500hp & 600hp Bench Racing thread

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19DUSTER73 said:
What I was getting at is the fact that this guy wants to basically say let's use the same top end to make the same power with both engines. When someone gives an explanation as to why it won't pan out he says yeah but if we change this this and that it should work. Which is fine and it makes sense but ya can't sit there and do that with every explanation given. It's a go nowhere type of deal.
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I get that. My point is we don’t have a lot of choices for cylinder heads. The Chrysler guys are always sucking hind tit when it comes to induction.

We’re it not for the W2 heads, Chrysler would have never had (IMO) the best as cast tunnel ram ever made, the Holley Pro Dominator.

The manifolds that Chrysler released for the W5 heads was a far cry from the Pro Domiminator.
 
19DUSTER73 said:
Explain to us why there is a difference in rpm.
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Basically it takes a certain amount of fuel and air within a range to make x amount of hp of course there’s other variables.

Just off the top of my head guess say 400 hp is about 550 cubic feet of air per minute, cfm.

now you got a 318 and 360 how are those engine gonna displace that amount of air and fuel ?

let’s just say were operating at 100% VE so a 318 is .184 cubic feet and a 360 is .208 cubic feet per cycle that’s how much of the 550 cfm they can process in one cycle which is two revolutions. So how many revolutions “rpm” does it take to process 550 cfm for both engines? 318 = 5978 rpm and 360 = 5388 rpm for both to move 550 cfm.

Of courses there variables so not gonna be the exact out come but why they do operate at different powerband.
 
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Rat Bastid said:
Let me see if I can help you out.

I don’t care what head you use, if the rockers are NOT a offset, that port is good for maybe, MAYBE 370 inches before it becomes a choke.

Think about this. There isn’t an aftermarket head out there (again, with non offset rockers) that can compete with the W2 head. Not one. Not even close. And the W2 head was based on 340ish inches.

The engineers that developed that head weren’t idiots. And look at the lengths they went to make a competitive cylinder head.

And from personal experience I can tell you the W2 head, FULLY ported to square, with a 2.100 intake valve and a tunnel ram is about used up at 8000, maybe 8200. That is a fact.

Now drop those heads on 408 inches and watch them struggle.

I say it all the time. Architecture matters. You can look at some of the head available for SBC engines out there. To make real horsepower they are using heads that flow over 350 CFM at .500 lift and have a port size (and a really nice shape) that 25 years ago would make a BBC blush.

I think way too many don’t understand how head deficient these engines are. And the upshot of that is it takes a bunch more cam timing to get the same RPM (at whatever RPM that we are talking about) out of an engine that is induction (and valve diameter) limited.

The best remedy for that is reduce the stroke.
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See, my argument is in line with this. Get good heads, and the 408 will outrun the 383. But not if the 408 is crippled with non offset heads.
 
273 said:
Basically it takes a certain amount of fuel and air within a range to make x amount of hp of course there’s other variables.

Just off the top of my head guess say 400 hp is about 550 cubic feet of air per minute, cfm.

now you got a 318 and 360 how are those engine gonna displace that amount of air and fuel ?

let’s just say were operating at 100% VE so a 318 is .184 cubic feet and a 360 is .208 cubic feet per cycle that’s how much of the 550 cfm they can process in one cycle which is two revolutions. So how many revolutions “rpm” does it take to process 550 cfm for both engines? 318 = 5978 rpm and 360 = 5388 rpm for both to move 550 cfm.

Of courses there variables so not gonna be the exact out come but why they do operate at different powerband.
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That's not an example of rpm fixing anything, that's an example of what happens when the heads are undersized.
Fix the heads and more CID makes more power. Going bigger CID without the commensurate amount of flow capacity is dumb. Like putting the driven wheels up front kind of dumb.
 
Phreakish said:
See, my argument is in line with this. Get good heads, and the 408 will outrun the 383. But not if the 408 is crippled with non offset heads.
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You make my point. What he’d can you fit to the 408 that you can’t fit to the 408?? Even the W2 is undersized for 383 inches.

If you could get into some W9’s or similar you might get ahead of the 383, but I know that the W7 head was developed from the W5 for 350-370 inch engines. At that time I think they were in the 8700-8800 RPM range. That was with a single 4.

So taking that head over 400 inches and it will start to lose VE right quick unless the cam timing is adjusted. And you will hit a point where you really gain nothing up top an you just kill the middle.

That’s the issue. I like to consider the cross section and when you do, you see how limited the induction we have to deal with is.

Even for street, street/strip, strip/street stuff.
 
Rat Bastid said:
You make my point. What he’d can you fit to the 408 that you can’t fit to the 408?? Even the W2 is undersized for 383 inches.

If you could get into some W9’s or similar you might get ahead of the 383, but I know that the W7 head was developed from the W5 for 350-370 inch engines. At that time I think they were in the 8700-8800 RPM range. That was with a single 4.

So taking that head over 400 inches and it will start to lose VE right quick unless the cam timing is adjusted. And you will hit a point where you really gain nothing up top an you just kill the middle.

That’s the issue. I like to consider the cross section and when you do, you see how limited the induction we have to deal with is.

Even for street, street/strip, strip/street stuff.
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100% agree, but I feel like that was never what OP was getting at. I think he must be bad at posing questions..

My contention from the beginning is that more CID is always more power UNLESS the head flow sucks. It just happens that most small block Mopar have few good options for decent heads, and so it's easy to think CID may not help - when in fact it's only that the heads and intake suck.
 
