Well, I will have the intake off the car shortly and need some things cleared up.

1. Are the ports on the intake manifold smaller than the ports on the head or is it the other way around?

2. If the ports on the intake manifold are smaller than the ports of the stock head, what would port matching them do? Would it improve flow and velocity in the port (leaving stock heads the same)? (NOT GASKET MATCHING!)


-Would the effect of this be the same as opening up the intake runner of the head - lower velocity at lower rpms but better flow up top or would the velocity only improve (result being no lowend loss but a hopeful gain elsewhere)?

I did use search - anyone have pictures of this bulge that is cast into the intake?

If your not porting the heads don't waste your time. If you have a 58MM tb gasket around or plan to put a 58MM tb on then you might want to port that section out but not the runner. a debur might help smooth out the air flow though.

The heads are going to be ported but I was under the impression that there was a gain especially with an aftermarket cam even if there was no headwork. Anyone know the answer to the first two questions?

My heads arent ported, & with stock fuel system & intake & TB and a cam with retune my car made 351rwhp 398 ft lb tq on motor 424, 501 on 100wet shot

So I am assuming that is with a stock ported intake? how the hell did you make that much torque with an lt1 intake? do you have a 383?

Also still looking for an answer to the question below.

-Would the effect of this be the same as opening up the intake runner of the head - lower velocity at lower rpms but better flow up top or would the velocity only improve (result of porting being no lowend loss (or loss of throttle response but a hopeful gain elsewhere)?

and how difficult is it to diy open up the ports on the intake to match ported heads?

The only thing I'd try to do is port the top of the runner, by the injector, to make the entry angle better. Material in that area is thin and you don't want to go though.

Yes, stock LT1 throttle body & intake manifold.- only had the SLP dual pipe CAI & BBK alum. elbow. I dont know how it made that much torque. its only a 355 lt1..

Even on my ported heads the Lt1 intake manifold runners are larger than the head runners. I port matched the intake using the gasket as a guide. It required taking alot of material off the area by the injector port on the manifold. It was good for a small gain. This is a pretty easy DIY job.

Sounds like you have a spike in your dyno graph. Do you have a scan of it to post?

Dan

For some reason I cant get my scanner to scan & post the picture in a usable format. it wants to use Adobe settings to save the picture.

Anyways- on the run i made 398.57 #ft tq the dyno didnt pick up until 3400rpm's & the run i made the 351.92hp on motor the dyno read all the way from 2300. peak HP was made @ 52-5300rpms.

Nitrous runs were peak tq of 501lb ft @2400rpms - there is a spike there from when the dyno picked up for some reason & 424rwhp @ 5,000 RPM
100hp wet shot using compucar 10lb bottle, -4 line, compucar solenoids, & NOS nozzle.

what about the divider between the intake runners? Would rounding the innermost or top edge of this divider yield gains? I have read not to "knife edge" it because this could cause turbulence.

Any other somewhat easy diy things one could do? I remember reading something about a hump or bump in the manifold runner?