This is my first LS build so please cut me some slack. I have built 10 or so motors, be it they were 20 years ago, so I'm lost on the torque spec's I found on the crankshaft torque on the main bearings. I found a site that said 15 lb\ft on the first pass and then 80 degrees on the second. What the heck is 80 degrees? I'm old school, I am looking for lb\ft to set my high dollar torque wrench to.

Thanks in advance,

Dogman..............

 

Great video to watch if you've got a few to burn. This guy's who video log of teardown and rebuild is very helpful for many.

 

I went to the local chevy dealership and asked if they could print out all of the all data info they had on my LS1. It's one way to get every torque spec you'll ever need for your motor.

The 80 degrees is referring to the final amount of rotation you need to turn the bolt. Think of it as a final torque step. So for that set of bolts you'd do the first pass for them at 15 lbs and then the next pass would be rotating all of the bolts an additional 80 degrees. Get a torque angle gauge!

I'm almost positive the mains are NOT tty yield bolts and CAN be reused.(not 100% on the 6.0, I have a 5.7)

Tighten the M10 bearing cap bolts (1-10) a first pass in sequence to 20 N·m (15 lb ft).
Using a plastic-face hammer, tap the crankshaft rearward, then forward in order to align the thrust bearings.
Tighten the M10 bolts (1-10) a final pass in sequence 80 degrees using the J 45059 .
Tighten the M10 studs (11-20) a first pass in sequence to 20 N·m (15 lb ft).
Tighten the M10 studs (11-20) a final pass in sequence 51 degrees using the J 45059 .
Tighten the bearing cap side M8 bolts to 25 N·m (18 lb ft). Tighten the bolt on 1 side of the bearing cap and then tighten the bolt on the opposite side of the same bearing cap.

 

I'm assuming you're building an iron 6.0? Just wondering as some of the torque specs for the iron vs alum block might be different im not sure. However here is a complete manual for an iron block 6.0. Ls motor use an angle setting in a lot of places. Generally that means the bolts are one time use only. For example, head bolt have an angle and torque setting and must be thrown out after 1 use. Same with the crank balancer bolt. Usuallly when doing head bolts I just eyeball it with a marker for 45 degree or 90 degree increments, however if you want to be exact there is a torque angle gauge you can get for your torque wrench to be completely accurate

http://www.pleasurecraft.com/manuals/L510016.pdf

 

It's a LQ4 iron block 6.0. I ordered a torque angle gauge and it'll be here Wednesday. Thanks again.

 

sounds good man just make sure you use new head bolts on the engine along with a balancer bolt. What year is the block? If you are doing a complete rebuild and havent had the rods line honed I would recommend doing a set or arp rod bolts then having the rods check for roundness. If youre past that point stock bolts would be fine.

Personally after going through these engines a few times there are certain bolts I like to upgrade from stock to ARP. I have either broken these torquing them to spec or find the aftermarket ones nicer to work with.

Cam gear bolts (broke torquing down)
Cam retainer plate (broke one on final torque sequence)
Flywheel and TC or Pressure plate bolts. (just makes life easier lol)
Head Bolts (honestly the stock ones just scare me)

You can skip the flywheel and tc or PP bolts because they really arent that much different than stock minus the head type. The cam retainer and gear bolts are very small and frankly every time I torque a stock set down I feel like they just stretch and stretch and have had a couple break using a snap on torque wrench. Arp's just feel much more solid.

The head bolts I have never had an issue with however it gets pretty scary when you have to use a pipe on a breaker bar to get them to go that last 45 degrees. Not only that but if you have to pull them you have to buy a whole new set at 25 bucks per side. They also come with thread locker on the bolts that leave the holes all gummed up with crap. The arps are 100-150 for a set depending on what year the block is and are the good ole' torque in 3 passes and forget it deal and they just use moly lube so no thread locker left in the hole, and they're reuseable lol

Overall for all the bolts I listed expect to spend around 200-250.


C

 

I'm going to use ARP head bolts for sure. I plan to use the stock rod bolts. What head gaskets does everyone go with on a NA LQ4 6.0? I have read about folks using the LS9 head gaskets but not clear as to why.

thanks in advance

 

Ls9 gaskets are better because they were made for boost. While they are the same thickness as the normal gaskets they are made of more layers of steel just thinner so you get a better seal. Although if the build can take it I would use cometics to get the compression up and quench down