Hot Rods How to Make Engine to Tranny Adapters.

Gee Rich, based on my failures, I must be Einstein!!! LOL!!

 

Very wise observations...
...and since people don't like to advertise the failures we'll probably never hear about them.

To those considering trying it, I say go for it. What have you got to lose? some time and energy, maybe a little green stuff? If you can't get it worked out then you are back at square one. My attitude is that the only difference between me and the master builders is tools and experience. You don't always have to have high tech, high dollar tools to get results. Sure, they make life a whole lot easier, but you can get results with a little brain work, determination and perseverance.

Bobby

 

I agree, go for it!
Actually, I walk guys through the process on a half-way regular basis. I even have the EarlyHemi block pattern posted on my web site for that group of 'inventors'...
Having the desire is important, but an individual must also have some decent mechanical aptitude and spatial visualization skills. The basic tools are the easy part.

.

 

Here is a youtube video using a plexi sheet to map the holes for an adapter.

http://tinyurl.com/y6vyqlk6

Nick

 

Man that is a great idea for making a adapter plate template.

 

There are a lot of ways to do things. Transfer punches are the quickest and most direct way to locate bolt holes that I know. Right on your work piece. What gould be better?

 

There are 2 kinds of adapters one between the block and bellhousing that is indexed off the crank usally off the pilot bearing and the other between the bellhousing and the trans and they can be indexed off the hole for the imput retainer.

 

Yeah. I don't think you ever said what engine and what transmission. A SBC to a Chrysler semi automatic might be different from a 392 to a T10

 

Those would have been very helpful to me!! I had a set of the smooth bore transfer punches but it didn't even cross my mind to look for a set of the short threaded style. I basically fabbed my own by cutting a bolt down, chucking it up in the drill press and filing the end down into a point.

Thanks for sharing that
Bobby

 

When I first made the jigs to build tranny adapters - 700r4 to Hudson, and GM to Stude and Packard, I made a mock up of the adapter plates using thick plexiglass to get all the bolt holes right, then I copied it to steel, then made a "hardened drill bushings" drill jig for repeatable exact hole locations. Once the holes were exactly where they should be in the master jig, it was a precisely-repeatable drill press project after that. The precision drill bushings kept the drill bits accurate to 2 to 4 thousandths. Good enough for bellhousing bolts.
Tomorrow I will dig out my alignment jig and get a picture of it to post here.
Basically it was a large precision-ground hardened steel shaft that clamped in the main bearings of a block I used as a master pattern, and ran thru the machined bearing bores of the various transmission cases.
That gave precise alignment without spending huge amounts of time dialing things to a crankshaft flange.
Once I dowel pinned a small crank centering plate to the adapter, using my jig, the adapter plate could be put on any engine quickly, and it automatically centered to any engine you put it on.
My Studie truck is still running the same 700r4 I put in around 1990 (I used a th350 for a couple years 1988-1990) and after more than 20yrs still has never given any indication of a flexplate that needs replacing yet. That tells me the alignment worked out great.
I eventually sold my patterns, but I kept my alignment jig.
I'll try to dig it out and take some pics so this makes sense when you read it again.



why be ordinary?

 

I made my straight 8 Buick to 63 or newer Chevy bell housing adapter and went by two rules: the center line of the crank and the one of the trans main shaft must align exactly and the dowl pins must be located exactly. After that the rest if just fitting flex plate to crank and making whatever spacers are needed to get stuff in the correct position as far as front pump and starter ring gear are concerned. Don't even know what "CAD" is unless it has tail fins but do have good measuring tools, an old flat belt lathe, and a Taiwan vertical mill I paid $500 for years ago. Here are some pics of the beginning of a prototype, final one in steel, and do have some of the 350 trans in old 37 Buick but can't find them.

 

^^^^^ This is what I suggested earlier, using a "bar" in the main journals, like the dragster chassis guys use to keep a centerline. Never thought about using a driveshaft however. I am Butch/56sedandelivery.

 

Yes drive shaft and transfer punches are two great tips for the uninitiated amongst us...
I am keen to see the pic's "dare-to-be-different" is planning to show us soon.

 

Yeah I have made some of them myself. But a set used to be around $10 and they are still under $20. You get the holder installer with it. Pretty neat.

 

You guys are gods.
Granted, probably the foot hills of Mt.Olympus, but none the less...

