The Stovebolt Site Forums The Shop Area Engine Shop Rear motor mounts - 216 to 235

I know that a lot has been posted here regarding this subject,much of which has been very helpful. But I still have a question regarding the rear motor mount. I am restoring a 46 1/2T and swapping to a 55 235 engine. I would like to mount the 235 in the same way as the 216 and avoid any frame mods. My 55 235 came back from the engine shop with the 235 bell housing, all sand blasted and painted - I would like to keep it. But the mount location on the rear of the 55 bell housing is at a different angle, eliminating the use of a 46 engine mount. Does any one have a solution that I can employ?

You will need to use your 46 bell housing.

Well, thanks for a response. But the engineer in me just can't accept a simple "can't be done". It may be prohibatively expensive or difficult; on the other hand, I REALLY don't want to disassemble the bellhousing, clutch, etc. in order to put the other bellhousing on. I will have to study the problem. Can you answer a question about the 216 mounts, though - I understand how they bolt to the engine, but it then appears as though they simply 'rest' on the cross member, relying on the teh mount at the rear of the transmission to hold the rear on the engine down to the frame. Am I missing a second piece?

Thanks,
Bob

First, it is not a matter of 216 vs 235; it is matter of 1955 vs 1946.

From 1954 and newer, there is no need for a transmission rear-mount because of the angle of the rear motor mounts on the clutch housing and the frame cross member from 1954 onwards.

Use your 1946 clutch housing with your 1946 clutch assembly, unless you have converted to 12v, in that case use you 1955 flywheel with the 12v starter (with your 1946 clutch housing).

The '216' mounts / 'rest'

If that engineer trait whats to use that shiny new bellhousing,the angle mounts will require the same specs to mount to frame. Modification has never been a challenge to this old wrench. I hear ya.

As I recall, the transmission does infact position on the cross member, however the mounting is shy of the original mount spacing on the bellhousing. Letting the bell mounts ride free will permit torque to load at the transmission mount. Good luck with your study.

How about the mounting for your clutch and brake/master cylinder, will you lose that with the 55 bellhousing?

Unless you did not mean what you said the 46 bell housing is the only way you can go. If you want to modify every thing then the possibilities are there.

The bell housing mounts do not just sit on the cross member, they have a 7/16" bolt going through each mount and cross member.

Homer52 also makes a good point in that the brake/clutch mount attaches to the bell housing on a 46.

One more question, what transmission do you plan to run?
Your 46 trans has a different bolt pattern then the 55 bell housing.

You are correct. There are some interchange, but not all is right with the required application. I will ckeck the 55 cast iron bell in the morning. It was an option for the 350 small block. It mounted up to the frame via kit mount. The 55 bell mounted to the '49 4 speed. For ten years, the project was idle. My solution was to bring the 216 back to life. I have done some modification in the past, but that is in the past. For the 350 to set in, the heart of the firewall was cut out for the HEI. That alteration has been resolved. The 216 is in the engine compartment and the 3/4 will make it's debut mid Jan from the paint shop. I will get the specs on the 55 bell in the morning.

Sorry about not getting back to anyone sooner, but there some info to digest. Let me start with - the 46 4 speed transmission does seem to bolt up to the 55 bell housing. I had not considered the brake and clutch - might be a problem. I am still in a quandry over the motor mounts. Even the 46 mounts seem to have an issue. The Master Catalog calls out p/n 3702173. They bolt up to the engine, but there is no way to bolt them to the frame, unless there is a second piece involved. I would really like to see a picture of the stock engine mounts when installed in the truck.

I sent 2 photos to the e-mail on your profile. Dave

Hey, thanks. Your photos really blew me away. It appears that the bell housing that I took off the original 216 is not even a chevy part! Go figure. my old bell housing has mounting pads that angle down wards to the center, where your 41 housing has mounting pads thatr are essentially verticle - the same as my 'new' 55 bell housing. 41 and 46 used the same bell housing. It appears that the 55 used a similar housing with minor differences - notably the mount for the clutch and brake pedal. Changing that around seems significantly easier than figuring out custom motor mounts.

I have no idea where the old bell housing came from. The casting has the number "GM3838315" cast into the face that bolts to the block. I suspect that the truck belonged to an old rancher that just replaced parts with something that came close to fitting. The front springs don't match each other and neither matches original equipment.

Thanks alot,
Bob

FYI. If you go with a 1938-46 bell housing, the transmission you have that you said fit the 55 bell housing, will not bolt up. Some one also swapped out the transmission.

I certainly won't argue that. But what is the problem - distances across the bolt pattern, depth of the input shaft, what?

Bob

The big hole in the bellhousing is too small. and the bolt pattern for the transmission is different. 1948-1954 bellhousings will have the correct transmission pattern, but will not have the mounting holes cast into them for the brake and clutch pedals. Jim Csrter use to sell a modifoed 48-54 bellhousing for putting a more modern transmission in the prewar and deco trucks. This Modified bellhousing will bolt to your engine, chassis, pedals. and transmission.

Bigbadswingdaddy,is this what you are referring to,he does list them in the catalog. bellhousing


Tim

Final update on my progress. There has been a lot of confusion. It appears that the 55 bell housing (the one that I have) has the same mounts as the 46 should have had. It turns out that the bell housing I had never belonged to a 46 chevy p/u. Don't know why it was there. The 4 speed tranny that I had does fit the 55 bell housing - just finished mmounting it. Maybe it was also not from a 46 Chevy truck. The front motor mounts I will modify as mentioned in the tech tips. Brake and clutch mounts - well, I figure that it can't be that hard to fab some sort of mount - it does not represent the structural support constraints of an engine mount. Sky hook maybe? One last questgion regards the transmission mount. Some suggested that this would not fit. Can I get some more thoughts on this - what is the problem of not including it?

Thanks again for all the input.
Bob