engine and drivetrain What to look out for in a used engine

[Collinster742002]

I've finally been able to find several used engines to look at for my '74, whose engine catastrophically chewed itself to pieces.

Today I'm going to look at a '72 engine that sat since 1992. I have no fear of engines that have sat for a while; my SAAB 900 SPG sat for 22 years. This engine appears to have been stored properly and is said to turn over well.

I'm bringing a fresh battery that's always on a float charger, MMO, a carby, some fresh gas, good plugs and a compression tester. The plan is to see if it'll run for me, and I'm also gonna take a peek inside the valve cover.

I know to look for any signs of major oil leaks; but what else should I look out for?

Thanks!

P.S. I WILL be changing ALL gaskets.

[jgerock]

Take a thin-wall 30mm 1/2" drive socket with breaker bar to rotate the engine.

If it doesn't move, then go to the next patient.

If it moves a little, then you might have a broken ring or something stuck in the combustion chamber (like birdseed, nuts and other gunk).

Pull the spark plugs and check their condition.

Pull the dipstick, look at the oil condition closely. Smell the oil then dab some on your fingers and rub to see how bad it is.

[ahlem]

Harbor Freight has a bore scope on sale for about $80. I'd at least pull the plugs and look at them if you don't go for the bore scope.

You can also tell a bit about a motor by smelling the oil. If it smells like gas you may have a ring issue. You can squirt a little oil in the cylinders before you try turning the crank by hand. If I was selling a motor I would require that rather than let someone turn it dry. If you can do a compression test by all means do one. When you turn the motor over by hand, listen to it as it relieves itself of compression one way or another. You can rotate it through 4 cylinders of compression. The seller will wonder how you know so much even if you are just blowing smoke.

[FB73tii]

+1 on all above. Suggest bring a fresh distributor cap, rotor, points and plug wires as well. You want to eliminate as many variables as possible. You likely know white film on the inside of the oil filler cap and valve cover means a blown head gasket or cracked head. While opinions on cold compression tests vary, if you can't get the engine to turn over and fire, but it will crank, it can be useful for seeing if all cylinders are about the same compression. Do both dry and wet. Reading will be much lower than a hot engine, but still useful to identify a cracked valve or hole in a piston. Suggest a leakdown test as well if you have the equipment.

Best of luck, Fred '74tii & '69GT3

[pkbinplano]

check for rods and pistons sticking out the side of the block , check for outward bulges on top of the valve cover, grab the crank shaft pulley and see if there's more than a inch of play up and down and left to right., check oil pan for holes that look exploded outwards, get back with us.

[jgerock]

If a tii, look for rodent turds in the intake

[Collinster742002]

Well, the engine looked VERY clean inside. It's been sitting since 1992. the spark plugs were the normal running fine color, the oil was still clear and smelled fine, oil cap completely dry, inside valve cover looked nice and clean, and the engine spun well by hand (could feel it building compression)

Annoyingly, there was no power going into the cabin so the ignition wouldn't work. Shorting the solenoid yielded only a spinning starter.

Guy told me not to bother with a carburetor, and when told I had a starter in my trunk he said he'd rather not...

Might go back in a week or two when he pulls the engine with a good starter and see what it's got.

Or should I just move on to the next?

Side note, this was a 72 car, but I noticed it had an E12 head. Didn't 72's have a 121ti?

[BobBreed]

my engine just sold sorry....

Bob

[SamAdams]

my engine just sold sorry....

Bob

Bet that would have been a great engine to buy. Bob is top notch when it comes to engines.

[BobBreed]

Sam,

This one was Mike's engine out of the touring.... It will continue to live in his new Baur.

Bob

[SamAdams]

Sam,

This one was Mike's engine out of the touring.... It will continue to live in his new Baur.

Bob

Bob

That is one sweet engine. I have travelled thousands of miles with that Touring while Mike owned it. The Baur will have a nice powerplant in it for sure.

Can't wait to see what you built for the Touring.

[Collinster742002]

Anyway, going to test/pick up a '75 motor tomorrow. Hopefully she's a good'un. Saw it running in front of me, in a video and have several pictures of it in the car about 8 months ago. Guy did an M20 swap and I got the transmission from him several months back.

[jgerock]

Anyway, going to test/pick up a '75 motor tomorrow. Hopefully she's a good'un. Saw it running in front of me, in a video and have several pictures of it in the car about 8 months ago. Guy did an M20 swap and I got the transmission from him several months back.

If it is an original 1975 engine, they had thermal reactor exhausts which I have read choked the life out of the engine and made them work harder.

[SamAdams]

Anyway, going to test/pick up a '75 motor tomorrow. Hopefully she's a good'un. Saw it running in front of me, in a video and have several pictures of it in the car about 8 months ago. Guy did an M20 swap and I got the transmission from him several months back.

If it is an original 1975 engine, they had thermal reactor exhausts which I have read choked the life out of the engine and made them work harder.

Good point Jim. I would really want to make sure there were no issues on a '75 engine. Hopefully by now any issues related to the thermal reactors and emission controls would have been addressed/corrected. Did the excess heat tend to crack the heads on these?

[Collinster742002]

Yes, it is a very original '75 engine, down to the pilot bearing felt seal and dust cover. All pollution crap was removed long ago, including the thermal reactor. Cold compression test yielded 150psi +/- 5 across all 4.

Car was driven regularly on the highway; oil was clean,smelled right and the block drain wasn't even clogged like all the rest are.

Taking it apart for re-gasketing.

She's a good one, thanks everybody!