pulled the heads off. i honestly dont know if i could just clean the heads and leave the block as is or what would be the thing to do here?







this was what Cyl 8 looked like looking in from the intake port



the motor is a 2001 GMC Sierra with the LQ4. the wholesale yard said the motor was fired up before it was removed to know if it was labeled good motor or a core and it was labeled a good working motor and was pulled about 10 months ago and was stored in a heated warehouse. motor has ~106k miles. my initial thought was the moisture from the gas settled on the intake valves. not all of the intake valves looks like Cyl 8 but the exhaust valves looked fine. the plugs when i pulled them were lean and did have some orange discoloration.

i googled around and found something called methylcyclopentadieyl or MMT or MCMT that some gas station used as additive would cause orange build up as well in the motor. perhaps its hopeful thinking but those who know and with experience what are your thoughts and suggestions?

 

Looks the same as the rust in my old c10 motor (#7 cylinder) from sitting after a popped head gasket. #8 cylinder on yours seems pretty clean, so it might have gotten steam cleaned.

 

so can i use the block without tearing it down/rebuild? i was hoping to just get a cam swapped in...new arp head bolts with the necessary springs/valvesprings setup and drop her in.

 

I couldn't tell you boss. Sorry

 

i have 243s for sale .

i think if you clean the heads up youll be fine if thay say it was a good motor not a core and 106 isnt that much

 

thanks sand man for the input. im planning on sticking with the 317's though as i plan on going FI and i saw the vid on ls1tech of the stock 317s reaching 1000hp. i appreciate the offer though. the pistons turn over fine when i turn the crank pulley by hand and although there are a bit of surface rust on #8 its smooth.
the motor from what i was told was fired up to see if it was a working motor and it was then yanked out of the truck and stored in the warehouse for 10 months.

 

Of course this is only advice: my 5.3 has 240K and still has over 190 psi wet on all cylinders, and continues to run great. HOWEVER if it were me, since the block is out and you do not know how this engine was used, I would pull the pan and check clearance on at least one rod and one main bearing. Might be cheap insurance.
if you find issues in the bottom as well as the top end, better now than after it is installed.

 

point taken mike. noob question but if i remove the oil pan, i'd need new oil pan gasket as well as torque it down to spec afterwards correct? also how do i check clearance on the bearing and rod? a special tool needed?

 

Some say it can be reused but I've seen so many LS engine oil pan gaskets leak I wouldn't even consider reusing one. Felpro makes a good oil pan gasket for these engines. Seems to have a little thicker and tougher rubber portion of the gasket and seals better. Don't forget to put a little silicone on each corner of the block where the rear cover and front cover meet the block or it will leak. Torque the bolts to 22 ft lbs or snug whichever works best for you. The back two long skinny bolts don't get as tight. They are something like 96 inch pounds but snug works great there too.

Plastigauge is what you use to measure bearing clearance. Its a soft little plastic strand that you lay on the journal and it gets sandwiched between the crank and bearing once you put the cap back on and tighten it down. You then remove the cap and measure how wide the plastigauge squished out too. The wider it squished the tighter the clearance on that bearing. The wrapper the plastigauge comes in has a guide on it for how much squish equals how much bearing clearance.

 

i never touched the crank/bearings in the motor before but if i remove the bearing wouldnt i need new bearing bolts(TTY) or are they reuseable? i may not even want to loosen the bearings to see if its loose or not. i imagine the rod bolts are updated from the previous 97-98s(read they tend to loosen up with high RPMs) which i think was how my 98 motor blew a rod out of the bottom of the motor few months back.