87nitefc

So I've been in and out on actually going the V8 route or not. I'm yet to decide wether or not I want to actually jump on the idea, I've found a Lm7 engine block for a few Jeffersons so I had to buy it.

These are the specs of the engine 01 gmc lm7 from a Burban with 706 alum heads. I was told it was removed because it had low compression not sure if it was on 1 or multiple cylinders. Prior from buying it I was told that it had recently seized from being left outside in the rain. Although it seems like a bad investment I see it as a learning experience best of all it was cheap LOL.

So the project has started like this. Me being overly excited to start working on this new project I began tearing it apart starting with the oil pan and heads.
(Got carried away should of poured marvel mystery oil in the spark plug prior from removing the heads)

My first objective was to try and unseize the engine. With the heads off I poured a significant amount of Marvel Mystery oil directly to the cylinders enough to fully submerge the pistons I did 1day1/2 on each side of the engine in between days I gave the flywheel a few back and forth motions until it released. Its a little on the stiff side as I can't turn the pulley by hand I need a crow bar and turn the engine from the flywheel. I'm still soaking the pistons with marvel hopefully it gives me less resistance. On a few pistons the oil leaks out after a while my guess these pistons need new rings and causing the low compression

(Would I still be able to do a compression test after I have removed the heads and removed the remaining graphite gasket from the block)

I found a very fine metal brush and I'm lightly using it to remove any carbon build up on the pistons I'm carefully running it around the edge of the piston to remove if any carbon build up that is between the piston and cylinder walls with the piston at top dead center to prevent any damage to the walls.

I'm most likely going to remove all parts and have a machine shop tell me the damage of this block if it worthy enough to rebuild. I plan on doing a turbo setup so hopefully it's rebuild able and I don't need a large bore and kill my hopes of going turbo LOL

87nitefc

Engine torn apart getting her ready for the machine shop heads were taken apart along with Pistons unfortunately I need to get a pulley puller to access crank and cam meanwhile I've been doing a fair share of parts cleaning. I now hate graphite gaskets


Cleaned one of the heads with degreaser only from the exterior portion. I still need to disassemble the heads. To polish the valve cover or not??


What are these heads worth as is and how much for these same heads but ported from exhaust and intake side


I've managed to clean the Pistons with Berryman parts cleaner degreaser, paint thinner, wd-40 and a scotch brite pad how much should I clean them up can I damage the Pistons if I clean them too much I left a thin layer of I'm not sure if it's residue or a protective layer on this piston. It can clean up more if I want to get a cleaner look just I'm not sure if that is something that can cause problems


Some scars from piston slap my guess This is my main reason for wanting to get the block honed you can still see the original cross marks on the cylinder walls not sure what the mileage was when pulled


This is another piston that I had decided to clean much better it has a better shine giving me the impression it's cleaner lol. I'm not sure if I did any sort of damage, or if this is how they should all look after cleaning


Better picture

87nitefc

Based on the following pictures how many miles would cause this amount of wear? You could see easily where the Pistons had been slapping the walls.

Freeskier7791

nice work so far, that wear looks pretty bad

87nitefc

I was thinking maybe a good hone job would work best do you think i need to get it bored out instead

Freeskier7791

I would think a hone would clean it up, I would ask an engine shop though.

87nitefc

Im planning on running these pistons but i was tould i need 1.2top 1.5 2nd piston rings yet on ls1tech they mention that 1.5 top and 1.5 2nd piston rings are needed when searching there isnt many options that offer 1.2 / 1.5 rings

87nitefc

It’s been a while but I’ve been busy gathering parts engine is getting sent out to mullinex racing for final assembly ive been debating lately on what route should I build my engine carb or efi setup.