The Stovebolt Site Forums The Shop Area Engine Shop Commercial 235?

Does anyone know if there was a commercial 235 used in trucks and vans? I have a 58 postal van bodied by Gerstanslager with Chevy drivetrain. It has a 235 with a 4 speed hydromatic factory installed. I didn't know if this was the same 235 as in the cars and light duty trucks.

My 1960 sales data book shows 235 Thriftmaster Special using updraft carb rated 135 gross hp and 217
lb-ft torque, offered optional HydraMatic.

Updraft carb because of the engine’s position in the chassis? Like for doghouse clearance?

The 1958 Vehicle Info Kit shows two HP ratings for the 235 engine. Conventional trucks were rated at 145 gross HP @4200 rpm with a "Thriftmaster Conventional Truck Engine", while Forward Control Trucks were rated at 135 gross HP @4000 rpm with a "Thriftmaster Special 6-Cylinder Engine".
The basic engine was the same as the cars, except for bolt-on stuff like BC59 mentioned with the updraft carb.

Kevin,
That was pretty much what I found as well. Mine, being a step van has the forward control. Thanks for backing up what I thought was what my truck had.

We like pictures!

Trucks also used solid lifters & cam. Cars had hydraulic lifters & key starter.
Hydramatic Trucks may have been key start.
Fred

I'm pretty sure all the Hydra-Matic equipped trucks were key start. I KNOW the GMCs were.

I'm surprised to see the HP rating at 145 @ 4200 RPM. That's the rating I've seen for the 261. Was the marketing dept. fudging the figures a bit to make a big sale to, say, the Post Office?

Check the block casting number- - - -you might have a 261.
Jerry

The 1958 34-35-3700 models came with the Thriftmaster Special 235, 145 gross HP @4200 120 net HP @3800 rpm and updraft carb as standard equipment.

In your book is there a HP and Torque curve signed off by the engineer like I've see in other data? Otherwise, how do we discriminate between engineering data and marketing data.

I have read that in other situations engineering was reluctant to sign off on something just because that's what marketing wanted. Such was the case at Studebaker when marketing wanted 10 more HP out of the same old 170 C.I. flathead six to meet the spec for the post office. So they held their breath and turned it to 4,000 RPM to make the number. Those engines had piston pin problems under the best of circumstances. Early Larks came with the flathead. Seattle's L.E. Belcourt got the contract for Seattle and when they went out of business years later there were mountains of NOS parts for 50s era Studes around Seattle. I drove a stock 50 Champ clear up till '84 and never had to resort to boneyard parts.

Similarly when Ford brought out their OHV six as the base engine they were still producing the 239 flathead V8. The six made significantly more power than the V8 so marketing insisted that it be equipped with a tiny carburetor to strangle it down. The racers quickly figured that out and went faster than marketing would have allowed -- Or so goes the story. Having worked on all these engines I'm inclined to believe the stories.

1958 chevy data book
235 page 33
261 page 40

HRL probably knows if this story is bunk or has merit since he built dirt track cars in the 1950s.

Not me, but my father built some of the fastest flathead V8s in the southeast in the late 1940s and early 50s. The flathead was one of the most underrated engines in production, and it responded VERY well to modifications and race tuning. While the 223 Ford OHV six might have given a stock flathead a run for its money if the six was race tuned, they wouldn't have been able to stay on the same lap as a well built flathead. Now the Hudson flathead six- - - - -that was another story entirely! Those things could "shake the trees and rake the leaves"!
Jerry

Yeah, and they were 322 cubic inches too. Flatheads in general tend to be underrated. Per the ATHS magazine, Dodge kept a flathead six for the big trucks even past 1960. It was 413 C.I. and made more torque at truck-useful RPM than the 354 hemi that replaced it. I believe you could order a rig either way for a couple of years.

BTW- - - -one of the stroker 235 engines I've got on the drawing board uses Ford 223 pistons- - - -3 5/8" bore, and a lower compression height from the wrist pin to the top of the piston than the 235. That allows the crankshaft to be stroked to 4 5/16 inches for a displacement of around 270 cubic inches and more torque than a 261. The 223 Ford six was in production until 1964.