if you haven't yet, you may want to verify that your cam specs are actually what they are supposed to be.

I was just going to let it slide but I just can’t.

Who picked that cam? And why the 12 degree split in duration????? That’s way too much exhaust duration. You need maybe 4 degrees split with alcohol and that’s it. You are pissing your power right out the headers. Unless the headers are junk. The size may be a skosh small, maybe. I’d rather see a 4 inch collector on alcohol too but neither of the two can get me to grasp that 12 degree split. That’s insane.


I would call 4 different cam grinders not named Bullet and ask them about a grind for your combo and see how many give you a 12 degree split. The exhaust port on the B1 is more than big enough so that can’t be why all that split.

Andy
The 9 inches of vacuum was the reading for the vacuum pump. I didn't have a manifold vacuum gauge because he is running a big & ugly hat. The blowby numbers are the best i have ever seen on a methanol engine, with each pull the numbers kept improving.


Joe

Your results are similar to mine, a little less power but 70 more cubic inches, here a link to my build and specs for comparison.

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2864616/1.html
Block
- Keith Black aluminum RB 10.725” deck wet bock from 2014 (I think 440Jim and I were the last ones to get their blocks before they shutdown)
- Drilled lifter galley and tapped for oil restrictions
- Drilled for oil line access on top/back of block.

Heads
- B1 originals, Stage 1 hand porting by Scott Koffel, Ti Intake valves, T&D 1.7 rockers, flow 392 at .700 on Koffel’s flow bench

Intake
- B1 low deck intake with spacers

Cam
- Strange Magic solid roller 4/7 swap .767/.767 276/288 110 Lobe Sep 180 Intake centerline
- Isky EZ-Roll Solid Bushing lifters
- Jessel Belt drive

Rotating Assembly
- Callies Magnum XL 4.25” with 2.100” rod journals
- GRP Rods 7.100”
- Diamond Pistons 4.360”, gas ported, .043 rings, tool steel pins --- 13.2:1 compression ----
- Coated Clevite sbc rod and Calico coated main bearing

Carb
- APD Max Speed billet carb 1250 gas

Okay, that makes more sense but it also makes your numbers even worse since 9 inches of pan vacuum should be adding power to the engine. If everything checks out, cranking test, leak down test, plug read, etc. then I think you have a bad combination of parts. Most likely the heads aren't very good for some reason. Hard to say without taking it apart and looking at it.

Looking at the uncorrected numbers.......
It doesn’t look like a bad weather day at all....... barely over 5%CF.
I mention this to point out that the air wasn’t horrible, so it wasn’t causing the uncorrected numbers to be abnormally low.

660ft/lb from a 572 is pretty soft.

We had an EZ headed 580 on the dyno here a few moths ago.
The uncorrected TQ was almost 100ft/lb better.

OK.
In my defense I am an old man who has crippling CRS evidently. I have been working on parts for 2 different engines while researching rods for my exploded blower motor. And the 7.1 rod has stuck in my head for whatever reason. The rods in my 572 are 6.86 hemi length. So you caught me with my head up my A**
The real math is 6.86+2.25+1.105 = 10.215 deck height on a .500 short KB hemi block. Piston was .010 down in the bore. Piston is now .012 out of the bore after machining the o rings out.

Sorry for the confusion..

Dave

Andy,
All plugs looked great, and yes I looked at them. I don't remember the EGT's and I don't have anything in front of me to see. But the O2 readings are posted and shows a little lean. Engine was really responsive and firing order was verified. If you look at the blow by numbers you will see the measured blow by was 1.8 cfm at it's highest. Every pull the numbers got better indicating the rings were sealing.
The 9 inches of vacuum was what the vacuum pump was pulling, not manifold vacuum. We didn't have a sensor in the manifold, and if we did I would expect a serious drop at full throttle.

Dave

I was was just wondering if the compression was down also... if there was something wrong in the short block numbers.

I get the error heck I posted the other day that .001 over on a 4.28 bore was 4.29.

I say run it and see what the et/weight says....if it's not up to par then flow test the heads.

It is hard to tell, but I would have expected almost 100 hp more, and a higher RPM torque peak. If it would have made 900 hp STP before the inertia correction, that would be acceptable.
The headers are a touch small for a 572 (2-1/8"), and will reduce peak HP. But the Enderle TR intake should be good for power.

My guess (repeat just a guess) is the heads are just not very good.
Even Wade's 508 CID with 12.5 CR and "only" Koffel's stage 1 porting made similar power to yours. But with the expected peak torque RPM.
Koffel says 390 cfm, but IMO their stage 1 isn't a big power producer, but may be fine for 508 CID.

We refreshed a Koffel built low deck 526(4.375 x 4.375) few years ago that had been run in either a puller or a mud truck(can’t remember which).
It had what I would consider a stage 1 type job(bowls and chambers) on original B1’s.
Easy on parts roller with the original style black Dove rockers.
I guess at some point it had ingested some dirt, and was here primarily get taken apart, thoroughly cleaned, honed, heads touched up, new rings & bearings, and put on the dyno.

