350ci 470HP Peak at 6000RPM

[1980RS]

Here is a dyno test of a 350 sbc with both a dual plane and single plane tested.
It is 454 hp dp and 463 hp single plane.

In both cases you need to gear the #3600 car to rev it up thru the traps to make full use of the engine power.
Think 4.56 (short tire) 4.88+ (taller tire).
Needs a 4500-5200 stall converter
A 350. 470 hp to 500 hp will be THE SAME STORY.
This is a easy build. It will run 11's.

Sure didn't make a difference in my car, ran 11.30's with 4.10's and 11.30's with 4.88's the car just went through the traps at a higher RPM.

[mt-engines]

Hard to run these 12:1 CR examples on pump gas.

"peaked around 6000"
Means it peaked at a higher rpm.

I built a very similar 12.5:1 cr 350 with ported 305 heads sane valve size. similar flow.. It really liked to rev up.
Its the nature of built 350's.
The whole o point is if you limit rpm to 6200 you leave much of the power to accelerate the #3600 car unused.
You need to gear these 350 engines up to make use of the engine power available. Otherwise the #3600 car is not going to be very fast in ¼ mi.

Dude.. what are you trying to prove? So what if it peaked at 6300.. of it made the power at 6000rpm.. it made it at 6000 rpm.

I've built engines for guys that peaked 800rpm higher than they shift at.. does that mean the engine didn't make the power that it did 800rpm sooner? Just STFU

[Tom68]

The only reason I can't show you one that peaks at 500hp & 6000rpm is because I rarely feel the need to cap anything at 6000, it'd be stupid.

Well there is that.

[skinny z]

Or this combination of parts.

472@6000 again.jpg

472 @ 6000.
Oh shit. 2 HP over....

[skinny z]

I think the point is, despite "try again", is that is has been done. Ad nau·se·am.

[F-BIRD'88]

Here is a dyno test of a 350 sbc with both a dual plane and single plane tested.
It is 454 hp dp and 463 hp single plane.

In both cases you need to gear the #3600 car to rev it up thru the traps to make full use of the engine power.
Think 4.56 (short tire) 4.88+ (taller tire).
Needs a 4500-5200 stall converter
A 350. 470 hp to 500 hp will be THE SAME STORY.
This is a easy build. It will run 11's.

Sure didn't make a difference in my car, ran 11.30's with 4.10's and 11.30's with 4.88's the car just went through the traps at a higher RPM.

Un. , it ran well into the 11's... Whats your point?

[F-BIRD'88]

Lot of dyno minsters loosing their hair on this.

My point stands.. Your 12:1 cr examples are not valid and they all want to rev much higher too.

You All by you own evidence proved my point on a hot 350 sbc. 470-500 hp zone power curve.

[1980RS]

Here is a dyno test of a 350 sbc with both a dual plane and single plane tested.
It is 454 hp dp and 463 hp single plane.

In both cases you need to gear the #3600 car to rev it up thru the traps to make full use of the engine power.
Think 4.56 (short tire) 4.88+ (taller tire).
Needs a 4500-5200 stall converter
A 350. 470 hp to 500 hp will be THE SAME STORY.
This is a easy build. It will run 11's.

Sure didn't make a difference in my car, ran 11.30's with 4.10's and 11.30's with 4.88's the car just went through the traps at a higher RPM.

Un. , it ran well into the 11's... Whats your point?

My point was that you were saying it needs to be geared right. My point was that small of a gear change makes no difference.

[KnightEngines]

Lot of dyno minsters loosing their hair on this.

My point stands.. Your 12:1 cr examples are not valid and they all want to rev much higher too.

You All by you own evidence proved my point on a hot 350 sbc. 470-500 hp zone power curve.

No, we didn't, we proved you have NFI.
None of the sheets I posted were 12:1 engines, they were pump fuel streeters, 1 flat tappet, 1 hyd roller, both currently racking up miles in street cars.

[F-BIRD'88]

Sure didn't make a difference in my car, ran 11.30's with 4.10's and 11.30's with 4.88's the car just went through the traps at a higher RPM.

Un. , it ran well into the 11's... Whats your point?

My point was that you were saying it needs to be geared right. My point was that small of a gear change makes no difference.

I bet the cam duration is short... Valvetrain becoming unstable. Try again with a longer duration on the higher reving geared version.

[F-BIRD'88]

Lot of dyno minsters loosing their hair on this.

My point stands.. Your 12:1 cr examples are not valid and they all want to rev much higher too.

You All by you own evidence proved my point on a hot 350 sbc. 470-500 hp zone power curve.

No, we didn't, we proved you have NFI.
None of the sheets I posted were 12:1 engines, they were pump fuel streeters, 1 flat tappet, 1 hyd roller, both currently racking up miles in street cars.

