Does anyone know if someone manufactures adjustable Motor mounts for a C3 with 454 engine. The mounts would need to have some adjustability by either elongated holes ware it mounts to the engine or some other type of built in adjust-ability within the mount its-self?.
I don't want to go with solid mounts.

 

http://tech.corvettecentral.com/2011...148.1499775541

https://www.corvetteforum.com/forums...post1595343998

 

Thank you for the link to what looks like very nicely made engine mounts. The issue is my frame horn must be out of alignment as the only way I could install a stock engine mount is my oblonging out the three mounting holes of the mount and by drastically forcing the mount itself out of normal center i.e. stretching the rubber. I was hoping to find a mount that has some built in adjustability. Or a base plate that is not drilled out so I can match the mount placement to the engine.
Anyone have help on this subject?

 

Any way to realign the mount ? Cut out and redo ?
If I see something I'll post it.
Best.

 

How much must you move it?

 

I have attached the photos of the mounts that were removed. You can see the holes were sloped out a bit and you can see the rubber was forced to one side and therefore the mechanical safety interlock is forced to one side. The drivers side and passengers side are in opposite directions. I was hoping to find a mount that offered some adjust-ability as I don't really want to cut and re-weld my frame horn.

 

I think that your about 50 year old frame is tweaked. Cutting and welding or modding motor mounts is how Bubba fixes things .

I worked at a shop that had a car frame machine. You bolt and chain the car down and take accurate measurements. Then they pull it back to straight. Or in the worst cases it's time for a new frame

 

Sometimes you modify items that prevent you from having to re-engineer a lot more difficult things. If the car and drivetrain operates well with a modified engine mount, so be it.

You could consider having the frame attachment point for that mount moved so that you don't have to modify the mount.

 

The car had a 4-wheel alignment and runs down the road very very straight and tight. It does not pull in any direction. The drive line seems to be fine.
I need to find a frame dimensions sheet so I can start measuring the frame out to see exactly what is bent. If anyone has that for a C3 corvette frame that would be great.

Thank you for the input as I work through this problem to make things as proper as I can.

 

There are mock up blocks available but they are kind of pricey.

https://www.speedwaymotors.com/P-Ayr...lock,7441.html

 

You are not going to find an adjustable mount with rubber.......slot the new mounts and move on.
And I urge you to try solid mounts for two reasons:
1) They are smaller overall and much easier to work with and around.
2) They have more meat in the area you need to slot.
If you are worried about vibration or harshness......don't be......if the engine is well balanced you will never know the difference.

Jebby

 

I have a 73 bbc 4 spd with the same problem as you. I had to move the engine front about 3/8". I modified the rubber mounts as follows:

• I used Autozone mounts. The mounts were 5/16" wider than the OEM mounts. By pushing the offset to one side I picked up 5/32".
  • Not sure I'd use the Autozone mounts again. They are cheaply made.
• I slotted the holes 0.1" .
  • I used 1/8" thick washers and grade 8 cap screws. This allowed me to get the mount over as far as possible and still easily access the bolt.
  • With the 3/4" OD washers I didn't lose any strength by ovaling the bolt holes
• I took the steel reinforcement off the inside of one side of the mount and moved it to the outside. This gave me 0.2"
  • It was held with four small tack welds which I drilled out
  • I welded it back on with a Mig process
  • I used small tacks and immediately put it into a bucket of water after each tack.
• I made a shim That was about 0.51' (5/16"+.2") and tacked that shim onto the reinforcement on the inside.

I picked up about .45" by doing these three things.
When I was searching options I did find adjustable solid mounts, but I didn't want to use them.
Check what is deforming the mounts. In my opinion, it can only be the transmission mount or the driveline.

 

I wasn't thinking of this: Check what is deforming the mounts. In my opinion, it can only be the transmission mount. But if you moved the tranny tail shaft from side to side it would be possible to turn the motor slightly. When installing a vette motor I find it much easier to install the motor with the engine mounts on the block. I just use the engine mounts all bolted in and support the rear of the engine on a floor jack and then stuff the tranny to the block and then lift up the tail shaft and tranny cross member and bolt them in.

It could be feasible that your tranny and engine were together and they mounted and bolted the tranny tail shaft in first and it was off too one side and then your block and engine mounts didn't match up

 

Reasonable possibility. Not enough importance is placed on proper positioning of the transmission mount, IMO.

 

IMO The transmission mount is important for the right-left driveline alignment, but also, the holes in the bracket can be elongated to accommodate some (or all) of the engine push he has. The reason I chose not to elongate the holes is that I had the body off and I wasn't sure the distributor and the left valve cover would clear if I moved the engine back. Also, I couldn't easily get the driveline in. I had to take the caps off one of the universals to get it in and the trans yoke was within 3/8" of going solid in the transmission. I am setting the body now, and I know that the valve covers will clear even with a 5/16" gasket, I don't think the driveline would have been an issue. but I don't have the distributor in so I don't know if that will clear the wiper motor.

In my case, I am pretty sure it is not the frame per se. The frame is solid. Also, I had that frame on a rack twice, The first time it came back I thought it was off too much and took it back a second time and forced him to hold the work point tolerances to +/-1/8. I verified it, and it is on.

I believe the horns are off in my case. My first post on this site was to ask for dimensions to locate the horns and I got nothing. Nor did I find any information on the internet.

To the OP: I just went though this last month. If you have any questions I will gladly detail what I looked at and why I did or didn't do it.

Greg