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Premium Member
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Discussion Starter #1
I've got an appointment, next month, with a buddy that modifies and ports cylinder heads. Our purpose will be to help and inform a 12v V6 engine build, that will then go on an engine dyno.

We'll go at it for a day (if it takes that long) and the parts I'm planning to bring are:

Stock 2.5 head
Stock 3.0 head
Stock intake runner
Stock plenum
Stock 2.5 exhaust manifold if it fits on the bench
Stock 3.0 exhaust manifold if it fits on the bench

If I have time, I'll prepare a larger than stock intake runner and potentially massage a plenum.

What I'm after is a set of numbers I can plug into an engine simulation program.

Yes, I know Jim K has a lot of this information in his book (which I've read cover to cover several times), however I like to develop my own information.

Any thoughts on other stock based tests that I'm missing? This is a simple air flow test.
 

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Premium Member
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Discussion Starter #3
You'll need to know valve lift. We usually graph flow at every 0.010" of lift.
Yep, that's standard operating procedure. Thanks
 

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Joe Elwell
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138 Posts
So you're setting a baseline for all these components? Do you plan to move forward with modifications (e.g. porting, headers, etc) from this data?

I'm certainly happy you're investing in this - it will be great information for all us wanna-be engine re-builders.
 

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Premium Member
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Discussion Starter #5
So you're setting a baseline for all these components?
Yes, basically a baselining exercise. I prefer to know what I have before I start modifying.

We'll run the heads, then add the intake runners and then the plenum to help determine where the restrictions are. I hope I have the chance to test the 2.5 and 3.0 exhausts so that we can tell if the 3.0 has an advantage. Because they hug tight to the engine, they may not fit on the flow bench.
 

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Registered
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Yes, basically a baselining exercise. I prefer to know what I have before I start modifying.

We'll run the heads, then add the intake runners and then the plenum to help determine where the restrictions are. I hope I have the chance to test the 2.5 and 3.0 exhausts so that we can tell if the 3.0 has an advantage. Because they hug tight to the engine, they may not fit on the flow bench.
I've got a set of headers for a 12v motor if you want to add those to the mix. I can see if I can get them to John Pagel next weekend if you are interested.
 

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Discussion Starter #7
Interesting. That would be great. I'm not scheduled to go up until October 24.
 

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Premium Member
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Discussion Starter #8
I've got a set of headers for a 12v motor if you want to add those to the mix. I can see if I can get them to John Pagel next weekend if you are interested.
Just remember, we are just testing flow.

Exhaust tends to be a bit of a black art. I've tested an array of exhaust solutions on an engine dyno...which is about the only way to see what truly works. We built a set of headers based on all the scientific formula, had it built out of stainless steel (true things of beauty) and they got beat by a rusty pair of no-names from the stack of headers stored on top of the dyno cell.
 
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