The Stovebolt Site Forums The Shop Area Engine Shop Canadian 235 engine ID please

Hi, Jon G asked that I post my request in this forum.

I was recently in the Electrical Bay forum getting some great advice and support regarding a starter rebuild/fitment.
During that process it was confirmed to me that the engine in my '55 First series is indeed not of that vintage, but in fact post-'55 as the flywheel is 12 volt (168 tooth ring gear).

Some numbers were also found on the side of the engine block just above/obstructed by the starter, as well as another stamped number on the flats next to the distributor.

Gdads51 was kind and offered some info on these numbers, but only in general terms.

I think there must be more info on its Canadian origin, but so far can't seem to get very far in that realm as most data bases refer to US manufacturing.

So, can we narrow this down to its date of production (my guess is 1957 -- but don't know for sure) ?
I recall that the previous owner said that it was rebuilt in 1986 though. But cannot recall its production details if there were many.

Here are the found numbers:

3837004 GM by the starter (casting code?)
C252537 by the distributor (serial number?)
..and the raised letter "M" near the fuel pump.

Looking at both sides, that's all the identification there appear on this block.
Without stripping off parts, is there anywhere else to look ?

I have pics of this if interested.

Any help here is appreciated.

I'm thinking that probably the best source of info on where to find casting dates on your Canadian 235 is going to be from some of your fellow Canadians that own one or more.

There is just really very little resource information online on Canadian units, even though I believe they manufactured a whole pile of engines over the years. Your previous pictures showing the "casting code" 3837004 GM just above the starter location is the first one I can recall seeing in this spot on the engine.

One thing that may help a bit (not so much for the block, but for the head), check the head under the valve cover on the drivers side towards center. That seems to be a fairly consistent place for at least "head" casting dates to be found. The casting code number is normally just outside the valve cover seal surface, same drivers side central area. IIRC, you said previously that you had an "848" head, which is known to be used on Canadian engines, both 235's and 261's.

Otherwise, maybe time for some really bright lights and taking some random pics with your phone on both sides of the block. Particularly down along the lower sections of the block just above the oil pan rail surface.

Post some "suspect" pics and we can try and help further.

Dan

Edited to remove assumed info on my part - Sorry!

The raised letter M confirms it as a Canadian engine. It means McKinnon foundry, a plant in St Catharines, incidentally, my uncle worked there for many years. GM purchased this foundry in the late 1930s, I think. The 848 heads were standard on the Canadian 261s. Even though they differed from the US built 848 heads they had the same casting number.

Leo,

Any helpful hints on where to find casting date codes on Canadian blocks?

Is it possible his "3837004" block may be a "261"???

I suppose the only way to know for sure will be to open it up and get internal measurements.

Dan

Sorry, I don't have that engine anymore.

Dan... sorry, but please direct me to the post where I referenced an 848 head on my engine --first I've heard of it

But I will do some more skulking around the engine. Perhaps this time in the bright sun and some camera lights ;-)

I'll get back to you with what I found.

Ok, I've read this before -- thanks for confirming the Canadian connection, Leo

My apologies on my post that indicated you said your engine had the "848" head.

I went back through and couldn't find the reference - duh!

May have just been the result of my brain being in mini-overdrive and thinking since it was noted to be a 1957 235, that it would have had an "848" head installed. I did do a check and found this truck specific engine head info that indicates the "848" head was standard for "All (235)" truck engine heads from 1955-62.

Sorry if this caused any misunderstanding or misdirection!

Dan

PS - So what is the casting code info on your engines head???

Hey, Dan ..no issue here, but thanks for the thoughts


So, I snapped a few pics of the head and these are what I came up with.



Parts can sure look ugly when up close, huh

After all that Dan, your intuition was right, he DOES have an 848 head!

I think the B 3 9 could be the date code...February 3, 1959. The other numbers are just foundry numbers for different pieces of the sand cast mold...

Mike B

Hmm... but that's not to say that the head and head are a matched set..

So, on the top of the block -- any more details on this 7-digit number .. and what's up with GM 20 ?


Guess we still need to establish the block's DOM

The casting date marks on my 1957 &1959 Canadian blocks (235 and 261)are located behind the intake and exhaust manifolds. They must be removed to see. The 'casting codes" are found just behind the starter.

