350ci 470HP Peak at 6000RPM

[Tom68]

That’s true, but then the question that you seem to be dodging is what is a lot more hp in your definition, or conversely what is the lowest rpm where you want peak torque to be made.

Me ?

In the go faster thread one bloke posted that his peak hp would be 470 at 6000 rpm on a 350.

Another bloke said that won't happen.

I'm curious thinking but 470 peak at 6000 is easy, look up a few sheets and low and behold it's very uncommon. Revs have to be higher for 470 in most cases.

Thinks.....can only be a runner length thing. Post expecting confirmation of that theory.

Not getting a lot of confirmation yet, still think I'm right of course.

I think there would have been some early 70s Sprintcars close to it with their long Hilborn injection stacks.

[In-Tech]

Hiya Tom,
I noticed you have been a member here for less than a year. There is a wealth of information on this site. Quite a few have quit sharing information.

Of course runner length matters and whether wet flow or dry flow and wherever the wet flow is introduced. Bring apples to apples questions, not apples to oranges.

If you have a desired rpm band to maximize, tune the runner length/size/taper to comply, also exhaust. IR is a whole different world(as you know) than carb dual plane or single plane manifolds, tunnel rams too. EFI dual plane and single plane is a different world too.

[lefty o]

That’s true, but then the question that you seem to be dodging is what is a lot more hp in your definition, or conversely what is the lowest rpm where you want peak torque to be made.

Me ?

In the go faster thread one bloke posted that his peak hp would be 470 at 6000 rpm on a 350.

Another bloke said that won't happen.

I'm curious thinking but 470 peak at 6000 is easy, look up a few sheets and low and behold it's very uncommon. Revs have to be higher for 470 in most cases.

Thinks.....can only be a runner length thing. Post expecting confirmation of that theory.

Not getting a lot of confirmation yet, still think I'm right of course.

I think there would have been some early 70s Sprintcars close to it with their long Hilborn injection stacks.

this thread and the other one made me go dig out my dyno sheets for my old clunker. 9.8:1 iron headed 350, on 92oct pump swill. dyno sheets dated 30jan2000 474hp/6400, at 6000 it made 473. thats almost 23 years ago with a flat tappet cam and a single plane intake. id say given the years, and better head options its probably easier to do it today.

[vortecpro]

IMG_2225.jpg

IMG_2225.jpg

IMG_2225.jpg

Borrowing from the go faster thread.
SBC Carb'd.
You can make 470 at 6000 if you're actually making a lot more higher up in the revs.
A 470 peak comes at higher than 6000 with a SBC.

The question is why.

I think it's just inlet manifold choices, single planes are too short in the runner for a 6000 rpm peak, a modified dual plane should do it but they start laying down and you may have to overdo the rest of the motor to get it.

470 peak at 6000 shouldn't be a problem with an injected LS 5.7, plenty of manifolds with a 6000 rpm tuned length.

I guess that means with a SBC you could use an TPI, or an IR intake, or a crossram to achieve it.

Here you go........

viewtopic.php?f=1&t=63429&p=893774#p893774

[skinny z]

Thanks for that.

So, based on this result:

490HP@6000.jpg

This recommendation (below) doesn't appear unreasonable.

472@6000.jpg

It may be of interest to Tom68, that the induction length is also recommended in that spec.

[F-BIRD'88]

That’s true, but then the question that you seem to be dodging is what is a lot more hp in your definition, or conversely what is the lowest rpm where you want peak torque to be made.

Me ?

In the go faster thread one bloke posted that his peak hp would be 470 at 6000 rpm on a 350.

Another bloke said that won't happen.

I'm curious thinking but 470 peak at 6000 is easy, look up a few sheets and low and behold it's very uncommon. Revs have to be higher for 470 in most cases.

Thinks.....can only be a runner length thing. Post expecting confirmation of that theory.

Not getting a lot of confirmation yet, still think I'm right of course.

