My last car was a 400 with a purple shaft an a torker 1 or 2.. the one that's not on a weird angle.. loved that setup... if i have clearance i will prolly get a victor later or something else when i go stroker.
Interesting video RPM Airgap intake flow.
- Thread starter psi_duster
- Start date
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Rat Bastid
Dunamis Metron
Yep. Porting the heads and ignoring the intake manifold leaves a TON of power on the table.
It makes no sense if you think about it but it’s is done every single day.
I’ve told this story before but I’ll tell it again. I ported a set of cast iron Dart Platinum heads for a friend. I took them from 260cfm to 300 with the stock valve. We bolted his Victor Jr on and did a flow test. We topped out at 260cfm. He was all excited and said but we gained nothing. And I said no you probably flowed 220-230 before I ported the heads. So now he wanted the intake ported but being the panic type of guy that he is order the “new” Dart intake. So I finished porting the intake and he received his new Dart intake and drove to my house. We did a flow test with the Victor Jr and maxed out around 292cfm. We bolted his new expensive Dart intake on and we maxed out at 270cfm. Boy was he pissed. He then sold the Dart intake after I ported it. Lol
(With an asterisk!) The engine will respond better because the head is better but not being fully utilized. When a head porter works his magic, the magic starts with the valve. The valve & seat gets worked on and then the bowl area. The quality, read that again, the quality improves as well as the air flow. It’s all in the shape and area of the work done.
Now, if the bowl work flows more than the intake, there will be only a gain until the intake can not supply more air and fuel. Now IF the intake can flow enough air and fuel beyond the valve, valve seat and bowl work, the next in line (depends on who is porting) is the short side radius. This is often included but not always. Then the work goes up the port into the area you can easily see when holding the head.
Now, since the intake can flow well to 200 cfm, the amount of A&F flowing through the head can improve and more power can be made.
The RPM has shown to be able to make some really good street power numbers. The A&F must be getting through to be able to make that power. How? In this area, I can not offer much help.
But it’ll have something to do with the ram effect and the amount of time the valve is open. The intake is known to be able to make over 500 hp.
As I said earlier, (perhaps in another post/thread) this is why I had John port my M1 single plane. It is going on an engine that will see sizable camshafts and increased compression that will take advantage of not only a single plane but a well ported one.
If you’re in your he street, use a dual plane and (IMO) camshafts under 240@050. Over 240, you may - MAY - like a single plane intake. A lot depends on what you’re doing with the car. A single plane will really like a cam in the mid 250’s and larger.
Despite the seemingly low flow combo, it’ll still make power. The owner of the heads is looking for 400+ HP, he can get there. He may not like the combo to get there though.
A little more insight in this thread on intake porting.
Some M1 porting pictures and flow numbers
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replicaracer43
Grumpy Old Man
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Dual plane, dual lame. Step up and run a tunnel ram! Tunnel ram swap the world!
psi_duster
Member
Was an eye opener for me. I'm gathering parts for a 3.79 stroke 360 build. have an rpm airgap manifold I was going to use but will think on it some more now.
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