Are lump ports a benefit when using forced induction? (blower or turbo)

Will Willis

Yes it will help all the above.

MBHD

If you look at Leo Santucci's first book (second I think too) there is a photo of a lump port head done by Mike Kirby at Sissal's for a turbo application. I am pretty sure this head was originally built for Leo. I actually own that head (purchasded it used) although I have never used it. Epoxy lumps for turbo application.

Hey mdonohue05!! You saying to epoxy the lumps or that the lumps are epoxy?? Do you have a link???

The head I have is a sissal head that I understand was built for Leo santucci and was designed for a turbo application. The lumps in the head were done by sissal in epoxy as opposed to brass welding. The person who I acquired the head from I believe acquired it from Leo. My friend ran it on a 250 or 292 powered altered, I forget which, ran in the 10s with that head and a single 4bbl. He got out of six motors and I ended up with the head.

Thanks!! I just had a 4banger head done with T Lowe's bolt-in lumps. I've stumbled onto a Buick V6 turbo outfit and with the other parts I've selected, I can add the turbo without any danger to reliability. I need to find a copy if Santucci's tome for my own reference!!

WRT without any danger to reliability: I know what you mean "the engine will operate normally unless I use the turbo", but under boost you need more cooling (rad + ATF), and either spark retard, rich mixture or some combination as anti-knock, and there is always a limit to cast pistons and head gaskets.

Thanks, panic! I'm adding a large engine oil cooler with an extra filter and the tranny is on a free standing cooler system.

The pistons are turbo/nitrous, forged units and I'm only planning on 8 to 12 pounds of boost.

I'll have to richen up the carb anyway. It was already slightly lean at cruise/light throttle but not to the point of spark-knock.

The engine also sits out in the open, (no hood or closed in engine compartment) and I'm running a 2007 Caddy CRST radiator.

WELL!! MERRY CHRISTMAS TO ME!! I picked up a set of Comp. Cams Ultra Max Pro 1.75:1 roller rocker arms on Amazon for $96.00 a set of eight, tax, shipping and all!! Last set they had at that time. Next morning, they had more back in stock at $223.00 a set!!

One more piece of the new build on the 153.

Did you mean to say "a set of 16"?

NOPE!! A set of eight is taylor made for my little 4banger! It's really hard to find parts in quantities for a four cylinder in the high performance aftermarket unless it is something specific for a particular engine. Comp Cams has a package made specifically for this application. 1827-8 is a package of eight rockers and eight poly locks.