Re-motoring a lakes bucket style street rod project called Cassi.

Howdy,

As noted in my intro, I'm replacing a slant six in an unfinished street rod project I built (that returned to me recently) with a '48 248 straight eight.
Here're a couple pictures, and I'll keep the project updated as I do the rebuild.


55.JPG 56.JPG

This'll be an unhurried (re)project, and I'll certainly be needing my hand held a bit as I learn the Buick.
I'm presently starting to chase down the missing parts for the mill,
(please see needed parts post here https://www.teambuick.com/forums/showthread.php?26471-Distribtor-and-rockers-cross-reference-question)
and thrashing out the mods it'll need for my chassis (a titled Deuce) and to mate it to a pb904 from a slant six. I'll be going with a set of four SUs for carbs, and a mild street build for the guts. Hoping to have'er back on the street later this year, or early next.
 
Last edited:

firstofeight

Active member
Cassi

Old6, you got my attention. I cannot answer all your questions, some one will. I believe any year distributor from a 248/263 will work. The water pump changed in 1950, so will need to be earlier. Too bad you are so far away, as I will be selling a 1950 248 later in the year. It has been replaced with a warmed up 263.

Good luck, and please keep us in the picture.

Ben
 
Started on the 904pb's torque converter adaption. Turned an "adapter kit" for the job.
Took pictures with only two holes drilled & tapped, but all six're done now.

DSC00009.JPGDSC00011.JPGDSC00008.JPGDSC00005.JPG
 
Back at it.

With my manic level of Rose Parade work this time around finally over I got back to work on Cassi yesterday. I finished off the 904pb bell housing adapter, and assembled the engine/trans unit. Then started the job of tucking'er into the chassis.

First stab brought'er to 10.5" forward of target position, and 4" short of tucking behind the front cross member. Next up are cutting the floors & tunnel mouth to fit the 904's pan flanges, re-engineering the trans mount cross member to fit the new position, and cobbling up the bell & front engine mounts I've decided to go with. Then a bit of rework on the floor & tunnel mouth sheet metal, which'll finish the basic installation portion of the project.

Here're a couple pics of the process at the moment. I'll take some of the components at a later date, when I disassemble prior to final running assembly.

It appears I've forgotten to post that I'm installing this mill as a "slant eight", 28* off vertical, similar to the 30* of the slant six it's replacing.


5.jpg 3.jpg
 
Why so far forward in the chassis?? Would think that wouldn't be so good for handling. On the 320 installed in a stock car we made a "slant 8" in the mid 60's but to the left to put MORE weight on the left front. Not tilted as far as yours but made a BIG diff. in the handling dept. for our use.
 
Second stab.

Not lost, merely swamped with '17's float work. I got drawn in to helping out on three floats with various engineering problems, and having to do the whole job on three others. Tends to really suck up the calendar.

That was only the first stab, I use it to note & mark what cutting'll be needed to continue the installation. As noted, its target was back another 10.5".

Second stab has put'er in place, and I've cobbled up some very temporary "mounts" (a 1/4" pencil steel cradle under the front pulley, a chunk of 2x4 propping up the dist side, and just resting the tailshaft on the cross member for now :laugh_3: ) to hold'er there whilst I work out the real ones. Wound up with a bit more of a hole in the floor than I'd planned, but'll use the rework to grab a tad more room for the go pedal.

Here're some more pics ........


DSC00008 (1).jpg DSC00006 (1).jpg
DSC00003 (1).jpg DSC00010 (1).jpg DSC00012 (1).jpg
 
Engine mounts under way.

Have the outer plates of the forward two mounts in, along with the biscuit holders on the frame rails.
Also have the complete firewall/bell mount, but no pics of that today.
Still need to do the "web" plates of the fronts, but that'll have to wait for the 904's tail housing mount to be done, as I'll need to pull the mill/trans package to get the angles for the welder.

Here's a pic of the fronts so far, I'll take one of the firewall mount tomorrow ........

Front mounts.JPG
 

firstofeight

Active member
Pan question

I know you have probably worked it out, but would be interested to know the answer. What are your plans for the oil pump? It has a float that allows for sucking the oil from the top of the oil. I can't wrap my head around that with the slant.

Probably no big deal, but I believe that is an earlier engine than a '48 as you said in the first post. Buick changed from the front motor mount to a side mount in 1948. The 4-bolt pad is not there on your engine.

Ben
 
Engine mounts done.

Found time to work on'er again today, and got the engine mounts in. Not prettified yet, but doing their job properly. :cool:

Going to make part of the new tunnel removable this time around in order to access the front U-joint and rear trans mounts without having to go under in the future. That part of rodding tends to get boring after 70.

I'll re-angle the bottom of the pan to match the "lean", and adapt a slant six style pick-up to the Buick pump. I'll be giving up the floating feature, but see no problems in that department as the /6 style works very nicely on that engine.

The guy who gave'er to me claimed it's a 48, I don't know enough yet to verify. I believe the change over was mid year, so could be last of the old run? I've been trying to find out if all the front mount 248s were Babbitt, or if and when they switched to inserts, and if so whether it was at the same time. Unfortunately, my computer research skills lag considerably behind my rodding ones. I believe I've at least ascertained that the Babbitt & insert cranks are different, with the Babbitt being staged diameters, and the insert being like diameters on the mains. Also that the Babbitt crank will take inserts. Are these correct?

If, when I pop the rod caps, it's a Babbitt engine I'll have to make a decision, as I now have a 263 as well. Were the 263s all insert? I can pour Babbitt, having cut my teeth on 216 Chevies, but would likely go with inserts if I can. After all, this's to be a road car, and serviceable.


Anyway, here're some more pics ........

DSC00015.JPG DSC00002.JPG DSC00003.JPG

DSC00011.JPG DSC00012.JPG
 

firstofeight

Active member
Clarification. Hopefully

Glad to see the work progressing.

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.

I really like this project.

Ben
 
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.
 

Attachments

firstofeight

Active member
Mid year changs

Thank you ,sir. Did not know that. I am not sure I understand semi precision and full precision.

Am I correct on the rod bearing change? I sure do not want to mislead anyone.

Ben
 
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?
 

firstofeight

Active member
Engine number

Well, the 248 you have is a 1940.

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.

Hope I have helped.

Ben
 
Indeed you have, very useful. Thank you.

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. :cool:
 
Last edited:
Next pair of questions ........

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:

firstofeight

Active member
Heads

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.

Ben
 
:laugh_1: 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. :laugh_3:

DSC00001.JPGDSC00002.JPGDSC00006.JPG

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.
 
Top