Motor Mounts

The time finally came for me to set a Chevy small block in place. The snow finally melted enough to drag a junk block in from outside. I'm using some Chassis Engineering bolt in engine mounts so everything should work out well with the CE transmission mount.

A quick look at the CE mount instructions showed that they would be of no use to me. They wanted you to take measurements from the original engine mounting holes on the crossmember. My crossmember as all ready been modified deleting those holes. For the fun of it I did set parts of the original crossmember in place and take some measurements.

I thought it would be better to go off the trans mount that is already installed anyway. An empty TH350 case was bolted onto my fitting block and a new transmission mount bolted in place. The engine mounts were then bolted on the block and the unit was hoisted between the rails. The transmission mount was then lined up and some long bolts were threaded in place. This let me raised the motor and transmission up while keeping things lined up.

With the engine in it rough location I bolted the frame mounts to the engine mounts with the supplied CE components. The CE directions say the frame mounts should sit on and be bolted to top surfaces of the upper and lower parts of the frame rails. Okay, I did look at the rest of the directions. I made sure that was how they would fit would lowered down to the frame slowly released the pressure on the engine hoist. When the bottom part of the mounts touched the frame I stopped, centered the block, then continued lowering it in place.

Now I could see if I had any problem areas and check all my oilpan clearance. The pan was clearing the crossmember, not by much, and the motor mounts didn't seem to fit real good. I was a little surprised by this. The major problem was the offset driverside mount. The bottom part of the mount was overlapping the rear edge of the crossmember. You will also notice there are no holes on the lower part of the mount, there are predrilled holes on the top. A small section was cut off the mount to clear the crossmember and put back in place. Another problem was the way the mounts actually fit my frame rails. With the bottom of the mount sitting on inside edge of the frame rail the top part of the mount is raised a good distance from the top of my frame rail. You can see this in the top photo. To make it worse the front of the mount is about a quarter inch higher than the rear. I can draw them done by clamping them but they just don't seem to fit right.

One other item to note, from the rough measurements I took using the directions my frame mounts should be moved about 1 inch rearward. That would have cleared the crossmember on the drivers side but there is no way I could have mounted my engine and transmission. I did follow the direction on the transmission mounting plate and it fits the frame pretty well. If my measurements would have been off by an 1/8 or 1/4 inch max I would have blamed it on measuring from the modified crossmember. I don't think I could have missed by an inch. I think it would be a good idea for anybody installing a motor/trans combo to do as I did, start at one end and put the other in the place it needs to be.

Once I was satisfied with the locations of the mounts I clamped them in place and started drilling mounting holes. The top holes are easy, just use the predrilled holes to drill your frame holes. The lower required you to draw the mount pattern on the bottom of your frame and drill through all parts. I could have had my jack stand set a step higher for extra drill clearance. Once all the holes are drilled just bolt it in place.

With everything bolted in place you can see I have a small amount of clearance between the oil pan and crossmember. I may have some problems getting U-bolts under there. I'm not real happy with the way the mounts fit together and may try to do some modifications to get them to fit better. You can see on the passenger side mount that by drawing the upper part of the mount down to the frame has caused it not to sit level. The passenger side sits a little better but you can see that the front part of the mount is pulled down and the motor mount is sitting more on the rear of the cushion.

From the top the misalignment is not noticeable, the mounts are pretty easy to install and hold the engine in place but they do not fit great. I'll end up doing some more work to get a better fit but for now they are in place. At the rear you can see how the TH350 fits. This is an empty case with no pan on it and fits with no frame rail modifications. As you can see in the photo the frame could use a little trimming for clearance. If there was a pan on the case it may not clear the lower edge of the frame. It would also help if you ever needed to remove the transmission.

Since I'm going to run a 4-speed I'll take wait and see approach back here. If I'm right I'll need some shifter clearance.

I have the motor mounts fitting a little better. Instead of placing the lower flat of the mounts on the inside of the frame I spread the mounts over the outer the frame rails. When I wa satisfied with the fit of the mounts I welded them in place. I am thinking about welding in a boxing plate behind the motor mounts for a little extra strength. In the picture below you can see why I needed to trim the passenger side mount. I'm still not 100 percent satisfied with these mounts and most likely use the weld in mounts next time.