i just got some ported afr 220's and want to gasket match my LT1 intake. how crucial is it to get it right? being FI i didnt know if i could hurt anything by taking the ports all the way out to the gasket but with NA you have to be careful where you port! anyone know?

 

I would imagine it's all the same. The engine doesn't know/care if it's getting extra pressure from the atmosphere vs. a turbo/supercharger.

 

well i was thinkin that being na u might have to worry about angles and the path the air takes, where as in fi the air is being forced in! if that makes sense! lol!

 

IMO, You need to make sure the ports are aligned (LT4 heads vs LT1 intake don't align without some work).

 

I think what realquick said is important. Since its almost impossible to tell once the manifold is on there, i think its best if the manifold is slightly smaller then the head port. Think what you dont want is the manifold port bigger then the head port. If thats the case, the head port will overhang in the airflow and cause a worse restriction.

Ken R.

 

First of all, gasket matching is every bit as important on FI as it is on NA. The mechanism for air entering the cylinder is the same. The whole point of an efficient runner/port is to try and get as much air as possible out of the plenum and into the cylinder. This is the case regardless of the pressure in the plenum.

That said, gasket matching is an easy and worth-while exercise, but not where the greatest gains are on the LTx intake manifold. Grinding out .100" material from the top of the port where the injector clearance hump is will net a far greater return.

Also, I didn't think a LT1 intake manifold would work on AFR 210/220 heads. I thought I checked it and you could literally SEE into the runner with the manifold in place on the heads. There wasn't enough meat on the upper side of the flange to even cover the hole.

Mike

 

id like to update this, i got a lt4 ported by le. and man this thing is ported!!!!! right where the injector bump is there was material added and ported all the way out! i will go out on a limb and say i dont see how you could port one more!

 

I port matched my AFR's to my intake by using a mirror on an extension. Found where there was overhang and matched from there. Every single one had some work to be done to get rid of lips.