What to look for in a used engine

[92ranger18]

I recently picked up a running 351w that was supposedly rebuilt awhile back. It came out of a 74 grand torino. But i pulled it out of a bronco. I heard it run but the guy had the timing or firing order wrong cause it was running rough. I want to go through this engine before i put it in my ranger. What are some things i should look for when i do? I was gonna check the cylinders for scratches and out of roundness. Should i take it completely apart to check everything. What would you guys do? I want to run it stock for a little while and when i get the money saved up build a 393 or 408 stroker. Which would be good for a mild strip truck

 

[FlamedRanger87]

Things i would check for

Timing chain
-See if it has a lot of slack. If you can move it 1/2 inch be a good idea to get new one

Cam bearings
-see if they have a copper color markings if so you need new ones

Cam itself
-Check to see if it has bad wear (maybe google what bad wear looks like)
-Check cam gear for bad wear

-Take the heads off and check valves and piston tops use a wire brush clean them.
-look for burn marks
-Cracks
-Chunks missing

-Push rods
-Take all the push rods and roll them on a mirror to see if they are straight
if they are bent the rod will make a tick kind of noise.

lastly i would take the main caps off and see if the main bearings show that copper color after that re torque everything new head bolts and gaskets for everything you took off.

hope i helped a little...

 

[Scrambler82]

What does the oil look like, does it smell like oil or really bad, like a lot of stuff is in there too, which is a bad sign.

When you start the disassembly, look at the bolt heads, see how much wear there is, do they look like that have been taken apart a lot of not at all.
Pull the heads, see if the head gaskets are showing signs of leakage, look at the heads, check the valves do they look clean, is there rusting anywhere on the head/block surfaces indicating a blow by condition.

When you pull the oil pan and the intake, look for excessive oil/dirt-sludge build up in the valley area and in the oil pan, if there sludge then it is an indicator of the engine has blow by problems and probably was never rebuilt.

If there is a lot of sludge you will need to look at the bearings, mains, rods and cam, they need to be checked for excessive wear.
When removing the Main Caps and the Rod Caps, keep them in order, in fact take a needle punch and mark the main caps, if not already OEM marked, 1,2,3,4 and the Rods and Caps for each one, 1,2,3, etc.
Once this is one start to remove the Rod Caps and then the mains and take a look for wear and as stated copper showing through.
OK now here is where you need to decide is it worth a rebuild or just go get a low milage Explorer setup and use it.

Check the cylinders for two things, is there any cross hatching on the cylinder walls, a sign on recent rebuild and how much of a wear ring has formed at the top of the cylinders, that will indicate how much wear this engine has seen. a deep wear point indicates a lot of miles and/or hard use, (use you finger nail, run it up the cylinder to the top, if there is wear then your nail will catch and you will tell just how deep it is.
The wear ring at the top of the cylinder, if deep has to be removed before disassembly is done, to reduce any further damage to the block and possibly the pistons.
Also check the cylinders for any deep scratches, not a good thing.

If the motor is clean inside you can assume there has been work performed on it, how much is a call that I can’t make from here.

If the engine was running bad then it could be valves, head gaskets, plugs, cam, bad rings, broken piston, and the list goes on.

I can go on and on but use your common sense and see if it looks like work has been done, question being how long ago. A clean block and head will indicate this might be a good engine but look around.

Good luck on the 351W, it will be extra work to put in a Ranger, extra cooling problems and exhaust headers will need to be all custom.

 

[92ranger18]

the guy I got it from had it in a FSB that had a 302 in it before and it was running off the 302 computer. the firing order is different on the 302 and 351w. hopefully this is the culprit for running rough, and nothing is wrong with it internally. he said it was rebuilt and stored for a while, but we all know how the "he said" stuff goes. thanks for the advice guys.

 

[Scrambler82]

The “302” is a different firing order but the 5.0L is the same as the 351 !
Find out what you have and what cam is in the engine and determine from there.

The Cam will determine what firing order you will use.

In the distributor, the base plate is sometime held in by machine screws, check to see is they are tight; they come loose and can raise havoc with good ignition, they need to be tight. Also, do not use a loc-tite on the screws, they are meant to be a grounding for the electronic module or even points if you go back that far.

 

[85_Ranger4x4]

The “302” is a different firing order but the 5.0L is the same as the 351 !
Find out what you have and what cam is in the engine and determine from there.

Only the 5.0 HO is the same as a 351W, the standard 302/5.0 is still the old standby 302 firing order.

 

[doorgunner]

OR........you could do some of what the guys said without tearing down the engine....

remove all the spark plugs----use a good battery to crank the engine over in order to do a compression test on each cylinder.....

then.......rotate the engine with a big socket/breaker bar to T.D.C----use a fitting on the end of an air compressor hose to pressurize the cylinder to 100psi---turn off the air compressor and listen at the intake/the exhaust maifold/the dip-stick-tube (dipstick removed)......

The sound of hissing air at the carb/TBI means a worn intake valve....hissing in the exhaust manifold means a worn exhaust valve......hissing in the tube means worn rings.....

Test each cylinder...why tear down the engine when when all you might need to do is remove the timing chain cover to check/replace a loose timing chain....

This $20 home-made engine stand helped me test everything/knocking--tapping--missing--leaking-overheating--etc before I put it in my Ranger......

 

[92ranger18]

OR........you could do some of what the guys said without tearing down the engine....

remove all the spark plugs----use a good battery to crank the engine over in order to do a compression test on each cylinder.....

then.......rotate the engine with a big socket/breaker bar to T.D.C----use a fitting on the end of an air compressor hose to pressurize the cylinder to 100psi---turn off the air compressor and listen at the intake/the exhaust maifold/the dip-stick-tube (dipstick removed)......

The sound of hissing air at the carb/TBI means a worn intake valve....hissing in the exhaust manifold means a worn exhaust valve......hissing in the tube means worn rings.....

Test each cylinder...why tear down the engine when when all you might need to do is remove the timing chain cover to check/replace a loose timing chain....

This $20 home-made engine stand helped me test everything/knocking--tapping--missing--leaking-overheating--etc before I put it in my Ranger......

Thank for this advice. Itll sure save me time and money with tearing it down and nothing be wrong. Im gonna pull the intake and valve covers and oil pan and check the mains. If it does have gunk in it is there any way to clean and flush it out? I dont have a test stand so ill set it in the truck cause i know im gonna have to make headers. Any advice on making fenderwell headers and what size and material.

 

[shane96ranger]

Only the 5.0 HO is the same as a 351W, the standard 302/5.0 is still the old standby 302 firing order.

This.

BUT... I know the 302 F150 went to a 351/HO firing order in 95. I would assume Ford would follow suit on the Bronco. What year was the Bronco?

 

[92ranger18]

Not real sure i cant remember but it looked to be an 80 something.