 

Well, I am probably too old to attempt to build an engine/trans adaptor. I hate wasting good material where someone with the desire to may succeed. I do have a rather weird adaptor I came across a few years ago. It mates an early Hemi to a V-8 flathead trans. It seems strange that one would spend the money to manufacture such a rig. The first, and every time, one puts his foot into the firewall, he will be searching for another flathead trans, gears, case, shafts. Anyway, it is a nice picture frame.

 

Why not just use your Y block Flywheel and get the proper Clutch or Torque converter to adapt the 2?

 

I used to do all my work on graph paper and used cardboard mock-ups and prototypes from plywood. Now I go with CAD drawings and I can paste that 1:1 on something and try it out. I've also got a pretty good pile of "test" parts that did not work out so well. Foam board from craft stores is great stuff, so are hot-melt glue guns.

I tend to back up all my designs so I can go back and make adjustments as needed, or make another part for someone else. The beauty of CAD is to get the all the Z-axis numbers down cold.

I also find that on older parts, they were often laid out in fractions. So you get close with a measurement, round it up of down a tad and you have a number you can trust. And not overly dimensioned, things come in at the 1/6", 1/8" incremental marks quite often.

 

becuase it's for a b&m hydro and i need to use a pontiac hydro flywheel to bolt up the torus. i have the aluminum bell adapter, i need the crank adapter.

 

pictures are gone,... but still pretty useful thread
https://www.jalopyjournal.com/forum/threads/shoebox-flathead-to-t5-adapter-plate.625273/

 

Amen to this!........I have an old polished Crager one hanging on the wall and I just keep it for laughs when guys come over.

 

Here's mine. Sorry it took so long to dig it out. I hope you can see thru the dozen-year dust coating
On the precision ground shaft, I slide on different size bushings to fit the main bearing caps of whatever brand engine I want to fit.
The old wrinkled duct tape merely holds the "main" bushings from sliding out of position until the main caps are tightened.
This rig allows easy quick bellhousing-plate alignment to a variety of engines.
My regular Studey is still running on the same flexplate for over 20 yrs so far (late 1980s?), so that tells me the alignment was good

This particular one is for adapting the Chevy and B.O.P. bellhousing patterns to odd makes such as Stude, Hudson, Packard or whatever else you please.
I even used it once to make a starter mount plate for a Chevy guy who had a truck block from the 50s that was too old to have the usual GM starter mounting on the engine block. His Chev came with a bellhousing starter he couldn't get repaired anywhere, and he wanted a modern chev trans but the engine had no starter mount surface. I used this rig to make him a starter mount plate to mimic a bellhousing mount.





why be ordinary?

 

Many early Ford transmission were mounted up behind drag cars and land speed race cars and many of them were running Hemi's. The Chrisman Brothers went 196mph with a 1940 Ford side shift trans behind a Hemi in 1955 in their coupe.

 

215 Oldsmobile engine.......TH350 transmission......$950 store bought...comes with mini starter....NOT
Place the engine nose down. Mount the Oldsmobile "automatic" flywheel" that has 11" centered holes around the outside edge, same as a TH400 torque converter. Install pointed bolts in the engine bellhousing holes. Bolt a SBC to BOP adapter to the trans with the torque converter in place and place on the back of the engine. Align the torque converter to the flywheel outer holes and bolt together. Rotate the trans to align with the center of the engine. Tap the adapter to mark the hole centers for the engine. drill the adapter for the engine bolt pattern. Determine what spacers are needed to put the torque converter in the pump at the right depth.

 

Find a copy of the "Complete book of engine swapping" No.3 by Tex Smith from c. 1970. It has a full chapter titled "Homemade Adapters"...

 

Alignment dowels are available once you are close. Anyone know the depth of the 317 truck bellhousings?
Thanks

 

I started this thread way back in pre-covid days of 2017.
I have just read thru it today and must say thanks to all of you who have contributed.
It been a broad and good education for first starters particularly.
I beleive personally I hold very little fear now should I choose to do a homemade adapter from scratch.

 

Oh and I like pictures they do help...

 

The hardest part is where to start all your measurements from. From the crank flange, or the block mounting surface are common ones. I take it as a challenge. Make the whole dealie out of plywood and bolt it together for a fit-check.

Remember that all those pioneers of the 1950's that did the craziest of swaps or 4-engine dragsters had rudimentary machine tools to use. Or they had friends that worked the night shift at Grumman or Boeing.

 

WOW. Who is this ?

Ben