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By peeeot - 13 Years Ago
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I recently acquired a new y-block project, a '57 Fairlane 500 with its original 312 4-bbl and fordomatic trans. It stayed in the same family since new and racked up 84k miles. The car hadn't been driven since the 80s, and not cranked in at least 5 years at the time of purchase. The 312 was stuck.
I tore the engine down in chassis until it was apparent that cyl #8 was the holdup. There was a skin of surface rust on the cylinder wall. All of the other pistons came out easily and are in excellent condition. The rings retain their chrome plating. It is clear that I am the first to tear this engine down. After much chemical soaking, I had to take a light ball peen hammer to piston 8 to get it loose. Once it moved about 1/3" down the bore, it moved easily, and I was able to clean up the cylinder wall and remove the piston.
There is one patch of pitting in the cylinder wall about 3/4" wide by 1/4" tall. I don't know how deep it is but it's enough to feel with my finger. It's located close to halfway down the length of the cylinder bore, which should be in the lower half of the ring travel (I can take a measurement if it would be helpful).
Currently the engine is out of the car, the block is stripped down ready for cleaning, and I'm trying to decide what to do with it. The car is rough cosmetically and pretty much needs everything; ultimately I want a clean-looking driver. I don't think I'm ready to drop $2-3k on a full rebuild at this point, but if a thorough cleaning and refreshing with replacement of obviously spent parts won't yield a decent running engine then I may be willing to consider that road.
I have 2 questions:
1. Does it sound like the pits are bad enough to noticeably spoil engine performance (smoothness, smoking)?
2. The hammer left its mark on the stuck piston. Assuming it isn't cracked, can it be reused?
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By slumlord444 - 13 Years Ago
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My educated guess is that if you honed the block and re ringed it, you may get a small amount of blow by on that cylinder, but not enough to realy cause a problem on a street engine.
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By PF Arcand - 13 Years Ago
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Sounds like you need to do substantial work to the car before the engine will be needed. Not much point in fixing the engine to have it just sit there for a long time. Something to think about...
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By Ted - 13 Years Ago
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A sleeve in the pitted cylinder would be the least inexpensive fix but you still need one piston to replace the one that was hammered out. I’m assuming the rings are still stuck in the piston you had to forcibly remove? If so, then the odds are against you in reusing that piston at all. Cylinder boring and eight new pistons would be the long term fix. If you go the ‘fix what’s there route’ and need a used piston, just let the forum members know as a 312 std bore single piston is likely sitting in someone's stash of parts.
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By Dave V - 13 Years Ago
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I had this same concern years ago on a tractor engine. One cylinder was badly pitted all the way around about half way down the bore. It was going to be too involved and costly to remove the engine and do it right. I just honed it and reringed it. It never smoked or used oil. That was 26 years ago and a couple thousand hours later and still working great. Dave V
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By Grizzly - 13 Years Ago
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Peeeot, If you are restoring the car I cannot see the point of not doing a propper recon of the engine. the reliability and clean running of the car will out weigh any percived savings. the other thing is that because it's a 50's car you won't pay 50's prices for things. Today's classic car parts and restoration prices may have you second guessing. 312's are getting harder to get and it should not be disposed of because of minor damage. Check for cracking around the main journal bearing bolt holes. A bore or resleave may get you back on track. cheers Warren
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By peeeot - 13 Years Ago
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Thank you for all of your responses so far!
I agree that a proper rebuild is the only way to go for a full restoration, and it is my hope that this car will receive such a restoration one day, but my circumstances (budget and work space) push that option out of the realm of possibility for the foreseeable future.
My immediate goal is to make the car roadworthy. If I can get the engine to run like it has 60k miles, by which I mean reliable and thoroughly roadworthy but maybe using a bit extra oil, without a full rebuild then at this point that is my preference. It sounds like most people here (and elsewhere that I've looked) are of the opinion that a bit of cylinder wall pitting will not affect performance of a street engine in a way the average person could notice.
There is not much of a wear ridge, but I'm thinking that I'll ream it off in all the cylinders. I'm also considering whether I should do any bearings. Most of them look like they have been oiled properly and thus show minimal wear; the front cam bearing isn't smooth at the top of it though. Is that likely to present a problem in the next 5-10k miles?
