I have a 1946 GMC Canopy Express with I believed to be a correct 228 cubic inch engine. I broke an exhaust valve in #1 cylinder and punched a hole in the piston. I am in the process of trying to decide whether or not to rebuild the entire engine or to replace it. The cylinder head casting# is 2194819. I've located cylinder heads on line with this casting number but the ads specify that the head is for 228 engine with flat topped pistons. My engine has domed pistons. The casting# on my block is 6107326. The number stamped into to block to the left of the distributor is B 228496215. The engine ran fine for the 5 years I've owned the truck except for a vacuum leak problem which was solved by replacing the steel rings between the head and intake manifold. My question is can I use the advertised cylinder head meant for flat top pistons while rebuilding the engine using domed pistons. If the engine and head were not designed to run with domed pistons, I don't think I could have driven it for 5 years. Which is correct for my motor, domed or flat pistons ? Thx Hank.
i don't know about your head problem. but before you work on your engine check parts availability. i'm rebuilding a 270 for a 31 chevy pickup project i'm working on and can not find reasonable priced pistons. they have to be custom made. then lifters are hard to find reasonable. check bearings, also hard to find. parts are real scarce for these gmc's and when you do find some they cost an arm and leg. Jay D.
Hank's 46- - - - -if you would be interested in a complete 228 engine in rebuildable condition, make 3 more posts to get access to the "private message" option on the forum and send me a message. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Didn’t HRL just mention pistons from an old Ford engine were suitable for GMC engines?
GMC has 4 different heads that fit but must coordinate small port vs. large port, flat pistons vs. domed pistons. I no longer have casting number info!
Ed
'37 GMC T-18 w/ DD 4-53T, RTO-610, 6231 aux., '95 GMC running gear, full disc brakes, power steering, 22.5 wheels and tires. '47 GMC 1 ton w/ 302, NP-540, 4wd, full width Blazer front axle. '54 GMC 630 w/ 503 gasser, 5 speed, ex fire truck, shortened WB 4', install 8' bed. '55 GMC 370 w/270, 420 4 speed, grain, dump bed truck from ND. Works OK.
There's a piston for a Ford industrial engine that can be fitted to a 302 GMC with a little creative machining. It's a Dualoy #3145D for a 370 cubic inch Ford V8. The 302 has a 4" diameter bore with flat top pistons, much bigger than the other GMC inline sixes. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Fairly comprehensive list of GMC casting numbers here.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
My '52 GMC 228 has a 2136477 head with a casting date of 6/14/52. It has domed (original I think, at least the bore is still standard) pistons. The 1939-54 GMC Master Parts Book calls for one set of pistons for 1939-52 228 engines with 6.75:1 compression ratio (domed) and a different set of pistons for 1953 228 engines with 8:1 compression ratio (flat).
Pictures are of my #5 piston and combustion chamber. The exhaust valve was badly burned. Had a machine shop do a valve job, I re-installed the head and 40,000 miles later it is still running strong (as 90 hp will run).
Last edited by Bill Hanlon; 11/16/20224:19 PM. Reason: additional info
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Thank you all for your responses, but I don't think I've had my original question answered. I've seen that page on the oldgmctrucks.com website which cross references the various casting numbers to engine components. I have a block with casting number 6107326, which according to the chart is correct for my year truck (1946) and is also compatible with three cylinder head casting numbers, one of which is the 2194819 which I have on my engine. My question is according to on line listings for remanufactured heads with casting# 2194819, should be used in conjunction with flat topped pistons. My engine has domed pistons and until recently ran fine for the 5 year I've owned it. If I decide to try and rebuild the engine, can I use domed pistons with the refurbished head or did I need flat topped pistons. My original question seems to have wandered off course into a discussion of available pistons for alternative sources. Thank you. P.S. The rebuilder is unable to tell me if flat topped or domed pistons are correct.
Your combustion chamber looks like its for the 477 head that is used with the domed pistons. Domed pistons and the 819 head don't do well together. The 819 head was only used with flat top pistons or custom made pistons.
Joe
just retired and finally making headway on my project truck. 1940 GMC AC152.
Joe: The pictures above are of my '52, not Hank's '46. Mine is domed pistons and the 477 head.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Joe: The pictures above are of my '52, not Hank's '46. Mine is domed pistons and the 477 head.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
I have 2 4819 heads in my garage. Not sure of the years but casting numbers are in different locations. They both look the same possibly a very small dome piston? Not sure. Can we see pics of what you have on your engine?
