Don Terrill’s Speed-Talk

SpeierRacingHeads wrote: ↑Sun Sep 01, 2019 6:31 pm

Carnut1 wrote: ↑Sun Sep 01, 2019 1:36 pm They look great and I expect they will make a serious street sweeper. The fast floor doesn't bother me if it has a low speed gradient across the floor and has a smooth sound at higher depressions. Please share some cfm and shortblock specs. Thanks, Charlie

Port is about 188cc. 2.08 LS valve. Flows 300@.500 and 305@.600, and 308@.700

4.165 x 3.48
Scat 9000 crank and rods
Weisco Pro Tru pistons
TPiS 231/236 roller cam
.580 lift
Morel lifters
NHRA legal stocker pan

That is a fast port. That will work great. Thanks for sharing.

Carnut1 wrote: ↑Sun Sep 01, 2019 7:24 pm

SpeierRacingHeads wrote: ↑Sun Sep 01, 2019 6:31 pm

Carnut1 wrote: ↑Sun Sep 01, 2019 1:36 pm They look great and I expect they will make a serious street sweeper. The fast floor doesn't bother me if it has a low speed gradient across the floor and has a smooth sound at higher depressions. Please share some cfm and shortblock specs. Thanks, Charlie

Port is about 188cc. 2.08 LS valve. Flows 300@.500 and 305@.600, and 308@.700

4.165 x 3.48
Scat 9000 crank and rods
Weisco Pro Tru pistons
TPiS 231/236 roller cam
.580 lift
Morel lifters
NHRA legal stocker pan

That is a fast port. That will work great. Thanks for sharing.

I'm going to dyno it. Just will need to be with a manifold and carb. My dyno I use doesn't have the injector setup. And that would be a PIA.

ClassAct wrote: ↑Sat Aug 31, 2019 6:34 pm Chad, have you ever done any port development with the opposite shape?? As in, have you ever raised and made the roof of the port square, while leaving the floor round? Just curious as to what you think.

You mean a "Rectoval?"

SpeierRacingHeads wrote: ↑Sun Sep 01, 2019 6:31 pm

Carnut1 wrote: ↑Sun Sep 01, 2019 1:36 pm They look great and I expect they will make a serious street sweeper. The fast floor doesn't bother me if it has a low speed gradient across the floor and has a smooth sound at higher depressions. Please share some cfm and shortblock specs. Thanks, Charlie

Port is about 188cc. 2.08 LS valve. Flows 300@.500 and 305@.600, and 308@.700

4.165 x 3.48
Scat 9000 crank and rods
Weisco Pro Tru pistons
TPiS 231/236 roller cam
.580 lift
Morel lifters

NHRA legal stocker pan

I think it’s going to be surprisingly good. Looking forward to seeing the dyno results

Chad have you made a pass at the drag strip yet? Something to get a baseline from?

SpeierRacingHeads wrote: ↑Sun Sep 01, 2019 9:21 pm

Carnut1 wrote: ↑Sun Sep 01, 2019 7:24 pm

SpeierRacingHeads wrote: ↑Sun Sep 01, 2019 6:31 pm

Port is about 188cc. 2.08 LS valve. Flows 300@.500 and 305@.600, and 308@.700

4.165 x 3.48
Scat 9000 crank and rods
Weisco Pro Tru pistons
TPiS 231/236 roller cam
.580 lift
Morel lifters
NHRA legal stocker pan

That is a fast port. That will work great. Thanks for sharing.

I'm going to dyno it. Just will need to be with a manifold and carb. My dyno I use doesn't have the injector setup. And that would be a PIA.

It may be helpful it you flow it all together with cylinder head, carb and intake vs. Injection and throttle body before you dyno. If the airflow is close you will get a fair idea how the other will be.

What is the power and torque goals? Solid roller?

econo racer wrote: ↑Mon Sep 02, 2019 5:43 am Chad have you made a pass at the drag strip yet? Something to get a baseline from?

It's a street car, I would never race it.

Elroy wrote: ↑Mon Sep 02, 2019 1:08 pm What is the power and torque goals? Solid roller?

String of 500hp and string of 500 torque, peaking at 6200ish

Yes, small solid roller

Peak of 6200 cfm demand is about 290ish. 379ci
Better line of sight the speeds over the short side can be higher is what I found. I bet its pretty dam good. fast.

Chad, with your super-stock heads in mind, what's your velocity "uncle point" over the turn when you're not bound by rules? If it's pushing 420 fps but not separating on the bench up to .800 lift, is that a bad thing in this particular application?

It's not like a circle track deal where you're afraid it's going to trip over it's tongue on the back stretch.

This is a velocity chart with the different velocities shown in stepped bands of colors.
It illustrates what is going on when you raise the top of a port.

Chad, I`m thinking leave as is, put your whole induction system together and flow it. That should slow things down. That CFM and velocity would really help part throttle response.

Steve Haaf wrote: ↑Mon Sep 02, 2019 7:08 pm Chad, I`m thinking leave as is, put your whole induction system together and flow it. That should slow things down. That CFM and velocity would really help part throttle response.

Doesn't change as much as one would think.

SpeierRacingHeads wrote: ↑Mon Sep 02, 2019 1:12 pm String of 500hp and string of 500 torque, peaking at 6200ish

Yes, small solid roller

Walk in the park. 500 tq is more of a challenge than the 500 horsies but neither should be much trouble at all for something with some effort thrown at it. There are out of the box heads that could get that done. I have a suspicion you are intentionally understating your goals because of the TPI///understandable but dynoed with single 4.//solid roller 379 with ported heads and manifold////570 plus or its broken.