Carl Fausett

I have an email in to the flow-bench operator to ask him what his test-pressure was for you.

Strosek Ultra

Carl do you mean the port was flowed looking this way?
Åke

Carl Fausett

No. Here is a picture of the head after the new copper-nickel alloy valve seats were installed, but before any porting had been done to them. They looked like this when measured for our baseline flow test.

I see in these pictures that some of the seats have had their first rough cut, and some have not. The flow was measured after the first cut was completed to eliminate a false number that would be caused by the tumbling over the sharp edge if we hadn't.

Carl Fausett

He said it was 28 inches to both.

Carl Fausett

Here are some before, during, and after pics of the Extrude-Hone process we just had done.

You will see in some cases that impurities in the manifold casting are now visible. They were always there - just now you see them more prevalently.

I am trying to get some time at a nearby flow-bench with two intake manifolds that I have that are of the very same casting number so I can see what gains we may have.

Carl Fausett

After the manifold came back from extrude-honing, I sent it out to be media blasted with my new intake manifold shoe.

Here is what they look like together.

Catorce

Damn I can't wait to see the numbers on this little experiment!!!!!

Carl Fausett

The previous narrowest point in the intake shoe, where the incoming air turns to go up to each bank, was 50mm. There are two of these. These are now 70mm each at the narrowest point.

Shaun @ Tru6

Looks great! What are you going to paint it with?

Carl Fausett

So my question to the forum is: if I can get some flow-bench time with these two manifolds, I think I will have time to test about two runners on each intake (a total of 4 flow tests).

Which two intake runners would you like me to test? Do you have a preference?

Carl Fausett

Shaun - the extrude-hone intake manifold will have to bear fruit to get painted. I am going to change out the stock intake manifold on the engine dyno with this one, and see what the gain is. If it performs (as I am betting it will) then the customer will pick a color and have me paint it.

The custom intake shoe with the larger throttle body had to be made either way, no matter which intake manifold we use.

ptuomov

I'll bite...

Can you flow the whole manifold assembled together by blowing thru from the throttle body flange first? If you can, then measure with a pitot-static tube the exit flow velocity at each of the eight runner ends (the end which would be attached to the intake port in the heads in an assembled engine). Pick the lowest exit velocity runner and then flow that runner individually.

I'm not saying this will be the scientifically correct way to guess which will be the worst runners, but seems like a reasonable thing to do.

I wouldn't be shocked if #5 would be the worst flowing runner. So if you don't want to set up the whole manifold like above, I'd guess #5 would be worth flowing. One of the better runners (#2, #3 by my guess) might be worth flowing, too.

When flowing the individual runner, I think that one would ideally bolt the intake on the heads and then flow that runner thru the corresponding cylinder's intake valves, as with a live engine.

The challenge with extrude honing is that with complex runner shapes (like with #5 and #8) the process will not necessarily remove material from the points that would be most advantageous from the air flow perspective.

Carl Fausett

It would need to be a draw-through (as opposed to a blow-through), but no matter, I know what you mean. I don't think I can reasonably get it done. Been chewing on it a couple days. I'd have to make a fixture to seal and draw through all 8 intake ports at once, which is financially unreasonable for this project. If I was developing an improved intake for a SBC - then sure! I do wish I could.

I will test runner #5 and probably one from the other side as well. We will get good before-and-after individual runner data that way without much trouble. It will show the effect of the Extrude-hone alone. The rest of the data will come from the engine dyno.

Catorce

I agree; in this case, at least since I am the one paying for all this fun, the dyno is king. This mod will have to stand on its own two feet; I don't care what it flows in reality, as long as it a) adds horsepower, or b) adds torque. Absent those two, it's a loser ;-)

Carl Fausett

Agreed! That said, I'm pursuing this because I think it will be of measurable benefit. I will be very surprised if it is not.