Stuck piston on engine teardown

[Halstead666]

I am tearing down my 5.7 as crank would not budge......water got in cylinders over winter......turns out exhaust manifolds failed as I put it away last winter. I currently have the block on a stand got 3 pistons off without moving crank but #4 piston will not move after many attempts. I have PB blaster in the cylinder overnight and will attempt again. Any other suggestions on how to unstick it?

 

[Scott Danforth]

a 5# fist maul and a section of oak 2x4. piston is shot anyway, so remove it forcibly. First, hammer from above, then once it starts moving, hammer from below (on the piston, not the con rod), with the tear down you will be re-boring and honing all the cylinder bores, replacing the pistons and continuing with a full rebuild.

 

[Halstead666]

Thanks, I was hoping the PB frees it up or someone had another product or idea on how to free it up without too much force as I'd like to salvage it if possible as the others look good.............but will go at it once again

 

[Bondo]

Ayuh,.... Welcome Aboard,.... The cylinders will probably need a .030 overbore to clean 'em up, so none of the pistons will be any good to ya,......

I'm with Scott, only I'd grab the nearest chunk of ole 2x4 framin' lumber, 'bout 18" long, 'n start beatin' it with my converted 15# BFHammer,...

If that didn't work, I'd break out the 20#er,....

Ya oughta check out buyin' a Long Block Crate motor,...

They're many times, cheaper than you can get yer's rebuilt for locally,.....

Just swap over all yer marine accessories, drop it in, 'n Go Boatin',.....

 

[Scott Danforth]

once the cylinder bore is rusted, it has to be re-honed. there is no salvaging the pistons, as you are now into over-sized pistons.

 

[flipbro]

Grab a crank socket and johnson bar spray piston bores with pb blaster and try working the crank back and forth. Hopefully she will loosen up.As mentioned you will need a bore after words..

 

[Bt Doctur]

want a short block not frozen for free pm me . central NJ

 

[Fishermark]

Like mentioned above, the chances of not needing to bore out the block are slim to none.

You can get a rebuild kit for about $230 from Summit Racing. Includes pistons, etc. (Not sure what year of 350 you are working on).

Or you can get a complete engine for about $1,500.

Have you checked with your local machine shop on what they charge for boring the block?

 

[rob 135]

don't use crank bolt to try and free up . Some moron snapped my bolt off in crank ,and not sure how to get out.

 

[FreeBeeTony]

Build a Stroker!!!

 

[flipbro]

don't use crank bolt to try and free up . Some moron snapped my bolt off in crank ,and not sure how to get out.

That's right. That's why I said Crank socket. You need a drill and easy out..

 

[rob 135]

yes I was thinking drill and use good easy out . then heat slightly to soften locktite on bolt. then cross fingers for luck ...

 

[Halstead666]

Thanks for the responses, I live in WA so NJ free will not work (Thanks) Well I got that one out after a couple more hrs and lots of oak and the bore looks good. My problem now is that I got 7 of the 8 out without moving the crank as it is still stuck with the last piston. This last one I can only get one side of the rod assembly off the crank......I have all the bolts and bearing assembles off the crank so the only thing keeping me from removing it is this one bolt on the piston rod. My current thought is to cut the rod arm off which I can access or try pushing the piston back up the cylinder but this one is also very stuck. Which is my best option if you had this situation (besides get a new engine)

 

[flipbro]

What are your plans when u get it all apart?

 

[Halstead666]

looking at a rebuild kit from summit racing .......marine gasket set etc

 

[Rick Stephens]

Thanks for the responses, I live in WA so NJ free will not work (Thanks) Well I got that one out after a couple more hrs and lots of oak and the bore looks good. My problem now is that I got 7 of the 8 out without moving the crank as it is still stuck with the last piston. This last one I can only get one side of the rod assembly off the crank......I have all the bolts and bearing assembles off the crank so the only thing keeping me from removing it is this one bolt on the piston rod. My current thought is to cut the rod arm off which I can access or try pushing the piston back up the cylinder but this one is also very stuck. Which is my best option if you had this situation (besides get a new engine)

Is it positioned to where you can drive the stud through and off the con rod? What would happen if you drove the piston down, instead of up? Could you get the con rod bearing off and get the crank out?

 

[Halstead666]

If I drive it down I think I might damage the crank as there is still one nut on the bearing assembly holding the rod to the crank. I guess unless I pry from the one loose side

 

[Rick Stephens]

If I drive it down I think I might damage the crank as there is still one nut on the bearing assembly holding the rod to the crank. I guess unless I pry from the one loose side

Drive the piston down, which will turn the crank and give you access. Don't destroy a con rod for nothing, too easy to trash the crank at the same time.

 

[Fishermark]

Connecting rods are expensive. The kit I mentioned already includes the pistons. Do what you need to do to only destroy the piston itself. I personally would not be afraid of really hitting it hard with a block and hammer.

 

[Scott Danforth]

A complete stroker kit is $1200 (pistons, crank, rods, etc.)