I think there would have been some early 70s Sprintcars close to it with their long Hilborn injection stacks.

this thread and the other one made me go dig out my dyno sheets for my old clunker. 9.8:1 iron headed 350, on 92oct pump swill. dyno sheets dated 30jan2000 474hp/6400, at 6000 it made 473. thats almost 23 years ago with a flat tappet cam and a single plane intake. id say given the years, and better head options its probably easier to do it today.

This engine did not peak at 6000. It peaked at 6400 rpm...
Try again.

The statement was you can't make peak hp of 500 hp @6000 rpm on a 10.50:1 350.


Try it.

[F-BIRD'88]

Thanks for that.

So, based on this result:



490HP@6000.jpg



This recommendation (below) doesn't appear unreasonable.



472@6000.jpg



It may be of interest to Tom68, that the induction length is also recommended in that spec.

Power is still climbing past 6200 rpm. Try again

[Tom68]

The statement was you can't make peak hp of 500 hp @6000 rpm on a 10.50:1 350.


Try it.

Yer, it's an eye opener, a 6000rpm HP peak on a 350 small block with a single 4 barrel manifold however you go about it comes at a cost in other areas, you're better off gearing up for a higher RPM HP peak.

I think this is part of the reason they were playing with cross rams for circuit cars in the early 70's with the low flowing heads that weren't keen to rev, trying to get runner length and still be able to see the race track. They didn't need to be running two carbys since there were carbs that were big enough.

I built some headers for a resto project of a Sports Sedan that ran here mid 70's, 2" primaries on a 350 trying to get the thing to rev. It had Lucas mechanical timed injection.

28022012053.jpg

03052010314.jpg

[In-Tech]

Tom, don't waste your time with the Fbird idiot. Forget about his post count, most have concluded he is an internet idiot re-poster who believes everything he reads. Fbird = self proclaimed whatever. He has a clue, but on average on what he has read and only minimally done.

[Monza355]

Here’s another example. On what appears to be an honest dyno

[Stan Weiss]

Your missing the point.. You are not the first guy who tried to get a 350 sbc in a 3600 lbs Street trim Camaro into the 11's...
You can make 470 hp from the 10.50:1 CR sbc. fir sure..
BUT NOT AT 6000 RPM.. It will not happen.

This engine has been built to 470 hp + and minus over 1 million times... Your will be no different.
For Calgary air you ned to build a 490 to 510 HP engine
dyno tested.. To get 470 hp in the car @ 3000 ft elevation.. ON YOUR BEST DAY.
you need to plan and account for this in your build if yiu want that xar to run 11.'s. there.

It will not happen with a 3.73 rear gear....

Best to have a reality based conversation.
Then yoy can make a plan that gets your street car to a 11 sec ET @ 3600 lbs @ 3000 ft elevation.

Me ?

In the go faster thread one bloke posted that his peak hp would be 470 at 6000 rpm on a 350.

Another bloke said that won't happen.

I'm curious thinking but 470 peak at 6000 is easy, look up a few sheets and low and behold it's very uncommon. Revs have to be higher for 470 in most cases.

Thinks.....can only be a runner length thing. Post expecting confirmation of that theory.

Not getting a lot of confirmation yet, still think I'm right of course.

I think there would have been some early 70s Sprintcars close to it with their long Hilborn injection stacks.

this thread and the other one made me go dig out my dyno sheets for my old clunker. 9.8:1 iron headed 350, on 92oct pump swill. dyno sheets dated 30jan2000 474hp/6400, at 6000 it made 473. thats almost 23 years ago with a flat tappet cam and a single plane intake. id say given the years, and better head options its probably easier to do it today.

This engine did not peak at 6000. It peaked at 6400 rpm...
Try again.

The statement was you can't make peak hp of 500 hp @6000 rpm on a 10.50:1 350.


Try it.

