Hi all, need some help identifying this serial, W984294. It's in a 55 pickup in Canada, but I think it's a donor from something else. I checked all the sites that I could and didn't find anything. Is 'W' for Windsor? Thanks
hi Goach2, the serial number on the engine won't tell us much about it for a Canadian one, post a photo of the whole engine might be better. the block and head casting numbers would be best manufacturing location will be a cast marking on the block, not stamped
the letter prefixes have some meaning, but i don't have good sources, from 1946-53 W prefix could mean the engine is a GM 239, but that's questionable and perhaps not the only use for w -s
head casting 3835913 was found on a 1954 235 full pressure engine in the USA, it is a close second to the preferred 3836848 head for higher compression. this head might have been used on other engines, would need the block cast number next to the fuel pump to know for certain. -s
I hope you're looking at this with your eye's wide open...with moss growing on the head and the carb open to rain, this engine could be junk.
The cab looks like a 1/2 ton Chevy/GMC (has the parking brake rod next to the steering column), so chances are it's a 235 and not a 261, unless it was transplanted in at some point.
Mike B
Mike Boteler
1956 Chevy 3100 Resto Rod 1952 Willys M38 Army Jeep 1983 Jeep CJ7 Laredo 1984 Jeep CJ7 +++++ Silver Spring, MD
Mike - The story is the previous owner pulled the original 6 and got this replacement in. He died a short time later and most of the mounting bolts are still loose. The carb was open, but a hood was on it until yesterday. The engine is stuck, but for $150, I'm willing to try and get it moving again...
If the motor is stuck, I don't think I would pay 150 for it. If the head matches the block, its going to be a 54-55 motor with shimmed bearings and rope rear main seal. There is just not a lot of value in that motor, being stuck and all. Hold out for a 56-62 that is not stuck. You will be heads and hands ahead.
I should add that's $150 Canadian These don't come up around here too often and I do plan on doing a full rebuild on it. I can understand why there are deterrents to going with this one. I expect I will learn a lot and I will start a build thread to chronicle it. My 216 runs like a top, so I am in no hurry to get this one running. I hope this makes sense...
As long as you're willing to rebore, or possibly sleeve an engine, being stuck isn't a deal breaker- - - -just be aware that you might be getting into more machine work (and cost) than with one that still turns over. Check the block and head carefully for freeze fracks in the water jacket- - - -those are tougher to repair than pitted cylinders. 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!
The '913 head was used on '54 passenger service 235s, as well as on trucks.
Interestingly, Chevy also used that same block casting number on a 216 passenger service block from '42-'51, but of course, that head would not bolt on a 216.
The Canadian Pontiac 6 was based on the truck engine but had significant differences.
Most important was the fact that the Pontiac was 'a step above' the Chevy so the common 235 would not do, hence the bigger better 261.
"Basically, this larger engine was a 235 with the same crankshaft but GM engineers made various modifications to give it extra strength and horsepower.Its standard bore diameter increased from 3-9/16 inches to 3-3/4 inches. The connecting rods were heavier and attached to increased diameter piston wrist pins."
So same stroke, bigger bore.
Also, "Its higher lift cam shaft, for better breathing, was shared only with the early 235 six cylinder Corvette. A modified larger Rochester carburetor was also a 261 only feature. Unfortunately most of these larger sixes have long since had their original Rochesters replaced with 235's and therefore do not perform to their full potential."
Keep in mind: "the 261 truck engine came standard with solid valve lifters and an aluminum camshaft timing gear. The Chevy passenger car's 235 was equipped with hydraulic valve lifters and a fiber timing gear for quieter operation. During the 1955-62 Canadian Pontiac application the lifters were the hydraulic type, the cam gear was fiber not aluminum, and it did not have the full flow oil filter. These Canadian made 261's did not add the full flow filter in 1958 as in the U.S."
Quick update for everyone here, local machine shop estimated $300 per cylinder to sleeve. Since I would need two, I will be scrapping this block. In other news, I have a line on another Canadian Pontiac 261
Engine ID: W9204502 - GM documentation says it is from a 1960 Canadian Pontiac, apparently it came out of a 1959 Pontiac. Block: 3769717 - 261 for sure Head: 3836848 - Yes, I know, 235 head just like the last one, but this one has higher compression!
This one turns over, so I'm thinking put the starter on it and crank to measure compression? I'm looking for a good resource (have manual) for rebuilding one of these. I'm going to start a new thread on the rebuild of this and to track the modifications that I have to make to make it compatible with my truck.
Here is some information about drilling those six extra coolant passages:
From Deve's website: "A trick that people often use to increase the compression of their 261 is to use the higher compression '848 Head from a 235 engine. This head was the most produced and a great fit for your 261, however, you MUST drill the aforementioned water holes in this head. To locate the holes, place the 261's Head Gasket on the Head and then mark the holes. Verify these 6 markings are in the right place by measuring on the engine blocks surface just to be sure. Tape off or mask anything that could get metal shavings in it and cause failure. Using a 3/16" Drill Bit, drill the holes into the Head's water cavity at 12 degrees as shown. If drilling straight in would reliably intersect the water jacket GM would have done it that way. Take a look at why even a slight angle towards the manifold side will improve chances of flow. Note that 3 of the holes are pretty much can’t miss and the other 3 may not exit the head bolt boss if drilled straight. I’m sure there are folks out there that only have flow in 3 of 6 places but possibly that is just enough to get by. GM locations are in green and red shows straight in."
These don't come up around here too often and I do plan on doing a full rebuild on it. I can understand why there are deterrents to going with this one. I expect I will learn a lot and I will start a build thread to chronicle it. My 216 runs like a top, so I am in no hurry to get this one running. I hope this makes sense...
