Picking up used 350, need advice

[Tx Surveyor]

Hey Everyone,

I currently have a 305 in my truck and after having constant problems plus having a flat lobe on the cam I've decided to drop in a 350.
I found a decent deal on a 350 out of a blazer, the guy says it was rebuilt 25k ago and want $400 for the complete motor.
What are some things I should look for if he can't supply a receipt showing the work? What should I look for when I pull the valve covers? Should I go as far as pulling the heads? Anyway to check if this thing actually runs when it's on the stand?

Thanks

 

[badmix]

1) Can you hear it run? or did they yank it already. If you can hear it run:

a) look for smoke
b) listen for ticks, bangs, etc etc
c) look for leaks, not that big a deal
d) make sure it doesnt over heat while sitting at idle
c) make sure to fire it up cold. If you tell someone your headed over to their place and the vehicle/motor/bike, etc is all warmed up, id be leary.


2) If it is out of the truck and you cant fire it up,

a) do a compression check, take the time to do this, itll determine alot.
b) pull the dipstick and see what the oil looks like.


I wouldnt pull the heads, the compression check will tell you alot without doing this. Maybe pull the valve cover just to have a looksy.

If the flywheel is still attached, look to make sure the teeth are good and nothing weird went on.

 

[Tx Surveyor]

Ok, I don't think I will be able to hear it run. What's the easiest way to determine compression? How can I do a compression check with hand tools or should I swing by harbor freight first? What sort of compression am I looking for?

Thanks, I should be leaving to go get it in an hour. It's in Dallas.

 

[Tx Surveyor]

Also, all of the results I'm getting for testing engine compression is if I can crank the motor over. How can I check it if I can't crank the motor?


Surveyor

 

[badmix]

PUll the spark plugs and if the starter is still in there, just hook a batt to the starter (youll just want to touch the solenoid or starter for brief moment, not permanent) and just get each cylinder your test to go thru a full cycle. UP, down on compression stroke and up / down on exhaust stroke. I forget the numbers you looking for. but a 25k rebuilt motor shouldnt have any problems. you really looking for differences between cylinders. that is the main thing.

welp your probably gone by the time you read this. but all you need is a spark plug wrench and compression gauge, it screws into the spark plug hole and you bump the motor over one full cycle or two and take a reading. I wont even get into the wet test. lol

 

[Tx Surveyor]

I don't think that will be an option. I think he has just the motor on the stand by itself.
Any other ideas?


S

 

[dhcomp]

Most ppl agree with this. A used motor, no matter when they "say" it was rebuilt, is nothing more than a core unless you can hear it run, check compression, see rebuild paperwork, etc. If you want to chance it, go for it. But should be able to find one you can hear run first.

 

[imiceman44]

Most ppl agree with this. A used motor, no matter when they "say" it was rebuilt, is nothing more than a core unless you can hear it run, check compression, see rebuild paperwork, etc. If you want to chance it, go for it. But should be able to find one you can hear run first.

Yeah
I sold a few engines and I either leave it hooked so I can start it, or better yet still in a driveable truck so they can test it.
The other option I did with already pulled motors I provide the compression testing equipment and test in front of the buyer.
That is because I know what I have and want to prove it.
I sold a truck a couple of weeks ago with 180 PSI in each cylinder LOW miles engine.

 

[GNERGY]

I wouldn't buy a used motor unless I could hear it run. If it doesn't run good is he going to give you your money back. I bet NOT.
Tarey