Caveman tech - building a bellhousing for a flathead cadillac

[60 Belair]

looks great
lookin forward to the next segment

[zibo]

Originally Posted by captainjunk#2

great tech post , thats one burly welding table , looks like youd need a derek to move it keep posting as you build very interesting stuff

Its called an "acorn" table. Or so i've heard anyway.
These were at an old shipyard in San Diego, used since WWII probably.
They're great for bending stuff, hammering stuff, with heat.
I've made some all-thread clamps that hold things on for past projects,
so they've become more and more useable.

I guess there're also these wedge things that can go in the holes,
for pounding, i'll get some pics later.
(we used a crane truck and forklift to move em, heavy fokkers)

Will get some more updates soon...

TP

[zibo]

Originally Posted by brewsir

shweeet! You should have saved this one for tech week....great project!

The sticky post above said tech starts on the dec 15th,
but it just has to end after the 15th.
(hmm I better print that out for proof huh!..)
Anyway I've got alot more time needed to finish it so its shouldn't be an issue...
I think finishing it before January 15th is the issue!
TP

[tomslik]

damn you're ambitious!
ever think about using an outdated scattershield for some of it?
it AIN'T gonna pass sfi stuff anyway...


i vote this gets included in tech week!!!!

[T McG]

I am in the process of installing a 48 Cad flathead in a 40 packard. Weird combo but thats what the guy wants.

We went the easy route and bought the adapter from Bentsen. Fits like a glove but it was $800.

[zibo]

Yeah I considered it trying to adapt another bellhousing,
but the saginaw based ones are either cast aluminum or iron,
which is basically useless for this project.

The Bentsen adapter huh, cool that they make one for the oddball tranny.
kinda trying to save that $800 even if its only $2/hr after torch gas, discs, materials etc....

Well we have a ton of zinc chromated coated 1/4" plate,
which is nasty to cut, torch, grind and weld,
but its good stuff.


This is the start...



TP

Tomslik - Thanks for the entry vote!

[fiftyv8]

Dont you just love guys with no fear...
keep at it buddy.

[Flipper]

Originally Posted by fiftyv8

Dont you just love guys with no fear...
keep at buddy.

......and brains, tools, and skills

[InjectorTim]

Anything but caveman! Good work so far!

[PeteMattersen]

Interesting

[zibo]

Thanks guys...

While it woulda been nice to use less pieces and heat/brake-bend that plate,
it easier to get it more precise with the template-cut-weld method,
less grinding to fit this way.
TP

[Mr48chev]

That's quite an undertaking. How are you keeping everything square and true?e
Getting the trans mount plate square to the engine and having the input shaft on the trans exactly centered in the end of the crankshaft has to be a challange.

I could visualize a few of the guys milling the plates out with their Bridgeports but that is unreal.

[TV]

Travis, you always send chills up my spine. But I gotta hand it to ya, YOU THE MAN. We made something like that, but with aluminum and a big lathe.--TV

[Kevin Lee]

I like the galvanized templates.

[DYNODANNY]

This is some good shit CHAVES! keep up the good work. See you soon.

[ray]

Originally Posted by Mr48chev

That's quite an undertaking. How are you keeping everything square and true?e
Getting the trans mount plate square to the engine and having the input shaft on the trans exactly centered in the end of the crankshaft has to be a challange.

I could visualize a few of the guys milling the plates out with their Bridgeports but that is unreal.

that's the caveman part!

really though Zibo, i applaud your effort to make a bellhousing, but you really should have farmed at least a little bit out to a machine shop. you stand a real good chance of some driveline vibrations, or clutch chatter. the tranny and engine should be lined up within a few thousandths of an inch. that is possible with a homemade bell, but not really the way you are making it. being it is all torch cut and ground, there is nothing machined to come off of for dialing in the crank. the very minimum should be a nice round machined hole for the tranny to register in, with this hole true, you can fab up the bellhousing, and tweak it in using offset dowels to adjust it(or drill new dowel holes), and run an indicator mounted on the crank or flywheel around the hole in the bell. an even better option would be to leave the hole small, fab it all up and have a machine shop put the hole in based on the dowel pin locations, they could get the measurements off the block itself(preferred) or a stock bellhousing. the faces should really be flycut too, to ensure they are parallel to each other. when all is said and done, you will be very lucky if after all the welding the alignment ends up anywhere near where you think it will.

[DHD]

While I'm sure that the alignment concerns are well founded, why not wait until he's done and tried it out, you never know, the sky may not be falling after all.....

[30dodgeboy]

I'd recommend attaching a dial indicator to the engine's crankshaft and check the runout of the pilot diameter and trans mounting surface... before, during, and after the welding.

Maybe it is too late, but if I were in your shoes I would have made the trans mounting plate piece of the bellhousing a bit too small and then ground its diameter and face according to what the dial indicator told me.

Too much runout will cause the clutch to chatter as well as problems with the pilot bearing, trans input bearing, and clutch disc. If the runout were really bad, it could break the trans input shaft or tear the hub out of the clutch disc.

If you keep the runout down to acceptable levels (0.005" or less), your bellhousing will work perfectly fine. You can achieve that without going to a machine shop. I don't know if it will contain a clutch explosion, but that Cad engine won't buzz that high anyways. Excellent tech - who needs an adapter plate or kit???

[zibo]

Thanks for the machinist tips!

We do have a fake bridgeport to flycut? front and back, after everythings all welded up.

That tranny hole is so tight that when the tranny is inserted it makes a popping sound.
Its doesn't slide around even without the bolts.

There is a bearing in the crankshaft,
it aligns the input shaft.
Some engines have a bronze bushing which get a little sloppy,
but this one is an actual bearing.

The input shaft alignment is based on the slop of this bearing,
and in the line up "phase" I tried to shim the tranny up near the base plate
using something like a dial indicator to measure,
(basically had a magnetic pointer and feeler gauges)
and it wouldn't budge in there enough to be significantly measurable, esp. not 005.

Another thing I used was the throwout bearing and pressure plate arms to center everything.
Yeah this is relying on the circularness of those old arms,
but what i'd do is rotate the flywheel around and measure each arm (3) at different places.
Yeah the throwout bearing slips on that input shaft cover,
which has a little slop, but its very little,
and my thinking was if it was designed in the system then that was my allowable error.
even then there's no way its close to oo5 inbetween the bearing and the shaft cover.

Nothing was rushed really.

The main concern after all that was really the angles of the block/flywheel/tranny.

So when welding it will go in little inch sections symmetrical to the piece.

Hopefully it'll all work!

Thanks guys...

TP

[56sedandelivery]

UNBELIEVABLE! AMAZING! I'm sure any adjustments with alignment can be done after this piece is completed. That's some cutting/work table there. I'd never tackle anything this complicated; hat's off to you. But, the transmission is the old MUNCIE/overdrive unit, a Saginaw would be a bit stronger and be full syncro and came online around 1966. Nice work! Butch/56sedandelivery.