Dyno Results 540 CID Indy 345 CNC

This is the results of a friend's new big block Mopar engine.

New BMP aluminum block, new Indy heads 2023
540 CID, 4.500” x 4.250”
Aluminum rods
Indy 440-1 CNC 345 heads (Some work done after receiving from Indy, i.e. not Out-Of-The-Box)
Indy 4500 intake
1050 Dominator Carb
285/292 at 0.050", 108 LSA Comp roller cam (318/330 at 0.020")
Lift 0.753”/0.753” at 1.6, cam card 0.706”/0.706” at 1.5 rocker ratio

745 ft-lb at 5600 rpm
919 hp at 6900 rpm

The pic of the Dyno curve wasn't very clear, so I plotted his numbers.

Nice numbers. Compression ratio? Alchohol?

~13 CR 12.7 CR
Racing gas
vacuum pump

Interesting. Makes more Trq, and HP than my 563 with 345CNC heads, with less compression, cam, cubes, and carb. I must have done something wrong.

Precisely why there isn't a dyno racing class.

Very stout numbers for that combination. Any idea why the compression ratio wasn't higher? Maybe they prefer to run a certain fuel, or have another car with that compression ratio so they like to keep things the same? I know bracket guys who build all of their engines with the same CR so they don't get confused on the tuning or fuel.

This guy just buys parts and lets the builder put it together.
I told him over the summer the CR would be a little low unless he mills the heads. 78cc Indy spec
I think the cam has plenty of duration, and with 1.6 rockers that is the lift. I was surprised with the 108 LSA, but I didn't have anything to do with that either.
My friend didn't say, but from what I know of the machinist/builder, he would have zero decked the block to the pistons.

I do think he wanted to run 110 Sunoco, rather than more expensive stuff. But IMO, with that duration he could have run 13.5 CR.

I was expecting around 875 hp.

What does that -8 +26 HP sequence indicate at 6700?
Would a carb spacer help smooth that out?

As we all know what it runs in the car is the ultimate gauge. Dynos are dynos as they say. Dont get to caught up in those numbers especially when you dont have things like BSFC and correction to look at

Could easily just be an issue with the dyno.....

FWIW, Stuska dyno. Buck Racing
I am trying to get more info. But the owner didn't get much data.

~13 CR 12.7 CR If milled from 78cc to to 75cc, about 13.1 CR

The owner just texted me. He said the shop did mill the new Indy heads, but he didn't know how much. And the paper work doesn't list the CR (blank).

The dyno measures tq, and calculates the hp.

Since all the results are above 5252rpm, the differences from the tq curve will be exaggerated in the HP curve.

My guess is, looking at the jog in the tq curve, it was some sort of brief misfire(drop in tq), then the load cell gets a little tug when the misfire recovers(spike in tq).
If you applied some “smoothing” to the curve, in that area of the curve, the numbers should be more representative of reality.
Unless of course you see the same jog in the data on every run, in the same place…….. which still wouldn’t rule out a misfire, but would indicate something is creating the misfire(if that’s in fact the problem), and that it’s not completely random.

Be interesting to see how it runs. I assume he runs at the same track as you? The engine looks great, nice looking parts.

What is it going into Jim?

Yes,
I race with him at both Farmington and Piedmont in North Carolina.
1969? Dart, back half, ladder bar setup.

Me being a numbers guy...
I did a curve fit of the dyno torque, and then calculated the HP at each point from the "smoothed" torque equation. Here it is:

And if I make a separate curve fit to the TQ from 6500-7500, and calculate the HP from that equation; the results are the gray/black HP numbers.
The original dyno HP numbers are shown in orange.

Thank you

Nice Jim! That is basically my next engine but with higher compression.
Want low to mid 900s and looks like with more compression it will do it easily.

If you are looking for low to mid 900 HP, using a big bore block, and building with all new parts, then the 572-13 heads are probably a better starting point. Using the better head allows you to soften up the camshaft a little bit which allows the parts to all live longer. So you can make the same power but have a longer life.

Even though Moparacer has a stout 500" combo now and you think it'd translate to the gains he's expecting, I have to agree with you Jim. Not everyday you see a 900+HP -1 build.

Even though Moparacer has a stout 500" combo now and you think it'd translate to the gains he's expecting, I have to agree with you Jim. Not everyday you see a 900+HP -1 build. [/quote]

Nah according to dyno sheets and owners there are alot of them out there. Just not so many timeslips that confirm that sort of performance

Just had one of those come into the shop. 540 inches, aluminum block, Indy -1 heads with the 345 CNC port package. Be a few months before it is fresh and ready to go on the dyno. I'd be shocked it it made 900 hp, these things usually top out around 850 with a wet sump and cast intake.

I agree it would be easier, but already have 345 CNC-1s on my engine and I was trying to soften the blow to the wallet by reusing them. Going to 572-13s changes everything. I have been 5.47 with my setup at 502 cid with an iron block, and can only go 5.35 on a 8.50 cert so my thinking was 540/aluminum block should put me there pretty easy.

