Thread: Can you remove and replace a piston from a 350 from the bottom

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I'm in a dispute with a local machine shop owner that rebuilt a short block for me from a 89 K1500 4wd truck. I finished the engine out and installed it. When I fired it up after priming everything of course I discovered it had a knock and the oil pressure dropped off to nothing when stopped at a light after warming up. I took it back to him and he checked it over after many go rounds I took him to court. He showed up with a piston with a screw mark in the top of it saying a screw worked it's way out of the throttle body butterfly and into the engine. Now this might explain the knock but not the loss of oil pressure. I asked if there was any head damage. He said he couldn't tell since he didn't remove the head he took the piston and rod out from underneath without pulling the engine. Is this possible? I don't see how he could have gotten it past the crank. If he removed the crank from underneath is there enough room to get the flywheel clear of the torque converter? Assuming he did get it out would he be able to get a new piston back in without cracking a ring? Is this really the best way for a professional shop to do this?
Needless to say after court I went to pick the truck up and it still had the knock and loss of oil pressure. He claimed he forgot to tighten the torque converter bolts, another time it was bolts on the 4wd were missing and it was banging. Now we're going back to court and I'd like to dispute what he said originally as I don't think what he described was possible. I should also mention when I took the throttle body off there weren't any screws missing nor could I tell where one had been replaced.
Thanks for your time and advice.

Mcgyver

You know, I've never tried to pull a piston and rod out the bottom of a SBC motor, but I would not think it's possible. Why do you keep doing business with Houdini Motors anyway? Not sure where you are, as there are many Georgetowns, but if you're in the Washington, DC area, there must be scores of shops in the area who would be more trustworthy.

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It is not possible (at least not in one piece), as it hits the block webbing, a buddy and I just went over this on a sbc. Not only is it impossible to get out the bottom, the bottom of the cylnder is not square so there is no way to use a ring compressor to install a new piston. I agree with Tech, you can't win arguing with a idiot who lies. I am not sure about Georgetown either but where I live something like this usually comes down to a whippin' of some kind (if you know what I mean) and never gets to court. Sorry about your problems

If you go back to court take a clean salvage block on an engine stand, with a piston & rod installed and the head bolted on as Exhibit A, and ask him to demonstrate how he pulled the piston without removing the head.

Welcome to the forum, BTW, and sorry that you're having difficulties with the Ohio shop.

Take a look at these pictures and see if you think you can. In my experience, no - and believe me, I have tried it in the car without removing the heads or the crank; it don't work even with the crank out.

http://home.koping.net/u3243a/images...s/DSC01323.JPG

http://i.ebayimg.com/images/i/110890...-1/s-l1000.jpg

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Wowzer - the only way I know of to take a piston out of the bottom of a SBC is in pieces - lots and lots of little ones....

Intact - can't be done. Like others have already said, this clown is pulling your chain and needs to be called out and then legally disciplined.

Good luck with this,
Glenn

Originally Posted by Rrumbler

Take a look at these pictures and see if you think you can. In my experience, no - and believe me, I have tried it in the car without removing the heads or the crank; it don't work even with the crank out.

I've seen some reference to being able to get #7 piston out from the bottom, but none of the others. Not sure if that's right or not, but there are several places on different forums that say it's possible.

X2 on the short block demonstration in the courtroom. You could have it clean, all bolts finger tight, have a rubber mallet and ring compressor on hand. Be sure to point out that it would be easier on the engine stand than in the car. Thus, if he can't do it in court, then he certainly can't do it in vehicle.

Tom,

Plenty of quality shops in North Carolina, I'm betting you have at least two or three that would testify in court as to the validity or lack thereof in regards to the statements of the other shop owners claims.

Bill S.

PS: No reason to not use your proper location when posting on this site, as we are here to help, not hurt you.

Originally Posted by mcgyver01

I'm in a dispute with a local machine shop owner that rebuilt a short block for me from a 89 K1500 4wd truck. I finished the engine out and installed it. When I fired it up after priming everything of course I discovered it had a knock and the oil pressure dropped off to nothing when stopped at a light after warming up. I took it back to him and he checked it over after many go rounds I took him to court. He showed up with a piston with a screw mark in the top of it saying a screw worked it's way out of the throttle body butterfly and into the engine. Now this might explain the knock but not the loss of oil pressure. I asked if there was any head damage. He said he couldn't tell since he didn't remove the head he took the piston and rod out from underneath without pulling the engine. Is this possible? I don't see how he could have gotten it past the crank. If he removed the crank from underneath is there enough room to get the flywheel clear of the torque converter? Assuming he did get it out would he be able to get a new piston back in without cracking a ring? Is this really the best way for a professional shop to do this?
Needless to say after court I went to pick the truck up and it still had the knock and loss of oil pressure. He claimed he forgot to tighten the torque converter bolts, another time it was bolts on the 4wd were missing and it was banging. Now we're going back to court and I'd like to dispute what he said originally as I don't think what he described was possible. I should also mention when I took the throttle body off there weren't any screws missing nor could I tell where one had been replaced.
Thanks for your time and advice.

Mcgyver

First, it is kind of an aggravation to remove the pan in a 4wd with the engine in the truck (especially if it is the newer body IFS truck) let alone to remove the piston from the bottom. It sure sounds like he is making stories up on you. X3 on the court room demo. Good luck with it.

Not hiding I have homes in both... although you are correct the shop I'm having problems with is in Wilmington, NC. However, I spend most of my time and most of my vehicles are in Ohio.

Any thoughts on the screw falling out of the throttle body butterfly? I was looking at them today and they look very small and almost hammered on the back side. Kind of like an style rivet hammered on the thru side.

Originally Posted by mcgyver01

Any thoughts on the screw falling out of the throttle body butterfly? I was looking at them today and they look very small and almost hammered on the back side. Kind of like an style rivet hammered on the thru side.

IMO a screw that small might bounce around a bit, but it doesn't have enough mass to cause any impact damage, and it very likely would get blown through the open exhaust valve and get trapped in the Catalytic converter.

And yes, that screw is "staked", like a rivet, it is almost impossible to get them out without breaking... I can't say I've ever seen one come loose on it's own.

You can get a piston out the bottom of #8
You can get it out of number 1 if bore is oversized and/or front main boss is trimmed a bit----