What Will It Run?

[PRHeads]

Where were the peaks?

Was it run with the race car headers?
If not, do you know what size headers were used?

 

[ksurfer2]

Where were the peaks?

Was it run with the race car headers?
If not, do you know what size headers were used?

I have not seen the dyno sheet yet. I will get that tomorrow when I pick up the motor. Here is a pick of the motor on the dyno that shows the header that were used.

 

[ksurfer2]

I ran a compression check on the cylinders. All came back between 148 and 152. I was expecting higher. Below is the dyno sheet.

 

[PRHeads]

I ran a compression check on the cylinders. All came back between 148 and 152. I was expecting higher.

When you did the initial CR tests, did you ever try a different gauge?
Those numbers were lower than expected, and so are the new numbers.
Same gauge used for both tests?

Is that the only sheet you got, or do you have some sheets with the numbers on them?

Here’s a compression test story……..
A friends bracket race 540” Pontiac.
Long duration, wide lsa cam.
Been on the dyno a couple times……..hp is good, TQ numbers are kinda lowish.
Cranking pressure is like 165.
Motor is supposed to be mid-15:1.
My take on it was, even with the long wide lsa cam, the cranking number should have been higher.
He tested it a few different times, and with different gauges.
Then, at some point he was having a talk with the supplier of the short block, and it came to light that the CR was in fact NOT 15.5:1, but was actually barely 13.5:1.

And just like that……..the 165psi made perfect sense.

My point is…….a 12:1 512 with a [email protected] SR cam “should” pump more than 150psi.
Making an “educated guess” on the intake valve closing point, the Wallace cranking compression calculator puts the number at about 190psi.

Aside from all that, glad you had what sounds like a drama-free dyno session.

 

[ksurfer2]

Below is the selection of pistons available from 440 source. The 5072 was used in my motor. Edelbrock says a Victor head has a 72cc combustion chamber. The head gasket is a Felpro 1009 with a thickness of .039. That would put compression at 12.7:1. I am borrowing another compression gauge and recheck tonight.

 

[PRHeads]

I’m not saying you don’t have 12.7cr.

I’m just pointing out the cranking pressure numbers don’t make sense.

 

[dvw]

The peak HP rpm is about is about 800 rpm lower than when I dynoed my 498 with that intake. It had out of the box unnported -1 Indy heads, similar compression. Going from memory it had a mid 270ish roller .650 lift.
Doug

 

[ksurfer2]

I’m not saying you don’t have 12.7cr.

I’m just pointing out the cranking pressure numbers don’t make sense.

I have another compression gauge in my truck right now that I borrowed from a friend. We will see what it makes with this gauge.

 

[PRHeads]

By the looks of the graph, the short duration cam is helping to pump up the numbers down at the lower end of the curve……..where they can’t help you(since the converter stalls way higher than that).

With the CR now at 12.7, the cam can be back up in the range of your original cam.
It will lose power below peak TQ, with the expected result being to get the HP to peak at a higher rpm, and hold onto it past peak better(into the rpm range that’s typical near the top end of the run).

 

[ksurfer2]

With a different gauge, I got 185psi. That seems like it is more in line with what the engine should make.

 

[ksurfer2]

Made it to the track for the first time with the new combo. Results are promising. DA was about 1000'.

Run 1 (34* of timing)
10.352 @ 127.26 (1.472 60')

Run 2 (35* of timing)
10.305 @ 127.57 (1.447 60')

Run 3 (36* of timing)
10.253 @ 128.07 (1.424 60')

Machine shop said they got peak power at 38* of timing, so there may be a bit more in it. I also need to work on launch RPM and shift points as well. I was hoping to get around 10.00, but I will be happy if I can cover the 10.25 index.

 

[PRHeads]

Looks like a decent first outing.

Without trying to sound like a “Debbie downer”, to this point at least, you’re still several mph shy of having 10.00 potential.

 

[ksurfer2]

While I don't like the idea of moving away from the Indy 440-25 intake with the dual eddy 750's, will there be a measurable performance gain by switching to a manifold like the Edelbrock Super Victor and single 1000cfm carb? I am trying to maximize the performance of the combo I have.

 

[33 IMP]

While I don't like the idea of moving away from the Indy 440-25 intake with the dual eddy 750's, will there be a measurable performance gain by switching to a manifold like the Edelbrock Super Victor and single 1000cfm carb? I am trying to maximize the performance of the combo I have.

I would value @dvw's opinion on that. My half assed guess would be... no. Victor and dominator against a factory crossram, oh yeah!

 

[dvw]

While I don't like the idea of moving away from the Indy 440-25 intake with the dual eddy 750's, will there be a measurable performance gain by switching to a manifold like the Edelbrock Super Victor and single 1000cfm carb? I am trying to maximize the performance of the combo I have.

I know a few who have. Some have gained nothing. Some claim it's quicler. But I haven't seen it. Comparing a few similar engines to mine with the single Dominator deal. At a similar weight thet would run about the same. Holleys helped my starting line consistency. But overall they are not a bunch quicker than the Eddy's. A few racers in N/SS are running tunnel rams in as well. I haven't seen a Indy -1 headed combo any quicker than my 440-25 stuff either. Duell, Dechicho both have run tunnel rams. Last week I met with Tom Ghent. He was the first to try welding dams in the 440-25. After talking to him that was on a application that used a flat plate for the intake lid for hood clearance. He admited that using the standard lid there may be no improvement. Mine is not modified.
Doug

 

[PRHeads]

Years ago I tested a 557” build with -1 heads.
Tried a 440-3, 440-3x, 440-25.
Single planes were tested with a 1050 Dominator, x-ram with 2 x Ede 750’s.

This combo was in the 725hp range.

All made about the same power.

IMO, a cam swap to something more along the lines of what the rest of the competition runs would provide a better bang for the buck(although probably still not a “big” gain).

“If” I were try a single plane, it would be the new TF 4500 manifold and a 1050 dominator.
I’m not sure any of the good 4500 manifolds/4500 carb combos would fit under the hood.
Doug can probably answer that.

 

[ksurfer2]

Thanks all. I will stick with the 440-25 and look into a cam swap later this spring.

 

[biomedtechguy]

Thanks all. I will stick with the 440-25 and look into a cam swap later this spring.

I'm "out of the game" for now, but I do still have the 572 and it is about 80% parts complete, and one glorious day I'll have something to drop it in.
I'm mentioning that because now a 6bbl is not "necessary" and I really REALLY like what Doug did with his ModMan, but I also REALLY like the look and "mystique" of the 440-25...
Whatever intake I get will need MaxWedge ports for the TF 270s

 

[33 IMP]

I'm "out of the game" for now, but I do still have the 572 and it is about 80% parts complete, and one glorious day I'll have something to drop it in.
I'm mentioning that because now a 6bbl is not "necessary" and I really REALLY like what Doug did with his ModMan, but I also REALLY like the look and "mystique" of the 440-25...
Whatever intake I get will need MaxWedge ports for the TF 270s

Maxwedge sized intakes used to be pretty few, and far between. Lots more common now. I have three, and possibly another that might be big enough to open up to max size.(M1, dominator pad). Pretty sure the winner of my bunch will be the dominator pad SuperVictor.

 

[PRHeads]

I think the OP would find that those running “similar” engine combos as his, in the same classes, in NSS are running cams with 10-15* more duration @.050 than the current 260@ .050 cam.
That won’t make a tremendous amount of additional power…….but you have to pick away at it.

Maybe next year, pull the heads and have them ported…….milled a bit for even more compression, etc.