#41  
Old 07-23-2022, 07:04 PM
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Originally Posted by AG View Post
I'm building a 494 ci that is 4.32" x 4.21" stroke with SD CNC ported Eddy heart shaped chamber that flow 336 cfm, Bullet 235/241 at 0.50" HR cam, 0.632" lift, RPM intake with a 1" spacer and a 850 cfm carb, what do you think it will make?
My 4.350x4.21 Eddy heads maybe a click more porting Victor 850 Demon 268/272 solid roller made 690 HP. My 0.030 455 with a HFT 239/247 @ 0.050 Torker II 850 Holley is about 550-570 based on mph, conservative dyno was only 525.

So you should be in between.

FWIW the 455 on the street even on sticky DOT tires if you hit it in a turn it will break them loose real easy and you can get sideways!

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1978 Trans Am original owner 10.99 @ 124 pump gas 455 E heads, NO Bird ever!
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1964 Impala SS 409/470ci 600 HP stroker project
1979 Camaro IAII Edelbrock head 500" 695 HP 10.33@132 3595lbs
  #42  
Old 07-23-2022, 07:21 PM
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Originally Posted by 25stevem View Post
... or they choose to not spend what it takes for even a cheap computer engine analyzer program to answer there own questions!
I'm going to install a cam dot-to-dot just because I can. [evil laughter]

https://www.youtube.com/watch?v=Nz8ssH7LiB0

  #43  
Old 07-23-2022, 07:49 PM
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Hmm, is it advise or advice?
Just asking for a friend at the spelling and grammar police.

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Originally Posted by F ROCK View Post
I'm impressed at how some folks post on EVERY thread, and demand respect, are happy to critique the posts of others but cannot use or spell simple words correctly.
How can I take advise from, (or give respect to) someone who cant use or spell the words "Seams" or "There" (or spell dozens of other simple words) correctly?
I once asked about wheel lugs.
Steve posted that I was lazy and wasting bandwidth.
Is this thread wasting bandwidth?

  #44  
Old 07-27-2022, 03:53 PM
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...I asked my builder what he thinks my motor will make and he won't make a prediction. I understand where he's coming from. If he predicts a certain number and you don't get there then there's disappointment and maybe even blame...
Smart builder. There is an additional problem that the engine builder has to put up with. Every small block Chevy motor at a car show has in excess of 500 horsepower because that's what they wanted and that's what they were told. Very safe because the owner won't ever get near a dyno and won't ever race the car. Then the Pontiac guy wants "500 horsepower" since his Chevy friend has that.

Right now with aluminum heads we can go about 425 horsepower with a 400 or about 450 horsepower with a 455 and have a totally stock sounding and acting engine running on 91 octane. It will be a pussy cat at that level but still fry the tires down the block. From there on up as horsepower increases there continues to be an increasing loss of drivability as horsepower continues to climb. End result of loosing drivability is comparable to one's pain threshold, some people will tolerate much more than others. Some say they want 500 horsepower but also want the driving experience to be closer to what they have with their Honda Accord. For those that don't mind the sacrifices, we now have the aftermarket parts to achieve whatever level they want.

Anymore, I hear "500 horsepower" and my reaction is about the same as hearing fingernails down a blackboard.

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Old 07-27-2022, 05:09 PM
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Oh common Mick, it's not that bad is it?

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  #46  
Old 07-27-2022, 05:25 PM
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  #47  
Old 07-27-2022, 05:43 PM
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  #48  
Old 07-28-2022, 11:58 PM
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What's the 425 hp 400 cubic inch receipe ?

  #49  
Old 07-29-2022, 02:52 AM
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What's the 425 hp 400 cubic inch receipe ?
Edelbrocks head, cam and intake package.

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Old 07-29-2022, 03:50 AM
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Yep, "as-cast" aluminum heads and a mild roller cam in the 226/234 range with around .560 lift with a Performer RPM or similar manifold. Won't sound any different than a 400 with a flat tappet 068 cam and be 100% streetable.

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  #51  
Old 08-06-2022, 05:35 PM
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Originally Posted by Skip Fix View Post
My 4.350x4.21 Eddy heads maybe a click more porting Victor 850 Demon 268/272 solid roller made 690 HP. My 0.030 455 with a HFT 239/247 @ 0.050 Torker II 850 Holley is about 550-570 based on mph, conservative dyno was only 525.

So you should be in between.

FWIW the 455 on the street even on sticky DOT tires if you hit it in a turn it will break them loose real easy and you can get sideways!
I'm expecting 550-560 Hp. I never hit anything while going through a turn after my friend did and totaled his beautiful '68 Vette 4 speed.