1947.2 GMC 1/2T SWB panel 1947.2 GMC 1/2T long bed 1948 GMC 1/2T short bed
Too bad Patrick Dykes in no longer alive. He was a GMC guru and his old catalogs had a detailed discussion of the GMC 6’s, their blocks and heads. Sadly I threw mine out a few years ago when we were packing up to move. Maybe someone has a scan of one.
The 477 and the 412 are for domed pistons that were used up until 1953. The flat piston uses the 819 head. If you have an 819 head on your engine, it is not original. The 819 head was not produced until 1953. The pistons you picture are not OEM. Your engine originally had Zollner pistons and probably a 477 head. It looks like someone used some 1953 aftermarket high compression pistons with a 1953 or later head. I haven't seen OEM 228 1952 and older pistons for sale in a long time. However the old Zollner pistons ran forever. I would scrap the engine you have and start all over. 228 engines that will still hone standard are around. It looks like your block has been bored to the max anyway. Any way you look at it parts are going to be difficult, Some of the dome piston heads had 30° valves and some had 45°valves. Either will run with the OEM domed pistons. Do you want to keep your vehicle original or do you just want it to run?
Here is a photo of a NOS 819 head. It has oblong combustion chambers. The 419 and 412 have a large round combustion chamber like is pictured in Bill Hanlon's photo. A quick glance at the combustion chamber will tell you if you have an early head with domed pistons or a later head with flat pistons.
OK,guys, first of all, thank you all for your input. If I interpret the postings correctly, the 819 head I had on my truck was not original to the 1946 model year, nor were domed pistons. Furthermore, the pics I sent of the domed pistons which are in my motor are not OEM. Okay, I get that part, however "gmc-is-me" responded that my pistons were custom for the 819 head, while "crenwelge" replied the 819 head uses flat pistons. I'm totally confused. I had domed pistons in a 819 head, on a 228 ci engine, which until recently ran fine. As I go forward, do I search out 477 or 412 heads to accommodate the existing domed pistons, or do I search out flat topped pistons which are compatible with a 819 head ?
If you want to stay with the 228 engine, I'd suggest finding another complete engine to rebuild. With the amount of damage that piston is showing, it's very likely that the block, the head, or probably both will have some cracks in them you haven't discovered yet. Finding one obsolete custom piston to replace the damaged one is about as likely as finding a chicken with lips. These old engines are tough, but they're not bulletproof. Most people in your situation would probably look for a 248 or 270- - - -they're both bolt-in swaps and are more plentiful, and more powerful than the 228. Send me a PM- - - -I might have what you probably should be looking for. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Engines with he 819 head came from the factory with flat pistons. However aftermarket pistons with a dome were offered through the years to raise compression ratio. The factory domed pistons that came in an engine with a 477 or 412 head will not work with an 819 head. The dome will actually hit he head. The aftermarket domed pistons for the 819 head raised the compression ratio considerably. The higher compression ratios usually required the use of high octane gasoline.
Above is a link to what a factory domed Zollner piston would have looked like that came in our engine from the factory. It would hit he head on a 477 or 417 engine. What you have is aftermarket high compression pistons. Running gasoline with too low octane may have contributed to your failure.
I agree with Jerry. I haven't been able to find the domed pistons for the 477 or 412 head for quite a while. Of course you couldn't use them with your head any way. I would look for a 248 or better yet a 270. There are probably more parts available for a 270.
They are aftermarket high compression pistons made for 1953 and later engines using the 819 head. These look like they have a pretty large crown and would produce a very high compression ratio. Quite a few manufacturers made them years ago. I ordered quite a few of them 50 to 65 years ago from Warshawsky Bros which is now JC Whitney. I think finding one with the same compression ratio would be next to impossible. They were never very popular. It was easier to bolt a 270 or a 302 engine in and get more hp on regular gas instead of going to higher compression requiring higher octane.
Sticking that squared-off chunk of metal up into the combustion chamber probably plays havoc with the flame front as it tries to get from one side of the chamber to the other. I'll bet that engine would be very prone to developing some destructive detonation, and that much static compression would only be required with an extremely radical camshaft grind. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I don't have a copy of the GMC master parts book. Could I prevail upon you to send me the GM parts #'s for the domed and flat head pistons. Thank you. Before anyone else responds, I realize the stock pistons are standard bore and not be .060 over. Thx.
These are all the 228 pistons listed in the Master Parts Book from 1939 through 1953 which should cover all 228 pistons.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
