Mikey 97Z M6

iTrader: (37)

I'm looking for some assembly tips from those that have built/assembled their own LSx shortblocks. I've asembled my share of old school SBC shortblock assemblies, but have never tackled an LSx before. Here is my setup and a few questions:

-99' LS1 block
-Custom CP 2618 Forged 3.903" Pistons (coated skirts)
-Diamond .927 Floating Pins
-Total Seal rings
-Stock Crank
-Stock Main Caps and bolts
-Rods, (undecided but will be forged 6.125", probably H-beam)
-Ported Oil Pump
-New Timing Chain (LS2 ???)
-Cam (undecided)

After I purchase the rods, I'm going to have the rotating assembly balanced. I'm assuming the assembly should be an internal balance, so I probably don't need to include the flywheel and front balancer for this, or do I?

What brand of engine bearings are recomended for this setup. It'll be mostly a street car, with an occasional shot of nitrous (150 shot). RPM's will be limited to 7k, and hoping for 430rwhp NA.

Oil galley plugs, replace or reuse?

I've never dealt with a 6 bolt main cap before, is there anything special I need to know about these?

Tips for any of this is appreciated. I'm a little bit intimidated by this assembly for some reason.

Mike

Mikey 97Z M6

iTrader: (37)

No engine builders in here?

Maybe I should I try this in the advanced section?

Mikey 97Z M6

iTrader: (37)

OK one more attempt before posting in the Advanced section. <--(Moderator Note)

Maybe I should have posted a "which cam is the best" poll in my title LOL......

Brak Attack

iTrader: (10)

I'm getting ready to tackle the same task and there is a good write up on GM High-Tech's web site. I'll see if I can find it and post a link for ya.

Brak Attack

iTrader: (10)

LS1 engine build part 1

Mikey 97Z M6

iTrader: (37)

Ya, I actually have all those old issues of GMHTP (part I, II and III), and have been reading through them over the last couple weeks. They don't mention anything about the balancing technique used on LS1's. They just used a 'pre-balanced' rotating assembly from Lunati if I recall. They also didn't get into types of bearings etc.. Good articles overall though.

Mike

sroach20

iTrader: (31)

balancing is done at a machine shop unless youve got the machine to do it.

Mikey 97Z M6

iTrader: (37)

Good one.

There are actually quite a few different ways to balance a rotating assembly, and my machinist will need to know this before hand since they haven't done an LSx yet. Here are some examples for your own future knowledge.

-Internal balance = zero balanced rotating assembly, the front balancer is zero'd, and the flywheel is zero'd (neutral).

-External balance = entire rotating assembly is balanced with the harmonic balancer, plus the flywheel because both have an offset weight balance. Some older SBC's are like this (400's IIRC)

-Front bias balance = entire rotating assembly is balanced with the harmonic balancer because it has an offset weight balance, but the flywheel is zero'd.

-Rear bias balance = entire rotating assembly is balanced with the flywheel because it has an offset weight balance, but the harmonic balancer is zero'd. (LT1's are this way from the factory)

The main reason for the differences is with the factory bob weights. Sometimes it's easier for the factory to balance the engine by adding the weight to the flywheel or harmonic balancer rather than try to add more weight to the crank-throws.

Now, it gets tricky because you can neutral balance any rotating assembly, any flywheel, and any harmonic balancer. But, if you want to use factory parts (balancer or flywheel) in the future, you need to know if those parts have an external weight bias or not.

I hope that made some kind of sense. It's late and I'm tired lol...

Mike

Brak Attack

iTrader: (10)

Hmmmmm.....