I'm building a CMC camaro and getting ready to reinstall new motor. I have covette motor mounts and the original camaro ones. Which one , or should I get solid motor mounts to go in the car.
thanks Lee

3rd or 4th gen? Check your class rules, but if it's a 3rd gen I'd run the Energy Suspension engine and transmission mounts (and I have them in my car currently).

For a 4th gen race car, get the solid mounts: Moroso MOR-62635 and a poly trans mount Prothane PTP-7-1604-BL. The solid mounts won't wear out like rubber or poly, and are immune to heat and oil. The only downside is it's a bit more difficult getting the trans plugged in since the motor won't tilt as much. Bend the lip on the tunnel shifter opening, and loosen the thru bolts on the mounts, and it makes it possible.

If you go with the Prothane poly inserts (my second choice), assemble them on the bench, observe which corners will interfere with the bolts into the subframe or block, and trim those corners off before installing. The corner interference prevent the bolts/socket from lining up properly, and makes for lots of cussing, tool throwing, etc.

Are solid motor mounts CMC legal? It's been a while since I read the rules, but I didn't think they were.

They are now and have been for a couple years. Cost reasons. They are cheaper than OEM or poly's.

I've been pretty happy with the moroso mounts alan mentioned. I have about 5yrs on mine and wish I had used them when I first replaced the rubber mounts. there's a thread on here about solid mounts.

found the thread...

http://www.frrax.com/rrforum/index.php?sho...id+motor+mounts

Long term, but not initially.

http://www.jegs.com/i/Prothane/311/7-508-BL/10002/-1
http://www.jegs.com/i/Prothane/311/7-512-BL/10002/-1

http://www.jegs.com/i/Moroso/710/62635/10002/-1

Consider more platforms than your own.

Why? Other platforms certainly don't consider mine or the original poster's.

Any reason to not use the MOR-62635K kit?

Had Moroso solids on my LT1 for years. Only issue I had was the bolts backing out once. Used some good lockwashers and a little loctite and was A OK from then on.

I just put Moroso Solids in my 3rd gen. I was initially concerned that I wouldn't be able to lower the trans enough and it would be a PIA to get to the bolts but that was a non issue since the bolt holes in the mounts are large enough to allow for it to pivot some. Have not ran or drove the car with them yet.

Edit to add, I used nylon lock nuts and no loctite. Hopefully that holds.

I guess my point was missed.
There are two "kits" from Jegs.
MOR-62635 and MOR-62635K

If the picture is correct, I don't see the K kit working on an LT1 with OEM 4th gen Kmember without some fab work. I think someone pulled old Gen 1 SBC solid mounts off the shelf and bundled them with the LT1 mounts and mislabeled the app.

Here are the OEM pedestals:

PASS side:



DRV side:

Thats what I figured. I was wondering ifI was missing something. I already ordered the correct kit if that tell's you anything.

Think of the proximity to the headers. In applications with high radiant heat, I use deformed thread locking nuts. Deformed thread nuts are also re-useable unlike nylon.

I think nylons are rated for 250 deg. Just as a point for comparison, our PTU's (my career) are as close as an inch away from the exhaust without a heat shield in between and are rated for excursion lube temps of 300. I might be ok.

I custom made motor mounts on my 3rd gen (1/4" plate and custom tubes), welded them in place once I got the header spacing correct. I moved the engine back as far as I could without making the headers hit the frame (not to rules and don't give a shit) once that was done they are a permanent fixture to the crossmember. I am also going to put in a torque strap from the roll cage in the engine compartment to the head after I have some fun with the car. I am running a energy suspension trans mount that is poly and it seems to work fine so far.

Brian - Everything you mention here is OK for AI. You can even modify the firewall and subframes for exhaust clearance, just can't go THRU the firewall.

Torque strap seems redundant if you are using solid mounts.

I've seen some severe cracking and ripping of the floor pan and trans mount with poly mounts.

Won't solids make that worse?

I've seen that with the stock rubber trans mount too - I just weld them up as the cage is going in. They tend not to re-crack unless the car takes a big hit.

I think solid motor mounts are likely to reduce the stress on the trans mount - it only has to deal with trans mass loading the mount vertically, vs the twisting and shaking around that the rubber motor mounts allow.