The Hydro book from '63 shows how much to cut off your fins and what stall rates you can achieve by mixing bowls, material removal and torus. It also mentions the need for the brazing, however I think TIG welding is todays equivalent. It's a great book and shows three ways to build street or race and covers several details like the pressure linkage build and adjustment and B&M mods vs other competitors. I've run a B&M and currently running a Hydro-Motive (B&M's left coast competition), there are slight differences in the builds but all handle the same. Starters were mentioned above: If your using the truck bellhousing you must have the rare truck starter $$$. That starter is only for the GMC V8 application and not interchangeable, it features a longer snout and armature shaft to reach deeper in the bell housing to hit the flywheel. If you can find the B&M bell housing (C-5 CF-5?) its mount is offset so you can use the common car 3 bolt starter. Finding and buying a B&M bell housing is far cheaper than truck starter cores. On one of my B&M competition models they cut a chevy flywheel and bolted it with spacers to the original bowl/flywheel to get it closer - its crude and may work on a race car but not sure how long it would live on the street.
Thanks for the great information! Any possibility of getting a copy of that part of the book on torus and pressure linkages. Happy to pay for what ever you want for a copy of those pages. I am running an Olds engine with hydro so it’s a lot of just bolts up and the starter bolts to the removable lower part of the bellhousing . Let me know about the copies. Thanks
I'm dragging out my book this week, I got my copy from Autotran (Dave Edwards) here on the Hamb - he also has a pdf version. He's you best bet for parts and his site has great info http://www.autotran.us/ Middle of this page in purple for the book details: http://www.autotran.us/hmparts1.html
My B&M Hydro Stick trans is a Unblown Competition version, built by B&M back in the 1960s from a 1954 Olds slant pan dual range Hydra-Matic, It still looks new and unused inside, I got it from my good friend Ivan's estate, after he passed away, I had to buy the two piece 55-60 Pontiac V8 bell housing, and the furnace brazed fluid coupling halves, finding the brazed coupling halves was a stroke of luck on ebay, removed the slant and side pan to inspect internal condition, installed new selector shaft and throttle pressure shaft seals, new bottom and side pan gaskets, the B&M floor shifter was incomplete, which is ok, since I will still be using my 1953 Pontiac Chieftain steering column shifter and 1955 Pontiac gear selector rod and nos trans levers with nos rubber bushing, the Pontiac engine I am putting in front of the Hydro Stick is a 1959 389 high compression version, changed from the two barrel 2gc to a Pontiac four barrel intake manifold with a 692 cfm Rochester 4gc 4jet carburetor, not trusting my 1953 Pontiac's original 8.8 ten spline axle rear end to the torque of the 389, and the harsh shifting of the Hydro Stick, I am swapping in a 1957 Pontiac 9.3 rear end, 29 spline axles, and 3.23 gears. The shift pattern of the Hydro Stick is N, ^Drive^, Low, First, Reverse, so 1-4, 1-3 untill 70mph then 4th, Low is 2nd unless full throttle brings in 1st, 1st only, reverse.
My latest project that's B&M Hydro Stick related, going to deepen the slant pan with a flat pan turned upside down, the deeper pan will be 1 1/8 inches deeper, to allow a large aluminum heat sink to be what the screen filter will now sit on, the heat sink will be welded to an aluminum 1/8" plate the size of the pan mounting flange, another heat sink will be welded to the outside bottom of the plate, to shed the absorbed heat it took from the trans fluid to the under car air flow, a fluid cooler with no moving parts, both internal & external heat sinks have 1" fins on a 1/8" plate, 35 narrow V shape fins going the length and width of the pan, about 770"x 1" cooling fins on each side of the plate that will now be the deeper pan's bottom, deeper pan will now hold 2 more quarts of fluid.
You valve body has the B&M 1st gear hold valve that fits into the front governor feed tube. Stock trannys only had 'LO' position which was 1st-2nd which served as a semi torque converter for the fluid coupling. With the 1st hold valve installed, you need yo file a detent into the flat between 1-2 and reverse/park which yours has. I converted my '54 Willys flat pan Hydro by making my own 1st hold out valve. With the valve installed and the detent added, the only other modification was plugging a vent hole in the cast iron case behind the valve body with a small hex set screw. Here is how your unit has been modified to honor the 1st hold valve. I think the image of the stock valve below is a mirror image! The bottom one is the correct orientation. If your tranny is locking up in R/P/1st area my guess is your B&M valve is misadjusted. the picture below shows how it should be adjusted. Hole is open to governor tube in 1st position, fluid dump tail in R/P position.
Interesting note; racers usually started in LO instead of first gear. Since the Hydro has a torus and no torque converter, GM engineered the LO position for a quick 1-2 shift to act as a poor-boy torque converter. That shift had to happen so fast that racers simply let the tranny do it then go to 3rd and 4th manually. Thus the patent that 'made' B&M was mostly useful for off roaders to jog back and forth to get out of a bog!!
I had a slant pan hydro behind a 371 Olds. The hydro was stock as far as I know, the 371 not so much. That Lo 1-2 shift made the hydro the slush box of choice (in my mind), a very close choice to a 4-speed manual IMHO. I also thought the ungodly weight of the hydro was some sort of guarantee of strength. Being used in WW2 tanks and heavy dump trucks among other applications, I guess it was!
I have the original Dual Range Hydra-Matic operating instructions paper sleeve, that new car buyers and owners would find slipped on their driver's inside visor, selecting Low results in the transmission starting and staying in Second gear, not First gear, if a lot of throttle pressure is applied, then there's a down shift to First and the governor or letting up on the throttle causes the return shift to Second.
Having concerns about the slant pan bottom metal condition, I decided to buy another one, this time from Fatsco transmission parts in New Jersey, I was pleased that they were asking $50.00 plus $22.00 for shipping, it came today, and it is in excellent condition for being used, thank you Fatsco.
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