intake manifold flow # vs. head flow #

[69 GTX]

505 Stroker
No clue on power on this one except above 600.... and why I'm playing with the 6-pack manifold/flowing etc.,
we'll see power when I get it finished and on the Dyno, and where if time allows ? I'd really like to bolt an untouched 6-pack manifold back on for comparison.

If it's any help I got 590hp out of my 440 with a 6 barrel
Link https://www.forbbodiesonly.com/moparforum/threads/trick-flows-on-the-440.107369/
https://www.forbbodiesonly.com/moparforum/threads/69-gtx.51515/page-28#post-910400177

 

[rumblefish360]

Thanks for the detailed info on your method, much appreciated.

I've only tried porting one intake, a small block Strip Dominator. I'll admit that I just laid a gasket down on the intake face, centered it as best as I could then used a blue Sharpie to color in the space between the inside edge of the gasket openings and the outsides of the ports and ground away whatever was blue. Went pretty far up into the runner. Did not do anything to the plenum area except for smoothing out some rough parts of the casting. All that grinding did seem help the mismatch between the ports somewhat but who knows if it did anything else other than make a lot of aluminum dust.

Greg, putting the intake on the engine with the heads and using some type of video scope will really help with this. Once you know the intake fits just right and then torque it down and verify that is a good fit & where you want it, then with the installed a gasket on the head recheck alignment, clearances & identify any needed work, glue (like gaskacinch) the gasket to the head with the machinists dye applied first of course and scribe from there.

After a bunch of time really looking long and hard and the help of scribe marks and tape to get the intake as perfectly positioned as possible I moved the work out of the super cold garage into the basement shop and re set everything up like below.

Be As meticulous as you can as possible. This will work. Not fond of doing it this way, but it worked very well!

 

[Challenger340]

WE finally finished and Dyno's that Ported 6-Pack deal with the TF270 Heads noted back in post #8

Quick recap
505 Stroker
TF270 Heads, basically ootb
* The heavily Ported factory 6 Pack Intake Manifold that we did that dropped the TF270 Flow ~20 cfm on two ports
Street Roller Cam profile 260'ish @ .050 with mid .570's Lift
1.5 ratio Harland Sharp Rockers
91 Octane Pump Gas friendly

681hp @ 6,000 rpm
and
657 Ft/Lbs

A really nice running Engine

 

[BSB67]

Very nice Bob! Thanks for the follow-up.

 

[rmchrgr]

Wow, that's pretty good!

Do you have an idea of what would cause the slight drop in airflow in those two ports? Don't imagine that little bit of variation would make a huge difference in overall output though.

 

[IQ52]

Well done, well done. Nice 6-bbl torque curve. We just did some 906 heads for a 6-bbl 512 and I'm interested to see how that comes out on their dyno.

 

[Challenger340]

Wow, that's pretty good!

Do you have an idea of what would cause the slight drop in airflow in those two ports? Don't imagine that little bit of variation would make a huge difference in overall output though.

It's in the Plenum/Transition on that factory 6-Pack Intake.... and we experienced great difficulty(next to impossible) getting in there without cutting the Intake apart which was not an option..... again we heavily Ported this 6-Pack Intake to Max-Wedge size back/in as far as possible ?
We had good measured Port Velocities for the Volumes so the shapes were Puss !
Hard enough just to get in there to measure velocities with a Probe let be get in there to Port/Fix the problem at the transition ?

But alas....
there are two ports we could NOT get to Flow/(Turbulence as best we could measure at the Plenum transitions)... as well as the others when Flowing the basically OOTB TF270's on our Flow Bench with the Ported Intake installed
and we tried our best in those two Ports....
but again that Plenum/Transition would NOT co-operate.(I forget already but #1 & 4 I think ?)

IMO, we would have sailed right past 700 hp if not for those 2 Intake Ports/cylinders.

 

[Challenger340]

Well done, well done. Nice 6-bbl torque curve. We just did some 906 heads for a 6-bbl 512 and I'm interested to see how that comes out on their dyno.

Your Ported Cast Iron Heads are almost legendary with Mopars Jim...
we still sit around musing some of the numbers you recorded and Dyno proved a few years back ?
UN-precedented and I think still UN-surpassed maybe ?

Is the 512 guy FAST classes stuff ?

 

[IQ52]

I'm told it is a 'Cuda play car/street cruiser that he wants to look stock.

 

[SlinktRR]

When my tf240 stroker engine was built we did a quick test using a trick flow single plane and a street dominator on a dyno. The Holley SD was port/gasket matched, the TF was just bolted on. Peak HP was shifted higher rpm with the trick flow intake and a little more power, but the area under the curve advantage in both horsepower and torque for the modified SD was massive. I promptly sold the TF intake. The Holley fits under my hood, good bonus. I can't eliminate that working the TF intake would produce similar gains but I think matching the intake to the flow of the head is key and often overlooked. If I had just stuck the TF intake on there and not compared it I would have not noticed what I was missing.

 

[PRHeads]

How much flow loss was there with the untouched 6bbl manifold?

That’s nice looking work there.
I have to say, porting manifolds isn’t my favorite thing.

 

[rmchrgr]

It's in the Plenum/Transition on that factory 6-Pack Intake.... IMO, we would have sailed right past 700 hp if not for those 2 Intake Ports/cylinders.

Guess if you don't cut the intake in half you really can't do much with the plenum so it makes sense.

Most pictures of ported intakes I've seen have a lot of material removed from the plenum under the throttle bores and the port dividers get profiled from the top to open up the runners. Mostly these are single planes though.

Pretty good results just doing what you did.

 

[Orig69]

I have always wanted to try using abrasive flow machining on an intake manifold.

 

[Gunner1]

I have always wanted to try using abrasive flow machining on an intake manifold.

I ran the flow bench at Extrude Hone LA. It was a pretty amazing process. We honed lots more than intakes and heads. Crank oil passages, block oil passages. Smoother flow allowed a lower pressure at the pump to maintain the oil wedge at speed. Added only a few hp but at those levels of comp 10 hp was gold. What I saw was on average we removed less material for a given flow increase. Also if it was a wet intake then heads and intake needed to be honed. Race teams told us they usually needed to drop 2 or 3 jet sizes when they did a/b testing. Torque was usually more affected due to a smaller port cross section for a given flow. ‘Bob.