Slidin Gator
Well-known member
We'll sort of a Caddy guy :stirpot: got a worn out L92 with 234K miles out of an Escalade.
Talked to one salvage yard and they wanted a core charge, I said a 200K+ mile motor is a core, found one elsewhere with an honest price, no core. Gonna start with forged internals so I might as well put in a 4.00" stroke setup. Bore will be whatever it takes to clean up once I get in, but boring will be to the minimum. Ultimately I am looking to turn a 76" 3-4 wide blade with a 2.55 box on a 14'x7' Stossel hull. I plan to build the valve train to handle 7,000 RPM and configure to turn around 5,500. 450 Hp would be more than enough, I am aiming for 500 max at 5,500. I expect to normally operate between 3000-4000, so I am looking for torque to come in hard just below 3,000. I intend to run EFI and plan to throw away the worn out injectors, so upgraded injectors are planned. I'm still researching porting, valve and cam options, definitely interested in input, but I won't trade low end torque for top end power on this build.
I have just started researching ECU options and would appreciate input, Holley has a new ECU and harness assembly that seems to check all of the boxes :scratch:
Starting at the bottom, both of these threads and posts call for 0.0025" bearing clearance
https://southernairboat.com/phpBB3/viewtopic.php?p=693413#p693413
https://southernairboat.com/phpBB3/viewtopic.php?p=694708#p694708

Talked to one salvage yard and they wanted a core charge, I said a 200K+ mile motor is a core, found one elsewhere with an honest price, no core. Gonna start with forged internals so I might as well put in a 4.00" stroke setup. Bore will be whatever it takes to clean up once I get in, but boring will be to the minimum. Ultimately I am looking to turn a 76" 3-4 wide blade with a 2.55 box on a 14'x7' Stossel hull. I plan to build the valve train to handle 7,000 RPM and configure to turn around 5,500. 450 Hp would be more than enough, I am aiming for 500 max at 5,500. I expect to normally operate between 3000-4000, so I am looking for torque to come in hard just below 3,000. I intend to run EFI and plan to throw away the worn out injectors, so upgraded injectors are planned. I'm still researching porting, valve and cam options, definitely interested in input, but I won't trade low end torque for top end power on this build.
I have just started researching ECU options and would appreciate input, Holley has a new ECU and harness assembly that seems to check all of the boxes :scratch:
Starting at the bottom, both of these threads and posts call for 0.0025" bearing clearance
https://southernairboat.com/phpBB3/viewtopic.php?p=693413#p693413
unforgiven11B said:Welcome- here is my recommendation some will say differently but my research is from Proven combinations and proven engine builders
Not that it matters to this point but are you going carb or stand alone efi? On LS the difference can be a few grand. On to the assembly. Unless you are using the long block as Is, Get a good balanced rotating assembly I would suggest (lunati), Callie’s, stay away from eagle. If you are rebuilding throw your head, main, and rod bolts out they are Tq to yeald and should not be reused. If you upgrade to main studs make sure you have your machine shops line hone and bore using the new STUDS or you will be furious when it won’t rotate by hand or burn up some bearings
The build specs below are for a 500 hp 408 LS based off a L92.
Mains- .0024-.0026 in 50ft/lbs-out 60ft/lbs (ARP studs)
Rods- .0024- .0026 45 ft/lbs
Rod bolt stretch- .0055- .0060 “am for .0055” (ARP bolts)
Piston to wall - .0035
Bore finish-280
Crank end play- .004
Ring gap- use manufacturer recommendation for 150 hp shot of N02 mine is Top ring Bore x .0060, 2nd ring bore x .0070, oil ring min .0015 suggested use is .0035
That should get you started. Take it slow lay everything out and if something doesn’t feel right stop and recheck. Good luck and let us know how it turns out
https://southernairboat.com/phpBB3/viewtopic.php?p=694708#p694708
CarMotorBarge said:Been busy lately with work. Getting back to this thread. So I don't plan to spin 8000 RPMs. The max will be 7000 RPMs. Hopefully I will get a little more longevity out of this motor. :shock:
The interesting thing is the LS7 comes from the factory with a 7000 RPM rev limit. The LS2 from the factory has a 6800 rev limit. The LS3 from the factory has a 6600 rev limit. Hopefully if I put some aftermarket valve springs and lifters, I will be OK spinning 7000 RPMs. 8)
Here is the latest on the build. I have the main bearings in. Check the clearances. Here is the data:
Main Bearing 1: 0.0026"
Main Bearing 2: 0.0023"
Main Bearing 3: 0.0025"
Main Bearing 4: 0.0033"
Main Bearing 5: 0.0035"
The perfect clearance is 0.0025". Bearings 4 and 5 are a little higher than I would like. Think I am going to pull the main caps and swap a few bearings around to get all of the clearances closer to 0.0025".