Rat Bastid said:
You make my point. What he’d can you fit to the 408 that you can’t fit to the 408?? Even the W2 is undersized for 383 inches.

If you could get into some W9’s or similar you might get ahead of the 383, but I know that the W7 head was developed from the W5 for 350-370 inch engines. At that time I think they were in the 8700-8800 RPM range. That was with a single 4.

So taking that head over 400 inches and it will start to lose VE right quick unless the cam timing is adjusted. And you will hit a point where you really gain nothing up top an you just kill the middle.

That’s the issue. I like to consider the cross section and when you do, you see how limited the induction we have to deal with is.

Even for street, street/strip, strip/street stuff.
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I think that was what happening in the 360 vs 410 me and Rumblefish360 we're debating, there was only 300 rpm between peak hp and 200 rpm between peak torque and the lbs-ft per cid was 1.17:1-410 & 1.23:1-360 which to me means 410 ve% is lower than the 360.
 
273 said:
Just curious

What would your 500 hp combo’s be for a 0.060” overbored 340 block so 4.10” with each one of these strokes 2.96”, 3.58” & 4”

and what would your 600 hp combo be for a 4.375” bore 400/440 block with these strokes 3.38”, 3.75” & 4.25” ?

shooting for pretty close to those hp goals for each.
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I've better things to spend my time on so here is just one example......The 1st stroker my son Cody and I ever built............

March 3, 2006.....

451"/400
Ported 452 iron heads
2.14/1.81 valves
950cfm Quick Fuel
M1 single plane
Comp XR292R solid roller
9.5:1 compression
588 lb/ft @ 4,600 rpm
602 hp @ 5,800 rpm
621 hp @ 6,100 rpm
601 hp @ 6,700 rpm
 
And here's another example of size/spec/hp currently running in the '69RR.
589ci/mega block
-13 365cnc Indy heads
2.30/1.88 valves
440-2
Herbert .625/.625"-260/[email protected]
10:1CR, old 950HP DP
2.1/8" TTI step hdrs.

DYNO SHEET.jpg
 
Yeah I know John, it was built originally as a 605 with 4.625 crank with a big cam etc., hence the heads. Crank got damaged somehow and was rebuilt with the heads but more for street/strip with a mild s/roller cam etc., we bought motor fresh/dyno'd to run 10.50's in the 3800lb brkt RR, its gone 10.30's so far through the muffs, got it for a good price. Its all wrong really but works for what my mate wanted. Had to a have a race 727 built/converter, Dana 60, spent a lot of money, guess he ran out and used his 950 from the 12 sec 440 it had in it
 
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Phreakish said:
So it made more..

Also, peak isn't the whole story.
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I compare hp curves with optimal gearing in mind unless gearing is a fixed, already been chosen, so with optimal stall & gearing the curve is fairly equal but if your just talking 2800 stall and a set of 3.55 no matter what engine then the 410 especially if it's a mainly street engine.
 
How about this build, I'm guessing 550 if everything is right:
340 bored .030 over.
Trw flattops, block decked so pistons are .035 above deck.
Open chamber W2's, 11:1 compression
208 intake valve flow about 300 cfm @.600
M1 single plane intake.
Bullet solid roller, 296r
262 @.050 intake 266 @.050 exhaust. .640 lift 109 lobe sep
 
bigfoot said:
How about this build, I'm guessing 550 if everything is right:
340 bored .030 over.
Trw flattops, block decked so pistons are .035 above deck.
Open chamber W2's, 11:1 compression
208 intake valve flow about 300 cfm @.600
M1 single plane intake.
Bullet solid roller, 296r
262 @.050 intake 266 @.050 exhaust. .640 lift 109 lobe sep
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That should get close to 600 pretty easy IF it will run to 7800.
 
Guys you're being played! He bases his "facts" off theory and I read it (insert your choice) one time.

I'd like to see how many years of engine building are represented on this thread, this is real world experience, not theory.
 
justinp61 said:
Guys you're being played! He bases his "facts" off theory and I read it (insert your choice) one time.

I'd like to see how many years of engine building are represented on this thread, this is real world experience, not theory.
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Not true, it's based on all the engine build's I've seen in magazine and video where there's been dyno results', not saying that trump's other's experiences, if I didn't take that in account of others I wouldn't have started these threads, best argument so far is PRH there's more vacuum, pull etc... Which I can see per revolution but what about over time and what about when port shape, opening and closing valve event's, lsa etc.. Is taken into account.
 
Woooo ragazine builds. Talking trash here I see. They throw numbers around like I throw horseshoes. Scattered.
 
pittsburghracer said:
Woooo ragazine builds. Talking trash here I see. They throw numbers around like I throw horseshoes. Scattered.
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The mopar one's are built by some of the builders on this site, so their too liars then?
And since I don't and most of us don't have a dynos we got to extract from where we can do they lied more when building less displacement ?
 
273 said:
The mopar one's are built by some of the builders on this site, so their too liars then?
And since I don't and most of us don't have a dynos we got to extract from where we can do they lied more when building less displacement ?
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Let’s just say they stretch the truth and many gets free parts to test. Dyno number to me don’t mean diddly squat.
 
pittsburghracer said:
Let’s just say they stretch the truth and many gets free parts to test. Dyno number to me don’t mean diddly squat.
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of course you got to take all info with a grain of salt, why I don’t change my mind on just cause “we say so” which is pretty much what’s being said.
 
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