Don Terrill’s Speed-Talk

MadBill wrote: ↑Tue Dec 04, 2018 2:21 pm It's often said that heads that aren't up to the task can be 'crutched' to some extent by more cam duration, so the reverse is likely also true: heads that are ideal for the application don't need as much cam to deliver.

Ala.. LS engines in general.

My takeway is smaller heads/valves need more cam to hit a bigger peak power number.. which inevitably just narrows up the powerband. Larger heads/valves can better utlize the shorter time/area of mild to moderate grinds and don't fall off the proverbial cliff when the cam begins to run out which gives gives the motor a broader powercurve from idle to redline.

What I see ruffly is that in test 2 there is 10% more Intake flow available from from .140" lift to .280., so if we had a 50 hp gain we now have 55 hp.
Then looking at the added test 2 glow numbers from .280" lift to 490" there. Is another 20% gain on hand so you could be looking at a 66 hp gain over test 1.

The other thing I would like to know about is if in peticular this Intake flow / power gain from the test 2 numbers can be traced to having a better matched Exh to Intake flow ratio?

Quick update: DV will be using thin head gaskets to improve quench with upgraded Mike Jones hydraulic roller. Thanks, Charlie

How about throwing a stock 5.0 HO roller cam into the mix too? People practically give them things away.

travis wrote: ↑Sun Dec 09, 2018 9:48 am How about throwing a stock 5.0 HO roller cam into the mix too? People practically give them things away.

Travis, I throw them out for a reason!!!

Erland, Your post from a page or two back:-

I guess that 4-1 headers on a V8 are not as touchy as 4-2-1 headers on a 4 cylinder.

Absolutely correct.

There are a number of reasons for this and they mostly account for why almost all V8 headers are wrong including all the cup car ones I've seen.
DV

David Vizard wrote: ↑Sun Dec 09, 2018 2:05 pm Erland, Your post from a page or two back:-

I guess that 4-1 headers on a V8 are not as touchy as 4-2-1 headers on a 4 cylinder.

Absolutely correct.

There are a number of reasons for this and they mostly account for why almost all V8 headers are wrong including all the cup car ones I've seen.
DV

Could you explain the "reasons" and how to correct the headers both in drag and cup cars?

Old School wrote: ↑Sun Dec 09, 2018 2:22 pm

David Vizard wrote: ↑Sun Dec 09, 2018 2:05 pm Erland, Your post from a page or two back:-

I guess that 4-1 headers on a V8 are not as touchy as 4-2-1 headers on a 4 cylinder.

Absolutely correct.

There are a number of reasons for this and they mostly account for why almost all V8 headers are wrong including all the cup car ones I've seen.
DV

Could you explain the "reasons" and how to correct the headers both in drag and cup cars?

Yes I can - it's in the exhaust section of my BBC book complete with a bunch of dyno testing from in cylinder measurements.
DV

Carnut1 wrote: ↑Sun Dec 09, 2018 1:53 pm

travis wrote: ↑Sun Dec 09, 2018 9:48 am How about throwing a stock 5.0 HO roller cam into the mix too? People practically give them things away.

Travis, I throw them out for a reason!!!

I’m not saying it is a great cam, but that cam plus a set of stock E7’s would give a good baseline.

travis wrote: ↑Sun Dec 09, 2018 5:31 pm

Carnut1 wrote: ↑Sun Dec 09, 2018 1:53 pm

travis wrote: ↑Sun Dec 09, 2018 9:48 am How about throwing a stock 5.0 HO roller cam into the mix too? People practically give them things away.

Travis, I throw them out for a reason!!!

I’m not saying it is a great cam, but that cam plus a set of stock E7’s would give a good baseline.

You make a good point.

Good news - at least for some.

Thanks to just one more helping hand from Dave McLain we have a stock 5.0 cam as used in the Crown Vic.

This is on a 107 LCA which is far better than the 112 or so that most of Fords cams are on.

Will try, snow permitting, to get this up to Terry Walters for dyno tests before Xmas hols.

DV

Anything to share?

I think that this site was down for so long the a lot of folks have unfortunately have written off this web site, but I hope not!

You need to give people sometime. I believe David is giving a 3 day seminar this weekend.

Stan

D.V. is busy with a seminar this weekend and a porting seminar soon. I changed jobs and am on probation at work for six months. Jack the dyno guy at Terry's gave me a call a few weeks ago to figure which heads are for the competition and what needs to be done. Sounds like thin head gaskets, Mike Jones roller cam, D.V. / Charlie E7 heads, 1.94"/ 1.6" Charlie 289 heads and 1.85" / 1.6" Charlie 289 heads. To still be tested. Thanks, Charlie