What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Questions for buying used Engine

HawK5

HawK5

1/2 ton status
 Premium
Joined
Mar 13, 2022
Posts
211
Reaction score
90
Location
Snohomish WA
Well looks like I’m in the market for an engine, the Jimmy had a Jasper 350 installed a couple years ago with probably only a few thousand miles on it, and I’m pretty sure one of the heads is cracked. So far I know the heads are the lightweight crappiest gm heads, so I don’t think I should put a penny into them (thanks Wes for saving me the trouble) I’ve heard from a more than a few people to be suspect with Jasper short blocks as they do some pretty shady crap.
Obviously this was not in my plans or budgeted, so I’m looking to do this on a budget. Probably sticking with SBC to minimize swap costs. That being said what questions do you guys ask or things do you check when looking at a used engine? Here is my starter list:
Are you the original purchaser (for crate or rebuilt)
Do you have receipts/documentation?
Why is the motor pulled and/or being sold?
Are there any known issues?
I will do a leak down test regardless, compression test if crankable and run the motor if possible ensuring it gets to operating temp.
I understand there is an inherent risk any time you buy something used, I just want to do every test and ask every question possible to ensure I don’t get screwed.
Thanks in advance.
 
If runs, ideally you want be there when it is started cold, watch for excessive white smoke. Some white smoke will be normal depending on the condensation and dew point or your area. let it warm up, remove pcv valve from valve cover, look for blow by, put a piece of paper over the grommet in valve cover, see if it get blown off forcefully.
Maybe invest in bore scope that attaches to your phone. Use it to look in the cylinders via the spark plug hole. Nice shinny cylinder walls with a diamond shaped hatch mark would be ideal. Nice clean piston tops is good to, but not necessarily needed. If the valve are open look at the margin (edge) valve should be 1/32" -1/16" wide. if the margins are thin the valves are shot.
Leak down test on a non running engine is highly recommended. Leak can tell you much about an engine running or not. Be sure to put a wanted add in the classifieds here. I know at least 1 member not a horrible drive from you that probably has a runner he needs/should get rid of.
 
Probably not the best policy but I say “how does it run, any issues” if they say runs good no issues I show up with cash and load it up. I’ve bought 5 this way and never had an issue. Only two times I’ve got burned on engines were when I bought them from junkyards, one was cracked block and the other was totally trashed inside.

My .02, take this as an opportunity to upgrade to an L31 roller cam vortec engine.
 
Last edited:
Can you run a carb on those vortec 5.7s? Theres quite a few out there..they’re also serp belts, but I guess as long as it has all of the accessories it’s nbd, any other conversion stuff needed to mate it to a sm 465, the flywheels and stuff are the same?
 
I’d stick with the fuel injection given any possibility

The flywheel is different from the single rear main seal and split main seal engines

Heads on the vortec engines are a different bolt pattern, both intake and exhaust (raised runner)
 
Chickntrk said:
Yes you can run a carb on a vortec

JEGS 513002: Intake Manifold for 1996-2002 Small Block Chevy 350 Vortec with L31 Cast Iron Heads, Dual Plane [Satin] - JEGS

Jegs Intake Manifold for Small Block Chevy with 1996-2002 Vortec L31 Cast Iron Heads [Satin]
www.jegs.com www.jegs.com

SBC exhaust manifolds work on a vortec engine

As @Bent77 said, flywheel will need to come from a one piece rear main engine
Click to expand...
You might wanna measure runners. All the ones I’ve had were offset .200”
 
I would first open up your existing motor and inspect it. No sense in buying another, unknown engine if the existing one is OK and all you need is a set of heads. You could throw a set of new heads, a better cam, and a better intake at your existing one if it checks out for the price of a running, used motor around this area.
 
Yeah I was thinking I could sell the current motor, advertised honestly about the problems, for more if people could start it and hear it run and see oil pressure etc.. the heads are known to crack, and Jasper is apparently notorious for putting together crappy short blocks, I’ve heard this from members here and calling shops around here that refuse to work with Jasper because they get so many rigs coming back with problems. maybe I should checked the torque on the heads bolts, I suppose it’s possible they’re not torqued properly and it’s just a blown head gasket.
 
if it has good oil pressure, rip the heads off if all the pistons are the same size/part number. get some new heads and run it. Do you know how many miles on this Jasper engine ?
 
head gasket or head swap on older is stupid easy to do . pop it out if you want tear it down quick to a short block . look for blown gasket or crack in head .

but its a reman and we have seen a lot of socalled reman motors with crazy problems fixed real stupid from them . buddy at a shop had i think a jasper and the coolant was going on it . tore it down found cylinder wall was welded and bored and cracked back out . motor was junk .
 
The ears+ eyes tell a lot, blow by, pressure / bubbles in radiator. A stethoscope tells the tale of bad uneven sounds.
 
CT-BLAZER said:
The ears+ eyes tell a lot, blow by, pressure / bubbles in radiator. A stethoscope tells the tale of bad uneven sounds.
Click to expand...
Can you expand? Is there a way to differentiate a head gasket vs a cracked head? I bought a borescope so theoretically I could scope out my current engine for piston part numbers before I tear it apart and just look around in general for the things you mentioned. I doubt I’d see a cracked head using that tho..
 
Found a guy locally selling a jegs 350/350hp 450 miles, he put it in a project and got rearend totaling the vehicle, so he pulled the motor. He says it’s been sitting in dry storage for 5 years, says its complete carb to oil pan accessories to flywheel. Anything I should check or by leery of with an engine sitting that long? He’s asking $1200. Planning to bore score, turn engine over and do a leak down test.
 
Yeah, see if all the openings were sealed up, scope the cylinders. Prime the oil pump if post and check pressure
Look at the oil if it’s still in it, pull valve covers and see what the condition is in there
 
it is worth going to look at. defiantly check the bores with the bore scope, Like bent said if not sealed the bores might be rusted. esp in PNW. If bores are rusted is $350.00 core.
 
It's pretty moist where you are at so it could have some pretty crusty innards under the valve covers and inside it due to temp changes and humidity even though it was stored inside. Definitely pull a valve cover if possible.
 
If it has 450 miles it should look like its just out to the crate.... hard to evaluate on a stand..but pull a plug and look in the cylinders ...

a paper trail tells alot ...
 
You must log in or register to reply here.

Latest Posts

Top Bottom