And they ALL eant to and need to rev up well beyond 6000 rpm to get a 3600# sled street car going.
They All peak well beyond 6000 rpm.
The hyd may well be self crippled .

[Tom68]

The hyd may well be self crippled .

Sat a brick on the throttle of a points ignition hyd cam 307, just sat screaming at 7000 rpm until I got sick of waiting for it to blow up. Self limiting engines must have saved a lot of destruction back in the day.

[HQM383]

Lot of dyno minsters loosing their hair on this.

My point stands.. Your 12:1 cr examples are not valid and they all want to rev much higher too.

You All by you own evidence proved my point on a hot 350 sbc. 470-500 hp zone power curve.

It doesn’t work like that. You made the claim, you have to present the evidence as to why a 350-357ci sbc cannot have a 470-500hp peak @ 6000rpm.

KnightEngines showed dyno sheets of pump fuel 350ci making around 500hp @6000rpm but peaking higher. Why cannot cam and/or induction be dialed back to get the discussed figure at 6000rpm for that example?

I’m all ears and if your right, your right but it needs a solid understanding and explanation of why.

[Bigchief632]

If this was on a Super Flow dyno / software, you can not just take the uncorrected HP time the correction factor and get corrected HP. Super Flow also includes another factor using ME% which is not a constant during the pull.

Stan

No Stan, you're wrong. You can just multiply observed power by the correction factor, and it shows you corrected power. I've done it more times than I can count. I show the customer how the numbers work. I say, you take the lbs/hr fuel consumed, divide by bsfc off the sheet. It gives you observed, uncorrected power, with my back to the screen, going off the sheet just printed I calculate the power, I have Gary, dyno owner, pull up the screen that shows uncorrected power after calculating it. Guy is looking at screen, his face lights up, oh wow, it's exactly that. I say, ok, now, we divide corrected power by observed power, we have 1.062, I say, ok now pull up the screen that shows the weather, engine inputs, and correction, his face again lights up, wow, it's exactly that. I say right, now multiply the observed, by the correction factor, and it shows the corrected number on the sheet, they always say, wow, that's cool. I say yes, it's basic math and how you can spot check dyno sheets. There is also a screen that will show you the "theoretical" frictional losses, and it's usually a lot. Like over 100+hp on everything. That just shows you, how much "theoretical" power you're losing through frictional losses, and that you could work on that to gain power, but it doesn't account for if you already have thin low friction rings, etc. and you don't add that number to the corrected power.

The software does use the me%, but not for the correction. It's factored in when you input the bore, stroke, number of cylinders and may not stay constant as you say, but it's how the dyno measures the observed power, on any given pull, you can use fuel flow, bsfc's, to calculate observed, and then solve for the correction factor, etc.

In the 490hp engine, it used 154lbs of fuel. No bsfc's were listed. But I estimated them based on the combo and reality. I used .44, which is pretty good for a old fuelie head and dual plane. 154/.44=350 observed. Mark verified in fact, that is what it was, imagine that, the numbers jive!!. It was stated in the linked thread, there was a 1.26 correction factor, which is BIG, but, we know Mark's old shop was at 6400 feet, and that makes sense, and is reasonable. So now, we take 350*1.26, we get 441hhp. Now, divided 441 by 350, and low and behold, we get 1.26, the stated correction. If I wouldn't have known the correction factor, it would have been 1.4 to come up with 490hp which is, lets be real, off to see the wizard. There's no way it corrected 1.4. It ABSOLUTELY works that way. So what you're saying, is we need to add 50hp for some me% to get to 490hp? No, that is not how it works.

[vortecpro]

DYNOSHEET.jpg

DYNOSHEET.jpg

Not on my dyno you can't. Theres a formula that applies friction HP. Example: I used this formula, 500 HP X .30 = 150, 500 - 150 = 350 observed HP, so the correction would be 30 % and although the dyno would show that on a engine that produced HP at a certain RPM, I thought as you do. I would show this formula to Harold Bettes from SF and he would lose his mind "THATS NOT HOW IT WORKS" he would say. Lets look at another example from my dyno with track data:

SF 901 STP Corrected HP 820 @ 6700 RPM
SF 901 Measured HP @ 6400 feel elevation 570 HP @ 6500 RPM

You will notice on Wyndyn software the corrected HP will always have a higher RPM peak than the observed HP RPM peak, this is because friction HP is applied. Keep in mind I didn't design this I just know how it works.

820 X .28 = 229.6, 820 - 229.6 = 590.4 as you see the number don't line up, thats because as RPM rises friction HP changes.
Now to put this into performance, as you know STP correction is 29.92 60 degrees dry air, we would agree this is O DA conditions?
The above 820 HP engine, 570 observed @ 6400 feet ran 146.24 MPH @ 3440 in 615 feet positive air in ONE night of testing with limited runs. Now how much HP is that showing going down a 615 DA track?
https://youtu.be/E1Wz5qZDPAk