They didn't say who the engine builder was, but the engine combo is interesting. Aluminum block, TF 270 heads, Wilson ported intake, Bob Book carb, etc. so obviously the owner isn't afraid to spend some money! Probably a $30K engine.
They used a hyd roller cam which limited the power output but I assume it was designed to be a street thumper since it is a pump compression build at 10.5 compression ratio. Power output is almost square with 650 torque and 660 power. Lots of torque down low, power peak is 5700 rpm so it isn't going to be a screamer. I think it would easily go over 700 hp with solid roller cam, but the owner must have insisted on a hyd roller.

https://www.motortrend.com/how-to/505-aluminum-mopar-big-block-westech-dyno-test/

663 hp at 5,700 rpm and 650 lb-ft of torque at 4,800 rpm
I have been thinking of building very similar combo:

BMP aluminum block 4.350" bore (Jim 4.375")
4.250" stroke crankshaft (Jim 4.250")
10.25 CR (Jim ~12 CR)
TF270 Heads
252/258, 0.571" lift, Hyd roller cam (Jim Solid roller cam 276/283, 0.700" lift)
Indy intake with Wilson mods (Jim Indy intake only port match)

I wonder if their 5700 rpm HP peak is the heads, or the cam? With a solid roller cam and more duration, I would hope for 6000-6500 rpm (heads).

What does that TF sticker on the head mean? 52310-01

Their low RPM peaks are due to the cam. Your cam would move the peak up to around 7000 rpm and give you over 700 hp. A 276/283 cam might be too big for the TF heads but if you already have the cam you could try it and see how it works. If I was picking a cam for your combo I'd probably go 5 to 10 degrees smaller.

Definitely not afraid to spend money, and also an interesting choice to spend that much and only build a 505. I can understand wanting it to be primarily street with the hydraulic roller, but adding some cubes doesn't seem like it would have any drawbacks, especially with the high dollar carb and ported intake.

Jim- that's just the serial number of each individual head. It's also printed on the box.

AndyF, what are your thoughts on the effects of running multi-port Holley EFI and/or spraying No2 on this combo? How big of a shot could this thing handle? Asking for a friend....

10.5:1 505, 440 Source rotating assy, prepped EZ-295’s, HR cam(less duration than the one in the article), Indy dual plane(not ported), off the shelf Brawler carb, 615tq@3900……. 643tq@4500/642hp@5700, still 630hp@6300.

This engine was tested with the water pump being driven by the crank, not an electric unit.

It wouldn’t surprise me if the early hp peak of the article engine was partly due to the early stages of hydraulic lifter collapse happening.

That's very close to the engine I built for my Ramcharger, but iron block, comp rockers and Indy dual plane. Their cam is just a smidge bigger than mine. I have it finished but finding time to travel to the engine dyno has been difficult.

Yeah, I wouldn't be surprised to find out that the lifters (or the springs) were given up on the pull. The RPM number was just too low given the parts used in the top end. Has to be disappointing for the owner to spend a ton of money and then have the engine give up so quickly. But the guy writing the magazine article didn't seem to indicate that there was any issue with the engine.

Obviously Steve Brule has plenty of experience, and has developed his own preferences for his testing procedures.

But, we all have our own way of doing things.
That being said, with the quality of parts in that build, I’d have been making pulls higher than 5800…….if it were willing to go there.
This is pure speculation on my part, but I suspect they did that on earlier pulls and discovered where things started to get “unsettled”, and subsequently just didn’t go that high.
It’s not at all uncommon to have hydraulic lifters start to act up between 5500-6000rpm.

Had a 446 on the dyno here a couple years ago.
HR cam using lobes that were supposedly rpm friendly.
Kept creeping up in rpm for the upper limit of the pull, as the numbers hadn’t peaked yet. 5600…….5800……numbers still going up.
Tried 6000……..after the pull there were unhappy valvetrain noises.
One lifter had the plunger stuck in the bottom of the lifter.
Just think about it…….there’s only one way for the plunger to be stuck at the bottom.
So………5800…….hp still going up.
6000, plunger stuck at bottom of lifter.
That’s often the “light switch” type of issue I’ve seen with hydraulic lifters. Both HFT and HR.

