How to check engine that's been sitting

[gjk5]

Want to find out if this engine is worth any effort:

I have a parts truck ('72 K5) that has a recently (3-4 years ago) rebuilt engine and has been sitting for a while. When I bought it the PO had it out in a field. Supposedly only has 500-1000 miles on it and it looks pretty decent (no leaks/oil in compartment). It was sitting with no hood or air cleaner over the carb and a tarp loosely over it. I pulled the carb and there is a little surface rust down in the intake manifold, pulled the valve covers and everything looks nice there, pulled the plugs (looked OK) and turned it over by hand, seemed to turn over OK but with some resistance (but this is the first time I've tried this so I have no idea what it should feel like).


What else should I check and what should I be looking for?


I got the suffix code off the front of the block (CMJ a '75 145 HP) and the head codes ('74-'80 76 CC is all it said), doesn't look like anything special, the engine in my other '72 is just leaking like a sieve and probably has the full 105K miles on it.

 

[diesel4me]

probably fine..

It may have some surface rust in the cylinders from condensation,but if you were able to turn it over by hand and it didn't feel like it was binding up or anything,I'd say just start it up,I doubt there is enough to hurt anything if you can spin it by hand.. (after making sure the oil is full and clean,not milky from condensation),and let it run slowly for awhile until its warmed up--you'll know right away if it has any stuck or sticky valves,it will skip or misfire..after its warmed up you could do a compression test and see how much it has..

I woke up many engines at the junkyard that sat for years,and were seized!--had to dump oil in the cylinders and use a pry bar on the flywheel to coax them loose--after I got them to turn over,started,and let them run awhile,90% of them came out of their coma alive and well!--some spun a bearing or smoked like chimneys and never stopped smoking,because the oil was diluted with water and sludge..more of them would not have blown up if we changed the oil first I'd bet..

I usually can tell by listening,and seeing if any blue smoke comes out of the exhaust to determine how good the motor is (one thats sat a long time may smoke for quite a while though--sometimes it takes driving it a hundred miles to loosen up the rings if they were stuck in the piston grooves..) Many old engines I woke up took a long time before they stopped skipping,and the valves and rings freed up enough to stop smoking..the longer we ran them,the better they got..

 

[down4thakrown]

dunno if its posted above, but a compression check will tell u somthing too.

 

[3 on the tree]

How does the oil look? If it looks like a choc shake, it has water in it (BAD). Is there anitfreeze in the rad-if so, how does it look? Personally, I"d throw a battery in it and see what happens, just leave the coil unplugged, crank er over to get the oil circulated, then plug the coil in, fill the carb with fresh gas and hit the key.

 

[cybrfire]

Got an old truck out back that has been sitting the last 5-6 years. Got it off an old farmer for 100 bucks. bottom of the gas tanks had fallen out years ago so we dropped a fuel line into a 5 gal. can and fired it up. Runs like a champ. I say crank that sucker up!!

 

[gjk5]

Checked the oil, looks OK (not milky or anything), can't just start it up unfortunately; no battery, ignition's not hooked up, fuel lines unhooked, no radiator, and I'm sure lots of other issues too. This K5 was included as a parts truck, it was the PO's prev. truck and he bought the yellow one (which I'm driving) and I think just started pulling stuff off of this green one to put on the yellow.


Did find some info on the yellow truck's engine though, it's a '69 "Hi-perf block" (suffix: HN, website said 300 HP?), still haven't pulled the valve cover to check those heads nor can I get to the back engine #'s.

I think I may swap the engines and then see if the yellow engine may not be a better builder in the long run, and just use the engine from the green one in the meantime so I can drive.

Maybe I'll post some pics later.


Thanks again guys!

 

[diesel4me]

300 hp 350?...

I had a 69 350 with 4 bolt mains that came in the Suburban that I used the 4x4 chassis from to put under my 72 chevelle wagon I had years ago--I put a 454 in it instead--the 350 was a 300 hp version,and it went pretty dam good for a stock small block!..but it was a smoker so I swapped in the 454 out of my brothers rotted 73 Impala --

The 350 sat in my garage until last year,I sold it to a friend for his 62 Nova--its all rebuilt now,and runs stronger than ever!--that friend had to sell the Nova to move into a new apartment,another guy I know bought it and still has it..he had to put one rod bearing in it,it never hurt the crank though(I think the first owner over-revved it too much!)..

I like the older 350's,they ran a lot stronger than the ones after 1973 did..I never had any trouble with the valves,a lot of guys said unleaded gas would eat the valve seats,but I never had any problems..I'd definately keep your 69 motor and freshen it up!..I would have kept mine if I hadn't needed cash,abd I had nothing to put it in anyway at the time..

 

[3 on the tree]

If it is a HP block, I would bet on it being a 4 bolt main, esp given the vintage. Every HP block I have opened up (20 or so) had the 4 bolt mains. If the heads are orig, they will need hardened seats installed during rebuild. The last 300/350 I had was in a 69 4 door Chevelle when I lived in Texas. That blue beast sure surprised a bunch of pony cars. It would SMOKE the tires with no power braking or anything. I gave the car to my steepdaughter and she totaled it after about 2 months. I then put that motor in a 84 longbed S-10. That truck was almost dangerous, but alot of fun. At your altitude, I think you can even run 89 octane it and not hurt it. In Texas, I had to run 90 octane in mine to keep it from pinging when I jumped on it.