Re-Use 220k Shortblock?

[97Burban57]

Okay gentlemen, I have a 220k 5.7 vortec out of my 97 Suburban in my garage. It had excellent oil pressure still when pulled. Should I put the heads back on and keep running it?
The motor developed a slight coolant leak into cylinder #4 because of a cracked head so I need to get some refurbished heads to put on.
I don't have a ton of money but am slightly worried about the 220k the shortblock has on it! Can these go for 300k??? The cylinders look good, you can still see the cross hatching in the cylinders.
I would definitely change the timing set or at least the chain since it has developed significant slack. I would probably leave the oil pump alone since oil pressure is great. Also I would put new elgin lifters in it. Thoughts guys? Thanks.

 

[Erik the Awful]

Run it! If you can still see the crosshatching, I probably wouldn't even bother honing it. The newer engines had better metal, better machining, and ran with a better-controlled fuel mixture and didn't get the cylinder bore wear that was common in the '60s and '70s.

If you're going to slap heads and go, I'd just do that. If you're going to take the bottom end apart, I would take it to a machine shop and have the block vatted and magnafluxed - especially if it's ever been overheated.

 

[97Burban57]

Im thinking of not touching the crank, pistons or rods. Im assuming the bearings should be fine being that oil pressure is good? I didn't overheat it at all. It just slowly seeped coolant into cylinder #4 because of the cracked head. Also i compression checked all the culinders before tear down and all except cylinder 4 was in the 160-170 psi range

 

[Supercharged111]

I put a blower on my truck around 240k, now approaching 300k. I think you'll be OK. Years ago I did roll in fresh bearings for the hell of it.

 

[Jeepwalker]

I think if it were me ...living in MI, I would put er on an engine stand and 1) inspect the coolant plugs on the block and if they're rusty, replace them. ShopVac out any sludge accumulated inside the plug area around the cylinders. 2) I'd also inspect/replace the timing chain too ...if I were going to put it in my truck. Just because a) if it's got some 'slop' in it (which it surely HAS to have some ..if not a LOT) ..it'll run better and for longer. b) At least pull off the timing cover and inspect the t/c. 3) I'd remove the distributor and inspect the lower internals like the pick-up assembly, etc. Easy to do out of the vehicle. Or maybe there isn't a dist in it now. 4) Consider replacing the rear main seal (and the front one too) if your pull off the balancer ..or the balancer is already off. 5) If there's any deep rust pits anywhere on the oil pan I'd remove the pan and weld/braze the pits so you don't end up with a leaking pan. 6) I would personally remove the bearing caps and measure the gap, and either install new bearings, or slightly oversized, including rod bearings. You're more likely to have bearing issues if the cylinders look clean. Rod and main bearings are cheap. It's sitting on the ground, and you're talking less than an afternoon's worth of work to replace them (and nothing else). Then maybe that ole girl would go to 350k1+?? And 7) Of course a new water pump.

All those are pretty quick and easy to do. Put on GM crank seals if you do. Yeah, these engines can go 300k if maintained properly. But timing chains jumping a tooth is not uncommon on high-mile engines, so that's why I'd deal with that while it's out of the vehicle. But up to you....

 

[97Burban57]

Thanks guys, it is on the engine stand right now. The oil pick up looks to be in great shape and is tight ! The timing chain has a ton of slack, can i just replace the chain for $15 if the sprocket teeth look good?

 

[Jeepwalker]

Replace the whole thing. The teeth wear too. New front/rear main seals too. New water pump. If you don't do it now, you'll be slaving inside your engine compartment and do it soon anyway... and that's going to cost the same but suck a lot more.

 

[Supercharged111]

I would, but I'm a cheapass. My motor got a timing set with the bearings, forgot to mention that. Also, the distributor gear is probably done so good time to change that out as well. I would weld that oil pickup to the pump if I were you.

 

[Jeepwalker]

I'm cheap too ...but a lot wiser than I used to be. Going cheap always seems to cost me more in the end, in time if not money (or both). Better to do it as good as you can, the easy way, now, than the hard way later on ... (I've done too many 'hard ways' over the years ...lol).

Just my .02.

 

[97Burban57]

My distributor gear looks great!! It was probably replaced at some point.
Okay i will spring for the whole timing set. Any suggestions on which one?
Also i will need a new timing cover since the stock one is plastic. So that will mean a new front main seal.
I just dont see how im gonna clean up the mating surfaces without getting some crud into the rotating assembly? Can you just spray it all out with wd 40 afterwards?