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1967 Firechicken, 499", Edl heads, 262/266@0.050" duration and 0.627"/0.643 lift SR cam, 3.90 gear, 28" tire, 3550#. 10.01@134.3 mph with a 1.45 60'. Still WAY under the rollbar rule.
  #52  
Old 08-06-2022, 08:03 PM
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Building anything close to stock where you have the TORQUE And HP at RPM' that you ACTUALLY DRIVE at would just a be a Sin in this forum. Piece of paper with a Always calculated ( not measured) HP is much more important than Anything...
Don't Ever let a Dyno track your Torque below 3k rpm, who would ever use that??
Sarcasm, but true.

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  #53  
Old 08-06-2022, 11:31 PM
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When I bought my 461 assembly from Dave at SD I told him I wanted to run around mid+ 11's 1/4 in a 3 to 3200 lb car. He put together an assembly and said this should get you there. (I can't recall, but he also might have said somewhere close to 500 hp.) Good enough for me.

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  #54  
Old 08-07-2022, 04:03 AM
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If people want to dyno their engine, fine.
I mean, I kind of understand it when someone is doing a engine with some sort of effort. Nice set of ported heads, roller cam, money spent on a intake beyond port match, custom carb. Knock yourself out. Especially if the dyno is close by and you can afford it.
But I completely fail to see any sound reason to spend 800 bucks for a day on a engine dyno for these stock type 400s. Ram Air whatever cam, iron intake and a Q jet.
You know what kind of power it will make if you are any good. And you can get a good estimate at the track for 20 dollars.
If you like lighting money on fire just to say you got 360 HP out of your 400 you are strange or rich.
And it sure seems like a lot of guys spend that money on their 300HP wheezier.

  #55  
Old 08-07-2022, 08:18 AM
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A couple of times now I've installed a engine to find out it had a problem and had to pull the motor back out. Dyno session for me is around 550.00. I'll spend 550 for some insurance that it won't have a problem 1st thing along with setting optimal timing and jetting etc.

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  #56  
Old 08-07-2022, 08:18 AM
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Or they have no knowledge of carb tuning and expect the Dyno people to give them the answers to why the engine is running poorly and hope it will run better afterward.

And the GOOD dyno operators have the ability to get the air/fuel ratio in the ballpark in a few pulls. Timing is different question.

I have seen a bunch of Pontiac engines hurt by shops because they said he could get them another 15 "Bragging" hp by throwing 3 more degrees of timing at the engine. 99% of the people do NOT need optimal timing for their engine and Optimal Timing is not a curve but is a GRID of different timing points based on engine rpm and load across the whole grid.

Optimal Timing takes less work on a drag race engine running on the dyno as it is one set of load points.
This is the street section and you can have a nice running street engine but it will not have optimal timing,
PERIOD, as true street engines have lots of engine load points based on location, rpm, load, etc.

Tom V.

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Last edited by Tom Vaught; 08-07-2022 at 08:26 AM.
  #57  
Old 08-07-2022, 08:57 AM
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Originally Posted by scott70 View Post
A couple of times now I've installed a engine to find out it had a problem and had to pull the motor back out. Dyno session for me is around 550.00. I'll spend 550 for some insurance that it won't have a problem 1st thing along with setting optimal timing and jetting etc.
Exactly

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  #58  
Old 08-07-2022, 09:02 AM
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I wish to respond with 1 hp/CID at 5000 rpm, but that would sound snarky.

i infer the "high hp" is made with higher rpm. Being Street-minded, not vasco spring minded, the higher rpm is a fleeting, untapped capability since my OHC-6 days.

Thinking the Race Section ought to have emphasis on high rpm Valvetrain combination Threads. Roller combo is a financial bridge too far for me. Any flat tappets going to 7500 rpm?

  #59  
Old 08-07-2022, 09:04 AM
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Sure, solid flat tappets go that high.

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  #60  
Old 08-07-2022, 09:09 AM
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It's a pretty common misconception that just because an engine is built with a good set of heads and a bigger camshaft that it won't make power down low in the "driving range" or it makes "less" power than a stock engine down there.

When in fact most cases the exact opposite is true. They will generally make more power down low in the driving range than a stock engine. The biggest difference is that "peak" power occurs at a higher rpm point. However, that doesn't mean it makes less power at 3000 rpm or less than a stock engine does.

Paul has shown this time and again pulling his "built" engines down to 2000 rpm on the dyno. They might make peak torque at a higher 4000 rpm vs 3400 on a stock engine, but it still makes more at 3400 than the stock engine does and at every point below that as well.

But, guys that never run their engines on a dyno wouldn't know that, they just know what misinformation they've read on the internet.

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