engine seized

[timetraveller]

hi all
i have acquired a free 1100 engine to rebuild,the trouble is its pistons are seized solid in the bores
i have dismantled the top end and removed the sump which was 1/2 inch thick with gooey black tar oil
i have poured oil down the bore holes and will now leave it to soak
the front starting nut is seized and so is the flywheel and cam
any tips to get it moving again or is it another boat anchor
cheers
neil

[bmcecosse]

There's always hope..... Put diesel fuel oil down the bores and leave to soak - possibly for several days. Starter dog - you will just have to be brutal - but try not to bend the end of the crank! Then you can undo the big ends and the mains (note carefully what goes where - mark them..) and remove the crank.

[les]

Penetrating oil down the bores might be a better option. Maybe it had already been a boat anchor!

[robedney]

I've heard that Coke works (it being best to use the diet variety) but never tried it. There is some science behind it (Coke drinkers note; phosphoric acid is a listed ingredient in Coke). Also, carbon dioxide (the bubbly part) makes carbonic acid in water (which reduces iron oxide, aka rust). The other thing is that Coke is thin enough to really penetrate. You can also try 1/2 automatic transmission fluid and 1/2 diesel or kerosene. That combination actually makes a pretty good penetrant. The trick is patience -- don't rush it. Take enough time with it and and the pistons will break free. I -- for one -- would be very tempted to try the Coke approach!

[sirrom]

I have used diesel to free up a seized 1098. It was seized as it had sat for a long time without being turned. As the diesel disappeared I topped the cylinder back up again, did it over a period of time. Turned out to be a std bore and crank had hardly any wear. Just be patient and keep the diesel in the bore and it will work.

[timetraveller]

i currently have a mix of wd40 and transmission fluid in the bores and im gonna leave it until saturday
if it doesnt shift then i have a plentiful supply of red diesel from work
would this do the same thing as standard diesel or does it have a different make up
i have heard about the coca cola thing before but only for shining pennies up and cleaning i dont think its a heavy rust eater
it would be interesting to know from other members of their experiences with coke

[bmcecosse]

Put the red diesel in......

[les]

I have heard said--things go better with coke.

[brucek]

Apparently, it's the real thing

[mike.perry]

Drink half the can, have a good belch and pour the rest in the engine

[robedney]

I say try the Coke! How will we ever know if it works unless someone tries it??? Think of it as science, for the betterment of humanity. This could be big -- we could relabel the stuff and sell it to the government.

[StaffsMoggie]

I have never known anyone free off a seized solid engine by gentle means. Place a block of wood on each piston in turn and hit it with a beefy hammer. Eventually you will free up the pistons and can carry on dismantling the engine ready for machining.

[les]

If you are going to resort to that type of treatment, I would suggest using a cylindrical piece of timber large enough to make contact with the circumference of the pistons otherwise you might hole them.

[bmcecosse]

Do that ONLY if you don't mind smashing the piston rings and pistons!

[customjob]

Strangely i've just embarked on a similar project myself, it's 1100 engine from a MK II Healey Sprite. I found to use the seized cylinders to an advantage, by using it to offer resistance in removing dog nut, cam nut and fly wheel. To free off my pistons i used Rob Thomasson's advice in this issue of Minor Maters put some oil down the bores heat up a peice of metal (really hot, bright red hot) and place it down the bore. I've heard of it being used many years ago when i was in the motor trade, but have never done it myself until yesterday, two came out with a little tap from a rubber hammer, one came almost out using a hard rubber drift but the skirt broke 3/4's of the way out, the last one was an absolote s** resorted to breaking it out. QUESTION is. As i have to now replace pistons would a standard set of 1275's fit the standard bore of a 1098 ? Or is that being daft.

[bmcecosse]

That's being daft....... Your block will need boring anyway ! What on earth was the redhot wire supposed to do????? The oil did the trick - but red diesel would have been better.......

[customjob]

The red hot piece of metal heats the piston so it expands in the bore then as it cools the oil is thin enough to seep down between the piston and bore wall. thats the theory anyway. thanks bm thought i was being daft, any NoS standard 1098 pistons kicking around your workshop preferably with dished crowns?

[bmcecosse]

With the pistons seized in the bores like that - it WILL need reboring - so you will be needing oversize pistons! The 1275 engine is a very much modified version of the original A series - so there is no hope of fitting 1275 pistons to a 1098. I can't see a red hot bit of wire putting any significant heat into an aluminium alloy piston!!!!! It will set the oil on fire - maybe that's supposed to help!

[MarkyB]

The red hot wire thing sounds like something I heard about for cutting a bottle.
Like Roy I can't see it transmitting any significant amount of heat , if it was a big lump of metal, maybe it would do something.

[robedney]

To be fair he did say a piece of metal, not a wire. I can see this perhaps working -- or at least helping -- if the chunk was large enough and hot enough. It's easier to use a heat gun, all-in-all. I've done that (heat gun) with a good penetrating oil, several cycles of heating/cooling and an abundance of patience. It was a Detroit Diesel 8V71, and I had no desire to replace the liners. Just removing the heads took a chain fall rigged to the overhead. Of course -- if ever I again confront this -- make mine Coke!