Engine Mount Shims?

[waltreiss]

I've installed a set of ceramic-coated exhaust headers from Thunderbird Headquarters in my '64. Although the fit is as tight as you might imagine, I have contact between the #3 cylinder output and the and the aft portion of the passenger side suspension tower. My thought is a 1/4"-1/2" shim between the motor mount and it's frame plate would solve the issue in the least invasive manner. Any thoughts on this theory? I'm considering cutting a couple of pieces of sidewall from an old truck tire to fit this application by raising the engine slightly to get just a little clearance for the header.

[redbird1]

I see one problem right away.
Adding a shim to raise the engine(even a little) will cause the drive shaft to bind inside the torque converter, and flatten the teeth on both surfaces(that is if the shaft doesn't break first)
Another thing to consider would be added strain on the front universal joint.
I think it is a BAD IDEA.
Bob.

[waltreiss]

Good input Bob, thanks. I may be able to shift the engine slightly, but the clearance on the steering box is tight also. I've come too far in a 9-month rebuild to screw it up now.

[Cdhowell]

Originally Posted by redbird1

I see one problem right away.
Adding a shim to raise the engine(even a little) will cause the drive shaft to bind inside the torque converter, and flatten the teeth on both surfaces(that is if the shaft doesn't break first)
Another thing to consider would be added strain on the front universal joint.
I think it is a BAD IDEA.
Bob.

Want to re-think this? At most it will change pinion angle and need a degree shim under the spring. The drive shaft and torque converter are at different ends on the tranny.

[WC145]

FPA suggests a 1/4" motor mount shim for clearance, especially with new motor mounts because some are slightly under sized. This is per the fella at FPA when I ordered some for my '66 back in the spring, haven't gotten around to putting them in yet, though.

Hey waltreiss!! How about posting some pics and chronicling your header installation adventure? I'd love to hear how it went and what tricks you've learned or what you might have done differently. Anything that'll help make my installation easier would be most appreciated!

[waltreiss]

Hopefully I've attached the pictures correctly...
For the disclaimer, I haven't got this thing cranked yet, so I'm certainly not claiming victory until that happens!
For those who might save some time and effort from what I've learned so far, here are a couple points I've collected:
1. If you're changing the cam, make sure you've got the right type of distributor gear installed. The MSD setup comes with the cast iron gear which must be changed for a bronze gear if you're not interested in having to do another engine re-build soon after the first!
2. As far as I can tell, there is no possible way to install the headers with the engine sitting on the motor mounts. Too much geometry going on there and clearances are super-tight, hence my original post.
3. Although it was a difficult process, I think putting the engine and transmission into the engine bay as an assembly is the way to go. I thought clearance would be an issue with the bar connecting the Pitman arm to the idler arm, but it wasn't.
4. If you can put the curved support beam under the transmission bell housing in position as the engine/transmission assembly goes in, it will save you some grinding. Once those header outputs are in place, you can't get that support beam in without some work and a big hammer.
5. I had to grind some metal from the driver's-side diagonal support underneath the car to clear the headers. Not too big a deal.

Walt

[redbird1]

Originally Posted by Cdhowell

Want to re-think this? At most it will change pinion angle and need a degree shim under the spring. The drive shaft and torque converter are at different ends on the tranny.

What I meant to say was adding shims to the mount would put strain on the converter, and possibly the transmission, which in turn could cause a universal joint failure as well.
I still feel it is a bad idea.
The PO said nothing about adding shims to both mounts, only the side where the exhaust manifold is hitting.
That in itself would cause an imbalance, and could not only affect the converter, but other components connected to the engine.
Bob.

[waltreiss]

Although I didn't specifically say in the original post, shims on both mounts was intended. Since the transmission body mount will provide the slight pivot needed, my thought was that if the u-joints can still rotate the drive shaft freely with a visual inspection with the rear lifted, they can correct for the adjustment. Think of the up and down play in the rear diff during normal suspension travel while on the road...

[sseebart]

I haven't put headers on my 64 but was seriously considering it for a while. When researching, I found that almost everyone who had them was using a 1/4" shim under at least one mount. I can't speak to long-term reliability, but it does appear to be the common solution.

I am still amazed that such a large car can have such cramped working spaces.

~Steve

[paul.blouin]

I have FPA headers in both my 62 and 66. I put spacers in the 62 for clearance but it isn`t up and running yet. I just bought the 66 and I haven`t checked to see if it has spacers in but I did notice that the passenger side header is touching the idler arm bracket. I`m guessing that there are no spacers.

As for the installation of the engine in the 62, I lowered the engine into the car initially without the headers installed. I had the headers laying in the engine bay and lowered the motor onto them. That seemed to work for me.

[waltreiss]

Lowering the engine onto the headers might be the way to go. Now that my engine has been installed and broken-in, everything seems to have worked itself out. The only issue I found with the engine spacers is the length of the studs on the motor mount and making sure you can get enough turns on the nut from underneath to tighten them effectively. That's part of the reason I went with rubber spacers to give me that compression capability.

[WC145]

Thanks for the pics and info! My installation plans have been put on hold thanks to a broken leg and surgery to repair it so research and planning continues for another 6-8 weeks. I like the idea of using a rubber spacer, do you have any pics of the ones you made?

[waltreiss]

I don't have any pictures of the shims to share with the group, but it was an unscientific undertaking. I'm a big fan of using what I have available when certain challenges arise. With the truck tire I used to transport the engine back from the builder sitting beside the house, I cut rectangles from the side wall to match the frame support in the engine bay (about 5" x 2"). I notched them for the motor mount stud and job done. So far, so good after about 1,000 miles. I'll need to re-torque the nuts to allow for settling and compression.

I'm happy to report the car is now only occupying one spot in the garage! These T-Birds are large, but much less so with all their parts installed.

Hope the leg recovery goes quickly!