Gary Mac Posted June 17, 2016 Report Share Posted June 17, 2016 (edited) Hello, new here, have been lurking for a little while and learning about a car we recently acquired, Its a 48 Plymouth Suburban, its the first Mopar we have owned (I have a few Flathead Ford V8 cars and have built and hopped up quite a few of them over the years though so am not new to this) After going through the brakes, electrics and a bunch of other stuff on the Plymouth we started using the car before this (picture) happened when shifting from 2nd to 3rd. Have never seen anything like it in all my years of building and driving cars, I was actually expecting to find a hole in the piston crown from the way the engine was running but couldn't believe what I was looking at! This is as far as I have got with tear down, it looks like the engine has been rebuilt before as it's 30 over so my initial thoughts is just that it was a badly made or poor quality piston, as it was running fine up until this. It's not a fresh rebuild though so why it decided to fail when it did is up to now, a mystery. I intend to keep the Flathead and rebuild it and go through the transmission too, problem is being in England I have to import the parts, so the question is who has the best quality parts for these? I've looked at Kanter, Egge and Rock Auto who list Sealed Power pistons. Are there any other options? and are there any suppliers selling transmission parts? Thanks Edited June 17, 2016 by Gary Mac Quote Link to comment Share on other sites More sharing options...
dpollo Posted June 17, 2016 Report Share Posted June 17, 2016 Wow, In over 50 years involvement with these engines I have never seen this happen to a running engine, I have broken piston crowns trying to remove rusted and stuck pistons. I would try Vintage Power wagons for pistons .Your picture suggests a cleanup and new piston(s) may be all that is needed. Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted June 17, 2016 Report Share Posted June 17, 2016 (edited) Hello, new here, have been lurking for a little while and learning about a car we recently acquired, Its a 48 Plymouth Suburban, its the first Mopar we have owned (I have a few Flathead Ford V8 cars and have built and hopped up quite a few of them over the years though so am not new to this) After going through the brakes, electrics and a bunch of other stuff on the Plymouth we started using the car before this (picture) happened when shifting from 2nd to 3rd. Have never seen anything like it in all my years of building and driving cars, I was actually expecting to find a hole in the piston crown from the way the engine was running but couldn't believe what I was looking at! This is as far as I have got with tear down, it looks like the engine has been rebuilt before as it's 30 over so my initial thoughts is just that it was a badly made or poor quality piston, as it was running fine up until this. It's not a fresh rebuild though so why it decided to fail when it did is up to now, a mystery. I intend to keep the Flathead and rebuild it and go through the transmission too, problem is being in England I have to import the parts, so the question is who has the best quality parts for these? I've looked at Kanter, Egge and Rock Auto who list Sealed Power pistons. Are there any other options? and are there any suppliers selling transmission parts? Thanks 218 Piston.JPG Never heard of anything happening like that with a street engine operated normally. The only suggestions I have is to run a bore mic inside the cylinders to make sure that they were actually bored .030 over,and to determine if they will clean up good enough to accept and work fine with .030 rings. If they are just a tad oversize,you can use .040 over or even .050 oversize rings and just file the end-gaps to specs if you have to. To be extra safe you should check the bore taper while running the bore mic up and down in the cylinders,but if the bore is close to spec on top you should be good to go. Check back with me when you get ready to buy rings. I may have them in your size. I bought out the left over stock from a engine machine shop that had been in business since the 20's several years ago,and have hundreds of sets of rings for old cars. Nothing newer than 1955 or so,though. As for the pistons,this is just a low performance low-compression driver engine,so buy the cheapest set you can find from a major manufacturer after checked with the supplier a dozen or so times to make sure they were NOT cast in China,or even went there on vacation. I heard years ago that some of the pistons made in Argentina were junk also,but that was a long time ago. Best to stick with name brands like Sealed Power and new old stock if possible, If not possible,go with someone like Egge who make their own pistons in some cases. You might even want to send off emails to Hastings,Sealed Power,etc,etc,etc to ask them if they have any pistons in stock for your engine. Sometimes it is surprising what some companies still have sitting on shelves in warehouses. If not,ask how much they would charge to make a set for you. They are in the biz,make pistons by the hundreds every day,and most likely still have the factory specs in their archives for your size and car. Costs nothing but a few minutes of your time to ask. You may even want to check around with the British sporty car and restoration clubs in England and see who is casting and machining pistons locally. Has to be somebody. If I have to get something made,I MUCH prefer having it made within driving distance in case it is necessary to put my hands around someone's throat to adjust their attitudes towards production quality and customer relations. Hard to justify driving or flying thousands of miles to do that. Edited June 17, 2016 by knuckleharley Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted June 17, 2016 Report Share Posted June 17, 2016 (edited) Never seen that happen in a MoPar flathead! Those valves sure are sunk in the block. The block will probably need some valve seat insert machine work too. Edited June 18, 2016 by Dodgeb4ya Quote Link to comment Share on other sites More sharing options...
wayfarer Posted June 17, 2016 Report Share Posted June 17, 2016 If you feel a need to replace all of the pistons and plan to get them in the States then maybe consider moving into a forged piece so you can bump the c/r a bit... 1 Quote Link to comment Share on other sites More sharing options...
Cairy hunt Posted June 18, 2016 Report Share Posted June 18, 2016 Sweet Jesus! Looks like a bad casting. I did see a while ago some nos Pistons on eBay (uk) that kept on popping up, not sure if they ever sold so could be worth checking old listings. I'm uk based too so am always looking for spares to keep in stock, I'm in Yorkshire and have got a 51 desoto. HI! :-) Quote Link to comment Share on other sites More sharing options...
halffast52 Posted June 18, 2016 Report Share Posted June 18, 2016 I have a .040 piston that looks just like that. previous owner rebuilt the engine I bought it for a spare did a compression check and test fired it on the floor had great oil pressure so I put it in my car ran great for about two weeks someone forgot a connecting rod nut and it came apart and jammed the piston in to the head Quote Link to comment Share on other sites More sharing options...
greg g Posted June 18, 2016 Report Share Posted June 18, 2016 There was a parts supplier in Turkey, whom several members related good trans action with . decent prices quick and reasonable shipping. There was a Chrysler assembly plant there for a good many years and this fellow maybe aquired now stuff from that source. Maybe some one will chime in with contact details. By the way we need to see more pictures of your car as metal bodied station wagons weren't built here till 1949. Quote Link to comment Share on other sites More sharing options...
wayfarer Posted June 18, 2016 Report Share Posted June 18, 2016 The verbiage says "1948" but his sig line says '1949'....maybe just a case of fat fingers. Quote Link to comment Share on other sites More sharing options...
Andydodge Posted June 19, 2016 Report Share Posted June 19, 2016 I have had dealings with these guys from Turkey although it was probably about 5-6yrs ago, they were very good to deal with, cheap, well packed and genuine USA sourced parts in original boxes, didn't get pistons but other engine parts including valves, guides, lifters, timing chain & gears & oil pump........from memory they went under the "moparken" name or similar....I found them by doing ebay searches around the 1948-54 Plymouth title..........andyd Quote Link to comment Share on other sites More sharing options...
mikeww1962 Posted June 22, 2016 Report Share Posted June 22, 2016 On my rebuild I bored the block to the standard Chyrsler 230 bore and bought standard pistons and rings from Vintage Power Wagons - great to deal with and no complaints on the products at all. Quote Link to comment Share on other sites More sharing options...
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