Ported Chevy 083 heads, the tpi project

[RevTheory]

I'm guessing this runner is only for the Northern Hemisphere

Silliness aside, you have some serious cutter skills.

[Carnut1]

Resized_20190316_190627_1190.jpeg

Thanks Rev, After more work and very small gains I decided to just put a radius on the stock runners. Notice the messy red sharpie. This is also aimed at my friend "T" who is working on his tpi truck as well. This mod is within 3 cfm at every lift of very modified slp cut up and much larger runners. Input welcome. Thanks, Charlie

[Kenny M]

When I put the stock size round gasket on the stock lower, getting ready to install the runners. Just the gasket reduced the flow 3 cfm. Then I tried it with the Edelbrock lower and it did the same thing. It just reduced the radius. Going to the Large gaskets make the biggest gain I guess its like flowing without a clay radius.

[cv67]

Charlie regardless of #s I guarantee unless your friend cams it wrong its going to run harder than he imagined, btdt.
He will be real happy and your hands may not be numb...one day lol

[Carnut1]

Resized_20190317_184605_5914.jpeg

After a bunch of work with no real gains I decided to look closely at this chamber. I kept it tight around the quench side and cylinder wall side. Easy to see the stone cuts.
Flow at this point
.05 38.6
.1 72
.15 104.7
.2. 134
.25. 159
.3 185
.35 198
.4. 216.1
.5. 240.7
.6. 241.6

[Carnut1]

Resized_20190317_201335_9182.jpeg

Cut and flow, little by little. Interesting flow and airspeed changes.

.05 38.5
.1 71.5
.15. 108.5
.2. 139
.25. 168.7
.3. 195.3
.35. 217.1
.4. 235.1
.5. 251.7
.6. 254.7

[F-BIRD'88]

Beautiful.

[steve cowan]

Resized_20190317_201335_9182.jpeg

Cut and flow, little by little. Interesting flow and airspeed changes.

.05 38.5
.1 71.5
.15. 108.5
.2. 139
.25. 168.7
.3. 195.3
.35. 217.1
.4. 235.1
.5. 251.7
.6. 254.7

Charlie,
whats that step area around the exhaust valve,never seen that before

[Carnut1]

Resized_20190317_201335_9182.jpegCut and flow, little by little. Interesting flow and airspeed changes.

.05 38.5
.1 71.5
.15. 108.5
.2. 139
.25. 168.7
.3. 195.3
.35. 217.1
.4. 235.1
.5. 251.7
.6. 254.7

Charlie,
whats that step area around the exhaust valve,never seen that before

Chamber around exhaust is very much stock shape. This is 083 casting before the Vortec chamber. Thanks, Charlie

[Carnut1]

Steve, if you are asking how I change the chamber from quench to exhaust side then I do that to help flow when piston nears tdc to add flow to the long side of exhaust port. I wish there was more material there to give a better shape. Thanks, Charlie

[steve316]

Your ex valve is in the intake path, you can round the edge & or sink the valve, should help

[Carnut1]

Your ex valve is in the intake path, you can round the edge & or sink the valve, should help

Steve, I do not have the valves that will be used for this build so I can't finish the valves, guides or seats just the way I would like. So What you see in the pics are development parts and cuts. Yes, if you are talking about the face edge of the exhaust valve I do like to round that edge. Thanks, Charlie

[Carnut1]

Your ex valve is in the intake path, you can round the edge & or sink the valve, should help

Steve, I do not have the valves that will be used for this build so I can't finish the valves, guides or seats just the way I would like. So What you see in the pics are development parts and cuts. Yes, if you are talking about the face edge of the exhaust valve I do like to round that edge. Thanks, Charlie

I never thought about what you are saying Steve, That rounded edge on the exhaust valve will influence intake flow. That is good. Thanks, Charlie

[Carnut1]

After Chamber work I assembled the whole manifold with modified slp runners and radiused stock runners. very interesting results.

slp runners tpi runners
.05 37.3 37.6
.1 70.5 70.6
.15 103.6 104
.2 131.2 130.7
.25 152.3 154
.3 170.2 172
.35 183.8 186.3
.4 194.3 196.3
.5 207 207.4
.6 211.2 209.9

[Carnut1]

After Chamber work I assembled the whole manifold with modified slp runners and radiused stock runners. very interesting results.

slp runners tpi runners
.05 ( 37.3 ) ( 37.6 )
.1 ( 70.5 ) ( 70.6 )
.15 ( 103.6 ) ( 104 )
.2 ( 131.2 ) ( 130.7 )
.25 ( 152.3 ) ( 154 )
.3 ( 170.2 ) ( 172 )
.35 ( 183.8 ) ( 186.3 )
.4 ( 194.3 ) ( 196.3 )
.5 ( 207 ) ( 207.4 )
.6 ( 211.2 ) ( 209.9 )