Technical B&M Hydro-Stick Hydrostick

OK I know this might sound crazy but this is one of those things I'm 99.5% sure of but figure Id better ask the gurus before being wrong and spending a bunch of cash.

My questions is I have a 51 hydro-matic that backed my 303 olds. So if I was to buy a B&M Hydro-Stick configured for something else could I just changeover the bell housing and tail shaft and have it work on the 303 olds? A inquiring mind needs to know.

And secondly what shifters can be made to work on the Hydro-stick?

 

As far as I know there are two flywheel/torus cover sizes; the 18 bolt, 12 3/4" (Chevy) and the 30 bolt, 14" (Olds/Cad/Pont). Please note these are rough tape measure measurements. There may be more but I've never played with a Lincoln or Packard or any of the other orphan transmissions. According to my sources, the torus wheels and cover are interchangeable from transmission to transmission. I have a B&M Hydro that was adapted to a Nailhead Buick in which they incorporated the smaller Chevy size flywheel and torus assy. I will be removing the Buick adapter and the Chevy torus assembly and replacing it with Oldsmobile parts to put the B&M Hydro behind my 324 Olds. I have gathered all the parts but I haven't done the swap yet. The Olds bellhousing should bolt on no problem, you just need the correct one for the style of trans - straight pan or slant pan. The difference in the bellhousings is obvious.
As for the tailshaft, I would just modify my driveshaft as required unless you are comfortable tearing apart automatic transmissions, it's not just an unbolt and pull it out affair. I'm pretty sure you would have to get deep inside to change the output shaft. Look for PhilAs thread about his mild custom 51 Pontiac. He tore his Hydro apart and did a swell job of documenting the tear down and reassembly. You should be able to see from his thread what will be required.

Now my question, (should the real Hydro experts chime in here) is: could one use the smaller Chevy torus wheels in the big Olds cover and maybe get a little increase in stall RPM? Or can you only raise the stall speed by trimming the vanes on the Olds wheels?

 

https://www.jalopyjournal.com/forum/social-forums/hydro-tech.671/
https://www.jalopyjournal.com/forum...hydro-stick-installation-instructions.147409/

I had an identification table but it seems to have disappeared (Computer crash), it had details of types and models; street/strip, competition, blown, unblown et al.
I have an original 1963 manual "the hydro - building the hydro for street and strip"stored somewhere.
The above HAMB group may have information or be able to provide assistance

 

@Speedy Canuck might be able to chime in here.

 

Yeah, that one I can answer. The output shaft slots into the reverse ring gear housing, and that's more disassembly than most want to be doing on an automatic transmission in order to get it out (tailshaft plate off, lower pan off, 6 bolts around the periphery and then the mainshaft and planets will all pull apart, the shim might stay put but it's a fiddle to do).
Not impossible because I managed it but truthfully it would be easier to modify the driveshaft to fit the application.

The torus can be changed without having to dig inside the gearbox at all (added benefit of keeping it all clean too).

Phil

 

I used to look for a hudson torus to use for a Chevy v8 swap.

 

It looks like the Hudson used the smaller 18 bolt torus cover like the Chevys. Being a six cylinder application I wonder if the torus wheels had different blade shapes or angles.

 

Two up grades I remember in building the hydros were dynaflow clutchs they were flat instead of wavey and you could add one set and powerglide delevery sleeve seals.

 

Man I have one of those for a Chevy, someone needs this thing. Just getting over hernia surgery, wonder if moveing that chunk around had anything to do with that

 

Only real answer there would be on the part number list. The Pontiac specified 6-cylinder and 8-cylinder boxes have a number of internal differences, then again into the Cadillac specified ones.
From what I read in my Pontiac rebuild manual the torii are the same with the same stall speed, with the clutch packs being the primary change to accept the higher torque from the bigger engine.

The Chevrolet engine plate appears to be thicker than the one on mine, I guess two factors there- a heavier flywheel because the outer shell of the torus is not very heavy at all, plus the thicker plate would resist the pressure of the oil inside better without flexing, with the smaller diameter requiring fewer mounting holes.