Of course, it’s just as possible none of that was going on that day at Westech.
They could have just decided the motor peaked, and there wasn’t any reason to go higher.

There was an issue with the stated spring pressures and part numbers with the heads, not sure if you guys remember the valve spring math thread, but the spring pressures didn't line up between PAC and Trickflow for the same part number spring for the low lift hydraulic roller option head.

Many years ago, I would run across the “Hyd cam won’t rev” scenario pretty often.
And on a few occasions I actually did some spring testing/swapping.
Keep in mind, the first spring combo was presumed to be adequate for the task at hand.

Each time I went thru the trouble of increasing the spring loads, I was rewarded with essentially zero gain in rpm.

We chased it around pretty intently on my friends Pontiac Stocker.
The one test we did that was worth nearly 1000 additional rpm was running solid lifters, lashed at .004, on the Hyd cam.
Of course, that wasn’t legal.
This was before the Schubek lifter days.

On more than one occasion, the added spring pressure resulted in the power nosedive from lifter unhappiness being even more of a light switch affair.

I wasn’t really sure what the actual problem was then, but I understand it now.
It’s lifter collapse………and more spring doesn’t solve that.

There was a dyno test in MM where they went thru that lifter collapse situation.
It was after we had already been thru it with the Pontiac.

Search “mild mannered mauler” from like 2005.

The main thing I was interested in seeing on the 505 I referenced above was whether or not the combination of cam lobes designed for prolonged higher rpm use, combined with the pretty new at the time Comp Evolution lifters, would allow for issue free valvetrain operation solidly past 6000rpm.
On that engine at least, in my mind……… it was a complete success.

With 1.6 HS rockers, and springs that were set up at 150/400, there were no signs of unhappiness thru 6300.
In hindsight…….I should have attempted 6500.

Ever tried more oil pressure to see if it helps the hydraulics out? I also wonder how many people actually measure lifter bore clearance, be interesting to see if bushing the lifter bores helps add rpm.

As i read this article i pondered how did GM get 7000 rpm out of the 1004 hp 632 crate motor? There is some inowledge there. I read they used Ti valves, hr cam bee hive springs?

The 632 crate engine uses beehive springs and individual Jesel type rocker arms. I assume that the roller lifters use the same technology that GM uses in their LS7 lifters which are good for more than 7000 rpm. The technology exists to push hyd rollers past 7000 rpm, but you can't just order some random parts from Summit. The engine builder needs to know which parts to use.

My 2011 Drag Pak Challenger book says you can rev it to 7,200 RPM's but it doesn't say what brand of lifters they are. I don't know anything about hydraulic rollers. That sounds up there to me. I think of hydraulic rollers as being a 6500 rpm/.650 lift items. I'm not the type to push the envelope. If I was doing a wedge build I would just put the Trick Flow top end on a 512 stroker kit. Everyone says you will get 600 hp with that. And that would be enough for me. I love watching Andy's builds and admire his desire to get the last horsepower out. But that's just not me.

Anyone have any info on the cam in that 632 ?

Google says "The camshaft is a billet hydraulic roller rated at 0.780 inch intake/0.782 inch exhaust lift and 270° intake/285° exhaust duration @. 050 inch of valve lift. That's a big cam. The RS-X Symmetrical Port aluminum cylinder heads are named for Ron Sperry, the GM engineer who designed them."

Yes it is big. It must have fairly heavy spring pressures, regardless of spring "style".

I think the pertinent question is: What kind of hydraulic lifter can handle that kind of spring pressure ?
RPM be dammed, it's spring pressure.

Morel sells "limited travel" HR lifters. I have a set in the 440 I was running the last 2 seasons. I shift @ 6,000, and do not detect any drop off in power between 5500 and 6000. I would think that would also show up on the dragy G force curve?

Two things besides beehive springs stood out to ke in the 632 motor. Ti valves, and 1.8 ratio rockers. That has to he important.