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badly seized engine

Please,

I have a Gardner 3LW that has lain outside for a long, long time. I have the head off OK, but I cannot get the block to come up off the crankcase. I suspect that at least one piston is seized solidly in its liner. The engine will not turn at all.

Using wedges I have managed to get the block up about 22mm all round.

Yes, I have poured diesel into the combustion chambers and left it there for over a week.

Here's my idea: I will make a plate that will bolt unto the top of the block. Over the centre of each cylinder, I will drill a hole down through this plate. Over this hole I will weld a nut. Through the nut I will thread a set screw. This screw will pass down until it meets the top of the piston. As it tightens down it will force the block off.

I will do this simultaneously for each cylinder. Obviously I will put plates on top of each piston so as to spread the load and I will force each piston down simultaneously.

I do not care about damaging the liners, or the the pistons. All these will be renewed, but I do care about the crankcase and the crankshaft.

Is this a good idea ? Are there dangers in it ? Any other suggestions.

I make more wedges and continue, but I am worried about breaking bits off the block casting. Besides, it is painfully slow.

Thanks a lot.

Reply to
snark
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I was in a similar situation a few years ago. I broke the pistons up in the end, only way I could get things to move. Engine's still running fine with new pistons & a re-bore.

If you can't be a good example, then you'll just have to be a horrible warning.' Catherine Aird

Reply to
Duracell Bunny

I've heard lots of good reports about Diesel being a good penetrating oil, but for my money nothing beats Plus Gas.

Mostly though, IMHO you have not left it nearly long enough. Any penetrating lubricant needs time to work & a week isn't enough.. Heat and cooling cycles are important too, so a good gas torch to get it all nice & hot followed by clouds of smoke as you douse the pistons in old sump oil then take a turn on the jack screws, shut the door & walk away! Repeat as necessary ...........

regards,

Kim Siddorn

Reply to
Kim Siddorn

What about hardwood blocks, with the grain vertical, 1/2" or so longer than the piston/head space, tighten the head down onto them? Then when you've moved things a bit, head off ,add some packing & repeat. As Kim said, more soaking first. An impact wrench on the head nuts would speed the job up no end. Hydraulic rams under your plate would be better than your jacking screw, but not something you can make at home.

Tim

Reply to
Tim Leech

Another thought about your 'plate' is that it won't take much point force to distort a plate unless it's very thick, then it'll probably bind onto the studs and you'll have a different removal problem. Some sort of beam across the studs would be better from that point of view.

Tim

Reply to
Tim Leech

instead of trying to remove the block, extract the pistons by removing the big end bearings and easing the pistons down and out one at a time. this is what I did with a sized up Lister FR. The liners where impossible to pull so I lapped the old ones and ran at that.

Reply to
vic the barge

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