Ted, where should I post about the availability of such a piston? I would definitely be interested.
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By PF Arcand - 13 Years Ago
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For the used piston, post in Classifieds.. To late but you might have saved the piston if you had soaked it & used a wooden block to hammer on...
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By carl - 13 Years Ago
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If you need a used a standard bore 312 piston let me know more than likely i have one Carl
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By Riz - 13 Years Ago
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I would have to agree with the earlier posts, if you want an immediate driver and not going to run it too hard you could give a whirl to honing, rings and the minimal blowby can be monitored. That said, if you spend now to get it bored, and set straight it is one less thing you need to deal with. Tearing it down is the roughest part, why do it twice? It gives you a chance to deal with cam, bearings etc. The worst would be to do the band aid fix and then have something else to tear down. I once chucked a mustang project because I tried to get to the fun part too quick and neglected the foundation. I convinced myself that the burning oil was just a bad valve, a spun bearing and lost piston later it was a boulder again.
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By Pete 55Tbird - 13 Years Ago
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Most of the advice you have received is good but if I understood your question what you are trying to do is get the engine running and back in the car at a very cheap cost ( keep the old bearings and hone the cylinders and using the old pistons. Since having a running car to work on is such an advantage that is what I would probably do. And remember, in the day that is exactly what we all did. The cars of the 1940s and 50s were anything but high tech close tolerance machines. We knurled the pistons and the valve guides and used cast iron rings and if the did not seal we used Bon Ami cleanser. Get the car running and then go from there. Pete
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By peeeot - 13 Years Ago
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Well, I'm decided on taking the quick & dirty route. I may be losing my garage space to work on the car pretty soon and it would be hugely advantageous if the car could be driven.
As for the stuck piston, I haven't tried to remove the rings from it yet, but the damage from the hammer doesn't look as bad as I was thinking. You can tell it has been struck, but there is no evidence of cracking or deformation. Think it might be usable?
Also: I have been cleaning the engine block up with purple power degreaser. I let the block soak in the stuff for hours at a time. It can have a curious effect on aluminum; might I have compromised the cam bearings by exposing them to the cleaner?
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By bird55 - 13 Years Ago
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that purple power is good degreaser, BUT I think I would check on the web and see if it does have an effect on the bearings . Some one will know. It might be etching the surfaces, but I can't tell you. Hopefully it's not done any damage.
As other have sad here, It sounds like in your case fixing the one cylinder is the best stop gap solution.
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By Y-oh-Y - 13 Years Ago
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peeeot (9/22/2012)
Well, I'm decided on taking the quick & dirty route. I may be losing my garage space to work on the car pretty soon and it would be hugely advantageous if the car could be driven.
As for the stuck piston, I haven't tried to remove the rings from it yet, but the damage from the hammer doesn't look as bad as I was thinking. You can tell it has been struck, but there is no evidence of cracking or deformation. Think it might be usable?
Also: I have been cleaning the engine block up with purple power degreaser. I let the block soak in the stuff for hours at a time. It can have a curious effect on aluminum; might I have compromised the cam bearings by exposing them to the cleaner?Wondering if / when that piston might come unglued would drive me nuts. If possible go with a known good one.
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By Ted - 13 Years Ago
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If those hammer marks are anywhere near the edge of the piston top, then there’s a good chance that the top ring land is damaged. I would be extremely wary in using any piston that has been beat upon as any hammer marks would be a fracture point or source for failure down the road. If the piston looks questionable, then find a replacement. Besides the expense of the basic parts in just getting this engine back on the road, the time involved in doing it over as well as the repeat in expenses is also a big consideration.
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By peeeot - 13 Years Ago
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I'm on board with both of you. I'm not really sure why I felt the need to ask that  I'm working on sourcing a replacement piston.
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By Richard - 13 Years Ago
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I am not a proponent of quick and dirty, but your situation requires action. If you have a bore gauge hone out the hole as much as you can, get some oversize rings a decent piston. Knurl the piston, gap the rings accordingly. You should be fine. Its a moon shiners tanker rebuild.
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