Transamcrazy99

I have a 99 pontiac trans am ls1 350 engine. The car has been stock for 100 thousand miles before i decided to pull it out due to misfire issues. Does anyone know how long these blocks last cause i plan to rebuild the hole engine both bottom and top end. Is it safe to use my old block or is it smarter to get a new one?

NVR_SPDS

iTrader: (39)

you cant bore it far, but you can definitely reuse it without an issue. Just make sure a shop that knows LS1s does the work, and have fun!

itsslow98

iTrader: (18)

100k miles is nothign at all. I wouldnt not be worried one bit to rebuild it.

Transamcrazy99

Thats the response I wanted to here thanks guys.

lusting4ls1

iTrader: (15)

176k shortblock here and still going strong. Hopefully it will still be just as strong once i get ready to fire it up for the first time after this cam swap.lol

kendogg

iTrader: (2)

Whya re you pulling it for a misfire? Diag (and repair) your misfire, then do a compression & leakdown to determine if you need a rebuild. If not - start modding it till it blows up

lusting4ls1

iTrader: (15)

^^^^this is true. my car threw a misfire code a week after i got it. turned out to be a bad plug wire.

jthunderz28

On a side note, does anyone know typically how long the bottom end (crank, rods, pistons, balanced/blueprinted etc) last on LS1's seeing no more than 400rwhp and used as a daily driver???

I know typically when you do a cam swap you typically redo the entire top end (Heads, valvetrain, gaskets, etc.)

lusting4ls1

iTrader: (15)

i think it really depends on how well its been took care of and how often you beat on it. i know there are a few guys on here well above the 200k mark still running 11's. seems the major weak point are the rod bolts. I think the rod bolts are like the stock 10 bolts, some hold up, some decide to let loose.

Transamcrazy99

I couldnt figure out the misfire,
Spark plugs changed
switched coil packs to different cylinder
spark plug wires changed
compression check was good
I got so pissed i just pulled the bad boy out but it was a good thing cause i plan to redo whole motor and respray the bay.

LS100CAMSS

You may wanna check out your injectors as well. Played hell once chasing what i thought was a ignition related misfire that turned out to be a clogged injector. Never set any injector, fuel trim or o2 codes. Just a P0300. Wasnt even a misfire you could feel, just enough for the ecm to pick up.

Transamcrazy99

O nice ur lucky cause mine misfire lead to a drastic lose of power and hole car shaking pretty bad. i thought it was a rod or even the piston rings but i just took the pistons out last night and no signs of damage. i no sometimes clogged cats can make certain cylinders misfire.

MattBrown0761

iTrader: (6)

at least 150k

deion82

100,000 miles you can most likely see the cross hatch yet. haha

garygnu

seen a couple of motors on here with 200,000+.if its tore apart consider a 383 stroker kit from TSP or any vendor that sells them.