GLH

Also this is right behind:

ZZ572/720R DESCRIPTION
The new ZZ572/720R was engineered by GM Performance Parts and GM Racing exclusively for sportsman racers. The ZZ572/720R is built around an all-new Gen VI tall deck Bow Tie cylinder block. This all new race block is filled with a forged 4340 steel crankshaft with 4.375” stroke, shot peened forged 4340 H-beam rods, and forged aluminum pistons with full floating wrist pins. Plasma-moly rings are standard as is the screened and louvered windage tray. GM’s first purpose built drag race engine is filled with hard core race parts for hard core performance and long term durability.
The redesigned rectangular port aluminum cylinder heads result in a race gas only 12:1 compression ratio. A solid roller cam with 0.714 inch lift actuates the stainless steel valves. And, of course, hardened chromemoly retainers, roller rocker arms, and dual valve springs are used to complete the valvetrain.
A new GM tall deck single plane intake manifold and 1095 CFM King Demon carburetor deliver enough air and fuel to make the 720 horsepower at 6,200 RPM and 685 ft. lbs. of torque at 4,500 RPM. Ignition is handled by multiple spark discharge ignition. An SFI approved torsional damper is installed at the factory. Out of the crate and into your race car - it’ just that simple.
Race gas fueled, high revving horsepower, all from GM, the ZZ572/720R is the engine that will get you down the track consistently, pass after pass, season after season.
All we can say is it’s the stupendous! Not only is it a dream big-block engine but the R in ZZ572/720R stands for “Race” and race it will, that’s for certain.
Finally released by GM but gone is the bright red paint and Chevy Bow Tie logo on the valve covers. In are traditional Chevy orange paint and 572 on the valve covers.
12498825 Short-Block 12498826 Base Engine (Long-Block) 12498827 Premium Engine

572 C.I.D. - 12:1 Compression Crate Engine Technical Information
Horsepower 720 @ 6250 RPM
Torque 685 Ft. Lbs. @ 4500 RPM
Max. Recommended RPM 6750 RPM
Compression Ratio 12:1
Block New! Sportsman Tall Deck Bow Tie Gen VI, 10.200” Deck Height
Bore 4.560”
Stroke 4.375”
Crankshaft Forged 4340 steel
Connecting Rods Forged 4340 steel, H-beam style, Shot peened
Pistons Forged Aluminum, Full Floating Wrist Pin
Piston Rings Plasma-moly rings
Camshaft Mechanical roller (Valve lift: .714” I, .714” E; Duration @ .050” 266° I, 274° E)
Lifters Mechanical roller tappet
Cylinder Heads Aluminum rectangular port, 118cc combustion chamber
Intake Valves 2.25” Stainless steel
Exhaust Valves 1.88” Stainless steel
Valve Springs Dual valve springs, 1.567” coil dia., 2.050” installed height, 230 Lbs. seat pressure
Spring Retainers Hardened chromemoly steel
Rocker Arms
Aluminum roller rockers, 1.7:1 ratio
Push Rods High performance one piece
Intake Manifold New! Aluminum tall deck single plane, 4500 series carburetor.
Carburetor 1095cfm, mechanical secondary
Rear Main Seal New! One-piece design
Windage Tray New! Screened and louvered
Damper High RPM torsional damper
Distributor Multiple spark discharge
Ignition Timing 36° total advance
Spark Plugs R42XLS
Fuel Race fuel

http://www.sallee-chevrolet.com/Chev...ckV8s/572.html

Scarab28

MOJO-13 Does this mean the stickers are going on also?

Back4More

If you get one of these bad boys and want to use it for your boat your going to have to reclearence all of the internals.

tomcat

What about buying the short block with the hydraulic roller cam and using aftermarket aluminum heads with big combustion chambers? I think Dart sells heads with 140cc chambers which would make about 8.5:1 CR on a 572. Can you say 1000 HP blower motor?

Back4More

You can say it, but It will say kaboom back.

tomcat

Why are marine engine clearances different? Sounds like a new tech thread. Go for it Back4More, this subject needs a thorough thrashing.

Back4More

Blocks run colder and pistons run hotter....and with a blower on top even hotter.
More clearance between piston and cylinder...ring ends get more clearance too
Blower pistons are a must with that much power expected out of it...and a high quality set of rings too.
More clearance in the rod bearings for oil flow to remove heat from the bearings.
Re balancing the rotating assy...If its anything like the ZZ502 it will rattle it's self to death in no time.
If your looking for a 1000hp blower motor you better plunk down the cash for top of the line internals...not to mention a beefy aftermarket block...There is no such thing as a cheap marine blower motor making 700+hp.
I not slamming this bad assed crate motor, but it is not for powerboats...I read alot about people blowing up the 502s running them at the track.
I know nothing about detailed marine engine building but learned a bit while having mine built.

Oh, and we did'nt even talk cams and valve train yet....

Back4More

Wow, I guess I kicked this thread in the balls.

Back4More

LMAO

GLH

I did not research this throughly but this gives the best description of the differences between street and marine use (for a mear human).
Might also explain why world castings got out of the marine crate engine business if they did not modify their crate packages enough.

Thanks for the slap back to reality!