Just got a 401 Nailhead that had been sitting for awhile and one piston seems stuck due to some rust. I will probably have to sleeve that one cylinder but my question is...if the thing wont move, what are my options to get that piston out? Anybody ever cut a piston up to get it cleared?? thanks in advance.
Start by soaking it with a lubricant. I like Marvel Mystery oil. Have not tried Kroil of similar products.
Soak it with penetrating oil . Marvel Mystery Oil, Kroil, Liquid Wrench, PBBlaster etc. Soak the top of the piston. Let it sit. Everytime ya wander by it, give it a squirt. Don't even try it for a few days, have patience . Good luck. JIM
Kroil. Get it on both the top and bottom of the cylinder. And keep applying it. Then use a wooden 4x4 block on the top of the piston and whack it. Then use a 2x4 against the rod and whack it. Go back and forth and keep adding Kroil. It should move, but you need to be patient. Do your best to stay centered while striking.
ahhh.....patience....funny how I have plenty for everything else in my life but little when it comes to wanting to get things done with my cars. Okay, I will give this nailhead all the love it needs. thanks.
In worst case issues I have drilled a bunch of 1/2 to 3/4" holes in the tops of the Pistons until I had enough holes that beating on them with big blunt end punch and ball peen hammer made them collapse some and break loose from the cylinder wall. I have saved many a Block like this and never cracked a cylinder wall. This 1 hour or so processing can save you from days of soaking and still getting no where!
Thanks. this is the experience i was hoping someone has had. I will do the soaking but not for forever. thanks.
The piston is not really going to survive, so drilling it out probably isn't a bad idea, but I would still do the soaking thing to help release the skirt from the bore
Soaking from the top is necessary but after doing so and after a little time I flip the motor over, level the block relative to the problem cylinder, and fill the cylinder with penetrant as far as the cylinder skirt will allow. Then, I use heat, MAP gas will work, applied from below on the piston top to encourage the penetrant to travel. I usually heat the piston top until the penetrant begins to give off a little smoke and there will be bubbling from around the piston. I have had great luck with this method. I do this after removing the crankshaft to get better access. When the piston starts to move I flip the block and catch the penetrant in a drain pan so I can store it in a labeled container to use again and again. Tom
Real MAPP gas hasn't been produced in a decade. What they sell now is "MAP Pro", and it's not the same and not as hot. However, it will probably be good enough. I had a batch of Oldsmobile 425 and 455 engine cores I bought from a guy who stored them in a shed with no door. Mice lived in the cylinder bores. Mouse-piss on the cylinder walls did a great job of seizing the pistons. I just beat them out with a big hammer and a long 3/4" punch. If I were doing it again, I'd have warmed-up the pistons with a torch.
I had my DNA tested and I do have some Neanderthal in me...I tap into that DNA and hammer the ef out of them... not a recommended route. My 350 from 69 3-speed had every piston rusted in place. Saved the block. My wagon (425) had one that was really stuck and that came out in bits and pieces.
My dad always poured brake fluid in the cylinders and would tap it every so often.More times than not,it would work.I still use the same method on stuck mower engines..
Try sanding the cylinder walls w/ 80-100grit and PB blaster. Has worked many times for me. It it's from the bottom of the ocean, break the piston. Fastest-easiest
I suggested currently available Map gas (why would I reference something that is no longer available??) because I assumed he might want to save the piston. I removed all 8 frozen pistons from an Olds 394 a couple of weeks ago with no damage to the pistons using the method I described. I wouldnt use a torch on an Al piston, at least not if I was considering saving it, because Al is not as forgiving as steel and by the time one realizes the Al is about to turn soft it is too late. I have 40 plus years as a pro tech (retired now) and after decades of providing advice to various club`s members I learned to never assume whoever I am giving advice to has the same level of experience/tools as a pro. If they did they wouldnt be asking for advice. So I tend to err on the side of caution when giving it. The Map gas works well for the process I described. Tom Mooney
Please note that with my procedure I posted if you go up to a 3/4" drill bit your gonna need a big 2 handle type drill motor if you don't want to break your wrist!
