Cylinder head dyno shoot out

Any interest in a dyno shoot out of a few popular SBM heads?

  • Yes

    Votes: 131 97.8%

  • No

    Votes: 3 2.2%
  • Total voters
    134
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NC Engine Builder said:
I have said many times, there is more to HP than cfm. They can be related, but flow isn't the end-all be-all. I think the trick flow is a good example of that. And I also happen to know what the bloomers flow, and I'm not gonna say what the numbers are, but they appear to make power beyond what the flowbench would indicate.
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Yep. You can say this until your tongue wears out but the vast majority of people will go right to flow.

It’s all about shape and sizing. Flow is down on the list of things to look at when flowing a head.

The math I use to pick a cam doesn’t even care about head flow.
 
My Bloomer headed 421" before the cam change and on gasoline.

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NC Engine Builder said:
Any reason all the important data reads 0?
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Not that I know of. That's what I was given when I purchased the engine. In that configuration the car went 113.9 mph in the 1/8 at 2870 lbs. We changed the cam, alcohol fuel, and a vacuum pump now it goes 116.6 mph at 2880 lbs
 
NC Engine Builder said:
I have said many times, there is more to HP than cfm. They can be related, but flow isn't the end-all be-all. I think the trick flow is a good example of that. And I also happen to know what the bloomers flow, and I'm not gonna say what the numbers are, but they appear to make power beyond what the flowbench would indicate.
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this is kinda what my porter believes. He actually told me he can tell how good they are just by the SOUND. I know nothing about flow benches but my guy makes it "understandable"
 
PRH said:
I dug out a sheet a customer sent me.
408 w-flat tops, TF heads with some rework, Wilson ported SV intake, PRH cam, 1.6 HS, E85 Book carb, 1.75-1.875x3.5 dyno headers:

View attachment 1716368572
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I'm curious how these numbers would stack up against the same combination on race gas. Just thinking out loud how much difference the e85 makes (if any!) at different points in the curve as opposed to gasoline.
 
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Newbomb Turk said:
Yep. You can say this until your tongue wears out but the vast majority of people will go right to flow.

It’s all about shape and sizing. Flow is down on the list of things to look at when flowing a head.
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Not saying I'm right but from what I've read and watched, seems like they will sacrifice almost everything else if they have to, to get the size needed to turn the rpm they want (peak/shift) without choking the port. And the better the shape the higher velocity their able to run. Hp per cfm has a fairly wide range seem like as long their in the ball park with flow it will work.

Is my take so far.
 
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9secRR said:
any chance you would throw it back on the dyno to see how much more HP it's making after the changes?
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I'd love to , but time and money are holding me back. I'm deep into my W5 Dakota project. According to the Wallace power speed calculator it probably picked up about 50 hp with the cam swap, alcohol swap and Star vacuum pump. Wallace power speed calculator says that it takes 707 hp to run 116.6 mph in the 1/8 at 2880 lbs. BTW The AMX will be for sale later this year when I get my Dakota race ready.
 
tvt59 said:
I'd love to , but time and money are holding me back. I'm deep into my W5 Dakota project. According to the Wallace power speed calculator it probably picked up about 50 hp with the cam swap, alcohol swap and Star vacuum pump. Wallace power speed calculator says that it takes 707 hp to run 116.6 mph in the 1/8 at 2880 lbs. BTW The AMX will be for sale later this year when I get my Dakota race ready.
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both time and money are limited in my world as well. just switching over to the W8 from the W2 cost more then i thought. all the little things add up quickly.

AMX will sell easily. to bad you can't keep them both.
 
Behind the scenes we are progressing with the 408 dyno mule, and would really like to find a old milodon superstock oil pan and pickup to borrow for dyno testing. @Earlie A is going to buy the shortblock at the conclusion of our testing, and it will be going into a early A body, and I dont know if there is a suitable oil pan that fits those cars, that will be up to high rpm dyno testing. Definitely like to keep the bearings happy during our flogging!
 
NC Engine Builder said:
Behind the scenes we are progressing with the 408 dyno mule, and would really like to find a old milodon superstock oil pan and pickup to borrow for dyno testing. @Earlie A is going to buy the shortblock at the conclusion of our testing, and it will be going into a early A body, and I dont know if there is a suitable oil pan that fits those cars, that will be up to high rpm dyno testing. Definitely like to keep the bearings happy during our flogging!
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PM me on the pan. We might work something out.
 
Wow, not sure how I missed this thread. This is a pretty big investment of work, money and time and NC Engine builder should be commended for taking on such a monumental project. Looking forward to seeing the results.

I didn't read through every post so forgive me if this has come up in the discussion already but I have a question about the intakes being used. Correct me if I'm wrong but almost all of the heads in the test will generally match up with a Victor 340 port size-wise. However, with a 2.5" tall opening the BPE heads create a significant port mismatch with that intake even if it's been gasket matched to a Fel-Pro size opening size of 2.270" x 1.160".

Trust me - I destroyed a perfetcly good Victor intake trying to port match it to those heads because there's physically not enough material to take it out far enough. Even the taller S.V. required a bunch of material to be removed from the top and bottom for the ports to line up decently. Forget about using a regular intake gasket without cutting it either since no OTS gasket exists for that size opening.

Guess what I'm saying is that Rod's heads almost require a ported Super Victor intake since the intake ports are so tall. I'm not sure the other heads in the test come with that same caveat. Just something to keep in mind.

That also does not mean the Victor won't physically work with BPE heads because it will. Don (B3422W5) uses Rod's heads with a regular (though heavily ported) Victor and his car runs pretty good. He acknowledges the port mismatch as less than optimal but he said he's OK with it since it's not a max-effort build up and the regular Victor fits under his hood.

Also, I did see that there was some discussion about iron heads. Would you guys have access to a set of the Indy/RHS-X heads? I have a set myself but they are HEAVY and would cost a fortune to ship back and forth between NC and CT. They don't have roller springs either but they are CNC ported (by IMM) and flow almost 300cfm on the intake side. Just throwing that out there, not sure if it would be useful/practical. I'd bet they would rival the TFs.

Carry on, thanks.
 
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