Ported Chevy 083 heads, the tpi project

[Carnut1]

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Fully Siamesed stubby runner. Lots of aluminum to remove!

[Carnut1]

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Siamesed plenum and matched opening to stubby runner. It looks way easier than it is! I will most likely never do another job like this but I am enjoying it. Thanks, Charlie

[Orr89rocz]

Looks great! Should be a fun street car

[Carnut1]

Looks great! Should be a fun street car

I am hoping the extra grinding gives the air a chance to turn and pic up flow. Thanks, Charlie

[RevTheory]

That looks like a runner "length" test more than a raw, bench flow test and I bet it works out well.

[Carnut1]

Thanks for the input guys. Gets me thinking, so I tested just the base with clay radius 254 cfm. Add shortie runner with clay 244 cfm, bolt it to the head that flows 237 cfm at .5@ lift and all together it flows 217 cfm. Just like series resistors. Thanks, Charlie

Rev, If you are talking about this it is very interesting to me. You would think the worst restriction would limit flow to that number but it seems the losses add up. This may be another benefit of short runners that isn't discussed much. Thanks, Charlie

[RevTheory]

I could be wrong but it seems to me like it's just stacking more length to drag along. I wonder how the length from the valve seat to the end of the base jives with Pipemax now that the runners have been siamesed and probably no-longer count, unless I'm wrong in assuming that the big change in csa will behave like a plenum.

[F-BIRD'88]

What happens to the total combined stacked flow of the system if the runner is straight off the manifold base instead of curved. Long and straight vs short straight runner. VS curved runner.
Then what happens if the curved runner is a not round tube shape (trapizoid or D shape or....)

Imho a round tube curved duct is not the best cross section shape for a curved duct. (And a straight duct is better, round or not.
What does the flow bench say. (When its connected all up)

[Carnut1]

I could be wrong but it seems to me like it's just stacking more length to drag along. I wonder how the length from the valve seat to the end of the base jives with Pipemax now that the runners have been siamesed and probably no-longer count, unless I'm wrong in assuming that the big change in csa will behave like a plenum.

That big csa change is attached to plenum so it will act like a larger plenum. Since the tpi was designed for a 305 I figured this little bit larger plenum would be a benefit. Thanks, Charlie

[Carnut1]

What happens to the total combined stacked flow of the system if the runner is straight off the manifold base instead of curved. Long and straight vs short straight runner. VS curved runner.
Then what happens if the curved runner is a not round tube shape (trapizoid or D shape or....)

Imho a round tube curved duct is not the best cross section shape for a curved duct. (And a straight duct is better, round or not.
What does the flow bench say. (When its connected all up)

I did work on this, Yes Mag, similar to a ssr. Should help. I agree F Bird. Thanks, Charlie

[BadSS]

Thanks for the input guys. Gets me thinking, so I tested just the base with clay radius 254 cfm. Add shortie runner with clay 244 cfm, bolt it to the head that flows 237 cfm at .5@ lift and all together it flows 217 cfm. Just like series resistors. Thanks, Charlie

Rev, If you are talking about this it is very interesting to me. You would think the worst restriction would limit flow to that number but it seems the losses add up. This may be another benefit of short runners that isn't discussed much. Thanks, Charlie

This proves how bad the base to runner transition (254cfm to 244cfm - 4% drop) and the compound effect of the base to head transition really is on the stock-type TPIs (237cfm to 217cm - 8.4% drop). It really does show how important it is to treat the entire intake tract as a whole.

Intakes like the StealthRam (tunnel ram) with a straight shot transition from the intake/runner to head are much more efficient, plus there's less length for the air to travel to pick up heat from the intake as well.

I know you would like to see better flow results, but the tuned midrange "boost" from the longer runners helps overcome a lot of the inefficiencies you're seeing. Regardless, you've put a lot of really good work in this intake system and it should deliver excellent results (much better than most “TPI” intakes).

[Kenny M]

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What did the stock head flow?
Stock head with stock base?
Stock head with stock base and stock tubes?

The work looks good.

I knew it would all get some work so I wasted no time flowing stock heads. I doubt they flow much above 200 cfm which seems a bit more than the stock system will flow. Thanks, Charlie

I just flowed a stock 083 it maxed out at 185 CFM.

[Carnut1]

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What did the stock head flow?
Stock head with stock base?
Stock head with stock base and stock tubes?

The work looks good.

I knew it would all get some work so I wasted no time flowing stock heads. I doubt they flow much above 200 cfm which seems a bit more than the stock system will flow. Thanks, Charlie

I just flowed a stock 083 it maxed out at 185 CFM.

I had a conversation with a pro cylinder head guy who gets 270 cfm out of the 083's with a 2" valve. He also said it is a ton of work to get there. I have no doubt. Thanks, Charlie

[Carnut1]

Resized_20190303_110810_6263.jpeg 083 ported head 2nd port design, ported stock base, ported aftermarket siamese runners, ported stock plenum and ported aftermarket throttle body on bench. @ .5" lift 195.2 cfm. Pathetic.

Ported stock runners on same setup @ .5" lift 199.2 cfm
This was after quite a bit of work to aftermarket runners.Thanks, Charlie

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All bolted up with Siamesed stubby runner for an amazing 203.8 cfm! Wow, a 8.6cfm difference! This thing is killing me, well a gain is a gain and I think the torque peak will work better with this combo. A bit more intake port work I think. Thanks, Charlie

[Kenny M]

Yep I'm playing with the same junk. A 89 305 stroked to 334 LB9. Only I'm using the Trickflow 175 heads. With a Edelbrock lower, TPS Runners I'm at a Big 187CFM.

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