Some dyno testing you guys may want to follow on YouTube

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Here are screen shots for over under comparison…Sorry if they’re grainy. These tests are cool to see, and I’m glad he went through all the work to set them up, but the “pay off” is disappointing without a wrap-up or some kind of final side X side (guess I’m spoiled by all the episodes of Engine Masters). So, here’s a super basic one for anyone else that might want the info in one place like me.

Trick Flows, 507.4hp at 5,800rpm, 546.4tq at 4,200rpm:
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CNC Speedmasters, 473.4hp at 5,400rpm, 500.6tq at 4,500rpm:
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Looks like the Trick flows are making 30-40 hp more across the rpm band.
 
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Pretty substantial difference …….. especially at that power level.

If you built the SM combo, what are you going to buy with the $700 you saved to get back the missing 40tq/30hp?

I agree it would be interesting to see how a set of “prepped/blended” SM’s would stack up.
 
I asked him on Facebook why the big drop off of horsepower from 5800-6000 rpm. I swear I honestly hit higher than that in Moms Malibu merging onto an expressway. I think we all know by now the cnc Speedmaster head is not a good program. An engineer must have programmed it.
 
And just imagine how good the TrickFlow heads could be. Several of us found some terrible ports and I’m not talking 10 cfm.
 
The SM's are the perfect example of a really bad port design. The S.S. is so atrocious they don't flow well anywhere in the flow curve. J.Rob
 
There’s mention of the SM’s being bought bare, and being assembled with better parts……… but I wonder if the seats were re-cut and blended.
And if not……… would that be worth anything on a build like that?

The one set of cnc’d SBM SM’s I had here had a valve job I didn’t love.
Cnc’d pretty much right to the 45, and then a 0* top angle.

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Looking at the flow numbers in the SBM head thread it appears the prepped/blended unported version out flowed the cnc’d/as from SM version …….. thru .500 lift, on the intake side.
 
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Here’s the intake port flow tests I ran on the stock SM head, the CNC SM head and the TF head.

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Up to .450 both the cnc and stock SM are very similar, stock SM probably wouldn't lose too much to the cnc with a .500-.550 cam maybe 450 ish hp similar torque. Some porting probably pretty close to one another.
 
Up to .450 both the cnc and stock SM are very similar, stock SM probably wouldn't lose too much to the cnc with a .500-.550 cam maybe 450 ish hp similar torque. Some porting probably pretty close to one another.


Yep. Once you get a port half assed developed you learn you won’t find much below .300 lift no matter what you do.
 
Yep. Once you get a port half assed developed you learn you won’t find much below .300 lift no matter what you do.
I've noticed there seems to be a ceiling at these lower numbers.
 
Like we have seen from several members some have cnc’d chambers and some don’t. Not sure what’s up with that. I’ve never touched a set of the cnc’d heads because why would someone spend the extra money then send them to me to pay again on a budget head.
 
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