Engine Locked Up

[69 C10 LWB]

I just bought a 65 C30 knowing the engine was locked up. I have a spare 350 I can drop in but Id like to get the 230 running if at all possible. The guy I bought it from had dumped some tranny fluid in the cylinders. I have sprayed Seafoam Deep Creep into the cylinders 3 days in a row now. Yesterday I changed the oil (using spare oil and a filter someone gave me) and primed the engine with a drill. I had oil come out of a couple pushrods and the drill built up some torque so I know it was pumping. The top of the head is clean and I stuck a bore scope in the cylinders and they look good. I tried to bar the engine over through the starter hole but no luck. Then I decided to give it a little more incentive. I pushed the truck with a track loader and let the clutch out slowly. When the clutch grabbed it drug all 4 rear tires. I think this engine may be a lost cause but I still have a little hope.

Does anyone have any suggestions on other things I can try? My next step is to yank the engine and pull the pan off but there's a good chance when that happens the 230 wont go back in.

[62chevy302]

Have you tried rotating it the over direction? Like counterclockwise?

[65c10restomod]

did you try it with spark plugs removed

[69 C10 LWB]

Spark plugs are out and I’ve tried both directions.

[andyh1956]

Take an old spark plug & weld a 1/4" fpt coupling to it. Then screw in a grease fitting & install into a cyl that (Use your best guess here) you think may be stuck. The remove the rocker cover & remove the rocker arms so as to close the valves. Pump that cyl full of grease. You may have to try multiple cyls 'till you find the stuck one. When it lets go you'll know it!
Hydraulics works wonders!

[Warrens69GMC]

I had a stuck engine and I did the transmission fluid trick. I put a 4ft cheater bar on 1/2" drive breaker bar and rocked the engine one way the the other, applying more force every third time or so. I did it for 20 minutes per day. At the 3 day mark, it finally started to move, like 1/64" inch. The fourth day, it was free.

[Macdaddy1]

I just did the exact same technique as Warrens69gmc on my 5.3 ls motor that had been sitting for some years and it finally came free.

[69 C10 LWB]

Im going to give it a few more days but if it isnt free by wednesday Im going to start prepping the truck for my spare engine. I parted out a truck that has been in the family since 73 and I almost feel guilty even trying to get the 6 free when my spare engine has so much history with it.

[Pontiacgurudan]

Remove the rockers, take the Schrader valve out of the hose for a compression gauge, screw it in a hole, and hook it up to your air compressor. Let it sit with pressure for a day then try another cylinder. It will force the tranny fluid down into it and most likely break it free when you hit the right cylinder. 100psi across a piston works out to quite a bit of force. I've broken free many very old motorcycle engines this way and more than a few old cars and trucks.

[vince1]

I know it seems like a remote possibility but I actually cracked a Mercedes 6 cyl aluminum head with shop air of 185 psi in the cylinder when doing a valve seal change. The welder at work fixed it and the machinist took it down with a flat file. In that shop the compressor ran almost continuously. After that I changed all their leaking fittings and brought it back to about 150 psi.

If the seized piston is half way up your chances should be good. Even if not then using the one with a piston close to 1/2 way up should turn the crank.

Good luck with it. Even after you get it running there is nothing stopping you from putting in the bigger engine. 230 is a little small.