Von Tiergarten Posted January 27 Share Posted January 27 Anyone got experience with new repro pistons from the vendor “Old Parts Source” on eBay? Sadly a broken pistonring has cracked a piston in my Pontiac torpedo from 1947 (or vice versa). Link to comment Share on other sites More sharing options...
mobileparts Posted January 27 Share Posted January 27 (edited) It is all the Chineseum reproductions --- better than nothing.... They may sell sets only --- and no singles, also..... I may have *** N.O.S. *** U.S.A. made *** Pistons and Rings.... Designate size and quantity wanted and I will investigate.... Craig.... Edited January 27 by mobileparts (see edit history) 2 2 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 27 Author Share Posted January 27 (edited) 1 hour ago, mobileparts said: I may have *** N.O.S. *** U.S.A. made *** Pistons and Rings.... Designate size and quantity wanted and I will investigate.... Craig.... Ohhh that would be fantastic 👍 its a 1947 Pontiac torpedo 8 - standard size piston. silvolite 1505 1 piston + rings would be fine. But it might be a good idea to change all the piston rings - they are all of the same age and wear. If you have rings for all eight - I would be a happy camper 😁 edit: I’m in Europe. Edited January 27 by Von Tiergarten Geographic clarification (see edit history) Link to comment Share on other sites More sharing options...
mobileparts Posted January 27 Share Posted January 27 I will investigate and let you know.... I just sent an order to Wein, Austria.... Shipping is not a problem.... 2 1 Link to comment Share on other sites More sharing options...
Bloo Posted January 27 Share Posted January 27 Original pistons in the Pontiac Eights are all cast iron. Is the one in the picture? You'd better either match the weight or replace all of them. 2 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 27 Author Share Posted January 27 (edited) 30 minutes ago, Bloo said: Original pistons in the Pontiac Eights are all cast iron. Is the one in the picture? You'd better either match the weight or replace all of them. I will. its either one original to “match” the rest or all new. The pistons I took out are stupid heavy. Edited January 27 by Von Tiergarten (see edit history) 1 Link to comment Share on other sites More sharing options...
mobileparts Posted January 29 Share Posted January 29 I don't have, and the few people I deal with DO NOT have any Cast Iron Pistons for a 1947 Pontiac ( they fit 1937 - 1949 Pontiac 8 cyl. ) You are going to have to purchase a set of the reproductions--- and they are Aluminum, so you will need to purchase a complete set, unfortunately... Wish I could do more for you , but sadly, they just aren't out there..... 4 Link to comment Share on other sites More sharing options...
Walt G Posted January 29 Share Posted January 29 I have said this before and will state again, Craig at mobileparts has learned his information from his family going back at least two generations. I was buying from his grandfather's store when i was working on my first old car in 1964 , was happy then am happy now. Everyone at that time who had an old car on western long island in Nassau and Queens county knew his grandad's place of business and the friendly guys behind the counter. He is "one of us". Walt 9 1 Link to comment Share on other sites More sharing options...
Swear57 Posted January 29 Share Posted January 29 Try EGGE Piston & Machine 800 866 3443. They have had what I needed. Great people. Jim S 2 Link to comment Share on other sites More sharing options...
mobileparts Posted January 29 Share Posted January 29 ^^^ They ^^^ are the laaaaaaaaaaaast resort --- thanks to their price structure.... I don't even think of them --- because of just that.... I suppose that is an option ??? 2 Link to comment Share on other sites More sharing options...
dodge28 Posted January 30 Share Posted January 30 Swear 57 is on tract. Try EGG Machine in Cali. You may be inclined to make all 8. My friend had one piston made for an 1918 Buick. The previous owner sold the car cheap because of the broken piston. Engine would not run. 1 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 30 Author Share Posted January 30 Thats some hefty prices on EGGE!?! With shipping and customs/taxes its border line insane🤪 I will continue my search for a single piston. I might try the full set from old parts source while searching 👍 At least I will be driving this summer. Thanks all of you - and please keep giving me “heads ups” on where to search. Its almost impossible to find parts when sitting on the other side of the pond. Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 30 Author Share Posted January 30 22 hours ago, mobileparts said: I don't have, and the few people I deal with DO NOT have any Cast Iron Pistons for a 1947 Pontiac ( they fit 1937 - 1949 Pontiac 8 cyl. ) You are going to have to purchase a set of the reproductions--- and they are Aluminum, so you will need to purchase a complete set, unfortunately... Wish I could do more for you , but sadly, they just aren't out there..... Thank you so much for trying 👍 Link to comment Share on other sites More sharing options...
