Getting a seized piston out of a 460.
Asked by Qc_pepsi Sep 19, 2020 at 11:47 PM about the Mercury Meteor
Question type: Maintenance & Repair
Hey guys! I have a 1974 460 from a meteor. I am in the process of rebuilding
the engine but hit a bump and i need some help. The engine is completely
stripped apart. The only remaining things are pistons 1 and 3 which are
completely seized up. So far I tried filling the cylinder with penetrating oil and
let it sat for 3 days giving it a couple of fair taps with a sledgehammer and a
2x4 every 24 hours to no avail. I then proceeded to do the same thing with
some metal rescue over the course of 5 days but still nothing. Tonight I tried
putting about an inch of trans fluid mixed with gas and a rag in the cylinder
and set fire to it. it burned for close to 1/2 an hour. I then took back the
sledgehammer with my 2x4 but the darn thing just won't budge. So, my
question is. Do you guys have some tricks that could get me out of this one?
Thank you!
10 Answers
I am having my doubts that the engine will be rebuildable without sleeving it. Did you try knocking them out the other direction?
Yes, tried both ways. the engine hasn't run since 1982 and after taking it apart this is the best- looking engine I ever saw (apart from the 2 pistons.....) So yea it would really be a shame to have to sleeve it.
ok, I don't have diesel on hand but yea il go get some tomorrow and try it. I really wanted to save the cylinder but yea... I'm probably gonna have to get used to the idea of sleeving number 1 and 3 :(
I don't know how much you can bore a 460 but keep in mind that boring it out a lot is a bad idea as it weakens the engine and under full throttle the cylinders will warp and create a lot of blowby. You should aim to keep the bore no more than +0.030.
yea, unfortunately, I don't have any ''renowned'' machines shop where I'm located and the rare time I went to them for help they ended up screwing things up even worst... a real shame. I know this may not be the best information but I remember watching a show about some guys stroking (and boring) a 460 to something like 570 if I remember so boring it doesn't scare me too much
Here is a 500hp build for you. https://www.hotrod.com/articles/build-a-501-inch-ford-big- block-stroker-that-makes-590-lb-ft-of-torque/
Automatic transmission fluid or Marvel's Mystery Oil is good for freeing up a seized piston. But you need to let it soak for two weeks, minimum. Hope that helps! Jim
You are better off buying a different engine or even a new aftermarket block. You will probably save money in the long run.
This is the original engine so I don't really mind giving it a little more elbow grease and money to get it back in the car. Bought some acetone, I'm gonna mix it with trans fluid and give it a try. Saw a couple of forums talking about this, claiming decent results. I wanna get this done before it starts snowing so I still have a good month and a half in front of me.
Hey hey! Was able to get both of the pistons out of the engine today! I ended up taking a 4x4 and trimmed the edges so it would fit snuggly into the cylinder went to town on it with the hammer and it finally gave up. Unfortunately, I did crack one of the pistons but on the other hand, the cylinders are in much better condition then i was expecting so I'm happy!