If I was going the 572-13 route I would build a 572 and not a 540.

I really don't want to go much faster in the old crate anyways....

Yes, if you are going to be reusing parts then the build goes down a different path. Sounds like the short block will be all new parts though?

Yes, I would be starting from scratch on the short block unless I stumble onto a good deal used. I do like the idea of going bigger with the engine and being easier on parts. Lower RPM etc. I race a lot and longevity is a requirement.

Mine is a -1 engine. It's never been on the dyno. But its gone 5.639@121.4 at 3350 lbs. That was at 1.030 correction factor. I would bet it makes around 900.
Doug

Aluminum block lets you go 4.500 piston which is a good size to use since lots of choices for rings. I'd go with a 540 if you use an internal oil pickup, or a 572 if you are already set up for external oiling. The weight reduction from the block plus the extra torque from a bigger short block should both help the car get moving.

I had a customer step up from a 505 to a 572 last year and the extra torque scared the heck out of him. First time at the track with the new motor the car lifted the front tires about 3 feet and that freaked him out. It looked cooler than hell but his eyes were big when he got back to the pits! He ended up swapping out the 727 for a Glide and that helped to settle the car down. Also made it more consistent.

I was surprised to see the >900 hp number too.
But everybody should remember, the heads had some work, not OTTB CNC345, and the -3X intake was tweaked. And he does have a vacuum pump on it.
Still, better numbers than I expected. If, if, if, we ignore the drop at 6800, and peak at 6900 rpm, this dyno still says 910 ish.
About the most I could expect from a 540 CID with CNC345 heads.

So Jim, all along here NO DISRESPECT for your friend intended. If anything, I give him respect to pick a good shop and let them handle the build because most of us know enough to be dangerous. Buck is a good shop from what I understand. When i learned that they did the build, I started to reconsider the number may be closer to reality. And it's possible we may not have the most accurate details in the build. Doug's motor is a good example of a 900HP -1. It has some really good heads, a big cam with a 4/7 swap, 15:1, good piston/ring pack, good machining, good oiling system, and it's 58x CID. I have no doubt there is more in a better cam, Ti valves, better headers and a better intake. One other thing that probably isn't emphasized is the rest of the car when considering how much corrected HP a motor makes as measured on a dyno (let alone WHO'S dyno facility). How good is the trans, converter and the tune-up when it's in the car vs. on the dyno? How much effort was taken in most cases to find the most in the combo? Even if it makes 'only' 850HP that's pretty good when you consider it's still a low-port max wedge head. This all may make me more unpopular but, if we can't share our thoughts and debate, we'll continue to evolve slowly.

Why not put 572 cubes under your 440-1 heads? They may be restricted on max power, but you will see that max power EARLY. Don't forget you will be running less rpm and putting less stress on the motor, which means longer life.

It is all good. The dyno numbers are that dyno, thats all.
I just don't want anybody to buy the same parts and expect the same results. Heads and intake were worked somewhat (I don't have details).

I can vouch for Charlie Buck his dyno is very accurate and one of the best engine builders in the country. Solid as they come.

With Todd’s combo and assembly and a pull on Charlie’s Bucks dyno my 540 with -1’s made 880, I am getting close to having it ready to hit the track so we will see how it translates to real track results. Doug

i have no doubt your motor will be making great power, and given all the driveline and suspension are set for that motor, you will be pleased with the results. As i said in an earlier comment, it is just a little easier to pull 880 to 920 hp out of a bigger shortblock like a 572 or even bigger. It may require a different converter and rear gear should it be a big increase, like more than 572. I have a 580 inch combo i could run with my 572-13 heads, but it would require a gear change minimum and i am already certain my 549/572-13 motor will go faster than my 8,50 cert, plus i would need to retune it as well.

Aint always about cubes My little 540 pushes my 3600 turd into the 8.80's here in Vegas. I have no doubt it made that number for sure on the dyno. As said before the track is always the true barometer of an engines performance.

Well sportsfans
yes I was involved but did not assemble or machine. Charlies crew did all that. He does almost all of my machine work. Having dynoed all of my engines at Charlies over the last decade or so I can tell you that it is not a happy dyno and we have backed up almost all of the numbers it posted at the track. People have been telling me for 25 years now what Indy headed motors will or will not do. My friend Larry was a big part of what success we have had and yeah he worked on these. That dip in the numbers has happened on every motor that we have tested there. It is a glitch in the software and yes Charlie knows about it and had had the manufacturer look at it several times. The combination was simply reusing some existing parts and marrying them up with some new stuff. Yes it is a 540 (4.25 stroke 4.500 bore) . All I can tell you is that over the last decade and at least 30 to 40 motors tested at that facility the numbers have proven to be reliable data for me.
Todd