Andy J Posted January 30 Share Posted January 30 A couple of years ago,my '51 Pontiac eight had to be bored so I called Kurt Kelsey about rounding up all the parts.He found a set of eight aluminum pistons and the machine shop bored the block for these pistons.I never asked where they came from and unfortunately Kurt passed away.Dumb me,I should have asked who made them,but I didn't. For what it's worth,my crank had a bad journal and the machine shop said .030 wouldn't clean it up so look for another crank.I called Kurt again and he found a set of .040 under rod bearings,which would work. Did you know that there are .080 under rod bearings available for this engine? I hate that I didn't ever get to meet Kurt,but I talked to him on the phone many times. He helped me immensely and I surely miss him. 2 Link to comment Share on other sites More sharing options...
mobileparts Posted January 31 Share Posted January 31 I CAN supply you a full set of the Aluminum Reproduction s in .030, .040, and .060, and probably save you money over the $ 555 you see that they sell the set for --- but my place does not have Standard.... If that has any value for you...... Craig...... 4 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 31 Author Share Posted January 31 15 hours ago, mobileparts said: I CAN supply you a full set of the Aluminum Reproduction s in .030, .040, and .060, and probably save you money over the $ 555 you see that they sell the set for --- but my place does not have Standard.... If that has any value for you...... Craig...... Thanks Craig - but I’m not keen on making my 7 good piston unusable for me by increasing the bore just yet. I Think I will get the standard size alu. Drive them until I find a cast piston - and then change back. I really do appreciate you guys trying to help me out. Some times the love for old US metal can be a bit of an headache when being in Europe - especially when being a “newbie” in the hobby😁 These kinds of fora’s is pure Gold for me. Chris. Link to comment Share on other sites More sharing options...
TAKerry Posted January 31 Share Posted January 31 Just following along as I am not a mechanic, but would running one aluminum piston alongside the rest not being aluminum have an effect on how the motor runs? 1 Link to comment Share on other sites More sharing options...
dodge28 Posted January 31 Share Posted January 31 Bingo, all pistons must be balanced. My thought is do it right. Take your time and do it when you have the money. 2 Link to comment Share on other sites More sharing options...
JACK M Posted January 31 Share Posted January 31 14 minutes ago, dodge28 said: Bingo, all pistons must be balanced. I tend to agree. putting a lighter piston in there just to get by would be a mistake. When we take the cheap and easy route it usually ends up costing more in the long run. We all know someone that will spend a hundred bucks to try to save a ten spot. On the other hand, back when used up cars were 30 to 50 dollars a high school buddy of mine bought an old truck that ran but lacked power. He drove it around like that for quite some time. When he finally got into the engine, he found that it was missing a piston. So, if it's just to get you by, why not just take the offending piston out? 2 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted January 31 Author Share Posted January 31 1 hour ago, TAKerry said: Just following along as I am not a mechanic, but would running one aluminum piston alongside the rest not being aluminum have an effect on how the motor runs? No no - I would never drive it with mixed pistons. I will instal a full set of new alu pistons and drive them while searching for a single cast piston to ad to the good 7 that I got. Then (when I find one) switch back from the alu pistons. Difference in weight would “kill” the balance of the engine - it might even kill the engine. 1 Link to comment Share on other sites More sharing options...
Bloo Posted January 31 Share Posted January 31 (edited) I don't really know what to say here because I know that getting parts to Europe is super expensive. The first thing that occurs to me is that if it broke a ring, the bore in that cylinder is probably bad and it probably needs boring and a set of pistons anyway. I have never pulled broken rings out of an engine and found a good bore. Vertical scoring causes the engine to burn oil and have a lot of blowby. The second thing that occurs to me is that if in fact the bore is OK, then maybe a used piston out of some junk engine should do, of course subject to it being the same weight or heavier so it could be matched. Maybe with some knurling if the skirt is too loose. All the Pontiac Straight Eight factory installed pistons were cast iron, all years. The third thing that occurs to me is that lighter pistons would be a nice improvement, and take a bunch of load off of the rod bearings. Does a straight eight require rebalancing the crank though? I'm not sure. I think it probably does, where a straight six would not require it. If aluminum pistons are made intentionally super heavy to match the cast iron ones, I would not want them. The fourth thing that occurs to me is that if it needs rebore and rebalance anyway, I would want some custom pistons to take advantage of modern rings and any possible weight reduction. Yes I know they're expensive. Edit: I think maybe @AWISE would be a good person to ask about this. Edited January 31 by Bloo (see edit history) 3 Link to comment Share on other sites More sharing options...
