Inliners International Forums General Discussion Drive Train 58-62 - 261 into a 52 hardtop

I have a 61 - 261 sitting next to my 52. I understand the the orig 52 side engine mounts could be modified to get the 261 in the car. Can anyone help?

I just finished looking at side mount options for my 261 but doing it in a truck. Side mounts that attach to the 261 engine would fit from a 230, assuming you have the triangle bolt holes on your block like I do. From there you can adapt either the other half of the 230 mounts or something fabricated. I know somebody has done this before.

I'd be interested to hear from experience on this too. I've got a 59 261 sitting beside my 53 150 sedan. My 261 came out of a '50 truck and appears to have been front plate-mounted. I'm debating whether to use that or adapt the stock high side mounts.

I managed to scrounge up this pic on the HAMB.


This guy used his stock (53?) mounts cut down and fabbed a triangular adapter plate. You can certainly see the triangle mount for the late block and the top hat from the early side mount. Not entirely clear what the bottom bit is but I think its the part with the old bolt pattern that gets tossed out.

From the image one would guess either A: this didn't work; or B: the late triangle side mounts and the 52-54 high-side mounts are in the same location on the block (ie: this locates the engine under the hood so that the bell housing mounts fall in the right place and the engine doesn't end up through the radiator on the one hand and firewall on the other.)

I never payed much attention to the mounts on my 230, so I can't speak to that without looking.

Gentlemen;

It's a lot easyer to drill the front crossmember & mount it there (like the 41-48) than make the 'side' mounts.

There's more room on the L-side then for the header pipes etc.

Good luck.

John, then would you use a bellhousing mount like on a 56 passenger car? the bigger ones (compared to the 41-48 bellhousing mounts?)

I think so.

There might not be room on the left side though. I can't remember. There's a lot of things there & why they (GM) used that type of mount for those (49-54) models.

The (rear) crossmember for the transmission supports it too.

Try this: www.49-54nca.com

Good luck.

Hi 6inarow.

As I said, I'm thinking through the same problem. Here's some of my research.

Here's a pic of a 53 car with the body off. You'll note: one rear tranny mount, two high side mounts.



The picture gives good perspective on why the dual bellhousing-mount setup is tough on a 53.
There's no crossmember there and there's not much room for putting one in. The left side looks like the biggest problem.

I don't know how representative this is for your 52. Does this mount tower look like yours?




My understanding is that the high side mount bolts to the block on an inverted scalene triangle like the one below:
(ignore text, see left)



And we want to bolt the upright equilateral triangle type mount shown below to the 52-54 mount tower:


So, if our situations are similar, the question is whether or not the 52-54 sidemounts are in the same spatial location on the block as the 55-62.


If they are, then it should be cake to fab a plate with the late upright triangle bolt pattern and weld the "tophat" half of the old mount to it.

BUT, even if they line up front to back we're still not out of the woods.

If they are higher up on the block, the engine sits lower between the rails and the oilpan hits the center steering link. Lower down on the block and the engine sits up too high.

I guess the right way to do it is lift the engine into the frame, connect everything up to the driveline, mount the tranny, put the engine where you want it and then see whether the mounts need to be lengthened, shortened, or offset front to back...

But somebody MUST have done this already! In fact lots of people must have done this LOTS of times. There must be some knowledge out there. I'm actually surprised there isn't a downloadable pdf template that you can just print out and transfer to steel...

I think you are right. Can anyone help us???

Gentlemen;

This is easy.

Drill the front plate and crossmember & mount it 1948 style. Discard the side mounts and your done.

Happy trails.

6inarow, Tom, et al.,

Before just drilling the front crossmember to accept the 1951 and earlier front mount, please read pages 6-18 through 6-20 of the 1949-53 Chevrolet Shop Manual .

The rear side mounts that react the engine torque must also be installed between the frame and clutch housing; if not, the car will not be pleasant to drive. I learned this the hard way - twice- in 1958 and again in 1960. In 1958 I installed a 1954 261 in my 1953 210. The bosses for the sidemounts were not drilled and tapped for attaching the brackets, so, not wanting to take the time to drill and tap the six 3/8-16 holes, I drilled the two holes in the front crossmember to accept the 1951 front mount. The front engine plate was already drilled. The engine did not fall out, but it was almost as bad. The torque reaction would first cause the engine to rotate so much that it was hard to shift. Then, after a couple of weeks, the front motor mount separated, and the car was barely drivable. It was then time to install a new rear main seal, a hotter cam and some other goodies, so I pulled the engine, acquired a good drill motor, and drilled and tapped the bosses.

Two years later I installed another 261 in a 1951 Chevy, which does not have the frame towers for the side mounts. Thus I decided to stay with the 1951 mounts. However, I forgot to reinstall the sidemounts. As soon as I started to drive it, I realized what a dumb thing that was. With the rear sidemounts back in, the car was drivable, but not as smooth and well-balanced as was the 53 with the good sidemounts.

The engine mount experts that I work with tell me that the engine mounts should be aligned with the "principal axis of inertia" of the engine, which generally passes through the center of gravity of the engine assembly. The 1952-54 mounts are much closer to meeting this goal than is the earlier mounting system.

If you have the time and inclination, using the 1952-54 sidemounts should provide for a "better" installation. However, the 1951 mounts will work, as long as the 1949-51 rear side mounts (or a home-made equivalent) are used to react the torque.

Mr Hoyt is correct.

I should have stated "original" (center) mounts for your application as; you don't have them on your Bell Housing. Bracing there (rear) is always better as he states.

If the center mounts (orginal) will fit, use them alone, like GM did.

I put a 55-235 from a passenger car (no center mounts) in a 53 passenger (both stick) and didn't have a bit or trouble. I can't recall if it (53) had the rear (bell housing) mounts. But I don't think so.

Are you speaking of the truck mount (front) which is in the center, under the crank?? I have always used the ones (L & R) of center, on the front plate.

Checkout pages 128-130 of Chevrolet Master Parts Catalog . It shows images of the 35-51 front and side mounts, along with the truck front mounts and the 52-54 side mounts. I recall, after looking at the parts catalog, using the 3693425 front mounts in my 1951 Chevy and also in the 1953 210 before going back to the 1953 sidemounts shown on page 129.

Thanks HOYT!

Just pulling a few things out of your post:
This is exactly my concern.

Makes perfect sense to me

Right. My (53) bell doesn't have any provisions for lateral torque support. So its waaaaay easier (and better--how often does that happen!?) for me to hack up existing motor mounts than it would be to fool around with trying to locate front crossmember holes, rig up some sort of support on the bell and then finally rig up a new crossmember that clears all my under-floor brake stuff.

Nice to know my logic makes sense. Thank you!

Hey 6inarow did you see this? How's yours coming? I'm working on this stuff this week.