Cam Spec.’s for GM’s new 1000 HP pump gas engine

[lefty o]

The Silver State Classic guys can run WOT for what, a total of about 85 miles? What's the record in that now? 219mph or so?

RAS is right. Of all of the stuff that I've been involved with though, the offshore powerboat guys have to win the award for wrecking stuff. Us asphalt oval track guys have nothing on those guys. And we could flat break some shit.

yup, 219, and that is average speed, not max speed.

[Ron Miller]

Heads look impressive 480 cfm intake 340 cfm exhaust, beryllium seats, titanium valves, shaft rockers. No crate engine has ever offered this that i know of.

I wonder why a 15 degree cam duration split between intake and exhaust was used.......270 intake / 285 exhaust?

bob460,
Where did you find the cylinder head specs?
Thanks

[bob460]

Heads look impressive 480 cfm intake 340 cfm exhaust, beryllium seats, titanium valves, shaft rockers. No crate engine has ever offered this that i know of.

I wonder why a 15 degree cam duration split between intake and exhaust was used.......270 intake / 285 exhaust?

bob460,
Where did you find the cylinder head specs?
Thanks

https://www.youtube.com/watch?v=6Fbev9fmCOo

[norm]

Good article here also-


https://www.theblock.com/article/2021/o ... heads.html

[plovett]

I wonder if the intake has a Dominator flange? I'd rather have it with a carb.

[Roundybout]

The offshore power boat engine probably leads the toughest life. There’s a reason why there’s often one guy who’s only job is to work the throttle. The guy driving already has his hands full. Miss a prop out of the water and back in a few times wreaks havoc with RPM spikes. Constant heavy load while under way. Constant high RPMs.

Rally drivers/engines and those nuts on motorcycles at the Isle of Man is a close second lol

[swampbuggy]

SupStk, about your reply on the Heads on the New GM 632 C. I. , did some math. Assuming the pistons are flat tops w/ two valve notches and they are down .025" below deck, an 85 cc Chamber would put it at 12.07. Some cylinder heads would require dished pistons obviously . Mark H.

[SupStk]

SupStk, about your reply on the Heads on the New GM 632 C. I. , did some math. Assuming the pistons are flat tops w/ two valve notches and they are down .025" below deck, an 85 cc Chamber would put it at 12.07. Some cylinder heads would require dished pistons obviously . Mark H.

I read the previous post about Ron Speery and the design of the heads. 12 degree intake, 8.5 degree exhaust and "small chamber". The pistons are "swamped" which I assume means they are dished.

Thanks for your reply and the effort involved in figuring.

[RAS]

I would caution everyone on head flow numbers. It's the dyno torque numbers that matter. Then it's ET. Hard stop. Flow numbers mean something to some people but in general, the mid lift flow where the valve spends most of it's time is really critical. Then it's about acceleration. How fast does the engine spool. I remember John Kaase flowed his Boss 9 and SR71 BB Ford wedge heads and they were about identical. In flow numbers. The Boss 9 though made 100 more horsepower. So it's the design over all that matters. Flow numbers tell a story but were not story tellers and we don't race flow benches. Size of the valves, location, angles, chamber shape, runner length, bowl shape, bias, there's an endless criteria for each application, get it right your going to be happy. I bet Bob Glidden never gave a damn about flow numbers. He was always on the dyno ! Winning.

[swampbuggy]

RAS , I will agree with you that Flow numbers are probably worried about too much, but i am sure you can agree that exceptional engines that win races and make exceptional power numbers do have Cylinder Heads that "Do" flow or wet flow a lot of air ? Mark H.

[thatbikeguy]

The heads look great, and have a figure eight style combustion chamber. They are available 3 ways:
1. Complete with Ti valves, springs, locks, retainers 2. Bare with CNC work 3. Bare, porter's casting - seats and guides included but not installed.

Here's the intake corporate propaganda with a lousy image:

Pt. No. 19366614
High-Rise Intake Manifold – Tall Deck with Spread-Port Heads
- Used on ZZ632 Deluxe with unique RS-X
spread-port heads and Bowtie Sportsman
tall-deck block
- Will not fit conventional rectangular- and
oval-port heads
- High-rise, open-plenum design
- Accepts 4500-series (Dominator) carburetors
and EFI throttle bodies
- Cast aluminum construction

Screenshot_20211109-225009.png

[Orr89rocz]

Wonder how that top end would work on a 555?

[plovett]

Wonder how that top end would work on a 555?

Not trying to be a smartass, but I think it would work fine, just higher rpm. The 555 has about the same size bore, but 14% smaller displacement. So with otherwise similar components will make similar peak power, with the rpm about 14% higher.

edit: The link says peak power is at 6600 rpm on the 632 shortblock. 632 / 555 x 6600 = 7516 rpm for a peak on a 555. ........Roughly.

[Orr89rocz]

Just roughed it out in pipemax, seems that is correct, should be about same power just 1000 rpm higher. If trying to stay under 7500 its probably too much head

[RAS]

The cylinder heads have a strong resemblance to the CID symmetrical Port heads. Specs are really close too. Not taking anything away from Ron Sperry. I can't imagine how they got the OK from GM to do this build. That would be the story of the decade. I like the rocker bar. I'm thinking an additional atmosphere from a screw blower and this deal could get serious. I here it's intended for the new NHRA Factory FX Class.