Ozstatman Posted February 1 Share Posted February 1 On 1/31/2024 at 1:24 PM, mobileparts said: I CAN supply you a full set of the Aluminum Reproduction s in .030, .040, and .060,.........Craig...... Expressing my ignorance here, but could an oversized piston be turned down to stock size and retain sufficient integrity and strength to be viable? Would think, using the .030 oversize wouldn't lose much material. Link to comment Share on other sites More sharing options...
dodge28 Posted February 1 Share Posted February 1 The initial sweetnes of cheepness leave a bitter taste in the mouth for a long time. 1 Link to comment Share on other sites More sharing options...
dodge28 Posted February 1 Share Posted February 1 Sometimes if you find a piston made by the same maker and same metal but slightly larger it can be machined to match the rest. Weigh them individually . There is a video of the Dodge Brothers on UTUBE you will see the worker weighing the pistons on a scale. Link to comment Share on other sites More sharing options...
Restorer32 Posted February 1 Share Posted February 1 How about engine parts, pistons, valves etc for a 1938 Willys Sedan ? Link to comment Share on other sites More sharing options...
JACK M Posted February 1 Share Posted February 1 9 hours ago, Ozstatman said: Expressing my ignorance here, but could an oversized piston be turned down to stock size and retain sufficient integrity and strength to be viable? Would think, using the .030 oversize wouldn't lose much material. Believe it or not, it is standard procedure to bore one cylinder on OMC outboard engines. (Johnson and Evinrude) OMC (now defunct and sold to Bombardier) service schools insisted that oem replacement pistons will all weigh the same regardless of oversize's and there would be no noticeable performance issues. I also agree that if this Pontiac was to be fitted with aluminum pistons it would be an upgrade. 1 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted February 19 Author Share Posted February 19 Well - it seem that the pistons in my Pontiac is not the original size. The engine has been bored at some point in its life. So now I’m not looking for standard size pistons - but an rather extreme oversize. The pistons in my car is Silvolite 1505 - a piston that is completely “unknown” to the whole internet (as far as I Can see). What I need is a full set of pistons with these measures. Link to comment Share on other sites More sharing options...
John E. Guitar Posted February 19 Share Posted February 19 You could try JP Pistons. https://www.norndaautomotive.com.au/jp-pistons.html Link to comment Share on other sites More sharing options...
Von Tiergarten Posted February 19 Author Share Posted February 19 Hmmmm - am I completely off when thinking these could fit in 0.030 oversize? 1950-54 Pontiac 268ci 8 cylinder engines Standard Bore Size: 3 3/8 inches Piston Type: Precision Cast Aluminum Compression Ratio: 6.8 : 1 (Std Trans) 7.7 : 1 (Auto Trans) which is to OEM specs with stock heads (will differ when different heads are used) Compression Height: 2 3/32 inches Piston Pin Diameter: 0.9375 inches Link to comment Share on other sites More sharing options...
Bloo Posted February 19 Share Posted February 19 It sounds very likely that 50-54 .030 is exactly what you have. 3-3/8" = 3.375 + .030 = 3.405 . Of course you would have to go by actual measurements of pistons and block to be sure. 3-3/8" was also used in the 1935-36 flathead sixes. 1 Link to comment Share on other sites More sharing options...
Rusty_OToole Posted February 19 Share Posted February 19 Have you considered pistons made by a European company? If you replace a full set, and they are the correct diameter, pin height, and wrist pin size they should work perfectly well. I know there are companies in the US that will make custom pistons. It might even be possible to find stock pistons from some other car or truck that will fit. Off hand the only names that come to mind are Kohlbenschmidt and Mahle but there must be others. You might try emailing a few suppliers, giving dimensions, and see what they have. Link to comment Share on other sites More sharing options...
DFeeney Posted February 19 Share Posted February 19 I would post on the Pontiac page. They used this bore for a long time and someone must have a parts engine apart with a good piston. Shake the Bushes and you will find one. 1 Link to comment Share on other sites More sharing options...
Von Tiergarten Posted February 19 Author Share Posted February 19 10 minutes ago, DFeeney said: I would post on the Pontiac page. They used this bore for a long time and someone must have a parts engine apart with a good piston. Shake the Bushes and you will find one. Well - I might like the thought of a complete and new set in aluminium. I think I will go that route. Link to comment Share on other sites More sharing options...
Restorer32 Posted February 20 Share Posted February 20 Call Ross Racing pistons. They have heled us out several times . 2 Link to comment Share on other sites More sharing options...
zepher Posted February 23 Share Posted February 23 On 1/29/2024 at 10:18 AM, Swear57 said: Try EGGE Piston & Machine 800 866 3443. They have had what I needed. Great people. Jim S Egge used to be great but they have since gone way, way down hill. Egge made pistons for our Rickenbacker back in the 70's and they were stellar. The reason they have Rickenbacker pistons listed is because they used one of ours for a pattern. But, there has been a very precipitous drop in quality since Egge was sold off. Personally, I would not buy and run Egge pistons in any of my cars. 1 Link to comment Share on other sites More sharing options...
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