Phil

 

I believe that the Chevy versions used an O-ring instead of the paper gasket to seal the torus cover. A big improvement that may have allowed them to use fewer bolts. But, it appears as though the Hudson used a gasket and fewer bolts (?) The gasket must have worked ok, I don't remember ever having a leak from the torus cover or crank interface, just pan gaskets or rear seals.

 

The bell is separate on the slant pan. if you are already running a slant pan hydro you should bolt right up.

 

Relief pressure on the 30-bolt ones for sure is meant to be 40psi so holding that kind of pressure in with an inch of paper and a flat surface isn't that hard. And yes. The rear seal design is mediocre.

Ultimately if the vanes of the torus are 90 degrees then the main factor affecting stall speed would be clearance between the two sets. Mine is bone stock and stalls at about 750 RPM- in 1st that's nearing 1000 engine RPM.
How that compares to the smaller ones?

 

https://www.jalopyjournal.com/forum/threads/ansen-posi-matic-hydro-shifter.913252/

 

OK that brings up another question, my Hydro is a 51 and not a slant pan. I just checked and the bell housing is bolted on. So do the non slate pans have the same bell housing bolt pattern as the slants?

 

now that is a question. I am not sure. I have fooled with a few slant pans (which is what B&M used for a hydro stick) but I have not played with the earlier transmission. Someone here no doubt knows that answer.

The V8 block should have the same bolt pattern as other rocket motors.

 

Pics of the inside of the Hydro-Stick I'm looking at picking up. You all see anything I should be concerned about seeing how its been up for sale for at over a year!!

 

The '51 is not the same as the '53 -'55 Dual Range hydros the the big tranny guys used for racing apps. There are differences in the valve body - Dual Range allowed holding unit in 3rd whereas the older unit always shifted automatically into 4th. Also the earlier trannys had different method for holding in reverse. That being said the early units are plenty strong and were also routinely modified. Many parts are interchangable.

I agree with the advice above, swapping tail shafts is a major tear-down and as I recall requires removing the rear pump/governor. You need an alignment tool to remount the governor.

My tranny is a '54 Willys Dual Range. It was a low duty unit with fewer clutches and 3-planet gears vs. 4-planet gears in the big engine units. My adaptor was made by Drag Machine sold thru B&M for my '52 long bell housing 331 hemi. It came with a 30 bolt flywheel for the big Olds/Pontiac torus can. I found a small Chevy torus to run in the big can as mentioned above to get a higher 'stall speed'. Finally I found an old tranny shop in Fresno when I was attending Fresno State, 2008 NCAA World Series national champs, in 1970 who showed me how to do the B&M modification to hold the tranny in first gear. I machined my own slide valve, plugged an exhaust hole in the iron case, and ground a new detent in the shift cam. Works like a champ. Humorous note; the 1/2 shift in these boxes comes very quickly when accelerating. It simulates a torque converter's torque multipication off idle. Drag racers all took off in second gear to take advantage of this design feature. Thus the patented mod that made B&M famous is only really useful for rocking a 4-wheeler out of the mud.

Point of all this is Hydros are great trannys, pretty easy to work on and modify, just depends on how deep you want to go. I recommend these videos to all guys interested in knowing more about their baby.

My tranny


Still has the big torus in this photo.



A Willys Hydro in my '36 Willys coupe!



this is the B&M valve that is insertred in the outer governor tube. It us actuated by the iron flapper arm above it. Other tranny companies did the same mod but couldn't use this patented valve. They did some mods to the valve body, drilled holes and a jumper tube. As mentioned above, it isn't really necessary even for a race unit.


This is the adaptor my folks bought me from B&M in '67 as a high school graduation present!

