Hey all, I just found out that GM is going to release a new ZZ6 crate motor. I was looking at the specs and it is very close to the motor I built for my car last year. And it kind of got me wondering...this new ZZ6 motor supposedly makes 405hp @ 5600 and around 400 ftlbs. @ 5800 (actual numbers not disclosed.) Anyways, it just got me wondering. Last June, my car went on the chassis dyno at a car show for 2 pulls. I'll let you guys look at the dyno sheet, the RPMS are hard to decipher. (Atmospheric conditions are at the bottom)
Those pulls were made when the car had 2.56 gears. And the transmission lost 2nd on the way home, so I'm gonna assume it was slipping on the dyno too. Car also has a really bad stock converter. It really needs a 3000 stall. So I know a lot is left on the table there. Now I know that this is a debatable subject but from what I've read, and auto car usually looses like 20% of its horsepower through the drivetrain. So that would mean this motor is actually making like 360hp, and 380 ftlbs of torque. Here are the engine specs:
Stock Bore/Stroke 350
Speed Pro Hyperutectic Domed Pistons (can't remember dome size (in CC's)
906 Vortec Heads.
We did a mild gasket match on the intake side with these. 2.02/1.60 valves. The heads were milled very very very slightly to true them up, but not CC'ed.
Stock valve springs were replaced with comp cams beehive, to support life.
With the stock 62cc combustion chambers, and all the head gasket bore size, and compressed thickness, the comp. ratio worked out to be around 10.5:1. Im not home to see all the specs I wrote down on this, otherwise I would have included them.
Comp Cams Thumpr Cam (Full Roller)
.513 intake/ .498 exhuast
dur. @ .050- 227 intake/ 241 exhaust
1.5 Ratio roller rockers
Edlelbrock Performer EPS Intake
Summit Racing 750 CFM Carb
Full 2.5" Exhaust, Long Tube Headers, No Cats, Flowmaster Super 10's
*if I missed anything the specs are in my signature*
Here are the specs to the new ZZ6:
Displacement (cu. in.):
350
Bore x Stroke (in.):
4.000 x 3.48
Block (P/N N 10105123):
Cast-iron with 4-bolt main caps
Crankshaft (P/N 12556307):
Forged steel
Connecting Rods (P/N 10108688):
Forged powdered metal
Pistons (P/N 10159436):
Hypereutectic aluminum
Camshaft Type (P/N 10185071):
Steel hydraulic roller
Camshaft Lift (in.):
.474 intake / .510 exhaust
Camshaft Duration (@.050 in.):
208° intake / 221° exhaust
Cylinder Heads (P/N 19300955):
Fast Burn aluminum; 62-cc chambers
Valve Size (in.):
2.000 intake / 1.550 exhaust
Compression Ratio:
9.72:1 nominal
Rocker Arms (P/N 19210724):
Aluminum roller style
Rocker Arm Ratio:
1.5:1
Recommended Fuel:
Premium
Ignition Timing:
36° total at 4000 rpm
Maximum Recommended rpm:
5800
I also know I'm still leaving a lot on the table with my car, it needs an MSD box so I can put more timing in it. It actually now has 3.73 gears. The carb could use some more fiddling, maybe a different power valve, bigger secondary jets? When we had an A/F gauge on the car they were spot on.
But how is this ZZ6 making 405 hp with only 9.7:1 compression? Ive kind of been thinking of putting a different cam in my motor, later on down the road. Would all the stuff I just mentioned (aside from the cam) equate to around 40 horsepower at the wheels when the car goes back on the chassis dyno? With round estimating that would put the flywheel horsepower at around 400. Just some pondering I was doing, I found it interesting and wanted to hear some others chime in.
Those pulls were made when the car had 2.56 gears. And the transmission lost 2nd on the way home, so I'm gonna assume it was slipping on the dyno too. Car also has a really bad stock converter. It really needs a 3000 stall. So I know a lot is left on the table there. Now I know that this is a debatable subject but from what I've read, and auto car usually looses like 20% of its horsepower through the drivetrain. So that would mean this motor is actually making like 360hp, and 380 ftlbs of torque. Here are the engine specs:
Stock Bore/Stroke 350
Speed Pro Hyperutectic Domed Pistons (can't remember dome size (in CC's)
906 Vortec Heads.
We did a mild gasket match on the intake side with these. 2.02/1.60 valves. The heads were milled very very very slightly to true them up, but not CC'ed.
Stock valve springs were replaced with comp cams beehive, to support life.
With the stock 62cc combustion chambers, and all the head gasket bore size, and compressed thickness, the comp. ratio worked out to be around 10.5:1. Im not home to see all the specs I wrote down on this, otherwise I would have included them.
Comp Cams Thumpr Cam (Full Roller)
.513 intake/ .498 exhuast
dur. @ .050- 227 intake/ 241 exhaust
1.5 Ratio roller rockers
Edlelbrock Performer EPS Intake
Summit Racing 750 CFM Carb
Full 2.5" Exhaust, Long Tube Headers, No Cats, Flowmaster Super 10's
*if I missed anything the specs are in my signature*
Here are the specs to the new ZZ6:
Displacement (cu. in.):
350
Bore x Stroke (in.):
4.000 x 3.48
Block (P/N N 10105123):
Cast-iron with 4-bolt main caps
Crankshaft (P/N 12556307):
Forged steel
Connecting Rods (P/N 10108688):
Forged powdered metal
Pistons (P/N 10159436):
Hypereutectic aluminum
Camshaft Type (P/N 10185071):
Steel hydraulic roller
Camshaft Lift (in.):
.474 intake / .510 exhaust
Camshaft Duration (@.050 in.):
208° intake / 221° exhaust
Cylinder Heads (P/N 19300955):
Fast Burn aluminum; 62-cc chambers
Valve Size (in.):
2.000 intake / 1.550 exhaust
Compression Ratio:
9.72:1 nominal
Rocker Arms (P/N 19210724):
Aluminum roller style
Rocker Arm Ratio:
1.5:1
Recommended Fuel:
Premium
Ignition Timing:
36° total at 4000 rpm
Maximum Recommended rpm:
5800
I also know I'm still leaving a lot on the table with my car, it needs an MSD box so I can put more timing in it. It actually now has 3.73 gears. The carb could use some more fiddling, maybe a different power valve, bigger secondary jets? When we had an A/F gauge on the car they were spot on.
But how is this ZZ6 making 405 hp with only 9.7:1 compression? Ive kind of been thinking of putting a different cam in my motor, later on down the road. Would all the stuff I just mentioned (aside from the cam) equate to around 40 horsepower at the wheels when the car goes back on the chassis dyno? With round estimating that would put the flywheel horsepower at around 400. Just some pondering I was doing, I found it interesting and wanted to hear some others chime in.
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