HAte

in a few days i will know if im going to buy a good deal on a 99 ta, they must have drove it every single day because it has 250,000 owner says orig engine and trans with no problems.....

but for hypothetical reasons am i smokin crack to want to tear the engine out and build it over the winter? new bearing all the way around, new rod bolts, arp main studs, cam,springs,lifters, push rods, maybe heads along with bolt ons.

point being, should i not trust the block or pistons

or if it the cylinders have wear in them and it has to be bored out

safe or no

LS6427

iTrader: (2)

If the block checks out, hone it and use it.

.

TheGreat4.8

I would just drive it and see how far you can push the mileage, maybe 300.000 ?

redtan

iTrader: (5)

You should do that because you want to upgrade for more power, but if the engine is actually running fine then why bother?

If you're fine with the current power, then just ride this thing until it breaks. Then do a full rebuild.

ROMERO98Z28

just get a lid,free mods,cat.back,and just leave the motor into it breaks

redbird555

iTrader: (14)

250k is a lot of miles and that engine has to be tired. If you have the money I would pull the motor out and tear it down. Have the bores checked as well reason being is that ls1 pistons already fit a tad loose in the block (which is what causes pistons slap) so chances are if the motor is severely worn then you may be better off getting new pistons and boring the block .010 over to get the bores round again.

If the bores check out fine then just re-ring it and put her back together with new bearings and a valvejob.

Btw the 99-02 blocks can only tolerate a .010 overbore while 98's will only take a hone so if for whatever reason it need more than a .010 over bore then make a nice coffee table with it and get a new block. lol

s346k

iTrader: (4)

if it ain't broke don't fix it. as already mentioned, if the block checks out, reuse it. the pistons...eeehhh i'd replace those.

HAte

in short:

point being IS to make power.. not a stock rebuild.

point of question is about block/crank/maybe piston reuse or throw away.


i wanted to get opinions on weather i could/should build an engine simply because of the fact its high mileage

LilJayV10

iTrader: (39)

Sorry if I didn't understand your question. Are you talking about modding it or completely rebuilding it or asking if you should rebuild it?

If it has good compression and oil pressure I'd mod it. However I would replace the oil pump and timing chain as a precautionary measure. I wouldn't trust either with that kind of mileage.

redbird555

iTrader: (14)

Sounds to me like you want to rebuild it and make some decent power with maybe a cam or something along those lines. In that case, as long as the block doesnt have any cracks in it I'd reuse it, however as I stated earlier ls1 pistons have pretty loose tolerances from the factory and the engine does have 250k. I would have the bores checked to make sure they're still in round and then have the block bored .010 over or at least a .005 and new pistons put in. The pistons after 250k are ehh anyway and then combined with the wear.... It would probably be a much tighter build to just throw some new ones in with a fresh bore job.

The crank and rods should be just fine, I'd do a valvejob on the heads to get them up to snuff and then just put new bearings in it providing the crank looks good, and run her hard!

One other thing I will suggest is that if you are putting a cam in and will be spinning the motor higher than 6200 is rod bolts. You can get katech ones that are 200 for a set and they just swap out or you can pick up a set of arp's which are about 80 bucks but the rods will need to be line honed to ensure they are perfectly round for the arp's. Its your choice in the end but the stock bolts are hit and miss about 6700

Tech

iTrader: (1)

If you're buying the car now.. why not buy the other supporting mods for when you swap the motor? Headers, clutch, suspension, lid, pulley, etc.

HAte

im buying the car cause ive been waiting to pick one up to build into a nice ground pounder and its almost winter here where i am so why wait?


as for the rod bolts, why does arp have to be line bored and the other dont?

chrisfrost

iTrader: (8)

The ARP's don't "have" to be honed out .002" but they need to be checked for size and roundness with the bolts torqued in the rods . Skoggin Dickey has the ARP's for about $70 . The clamping force of the ARP's is greater than the stock bolts so they do distort the big end of the rods some more than others . The Katechs are designed with a certain type of metal that is able to basically equal the stock clamping force but be stronger than the stock bolts at the same time . You're choice . BTW just FYI in case the machine shop does'nt know about LS1's , the norm is to hone the LS rods out .002" and Clevite makes rod bearings that are standard size ID but .002" larger OD for such cases . Finding a machine shop competent with LS based engines could prove difficult depending on where You're located . Good luck

BuckaroooZ28

iTrader: (1)

Omg pull that thing apart! Rotating assembly or at least pistons

VIPER EATER

iTrader: (1)

a local guy around here just bought a 200,000 mile lq4 from the junk yard and hes slappin a t76 on it and is gonna run 10lbs to it and see how long it lasts. its not goin in a race car, hes putting in his 69? impala convertible with a 4 speed. he tore it down and checked ring gap as well as the bearings and said it all looked good for the amount of miles. then again this guy is all about budget builds, hes the only guy i know that can take a 150,000 mile truck 350 from the junk yard, slap twin hair dryers on it and run high 9s with it in the 1/4mile in a 88 trans am GTA, ill see if i cant find the car craft issue of his trans am

edit: found it check out this guys build.
http://www.carcraft.com/featuredvehi...ird/index.html

dont mean to hijack this thread just thought id show ya that a high milage engine isnt something to be to terribly afraid of... at least he isnt hahaha

Pocket

iTrader: (22)

Newer engines dont wear nearly as bad as older ones. A properly maintained engine will still have the crosshatching in all 8 cyls with 300k on it. Since the OP seems bound and determined to pull it and strip what difference does it make?

LilJayV10

iTrader: (39)

Yeah I don't understand why people make threads when they have already made up their mind.

HAte

i picked up the car the other day and it seems well taken care of the car still seems to have its power and not tired engine

yes true i did make up my mind about building the engine, i just wanted to pick some brains and see what i can find out, since this is my first ls style engine build

but i have had my questions answered thanks everyone

Pocket

iTrader: (22)

Id advise picking up a rebuildable long block and driving this car until that one is done. Minimize down time

darkvader0

Just want to add that I have 230K on mine now with orig. engine and trans-- no probs. Valve covers have never been off lol. Only ever changed one water pump and one alternator. As for the rest of the powertain I have had a fuel pump, rear wheel bearing, and clutch pilot bearing fail. That rounds out ALL the maintenance I have EVER done powertrain-wise. Hell, the only other thing was I soldered some cold joint in the "BCM" to fix intermittent radio/power window issues.