PORT VOLUME-IS BIGGER BETTER OR IS LARGER LESS? Richard Holdener

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Ok, as long as we are hypotheticalizing, how about this....
Two engines built with similar intakes, maybe edelbrock rpm, similar camshafts, maybe 509 purple shaft hydraulics, same compression ratio.
408 small block with 190 trick flows,or....
406 big block (.035 over 400) with 270 trick flows
Which would you rather have, which would be faster?
 
33IMP said:
Ok, as long as we are hypotheticalizing, how about this....
Two engines built with similar intakes, maybe edelbrock rpm, similar camshafts, maybe 509 purple shaft hydraulics, same compression ratio.
408 small block with 190 trick flows,or....
406 big block (.035 over 400) with 270 trick flows
Which would you rather have, which would be faster?
Click to expand...


Big bore, short stroke, high R/S ratio for the win. Every time.
 
33IMP said:
Ok, as long as we are hypotheticalizing, how about this....
Two engines built with similar intakes, maybe edelbrock rpm, similar camshafts, maybe 509 purple shaft hydraulics, same compression ratio.
408 small block with 190 trick flows,or....
406 big block (.035 over 400) with 270 trick flows
Which would you rather have, which would be faster?
Click to expand...
The you tube dyno test was very narrow and will show different results on any given combo. The engine masters show showed similar results on a stroker Ford small block. The bigger head performed as good as the smallest head with the middle head showing more torque.

Your two examples are two different animals. The Max Wedge port size of the 270 may indeed show more power but I wouldn’t run it on a 406 B engine. The 240? Oh yea! The 270, ahhhh, No....

What would be the goal of the 408? With the TF head?
What cam? Compression, trans, gear and tire on what weight car? For what purpose?
Bracket racing?
Street stomper?
Heads up 1/4 mile?

3 different aspects are listed. I can argue for 3 different heads on a 408 and not care what the Dyno says it does.
The dyno is a tool and telling you how well it does on what combo that is actually in a car and how well it does as well as the most important item, how the driver likes it for the purpose it is slated for..... or not...
 
I agree with you, I wouldn't build a 400 with 270s either. Id put 270s on a 496 or 512, but the point was biggest easily available head for small and big block, on a similarly sized engine. I don't think that's too much head with the 270s,but I think the 240s would be better. I do think to 406 would make more power and torque than the 408 in spite of having a "too big" head on it.
 
33IMP said:
I agree with you, I wouldn't build a 400 with 270s either. Id put 270s on a 496 or 512, but the point was biggest easily available head for small and big block, on a similarly sized engine. I don't think that's too much head with the 270s,but I think the 240s would be better,
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I think the 270’s with a 50 or 52 degree seat would beat the 240’s all over the RPM range.
 
Some one better tell this guy then.......

360 cast head porting

"factory small block head castings with some time in them work better than most people can imagine.
Small block in Demon with 587 heads and a .590 Racer Brown flat tappet cam. 1.260 60ft.--6.09 at 111 1/8th mile --9.68 at 136 1/4 mile--No NOS"


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pittsburghracer said:
There’s a reason hidden here why 351 Cleveland’s and 426 Hemis were dogs on the street.
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only the 4v cleveland, they had 460 sized ports and valves. the 2v motor was much better in both respects, only they lumbered it with with too big a chamber which dropped compression. most aftermarket cleveland heads have 2v based ports/valves with 4v based closed chambers giving the best of both.
neil.
 
It's a bit of a stretch to call a 426 Hemi a dog on the street.

The best comparative example I can think of...the 383 versus the 440. Two engines fitted with the same heads and intake and cam, exhaust, etc. In theory, the 383 is a 'race' engine compared to the 440 - big ports, big cam, short stroke. In reality, the results are pretty much what you'd expect...the 440 makes more power everywhere and especially down low. On vehicles that are not traction limited, the 440's down-low power makes a big, useable difference.
 
Hysteric said:
Some one better tell this guy then.......

360 cast head porting

"factory small block head castings with some time in them work better than most people can imagine.
Small block in Demon with 587 heads and a .590 Racer Brown flat tappet cam. 1.260 60ft.--6.09 at 111 1/8th mile --9.68 at 136 1/4 mile--No NOS"


View attachment 1715608122
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Dan was runner up in both Pro and Super Pro at the Holley event at Bowling Green with the Demon. He's a very good racer.
 
justinp61 said:
Dan was runner up in both Pro and Super Pro at the Holley event at Bowling Green with the Demon. He's a very good racer.
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That is quite an accomplishment.
Who won?
I want to see they head data.
 
512Stroker said:
That is quite an accomplishment.
Who won?
I want to see they head data.
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Don posted a link to the results from the Moparty event.

As far as I know Dan does all his own head work, as far as numbers go I don't know. He does or did have a late 70's 300 with a small block stroker and the same heads as the demon that runs hard too and IIRC a tube chassis Lebaron.
 
33IMP said:
Which of these seems the most wrong?....
1. 408 mopar stroker with 170 cc. Rpm heads
2. 302 Ford with 225 cc. Cnc ported heads
3. 396 Chevy (big block) with 316 cc. heads, stock, that flow 325 cfm.
4. 440 mopar with stock heads that flow around 220cfm, if they are pretty good ones (215 cc.? 235cc.?)

....
1
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Everyone knows the 396 is a pos and loses to 155cc headed 340 in stock class.

440 do better with less gear than say a hemi... hemi need more gear, big port volume.
 
Port volume.....I don't give a damn.

I'm going to do to that cylinder head.....whatever I want to.....whenever I want to do it.
 
Anyone recall.....there was an article on a 68/69 Roadrunner feature car that one of the magazines had fixed up back in the day....cam, headers, port work, etc. 4 speed, Dana 60. The article said that with the 3.54 gears, it could be beaten off the line but the top end charge was 'unstoppable'....they eventually sold it off to 'some kid' who 'ruined' it with 4.88 gears. No real point in this discussion, but it reminds of that article....
 
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