I have never heard the side mount thing started mid year. Maybe so. From my knowledge and what I see. Side mounts started in '48, your engine has none, therefore a '47 or earlier. Other than mounts, I believe no difference. Still a 248.
Insert rod bearings started in 1949.
First 263 was 1950.
All 248 had increasing size main bearings, front to back.
All 263 had same size main bearings, front to back.
Your rods can be machined to accept inserts. Relatively inexpensive, I
believe.
If you will post the engine #, the year can be confirmed. Besides being on the side of the engine just in front of the distributor , it is on the front beneath the water pump, in that bluish area on the front of the engine.
The Buick Master Parts book confirms the change to side-mounted motor mounts began at the start of the 1948 model year at engine no 4999881. It also shows the 248 crankshaft introduced in 1941 was continued on with the same part number thru the last 248 in 1950.
The changeover to full-precision insert main bearings occurred mid-year 1947 after a trial run of some 1200 engines earlier that year. Another mid-year change occurred in 1946 to introduce semi-precision main bearings. So if it's a 1946-47 engine it could have one of three types of main bearings. Attached is a 1947 dealer service bulletin giving the engine number break points and markings for the various bearings.
Thank you, Gentlemen. As a Tyro to this engine I truly appreciate any help you're willing to extend.
So, the number on the front is 3820977, and the side is 53820977 (I'm guessing the added "5" denotes something other than bearing information). While not specifically among the numbers you were kind enough to supply, am I correct in reading this as pre-'46, and in supposing I'll find Babbitt mains inside?
Also, the side number on the 263 is b1888885 (the water pump's still blocking the front pad on that one). I'm hoping the front plate mount holes, the bell mounting holes, and the crank flange are the same as the 248, so that I'd be able to swap it directly in at a future date. Is that hope warranted?
The 5 on the side number can be ignored. Through 1942, all Buick engines were numbered with the series # first. 4 for 40 series, Special. 5 for 50 series, Super. The second digit is the start of the actual engine number for that series. The 5 says your engine came from a Super.
1940 engine numbers began with [5] 3,786,214
1941 4,074,859
Your number, 3,820,927 falls in between those, so it is a 1940. Babbitt rod bearings.
The 263, which came out in 1950, is a 1950. Beginning in 1946, the series digit was moved to the end of the serial #. 1951 #s started with 6,240,100. Your #, 6,188,888 comes before that. So, it is a 1950, 263 .
The front of the engines are all the same. The front plates will interchange. The crank, if the 263 came from a standard car, is the same at the back. If from a Dynaflow car, you will need to alter it as you have done the 248.
If the 248 runs acceptably I'll leave'er in for the set-up and initial sorting out, work over the 263, and swap that in when it's ready. With a bit of luck I may yet have'er back on the street this year.
Last edited by Old6rodder; 02-15-2018 at 11:00 AM.
Are the heads for the '40 248 Super and the '50 263 Super essentially identical as far as wall thicknesses around the intake & exhaust passages? I'd like to do my porting on the '40 as practice for the '50 (in case I run afoul of any thin spots I haven't read up on), and perhaps use that head on the '50 if I do a decent job.
I've read a bit on the differences in the coolant flow, so should be OK there.
And, is there much to be gained from larger intake valves? With the tortured intake path, it doesn't look like it.
Last edited by Old6rodder; 02-28-2018 at 07:55 PM.
I would believe the thickness are about the same. But don't sue me if I am wrong. I am thinking a '40 head will not work on a '50 anything due to the coolant changes. Water pumps are different.
The head work WILL help. I have oversized valves in my 263 as well as the intake and exhaust ported. I let a performance machine shop do the head work. Although he had never SEEN a Buick straight eight, his experience in other engines comforted me.
71 years, and haven't sued anyone yet, don't recon I'll start any time soon.
Due to some space concerns I'll likely have to go with a remote electric water pump and cobbled system anyway.
So as long as the head bolts up, should be OK. Planning to use the cobble necessity to take a shot at improving the flow as well.
Finished up the new tunnel. Wound up a total of ten pieces, most I've ever had to put into a tunnel. Had to wiggle my way around the 904 and still leave room for a gas pedal & foot. Won't have room for the bottom pivot pedal I like though, have to settle for a spoon style & heel rest.
Also added two removable hatches, one for the forward U-joint & rear trans mount, and one for the fittings & adjustments area below gas footrest. Getting too **** old to be crawling under cars when I don't absolutely have to.
Next up are the seat cushion/stowage boxes, then the finish up the firewall.
Also doing some more careful measuring up by the radiator shell, and may be able to squeeze a stock water pump in after all. No mech fan, and It'll be tight, but just barely do-able.
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