Looking for Horsepower Guesstimates on Friend's Build

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BrianT

BrianT

Here we go again...
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My buddy and I were having a few cold beverages the other night and he started talking about the engine that he recently had built. We got into a friendly disagreement about what kind of power his engine is making. I don't want to slant the debate by giving our opinions, but would rather you all look at the info we have and make your own guesses. Later, I will show him this thread no matter what the outcome. His builder doesn't use an engine dyno so all we have is guesstimates. I'm trying to get him to take it to a local shop that has a chassis dyno so we will know the truth in the end.

Here's his build.

440 .030 over
stock crank and rods
Ross forged/flat top pistons #82008
Edelbrock heads #60825 right out of the box
Howards hydraulic roller camshaft #720555-12 Advertised Duration 282/288, Lift .525/.525
Howards hydraulic roller lifters
Harland Sharp 1.5 ratio rockers
Mopar M1 single plane intake
Brawler 850 cfm carb
MSD distributor and Digital 6 box
TTI 1 7/8" full length headers

1697669409008.jpeg
 
The dyno or drag strip are the only way to know for sure…. Everything else is speculation and bench racing… it’s like guessing how many pennies are in this jar… 1 HP per cubic inch is a good place to start as a hypothesis…

8E248F9A-980E-4F94-8224-3CC7C3918245.jpeg
 
Scody21 said:
The dyno or drag strip are the only way to know for sure….
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True but it's not like similar builds don't make similar power, It's not like it's impossible to guesstimate a ballpark number, It mainly comes down to heads and how well the supporting parts are taking advantage of what the heads have to offer.
Scody21 said:
Everything else is speculation and bench racing… it’s like guessing how many pennies are in this jar… 1 HP per cubic inch is a good place to start as a hypothesis…

View attachment 1716155359
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I found something similar, eddy's with a "Our stick is a COMP Xtreme Energy High Lift hydraulic flat tappet, with specifications of 295/297 degrees gross duration, 241/247 degrees duration at .050-inch lift, and .545/.545-inch lift."

https://www.motortrend.com/how-to/how-you-can-build-a-stout-537hp-street-440/

On The Dyno
440 Chrysler Big-Block
RPM:TQ:HP:
3,600527361
3,700525370
3,800526381
3,900528392
4,000533406
4,100534416
4,200535428
4,300537440
4,400538451
4,500538461
4,600538471
4,700535479
4,800532486
4,900530494
5,000527501
5,100524509
5,200521516
5,300518523
5,400513527
5,500508532
5,600502535
5,700495537
5,800487537
5,900477535
6,000467533

4mulas said:
430-450 horse
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You don't have much faith in eddy heads I guess :)
 
273 said:
My Guesstimation is around 525/525 hp/tq @ 5500/4500 rpm.
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Yep. My guess too. A friend built a .030 440 with a Comp juice cam and ported 906's. He got just shy of 500 horse and 500 lb/ft.
 
As said 475-525hp and 525ish ft-lb of tq. I could see higher peak numbers with the M1 and 850 compared to a dual plane/750 carb. Either way it should be fun to drive.
 
We had something similar on the dyno here.
It had a little more duration, a Holley SD/850, Hooker 1-7/8” headers, and some minor bowl work on the heads.
It was like 540tq/515hp.

The last line on the dyno sheet was 5600, and the numbers were still going up a few hp per line.
The previous HR cammed 440 we’d had on the dyno experienced some lifter woes at 5800(Morel street lifters, plunger got stuck at the bottom), so there was a reluctance to run this one any higher, to try and prevent that from happening again.
Had it been successfully run to 6000 or so, I feel like it would have crested 525hp.
But at this point, that’s all “coulda, shoulda, woulda”.

My guess is the Howard’s/TF .600/.600 cam would have been worth upwards of 20-25hp more.
 
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PRH said:
We had something similar on the dyno here.
It had a little more duration, a Holley SD/850, Hooker 1-7/8” headers, and some minor bowl work on the heads.
It was like 540tq/515hp.

The last line on the dyno sheet was 5600, and the numbers were still going up a few hp per line.
The previous HR cammed 440 we’d had on the dyno experienced some lifter woes at 5800(Morel street lifters, plunger got stuck at the bottom), so there was a reluctance to run this one any higher, to try and prevent that from happening again.
Had it been successfully run to 6000 or so, I feel like it would have crested 525hp.
But at this point, that’s all “coulda, shoulda, woulda”.

My guess is the Howard’s/TF .600/.600 cam would have been worth upwards of 20-25hp more.
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DC Dart what is there to disagree with here?
 
480 hp @ 5400
535 ft lbs @ 4000
It will be a good cruiser.
 
MOPARMAGA said:
480 hp @ 5400
535 ft lbs @ 4000
It will be a good cruiser.
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About what I'm thinking 475 -500 hp depending on tune.
I don't see it going over 500.
I've seen some happy dyno #'s that weren't so happy at the track.
 
Wups.Did not realize I disagreed with PRH or replied for that matter. Must of dragged a finger or something. I always look forward to his input.
 
BrianT said:
Howards hydraulic roller camshaft #720555-12 Advertised Duration 282/288, Lift .525/.525
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Correction on your Howards hydraulic roller camshaft #720555-12 Advertised Duration 282/288, the Lift is actually .520/.530

Don’t go by Summit Racing’s website.
 
@ .050 229-235 duration. That's a baby camshaft
 
Car Nut said:
Correction on your Howards hydraulic roller camshaft #720555-12 Advertised Duration 282/288, the Lift is actually .520/.530

Don’t go by Summit Racing’s website.
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THIS is the kind of info I was looking for. My buddy has been repeating what he read on Summit's page and not what is on Howard's page.
Anyone care to change their guess now that we have the true cam specs?

Lift: .520 / .530, Duration @ .050: 229 / 235, Centerline: 108, Mild lopey idle, Street/mild bracket, Good low to mid-range performance
 
.005” of lift would make just about zero difference(very likely less difference than would fall within what the repeatability % of the dyno is).

Basically, your friends combo, assuming everything functions “as it should” would be “around 500hp”.

The observed numbers could easily be +/- 5% depending on the dyno shop that did the testing.
 
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BrianT said:
THIS is the kind of info I was looking for. My buddy has been repeating what he read on Summit's page and not what is on Howard's page.
Anyone care to change their guess now that we have the true cam specs?

Lift: .520 / .530, Duration @ .050: 229 / 235, Centerline: 108, Mild lopey idle, Street/mild bracket, Good low to mid-range performance
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I made my guess with the Howard's #, it's hp probably somewhere in the low 500's and tq closer to mid 500. The article dyno build I posted only had 12 @ fifty degrees more duration and made 537hp/538tq.
 
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