dhirocz

Ok, Im getting ready to port my Accel/Lingenfelter TPI/LT1 base and SLP runners. Yes, this is on an LT1 longblock with LT1 fuel injection.

It's a 350 right now, but I will be putting in my 382 ci engine when I get it's replacement. So I want to port it now. It's got LE2 heads on it, so I just need to find out from Lloyd what intake gasket he ports to.

It's clear the roof on the manifold base going into the heads is too low. I want to raise it a couple tenths of an inch and enlarge and smooth out the ports where the runners bolt to. To do this I will have to build up weld on the top of the manifold and on the manifold to head surface and have the manifold trued. Piece of cake. I want to make sure I am dimensionally accurate though so I dont create a port too large or leave power on the table.

What I would use is the proper info to calculate cross sectional area. All I can find is little tidbits here and there. I dont want to ruin this intake, not too often do you find LT1's running tuned port gear. Figured it would be great for a DD, and look somewhat stock in my '86. But if I were to improve the flow some more I would imagine it would put the motor more on par with the LT1 and LS1 without too much of a sacrifice in torque...the whole idea here is not so much just peak flow numbers, but to make the intake large enough where the design and the runner length is not a restriction or a significant restriction, but where it's not also so large that the velocity drops to where I loose torque. So I'm not going to fully siamese the runners or anything of that nature. So basically enlarge it and smooth it out to where the intake and the heads are pretty much on par with one another. Out of the box, even the aftermarket intake bases flow less the an average set of heads, and the stockers flow fairly poor.

I'm also considering using a set of stock runners and replacing the tubes with some 1 3/4 mandrel bent tubing and port matching to size. The largest aftermarket TPI runners I know of are only about 1.6 inches. Would take some time but cost next to nothing. This would help on bigger ci sbc's (or LT1's)

If I can get the intake to flow better, then I could eventually build a 408ci later model vortec TPI motor and know it would not be a waste due to intake restriction, though I would want a set of heads in the 290 cfm range at no more that .600".

So with that being said... school me!

FASTFATBOY

For the money it would take to get a stock style LT1 intake to feed a 408 would really be a useless proposition. A 383 is pushing it pretty hard.

To make a TPI style do it is futile, you are wasting your time. Even on a 383.

I would do a Super Vic or Vic jr conversion. Or a Holley Stealth Ram.


David

dhirocz

I would if I were looking for midrange torque and HP. Im not.... I am looking for low and midrange torque. It would be nice to get the flow numbers on par or close to some of the better intakes out there, but to flow like that requires starting with the right base, lots of porting, and welding. That I can do.

The whole idea is to port to a size where flow is not as greatly choked by the intake, like it would be if I just bolted it on.It wont flow like a ported super Vic, but it doesnt work in the same RPM range. I dont want to weld and port it so big that flow slows down either.

And no, no LT1 on this motor. It's strictly a TPI only intake. This one's for grunt Just need to know how to properly figure out the cross sectional area.

SStrokerAce

You can't port match a intake well without heads on hand to do so.

dhirocz

I was told the heads were port matched to a felpro gasket, I just dont know which one off the top of my head...

But I will have the heads available. I am also pulling the stock LT1 intake (no choice at the time) off the stroker and swapping it for another I had welded that Im going to port as well, for the time being, if that makes any sense. That is the longblock I will eventually put this TPI intake on. I'm porting the intake because I know its creating some turbulence issues, so the heads will be available to match to if needed.

I have 2 different intakes, BTW. In any case, I got it covered