You can make 470 hp from the 10.50:1 CR sbc. fir sure..
BUT NOT AT 6000 RPM.. It will not happen.

The statement was you can't make peak hp of 500 hp @6000 rpm on a 10.50:1 350.


Who's statement? Or should I ask which one of your statements

Stan

[Bigchief632]

My question, 490hp/471tq. 150lbs of fuel, bsfc's would be .43 to .45, likely higher, any less aint happening, .43 is being generous for an old fuely head with a dual plane, is about 350 observed. Stated in thread from that build, 1.26 correction, 441-450hp corrected

Don't have the sheets anymore, or i'd post them, 355, 12.5:1, Ported Sportsman 2's, Holley Strip dominator, mild plenum work and port match, Quick fuel 850, Erson "street" roller, 258-263, .585/.550 lift, 1.6 intake rocker, made 530hp at 6600 and 45X ft lbs. around 5000. I am sure it made at least 470 by 6000, probably 500+. Kinda funny, I've built very few 350"s over the years, I usually talk then into 383's. Obviously not 10.5:1 on pump gas, but take 2-2.5 points of compression away, all else equal, it would make 470 by 6000. It's not some mystical feat, it's possible.

[lefty o]

Me ?

In the go faster thread one bloke posted that his peak hp would be 470 at 6000 rpm on a 350.

Another bloke said that won't happen.

I'm curious thinking but 470 peak at 6000 is easy, look up a few sheets and low and behold it's very uncommon. Revs have to be higher for 470 in most cases.

Thinks.....can only be a runner length thing. Post expecting confirmation of that theory.

Not getting a lot of confirmation yet, still think I'm right of course.

I think there would have been some early 70s Sprintcars close to it with their long Hilborn injection stacks.

this thread and the other one made me go dig out my dyno sheets for my old clunker. 9.8:1 iron headed 350, on 92oct pump swill. dyno sheets dated 30jan2000 474hp/6400, at 6000 it made 473. thats almost 23 years ago with a flat tappet cam and a single plane intake. id say given the years, and better head options its probably easier to do it today.

This engine did not peak at 6000. It peaked at 6400 rpm...
Try again.

The statement was you can't make peak hp of 500 hp @6000 rpm on a 10.50:1 350.


Try it.

do you need a tissue??

[vortecpro]

My question, 490hp/471tq. 150lbs of fuel, bsfc's would be .43 to .45, likely higher, any less aint happening, .43 is being generous for an old fuely head with a dual plane, is about 350 observed. Stated in thread from that build, 1.26 correction, 441-450hp corrected

Don't have the sheets anymore, or i'd post them, 355, 12.5:1, Ported Sportsman 2's, Holley Strip dominator, mild plenum work and port match, Quick fuel 850, Erson "street" roller, 258-263, .585/.550 lift, 1.6 intake rocker, made 530hp at 6600 and 45X ft lbs. around 5000. I am sure it made at least 470 by 6000, probably 500+. Kinda funny, I've built very few 350"s over the years, I usually talk then into 383's. Obviously not 10.5:1 on pump gas, but take 2-2.5 points of compression away, all else equal, it would make 470 by 6000. It's not some mystical feat, it's possible.

I believe it was around 350 HP in the room @ 6400 feet elevation. The corrected number is right, figure the friction HP. The fuelie heads flowed 260 CFM @ 28 inches.

[Stan Weiss]

This what I get from one of those dyno sheets.

Engine_Size_=_355.11510__-__Volumetric_Efficiency_=_0.90753
BSFC_=_0.43760__-__Air_/_Fuel_Ratio_=_13.1700__-__Blower_Pressure_=_.00
BSAC_=_5.7632__-__Barometric_Pressure_=_23.6180__-__Temperature_=_60.00

__________UnCorrected______Fuel
_RPM______HP_____Torque___lbs/hr___SCFM
_6000___351.01___307.25__153.601__441.69

Stan