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.


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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/sho...rence-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.

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.

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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.


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Thought we had lost you! Slant eight. Different

Ben

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.

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 ........


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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 ........

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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

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 ........

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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.

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?

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:

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.

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:

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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.

Also did a (very) preliminary mock-up of the carbs. They'll actually mount about 5" lower in finish position, but the manifold (to be) length looks pretty close. :cool:

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Couple weeks worth of set-backs. Had to take this week to get our Rose Parade float chassis ready for its first inspection of the year this Saturday. Called a Mechanical Inspection, or MI, by Tournament, it's one of three required to participate in their parade each year.

Next week's out as well, as I'll be readying my HAMBster for Randy's "Dragfest" the following weekend. I'll be back at it though, the following week, and hope to have more pics for those interested.

Be cool. :cool:

​Well, got a couple more days to fiddle about in the garage. So ........ cobbled up the spoon gas pedal, and did the initial carbs mount. Used a head flange set I found through the site here, some EMT I had laying about, and a bit of plate for the carb flanges. All in all a nice couple days. Hope to get in a couple more in the next few weeks as well.

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Quote:

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Originally Posted by firstofeight

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

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Ben,
Yes, factory info indicates 1949 engines used inserts in the connecting rod bearings except for about 5000 built at the start of the model year.

Precision was the factory's preferred term for insert bearings vs. cast-type for Babbitted bearings. I take it precision refers to non-adjustable bearing construction. The Babbitt bearings were installed with shims which could be gradually removed to adjust bearing clearance and compensate for wear.

The meaning of semi-precision is still not clear. It may be explained in the '47 Shop Manual supplement as it pertains to the interim late '46-early '47 part numbers. I'll try to pick up a copy to learn the answer.

Managed a bit of playtime today, so added the balance tubes to the intake.
Also started swapping parts from the 6 garbage SUs (I got in a parts swap awhile back) to paste together 4 that'll work. Number stamped the intake runners & carb bases so's I can keep'em in order in the future as well (beats juggling'em :laugh_3:).

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Got in a few more play days, so did a bit more on the throttle linkage. Also got the rear brakes & parking brake functional (fronts need new drums yet), fuel system complete from tank through pump, and roll bar added.

Then rolled'er up to the HAMBster's trailer so I could bring the HAMBster down to go through the bottom end. Musical Cars is pretty much the name of the game when you hobby out of a 1918 one car garage. :laugh_1:

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Well, Kiddies, all the hoopla from this year's Rose Parade was finally over by the end of February, but I had to take most of March to make some drive train changes to our float chassis. But ....... at last I'm back to the garage.

Got the "common" shaft cobbled up on the throttle linkage, it's now functional to there. Went through the four SUs, and ordered the parts & pieces I'll need to get'em functional. And dug out the Willys Knight dash switch set-up I built for'er back when.

Also butchered a couple of second gen slant six rocker boxes to make a cosmetic "cap" for the Buick one. Just one of my oddball notions, may actually use it if it turns out decent enough.

Next up're the levers & drag links for the throttle. Burlen wants more than I can justify for their repros, so it'll have to be another cobble.

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he's back! the gangs all here!

do you think you're going to make the Lake this year?

Up in the air on that. I agreed to another year with both Cal Poly's and Sierra Madre's Rose float programs. With those and the drag racing, it tends to rather well saturate a years worth of weekends.

But, I'm putting the 'Brick up for sale this year. I've been racing'er for a decade now, and really want to get back to the street with Cassi. Once she's gone, and I'm back on the street that'll open up time for other meets and even some local runs & shows. So, pending that sale ........ :cool: