple years, and would like to run EFI in the meantime. Obviously the mismatched port size is not optimum but how much is it going to affect the drivablility of the car? I'm not looking to get every horsepower out of it, at least for now. Same thing for the injector groove. I really don't feel like taking the dremel to the heads while they're still installed on the car. I suppose I can put a shop vac over it and try to suck up the debris but I want to avoid it if possible.

How did you guys get around these issues?

I just remembered, I can have spacers made with tapered bore and use them in place of the original phenolic spacers on 3.2 engines. It's not the best solution but it should better than a 7mm step.

Can the injector groove issue be resolved by using the spacer too? I don't have the SC head to look at right now so I can't tell where the material has to be ground off.

If I do use the spacers, how hard is it to change the intake studs?

I ended up welding the injector notch on my 3.0 heads then porting them for the new injectors.

forums.pelicanparts.com/uploads9/1168927804.jpgintake+Adapter

Sorry, the picture isn't working!

I did find this thread: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/296579-930-efi-conversion-process.html

Note the bakelight spacers near the end of the page.

What exactly is the issue with injector grooves? Is the SC head blocking the injection path?

PS: In the above thread, Jim mounted MSD knock sensors on the intake and apparently they work well! That's an interesting way to incorporate knock sensing with aftermarket ECU. I'll definitely give that a try.