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454 dyno results. Input, thoughts, comments?

14K views 36 replies 20 participants last post by  Burt Munro 
#1 ·
I welcome anyone's input. Are these results what I should expect?

I just got my dyno results and would like anyone's opinon on the results.
I built the engine and all parts are new.

Engine: 468
Fuel: 93 octane
Heads: Edelbrock E Street
Intake: Performer RPM
Carb: Holley 750
Jets: 72/80
Timing: 38 deg.
Cam: Compcam EX274H-10 Lift: Int. .522/Ex .555 LS .110
Lash: int. 0 EX 0 Duration: @ .050 230/236

At 4,600 RPM it maxes out at 453.2 HP & 517 ft/lb torque.

These are the results of the 3rd pull after trying various jetting configurations.

I would posted the entire sheets but my lack of computer knowledge hinders me.
 
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#2 · (Edited)
Thats not the largest cam out there....but 4600rpm peak is early even for that cam. And am I reading right.....horsepower and torque both peaked at 4600? 4600 sounds about right for peak torque rpm, but peak horsepower shoulda happened a good thousand rpm later at least.

How long did the operator keep the pull going after 4600? What did it do after that? Did it keep climbing(did the rpm keep climbing), or did power fall off drastically to keep going? Almost sounds like the pull got aborted at peak torque. Hopefully, because it indicates something still wrong somewhere if it went flat right there.


What valve springs are in there?

If I were you.....try to get that sheet up or see if you can get somebody to put it up or host it for you. It will be useful to have the guys see it, because there might be something obvious.
 
#4 ·
My torque graph has a double hump i think it was caused by the corvette tri-power one peak was 4600 and was 532 then it dipped a little till 5000ish then started to climb again and peaked at 5500 and 543 ft/lbs. hp peaked at 5700-5800 and made 580hp

but yes our numbers are very close at 4600



 
#11 ·
I agree, I Think it easily would be besting 500 if they just kept the pull going.

I checked the numbers and for what its worth....horsepower and torque are pretty much what they should "mathematically" be based on torque at 4600rpm (517X4600)/5252 = 452.82 horsepower. so...all that jives.

Im just still waiting to hear back why the pull quit at 4600. Had you brought it north of 5500, you would have seen those 500 plus horsepower figures.

There is a problem though if it just cant get past 4600. Definitely get back to us on the answer about that.
 
#13 ·
yeah something is not right there.... take a look at my dyno sheet abotu the same size cam with a bit more lift and on a 112 LSA rather then 110 and my heads were still a little better but still even your torque comes in a lot sooner........... what were you running for headers/exhaust?
 
#16 ·
The 750 carb has nothing to do with it. The 750 carb on my 460 does just fine. ET's in sig. I would have liked to have seen a little more jet added, but this is not the issue. What is the compression on this engine? Do you have the correct valve springs? Wierd thing is it started to go flat then at 5000 it gained a few HP. I don't understand why in the world a dyno operator would stop the pull at 5k on a cam listed to run to 6k and not say why he did or what issues he noticed that made him not pull it higher to see what it wanted to do.
 
#20 ·
Brian you say you built the motor...how tight did you set it up? That cam is a bit stronger than a stock ZZ cam and they will pull very well to 5500. Motor sounds tight to me....JMO
 
#21 ·
I had it bored and honed .060 over. The machine shop proved the piston and ring set which are for .060 bores. I did verify that. There were no metal shavings in the break in oil. The lash is set to a quarter turn past. The dyno shop verified that. All the bolts, nuts, etc were set to spec. I plasti-gaged the gournals and they too checked to spec.
 
#24 ·
Hyper pistons? Rings too tight? Cranking compression?
 
#26 ·
From the dyno sheet, I really wonder if the engine was about to see another upswing in power. From 4900 to 5000 it was back on the climb. Should have ran the engine to higher RPM to be sure.

Also, why such low oil temperature? Are those right, because I would have thought to see about double that.
 
#27 ·
I welcome anyone's input. Are these results what I should expect?

I just got my dyno results and would like anyone's opinon on the results.
I built the engine and all parts are new.

Engine: 468
Fuel: 93 octane
Heads: Edelbrock E Street
Intake: Performer RPM
Carb: Holley 750
Jets: 72/80
Timing: 38 deg.
Cam: Compcam EX274H-10 Lift: Int. .522/Ex .555 LS .110
Lash: int. 0 EX 0 Duration: @ .050 230/236


At 4,600 RPM it maxes out at 453.2 HP & 517 ft/lb torque.

These are the results of the 3rd pull after trying various jetting configurations.

I would posted the entire sheets but my lack of computer knowledge hinders me.
Is that the flat tappet or the hydraulic roller?
 
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