I believe your 3837004 block casting code indicates a 55-57 235, The casting code numbers on all of my Canadian truck engines, two-235's Chevys, two 261's Chevys and two GMC 261's all followed the USA engine casting code numbers. Only the location of the information was different from the US engines.
The stamped numbers on the flat area behind the distributor is the serial number. Factory replacement blocks may be blank in this spot or have some unusual numbers stamped in by the installer.

55firstseries,

Thanks for the kind words and follow on pics of the head. I will breath a small sigh of relief that I haven't lost my marbles (yet - LOL).

From "No1300"s post, it sounds like your block casting date info will remain hidden until you get around to removing the intake/exhaust manifolds. Many thanks to "No1300" for adding these tidbits of info on Canadian engines!

Keep us posted as you can on further info.

Dan

So, unless someone has access to serial number logs, I could be lost for the rest of the info (other than checking behind the manifolds) -- including whether this is easier to id as a 261 or 235 ?

So yes, thanks for more details, No1300. Someone, someday may indeed do another strip-down and find (and hopefully record) those hidden numbers.
Enjoy your 3100 'inheritance'

In the meantime, I will enter this new info in my data.

Dan.. thanks for following me from the last thread to this one. Your input has been really helpful!

Leo and Mink B ..thanks for your contribution too

If I have any more questions and do run across more engine numbers I will be sure to post them here.


time to get back to the truck: never-ending home errands to run.
Wayne

Wayne,

We are all just doing what Bolters do - Bolters helping Bolters!

Thanks for the kind words and will wait and see what new info may break the light of day sometime in the future.

Dan

Btw, I did just run across this in some old online records:

http://chevy.oldcarmanualproject.com/models/engine.htm

Not much of it applies to mine. Perhaps others will glean some details about their own (US) power plants.

Fyi, my truck was a kind of rebuild by a previous owner.
He had it reregistered with a new VIN (after it was towed to Canada after being mostly toasted in a fire in New Mexico).
So the VIN is non-relavent, and so very few parts are original on this vehicle (ie, matching numbers, etc).

If your engine was a 261 it would have "captains bars" located just above the casting code behind the starter. Note the flat area shown behind the distributor opening containing the serial number. There would also be captains bars on the other side of the engine, under the manifolds with the date of casting, shown is L 7. They do not include a day of manufacture so I believe this is Dec 1957

Interesting -- I do wonder if that also applies to Canadian engines

Taking it a little further, there should be records attached to that serial number, huh?

The information and photos are for Canadian engines. Note the "M" cast into the block. This applies to Canadian Chevy and GMC trucks. If you want a 261 engine with solid lifters look for a 1954 to 1962 Chevy large truck or bus. All GMC 1956 to 1962 trucks came with 261 sixes. (including 1/2 tons). If you want a hydraulic lifter 261 engine find a 1956 to 1962 Canadian Pontiac six. Look for the captain bars and use the same engine codes as the USA posted casting numbers

Your last picture showing the Date Code looks like it has all three characters...looks like L 7 5 to me.

Mike B

It is actually easier to see in the picture than on the block. Lookin a little closer it is possibly L 7 6. That would make it December 7 1956. This would seem possible as engine came from a 1957 big Chevy truck.

That would make sense since production of the '57 model year started in late '56!

Mike B

Ok... you guys are now making me wanna rip off my manifolds just to check out the DOM

Take your valve cover off and on the driver side about the middle should be your casting date. The 848 head entered production for the 56 model year so the Wiki is wrong on the 55-62, its actually 56-63 (1963 there was one single application for a 235 motor, a NAAPCO 4 wheel drive, otherwise the new 230 style motors).

If the date code on the block is indeed December of 56 then it is absolutely a 57 production year block as the 57 production did not have the early and late designs like the 55. 55 heads would have been the earlier 913 head. If the head casting date is in that range, you might have a nice matched motor with its original head.


One thing to keep in mind, the 55 913 head and the 56 848 head used the small temp sender port. The 57 and up used the larger temp sender port. So while both of those heads will interchange with one another, the temp sender ports may not be a direct swap.