 

More great info from one who is actually running one.
I believe the bolt pattern on the front of the main case is the same for the slant pan and the straight pan just rotated for a smaller hump in the floor. I would verify and post measurements but my Hydros are packed away and difficult to get at.
The torus wheels shown in your pictures appear to be modified for a very high stall speed. The fins are usually flat across the face and undercut like yours to varying degrees to increase the stall RPM. Here's pictures of stock Olds torus wheels. Also note that the fins are just mechanically fastened by bending over two tangs. If you look closely at the ones you posted I'll bet you will see that they have a gold solder-like material flowed around the tangs - they were usually furnace brazed for high performance applications.
The bellhousing/adapter shown looks like an adapter for a Ford FE or Y-block (note the 3 5/16" bolts for the bolt starter) and the torus cover looks like a 30 bolt Olds/Cad/Pontiac. If he has the flywheel you have a complete Ford/Hydro adapter that you could sell to help offset costs. It's got to be very rare these days.

 

I put a 55 hydro in a 55 Chevy in 67. I could buy all the conversion parts new from Chevy. I think I changed the pan to flat. It has been awhile. The thing I found interesting is a guy in LA bent the vanes to give me some stall speed. He did not cut them as was the norm at the time. It launched fine but also locked up fine. It was a 283, tunnel ram,cam,etc. It would shift out of first before I went 60 ft. It was fun but I think it was a mistake. The trans must have weighed 300 lbs.

 

Yeah some of the hydro builders bent the vanes using a special tool and a checking fixture. It worked fine for street applications. I watched Donnie at C&O do that when I was a lot younger, looked easy. I'd like to try it but I'm afraid that I'd get them all done, looking great and then realize that I bent them the wrong direction. I have an internal radius cutting tool for my lathe, if I can find some extra torus wheels to experiment on.

 

That is how it is supposed to shift. Since a torus does not have the torque multiplying feature of a torque converter, GM engineers used the 1/2 shift to get that advantage. The B&M patented valve they put in their units provides a detent to hold the tranny in first. Racers didn't use it since the shift point comes up so quickly. They started in second as designed.

 

If you are considering cutting the vanes on the lathe, be careful. The tranny shops furnace brazed the fins to the the shell to prevent then from pulling out while machining. Probably can't machine them without that protection.

 

Yep, I’m hoping to find a place that would furnace braze the fins somewhere here in NorCal, anywhere for that matter. I wasn’t planning on a deep cut, maybe 3/8-1/2” deep. I’d be happy to bend them if I knew which direction and what angle.
Are you running the smaller Chevy torus wheels in the large cover? Did it provide more stall speed?

 

The one I have, was told it was on the back of a 348 powered drag car.

 

That's the good one. Short tail shaft, Dual Range ('53 plus two band adjusting screws on top), flat pan, small Chevy torus for marginally higher stall speed. Chevy bell housing so if you are running a SBC you are ready to go. Doubt it has ever been modified or even opened in view of the stock factory paint still there.

 

I should pull the side cover and have a look see.

 

Yes, that's my setup. Physics tells us it must have higher stall speed but I have never tested it. My Willys has all the correct old parts; Hydro, '56 Olds rear, 354 hemi. 'vair steering gear, etc. I don't want to break anything so it is just a cruiser! Hydro and 3:54 gears I am very happy with its responsiveness. In fact I was happy with the 3:23 gears it had but I stumbled across the vintage 3:54 pumpkin so changed it in for vanity's sake.

Torque goes up with the square if the diameter so the 12.75" Chevy torus has a 2 - 3% less than the 14" Olds at a given speed.

 

If it is a B&M it might have a slide valve and that is a sure indicator of a beefed unit. Probably not a B&M since they replaced the factory ID tag with theirvown thin aluminum ID tag. If another tranny shop, that won't help 'cause they did reverse hold with valve mods. Look for an extra notch ground in the shift lever. That is for first lock.
B&M indicators



If it has a notch cut on the long ramp shown by the arrow, someone has modified it to hold first gear and it probably a beefed up unit. Doesn't really matter, these things were first designed for military tanks so are pretty much bullet proof from the factory.

 

Thanks for all the info guys I pulled the trigger and brought the Hydro-stick.