Don Terrill’s Speed-Talk

I just flowed an Assault air gap on a Vortec head that flowed 256cfm@ .5”. Worst port through the manifold went 230, best 240. I hope this helps

Thanks Walter.

Thanks Tony, too easy. I finished my apprenticeship in 1981 and haven’t done a crack repair since. I’ve got some deck cracks in vortec heads to repair, not in the combustion chamber. Just a floor seeepings project for a hotrod.

Many years ago We used a product called Irontite as a sealer for taoered pins for cast iron crack repairs. What products available in Australia are suitable gor this Job now. Thanks in advance.

I can’t verify it but I believe that the PVRCs are larger on the vacuum secondary models over the DPs I’m sure I read it in a book long ago.

I will take that advice. I just ordered a set of 1.56” pin height pistons. One less thing to worry about and I’ve got too much time in the heads to ruin them Thanks to those members who contributed.

I’m left with a few options. Leave new quench pad there but radius edges. Reshape with a taper back from the chamber wall at around 7 degrees .Or grind and blend back to the plug threads. Given that I’m trying to gain compression, I wouldn’t do the later unless it was a proven HP gain. Looking for a...

Yes, there is a raised rocker cover mounting rail that’s not parallel to the gasket face. I’ll have to under cut that slightly.

Hi, I’m after some guidance on how to prepare the spark plug boss on 906 Votec heads after a .070” angle mill. The deck surface will take down the spark plug boss,dividing the combustion chamber with that much off,as its only .042” below the deck face now. What is the correct way to deal with this i...

Yes, I have, and use Pipemax. Just wondering if there is an advantage to having one bank of cylinders at the best harmonic and the other at a lesser harmonic length. Or just have even lengths at a longer, less advantageous length. Probably not something people have tested, but asking just in case.

Has anyone tested the effects of having different length collectors from one bank to the other on a V8? I can’t locate a PWTB at the 18 to 20 inch mark on one side as there is no room. Any help with this? Won’t bother building them if the benefit is lost.

Hi. I’m also very interested in this topic. Have also got DVs book. I am space limited for a correctly positioned PWTB on a hotrod due to under floor brake booster placement. Might get the volume but will be a very flat shape. Any one had one collecter at the 3rd harmonic length and the other at the...

I usually scribe a line for the throat diameter by using a valve turned to the right size shoved down past the seat. I grind up to that scribed line and stop to measure often. The shank of the burr can mark the seat so be careful. If you keep the burr parallel to the guide you should be ok.

RIP Paul, May there be many RPMs in Heaven.

No, went the conventional route. It ran well but didn’t win it’s class.