Big Block Powa!! ??

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PRH

PRH

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I was watching a couple of recent Nicks Garage you tube videos the other day. I think those guys do a pretty nice job with them.

The two videos I am referring to are one of a 426w with a single 4bbl, and a before/after rebuild of a 440-4.

In 30 years of dyno testing...... I don’t recall ever testing any BBM that made those kinds of numbers.



 
In your opinion are these numbers too low or too high ? IMO a '63 , 426w is on odd ball with odd ball parts and it is what it is . thanks , Tom
 
I saw the 426 video, that was a industrial or truck engine with a set of 906 heads, appears to be worn out, blow by out the valve covers looks quite excessive, and I was chuckling at the idea of shimming the oil pump relief spring to increase hot idle oil pressure........spoiler, that doesn't help.
 
“What I’ve heard” thru folklore is that a 375hp 440 would make about 315hp tested on a more modern dyno....... so the 320 he got seemed to agree with that.
Especially if you had the crank turning the water pump instead of it being electric.

(FWIW, My experience with the shims in the oil pump spring is that it absolutely works....... just like the HP spring MP sold also works(more pressure), as does the Milodon adjustable regulator)

The 426w was sort of a cobbled together mess...... but still...... under 300 is kinda weak........ but seemed plausible considering the power of the 440-4.

“What I’d like” to see them do is....... take a build like the 440-4...... after the rebuild...... where they had it in the 400hp range....... and then see what it takes to step it up another 100hp.
More cam, headers, intake, carb, etc.

It’s a business....... so it’s not like that would likely be a paying job for him...... just like I’ve never had the opportunity to do it here.
If I’m looking to end up at 500hp..... you build it to make 500hp..... and iiwii.

But going through the transformation would be fun.

From what I can think of, looking at 30 years worth of memories is...... the weakest BBM I’ve tested was a 400, that I got as a rusted seized motor, that I had to beat the crap out of to get it apart.
I cleaned it all up, hammer & chiseled the rings out of the pistons, and put it back together with new rings and bearings.
A set of very very used up 346 heads that I did yet another valve job on, along with a quick bowl blend. A used Crower 280H cam, swap meet DP4B, and a Holley 780vs carb I bought for $4....... I also went through an old 383 single point distributor.
With 1-3/4 headers on it, it made 400tq/350hp.

All the others I can think of made over 400hp, although they were all run with headers.

The “after” numbers on the rebuilt 440-4 are pretty respectable imo, especially using the stock intake/carb/exhaust manifolds.
 
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PRH said:
“What I’d like” to see them do is....... take a build like the 440-4...... after the rebuild...... where they had it in the 400hp range....... and then see what it takes to step it up another 100hp.
More cam, headers, intake, carb, etc.
Click to expand...
this....with any mopar.../6 on up...
 
Those numbers are disappointing to me. Mine= 1968 383, stock heads, carb, distributor, lower compression, roller cam, adj. rockers, dyno run w/headers= 390hp.
 
To me, those tests were nice honest assessments of what you get out of that type of mild build.
Just being a “440” or “426w”, in and of itself......doesn’t really count for much.
 
PRH said:
“What I’d like” to see them do is....... take a build like the 440-4...... after the rebuild...... where they had it in the 400hp range....... and then see what it takes to step it up another 100hp.
More cam, headers, intake, carb, etc.
Click to expand...

I just watched that today, he's good but annoying with his "here we go" all the time, anyhow, my old 446-6 motor with stock pistons+.039 fel-pro's, 9.8:1cr?.... big valve 906's temp ported to approx 260cfm, Team G, 850DP, 2" f/wells and that mild CCams 290@.050 SFT made around 529fwhp according to weight/mph....3338/125mph...no alternator/moroso w-pump same as he uses....wonder what that would've made on his dyno.....550+@my 6750rpm?
 
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I've been watch'n some big block builds like this...... I have a keen interest in the builds and what power level they are making..... Now that I have a couple of BB's.
 
Anyone remember that mid-80’s article where they laid out the various “recipes” and then tested them?
I think it was car craft that did it.
They build a short block that would be suitable for over 600hp, and started out with a basically stock top end, and then upgraded it from there.
As I recall, the first test had stock heads, iron intake, ex manifolds, and some sort of nearly stock(or actually stock) cam.
I think that first combo was in low-300’s for hp.
 
That’s not the one I was remembering, but that's the gist of the type of testing I was talking about.

Taking that one a few steps further......... next step, bowl blend the heads, then put in bigger valves with more porting....... then add a bigger solid cam.
 
Was that Car Craft or Mopar Action? That was when I was reading every magazine I could find. I think I even had a subscription to Super Stock and Drag Illustrated... lol
 
It appears that it was Hot Rod Oct. 86

I think Dulcichs 2001 article is probably more relevant for what most guys are doing for the basic hot street stuff, but the old HR article took the power up to a much higher level(with some serious parts changes).
 
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Something that "I wonder about" Nick is I have only watched maybe? 6 dyno pulls of his, you never hear him talking about jetting, timing, etc. Makes me wonder how relevant those runs might be at times.

But of course there's a HELL of a "lot of room" to lose power in a used engine. I remember once I pulled apart a 440 and the intake valves had huge cakes of oily carbon from stem leakage, almost filling up the ports. That thing could not possibly done more than idle around regardless of throttle setting!!!

Like this only a lot worse!!

ValveBuildup.jpg
 
I have several dyno carbs....... different sizes, and for different levels of power.
If I’m using one of those to baseline the motor...... I rarely ever change the jets.
If the a/f ratio is within a normal range, fiddling with the jets is a few hp here or there.

You might swap the whole carb and see the power numbers change a fair amount...... but a jet change on the same carb?
Not “usually” gonna change things much(unless the jetting is way off to start..... which means, if I’m using one of my shop carbs...... I grabbed the wrong one).

I use my shop carbs as known quantity items that can be used to get the motor running without any surprises.

I save the tuning time for when the customers carb goes on.
 
67Dart273 said:
Something that "I wonder about" Nick is I have only watched maybe? 6 dyno pulls of his, you never hear him talking about jetting, timing, etc. Makes me wonder how relevant those runs might be at times.

But of course there's a HELL of a "lot of room" to lose power in a used engine. I remember once I pulled apart a 440 and the intake valves had huge cakes of oily carbon from stem leakage, almost filling up the ports. That thing could not possibly done more than idle around regardless of throttle setting!!!

Like this only a lot worse!!

View attachment 1715662435
Click to expand...
There's quite a few of them videos where him & his little buddy actually tune for hp, but not really on the stockers
 
426 Industrial low compression engine it was not a passenger car 426. Dished pistons vs flat tops.
 
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