Solid motor mounts

[preith]

Did a search on this, but not much came up. Any of you experiment with solid motor mounts? I plan on using these on my solo1 car, and already have a pair made, but just wondering what I'm in for...

 

Phil

[Guest BigWhyteDude]

a rough ride i would assume. well lots of vibrations from the engine and drive train if you are doing those solid aswell.

 

Andrew

[Guest Zcarsmakemyheadhurt]

Souldn't be to bad if you have a mild or stock cam in the car. I like it.

[blueovalz]

I use solid mounts on my 289 SBF (it is a carry-over from my racing days). The SBF is externally balanced and not quite as smooth, in my opinion, as an internally balance motor, but with that said, I do not find the vibrations present to be objectionable. One thing I did with mine was make the tranny mount solid as well, and thus reinforce the stiffness of the unibody, but I had to use a 5-point system (front of engine, back of engine, and tranny) to make this effective. A 3-point mounting system (motor and tranny) would not be as effective in this regard but I would hazard a guess that it would be an improvement in adding regidity over the OEM rubber mountings.

[preith]

Thanks Terry, I searched some more and found some of your posts stating similarly. I was thinking along the rigitiy lines as well. I've been contemplating moving the motor back. In which case I'll fab it to accept the motor mount arms without any additional pieces, but then there's no turning back either!

 

To answer Zcarsmakemyheadhurt's question or statement, the cam a Schneider .560/300. I imagine it'll be pretty rough.

 

Phil

[Guest ZmeFly]

He has them in his 280ZXT. Motor mounts and trans mounts. I didnt notice an vibration in his car, it was really smoothe and nice.

[johnc]

You have to solidly mount the engine and tran, not just one. Also, nuts and bolts will tend to vibrate loose so check them periodically.

[Zsane]

I used to run solid mounts on my big block Mopar and it was fine, until it ripped the left motor mount bracket right off the k-frame. Then I was told to run one on the drivers side and rubber on the passengers side, that still allowed for some flex with the strength of the solid, I never had mount problems again, tranny, driveshaft and diff. but not mounts.

I thought the SCCA rules didn't allow solid mounts in Solo II? I guess it depend on the class, but I think this carries over into some of the upper classes?

 

Street Prepared 14.10

I.) One bolt-on torque suppression device may be used. A torque suppression device attaches from the engine to the body, frame, or subframe in one location, and controls engine movement at that location along a single axis only. It may serve no other purpose.

Examples of permitted devices:

) a chain

) a rod with spherical bearings at each end.

Examples of devices not permitted:

) one or more solid motor mounts

) any link which confines movement along more than one axis

) an engine mounting plate, or one or more plates rigidly bolted between the engine and the frame.

Holes may be drilled to mount a torque suppression device. The installation may not include the welding of any plate(s) to the motor mount(s) or bodywork (7/2002), nor may it include multiple non-parallel links.

This does not allow motor mount changes other than those which are update/backdates of factory components

[preith]

Thanks everyone for the input. As I stated at the start, I plan on running soloI, and not II, even though initially I'll run a few SCCA soloII events in AP. Even if this is not allowed, I don't think run into any problems since I'll most likely be the only one. 8) The local club (Midwest Council) which holds the soloI events bases their class structure on a point system. It takes very little to accumulate enough points earn a "race" classification, in which case "the gloves are off" and pretty much anything goes. A BSP car would be put in the race class as well.

 

Phil

[jeffp]

First question:

>One thing I did with mine was make the tranny mount solid as well, and thus reinforce the stiffness of the unibody, but I had to use a 5-point system (front of engine, back of engine, and tranny) to make this effective. A 3-point mounting system (motor and tranny) would not be as effective in this regard but I would hazard a guess that it would be an improvement in adding regidity over the OEM rubber mountings.

For myself, I did not want to go with the solid tranny mount to try to stiffen up the car. For me going that way puts to much strain on the tranny tail ahaft. I did not want to run the risk of breaking the tranny, or bell housing etc etc. I wanted a little flex in the tranny area when I really get on it. As it is the tranny moves very little and that is good for me. I did use the stock rubber mount, but installed the poly bushings in the cross member. That has worked out well for me.

I mounted my engine with solid engine mounts and have not had any problems with them in the least. They have not loosened up either, bolts or mounts.

The vibration, well it is not bad at all, in fact I like the way the car feels when I give it gas, beefy, and at idle there are no problems with vibration either. I went this way because of the close tolerances of my intercoolr pipes, fuel rail, and just about everything else LOL.

So for me, I say go for it, and consider my thoughts on the solid tranny mount.