It made about 830hp(no inertia correction) with a single 1050 on C12 race gas.

The heads flowed 392/266@.800 lift

That is about what Koffel's claims their Stage 1 porting flows.

A couple things fwiw. Id say the compression is a tad soft as well but just my opinion on a race motor, never understood why guys stay so low, unless they plan to run alot of jug through it. Especially with an aluminum block and alcohol on top of that, but just my .02. Next to me the cam seems kinda out in left field maybe. But not knowing anything about the heads who knows. Do you have a port dimension or runner CC for them? I dont really care so much for what the flow numbers are as a gigantic rectangle can move alot of air and be so lazy it wont get out of its own way, but its always the first thing people ask for, like dyno numbers It is definitely performing a bit anemic by the numbers, but since we have the dyno operator here he could best answer what that number translates to real world. Dynos area all different for sure and just tools.

FWIW our 572 B1 in the dragster ran .2 quicker and 3mph faster with a SMALLER header on it. We went from 2 1/4" to 2 3/8" step 3.5" choke 5" to a 2 1/8 to 2 1/4" with a smaller merge collector 3" choke 4"

B1MAXX,

At this point unless someone mentions a quick to do mod or repair, that is the plan. I'll run it this season or until I get my blower motor back together. Then I'm going to build a set of step headers and send the heads off for evaluation and repair/flow.
I m ay try advancing and retarding the cam to see what happens after I get it to the track, since a couple of guys here have said the cam is all wrong. It's been a long time since I ran a normally asperated engine and everything I ran with the blower had a lot of separation. But even those had a LSA of around 110-112. Not arguing with those guys as I am one to take the recommendation of the cam grinders and always ask for their mopar guy..lol And so far I have had good luck doing it that way.

Dave

Al, This engine is down from over 15.6-1 with Brewer heads 56cc to now 13.4 to 1 with B1's 69cc. because of the larger chamber and thicker head gasket to compensate for the above deck piston. I do not have the port dimension or cc, I only measured the exhaust port length to use with Pipemax, it was 4 inches at the floor. To be honest didn't think about needing it. I was recommended to use John Partridge @ Bullet as he is the guru for Mopar down there. I'm not opposed to a different cam but will wait to see what it does and how consistent it is before I spend another 6-700 for a new cam.
According to Pipemax single pipe should be 2.23-2.35 26-30 long with a 4-4.250 x 15 inch standard collector, or 2 step 1st - 2.23x13-15 long, 2nd - 2.35x13-15 long same collector or merge 3.5-4.5 with a 9-15 diffuser.
Headers on it are 2 1/8 diameter 29 length primary, with a merge collector 3.5" outlet x6 length with a 9* transition with a 4 " cone, Collector is 10 inch overall. Length is actually off as I measured from end of the slip to end of collector.

And I agree a dyno is just a tool. But it definitely is a good one..lol

Dave

Jim,
But I'd bet they didn't get those numbers with a hack port job..

Dave

Wade, yeah mine is pretty anemic in comparison. Your build is one I was sort of comparing mine to when it was on the dyno. I need to find a dyno simulator software to play with and see what your cam would do in my engine just for giggles..

Thanks

Dave

Last B1 Original we did, last year, was 540", heads with alot of work done, 420cfm, 2.300 x 1.78, Ti, cam I picked (kind of large roller, around 280-294@ .050, .870 lift gross on intake), 14.7:1, Q16, 1150, KB block, B1 intake I ported...Made 970HP and 825TQ using customers headers (2 1/4 step to 2 3/8, 30" long, 4.5 merge collector). Was a very nice combo, smooth lobes on the cam, made power at 7000 and carried to 7300rpm.
I think maybe tuneup is part of it, but heads sound like the problem...and maybe the Tunnel ram. The ram would have to be right (and the heads) to make great power on a 572.

Very good numbers..

Only disagreement with what you wrote is about the tunnel ram.. Seems everyone that is commenting about it either doesn't understand that all it does is direct air to the heads. Fuel is injected 1 inch above the port opening. I tune each individual cylinder separately unlike an intake with a carb where it has to be ported/flowed and modified to insure air/fuel distribution in the correct amounts get there.


I'm more and more leaning towards the heads and headers, also not totally disagreeing with cam. But in defense of John at Bullet I think he took my info and gave me a cam he thought would work. Part of that info was me giving him flow numbers for an unported B1 head since I had no clue what it really flows.

Thanks

Dave

Keep in mind for a typical cast tunnel ram to make power on a 572 it would need to be designed for an engine close to that size...I'm unaware of one that is. So I would not overlook that in the least. It's a combination of parts that make or break an engine's output. Almost NEVER just one thing!