dre

I have a 455 thats locked up and will not turn over. I've managed to get the #1 & #2 pistons out, removed the lifters and the cam. What can I do other than have the machine shop remove the rest? I've been trying to cut cost if/when I can and I know they will charge me to tear the motor down.

MDchanic

"Locked up?"

You mean seized? Due to rust, overheating, some other cause?

Or some mechanical failure while driving?

Are the heads off? The oil pan (I assume it is if you got to the bearing caps)?
What's inside?
Do you have all the bearing caps off? Is the crank out?
Next step if it's rust is to soak the rings in KROIL or similar for a week or 2, then whack pistons with the biggest sledge you've got. Tap out the ones that free up, then go to work on the one that's really stuck.
If they're rusted in there that bad, there's no saving them anyway, and you'll need a rebore, so just get violent.

- Eric

jensenracing77

you may have to brake them. just don't hurt the rods, they can be reused. try not to smack the cylinder and make it have to be bored farther than what it would need to otherwise. how hard were the lifters to get out? they looked crusty but didn't think they would be to bad to get out. i did figure you would have to brake a piston or two.

jensenracing77

with the block up side down, i take a steal rod or pipe and put it on the bottom of the piston and start taking out you frustration on it. you don't want to do this on the stand. i have it on a piece of plywood on the concrete floor when i have to do it.

dre

The lifters weren't that tough to get out. They were actually pretty clean on thi insides. I've broken one for the pistons I guess I should continue. The issue is, that I'm able to get to the # 4, 5 & 7 but they wont come completely out. I try to break the pistions. Everything else came off pretty easy. There is about 2-3 connecting rod bolts I cant get to and it seems it needs to be turned in order get to them.

joe_padavano

Two words:

Ridge reamer.

dre

Joe, what is Ridge Reamer?

citcapp

On an old engine very often there is a ridge at the top of the cylinder bore and the rings catch on the ridge when you try to take the pistons out. Go to this link http://mgaguru.com/mgtech/tools/ts311.htm

J-(Chicago)

You guys are breaking my heart.

Always ridge ream before removing pistons on an old motor. They should slide out of the bores with the push of a rubber mallet wooden handle and some light palm whacks.

If they don't move, it's because something is hanging them up.
Don't beat them out, have patience and soak them, or use electrolysis or something.

This is why I can't find any good Hi compression pistons. Everyone has ruined them all by beating the **** out of them.

jensenracing77

lol, this block was rusted pretty bad on a couple cylinders. a couple i think are stuck because of that. i had some in the past that no amount of soaking got them loose. i sanded, soaked and everything you can imagine. i just had to brake them. when i sold this one to him i figured that would happen. but yes, if they are stuck on the ridge at the top you need a ridge reamer. he soaked them when i dropped it off. this engine was locked up 10 years ago from sitting outside.

dre

I'll just bite the bullet and have the machine shop tear the rest of it down. I got further than I expected to. 2 of the 8 pistones out and the cam.

dre

It doesn't seem to be the ridges. I cant get the crank to turn not even a little bit. As I tried to tap out the #4, 5 & 7 pistons, the connecting rods start touch the block so I left them alone and soacked the crank, and cylinders in PB blaster.

Oldsmaniac

I know what you are up against.... The 400 I bought recently was locked up due to rust. Only a few pistons were stuck and one by one I got them out except for one. I let a concoction of solvents sit atop the piston and then hammered on it and had a bar on the wrench to turn crank. It was tough but got it to go. Yeah if the crank is not in the right position the piston/rod assemblys wont clear the block to remove. It can be a fight!

dre

any other suggestions will be greatly appreciated as taking it to the machine shop will be the last resort. I've also red that filling the cylinders with diesel fuel works as well, feedback anyone?

Rickman48

I've used Marvel Magic Mystery Oil - let it sit 24 hrs!!
Also Chrysler makes a good product for the exhaust crossover valve lubrication - [too early - old brain can't think of correct name!] if they still make it!

joe_padavano

If the problem is actual rust on the cylinder walls, everyone has their own favorite penetrating oil that they've used to soak the rings. In my case it was WD40, though ATF, diesel, and other concoctions all seem to work. The real trick is to soak the rings over a period of weeks then regularly try to move the crank. In my case it took filling the cylinders with WD40 (I bought a gallon can from Tractor Supply) and trying to turn the crank every couple of days.

In the case of badly rusted bores, people have actually ground out the pistons, freeing the rods and allowing them to be saved before removing the remains of the pistons.

dre

Thanks again everyone but I've surrendered and sent "The Beast" to the machine shop.....