LS1 Block Machining Questions...
 

Just recently purchased an LS1 Block with a full rotating assembly. Had one of my buddies go out and check it out for me and pick it up since i had to work. So when i was looking at the block, i started looking at the main caps, and i looked at the number sequence and it goes 1,2,2,4,5. As soon as i saw that i realized i just got myself into a basket case most likely.

So heres the situation, do i spend the money and get a machine shop to hone the block, and check the crank, and look into align boring it, along with new cam bearings just to be safe? How much am i looking at worst case scenario? What else is required with going this route aside from all new connecting rod bolts, and main cap bolts?

This is my first experience with LSX/Gen III/IV engines so its def going to be a learning experience for me. Also going to have start looking into machine shops, would like to see it go to a sponsor or someone somewhat local to me, that has experience with these engines.

Any help is greatly appreciated

Glen

Where are you located?

I'm not to familiar with ls internals but I know sometimes numbers like that could be for bearing tolerances.

But like I said I have no idea on lsx

Usually its so the main caps go back to where they were machined to be. So having two #2 mains is a little odd.

Yup.

Yea those were my immediate thoughts. I am located in Vernon.

Like I said unfamiliar with the bottom end of this motor. Most of the time when I see a combo like that it is stampes onto the block. I didn't look at the picture whoops.

You contact who you bought it from ?

Yea, he said he only bought the block as a long block, to keep around as a spare for his 99Z, then finances took a dump and everything went for sale he said. He said he pulled it out of totaled 1999-2000 T/A with 30kish and its been sitting for about 5 or so years

I got just as much knowledge as you on these engines. Ive just been lurking around here and ls1tech for a couple years reading and learning as i went. figured get some peoples opinions with more experience

Check out SSP, they are right over the border in NY

I dunno that's strange that there would be two #2 main caps in there being untouched unless years and years ago it was opened up

Yea just saw them on the side there actually like 20 minutes away from me. Definitely going have to give them a call about it tomorrow.

As for it being opened up years ago, its a possibility but would a dealership have done something like that or some small time shop done that and not used common sense to get a correct number 3, and just align bored it anyway.

Unless it was align bored just using another cylinder 2 cap. But that is about as far fetched as it gets.

Charlie is definitely a great guy up at SSP.

I'm curious though about the block

Number 3 main is your thrust bearing as well. Does that crank have excessive play?

Wonder if the 3rd cap and 2nd are different for that reason.

Ceralli Performance engines in paterson is also a very good shop

Not sure if there's excessive play or not, my GM service manual for 1998 says proper play is 0.04-0.2 mm. haven't measured yet or even touched it since i brought it home.

If you want you can check the bearings with plasti gauge and check thrust. If both are good I would say its good. But depending on your plans some new bearings and machine work always sounds reassuring.

I would imagine new bearings, machine work and labor probably .... 1000 - 1500ish for what you have listed. Probably hot tank the block as well.

I dont think you would need new caps just newly specd main bearings and maybe a new third cap if there is machining differences for the thrust and oil passages.

If it was my block, all mentioned machine work, new main cap on 3, new cam, main and rod bearings

Plasti gauge is junk and will only get you in the ball park .... The main cap is from a dif block , Most likley you will end up line boring the block ,

Do you think he should put an actual third main cap on ?

Is there any difference or revisions for the thrust bearings

http://image.hotrod.com/f/9255262+w7..._III+mains.jpg

Going to need to find the correct main cap , I would see if you can take the motor back if you have not had it to long. Your going to have a good amount of money tied up in machine work...

Doesn't get any clearer then that picture

You should not hot tank aluminum, FYI

Why is that?

Maybe its another process they use but they did something that cleaned my heads off

Certain types of solutions will damage or eat the aluminum. I'm sure there's a way to do it other than with a pressure washer but some hot-tanks are not safe.

When I worked at an engineering lab there was a guy that put his aluminum heads into the hot tank we had to clean iron piping. They came out looking like shiny beef jerky.

This. The solution is caustic in a true "hot tank" and the heat will etch the aluminum crazy fast. A quick search for hot tank aluminum revealed that there is a "cold tank" that may not damage the aluminum, but I think most shops use something non caustic and boil the solution or something? Not sure as I havent looked into it.

:rofl::rofl:

understand now


I just asked for a cleaning along with the other work I wanted done.