Who has solid motor mounts
06-06-02, 04:31 PM
#26
Old [Sch|F]ool
Plenty of people have high powered 1st-gens with front cover motor mounts with no problems! I know AJC13B is putting down 472rwhp on a Mustang dyno (~550 on a Dynojet) I'm fairly sure he's got front mounts...
06-07-02, 01:27 AM
#28
Thanks Ted. Hmm, I'll be shooting for high torque with a 20B, so no front mounts for me (unless they're used in conjuction with the stock rear ones).
Ted, do you have any advice for the tranny mount? Should I replace the stock rubber one with some sort of custom welded square tube with holes and studs in it?
Ted, do you have any advice for the tranny mount? Should I replace the stock rubber one with some sort of custom welded square tube with holes and studs in it?
06-07-02, 02:43 AM
#29
Lives on the Forum
We haven't gotten to the point where we had to worry about that, but that's a good question... 
We're more worried about the stock IRS "ears", as these things have been known to crack under high torque applications.  We're trying to design some kinda cradle to strengthen this weak point.
-Ted
We're more worried about the stock IRS "ears", as these things have been known to crack under high torque applications.  We're trying to design some kinda cradle to strengthen this weak point.
-Ted
06-07-02, 03:13 AM
#30
You're right about the tranny mount. Its job isn't really to handle the torque of the engine. Instead, it is there to hold the weight of the tranny (and the engine somewhat), absorb driveline vibrations, and provide support at the back end of the powertrain.
As for the materials to construct a new tranny mount, it is a good question.
If I left it stock, it would feel stock. (less vibes than aluminum or steel). If I did the steel square tube with holes and studs to mount it to the tranny and crossmember, it would have no 'give' when the engine torques up the plug side (driver's side in left drive cars)in burnouts and hard acceleration. I suppose stiffer motor mounts could prevent some of the twisting action of the engine, but it would still pick up the driver's side. Something will flex and eventually break if designed poorly, and even if designed well...
I think I'll keep the tranny's stock crossmember and rubber mount as is untill I have need to change them. I'll let my planned four motor mounts handle the torque of the engine. I'll probably add a torque brace or chain from the top of the engine to the driver's side strut tower as well.
Ted, is the cracking due to the IRS trying to raise the front of the car when torque is applied? The easy answer is a live axle, but who would want to wreck their handling with one of those things?
When trying to do a burnout, a friend of a friend's neighbor's '60s Mustang broke a motor mount and the engine lifted up several inches and the fan cut the radiator hose and the valve cover was damaged from hitting one of the support rods from the shock tower. If the hood had been on the car, it would have been dented pretty badly. That's what I remember from a phone conversation I had today with my friend. Kind of a coincidence since I'm interested in motor mounts for another high torque engine (20B).
I guess I've become a firm believer in motor mounts.
As for the materials to construct a new tranny mount, it is a good question.
If I left it stock, it would feel stock. (less vibes than aluminum or steel). If I did the steel square tube with holes and studs to mount it to the tranny and crossmember, it would have no 'give' when the engine torques up the plug side (driver's side in left drive cars)in burnouts and hard acceleration. I suppose stiffer motor mounts could prevent some of the twisting action of the engine, but it would still pick up the driver's side. Something will flex and eventually break if designed poorly, and even if designed well...
I think I'll keep the tranny's stock crossmember and rubber mount as is untill I have need to change them. I'll let my planned four motor mounts handle the torque of the engine. I'll probably add a torque brace or chain from the top of the engine to the driver's side strut tower as well.
Ted, is the cracking due to the IRS trying to raise the front of the car when torque is applied? The easy answer is a live axle, but who would want to wreck their handling with one of those things?
When trying to do a burnout, a friend of a friend's neighbor's '60s Mustang broke a motor mount and the engine lifted up several inches and the fan cut the radiator hose and the valve cover was damaged from hitting one of the support rods from the shock tower. If the hood had been on the car, it would have been dented pretty badly. That's what I remember from a phone conversation I had today with my friend. Kind of a coincidence since I'm interested in motor mounts for another high torque engine (20B).
I guess I've become a firm believer in motor mounts.
Last edited by Jeff20B; 06-07-02 at 03:22 AM.
06-07-02, 09:27 AM
#31
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Originally posted by RETed
We haven't gotten to the point where we had to worry about that, but that's a good question...
We're more worried about the stock IRS "ears", as these things have been known to crack under high torque applications.  We're trying to design some kinda cradle to strengthen this weak point.
-Ted
We haven't gotten to the point where we had to worry about that, but that's a good question...
We're more worried about the stock IRS "ears", as these things have been known to crack under high torque applications.  We're trying to design some kinda cradle to strengthen this weak point.
-Ted
06-07-02, 12:53 PM
#32
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on the first gens if you beat on the car the diff tries to unbolt itself from the axle housing. actually the fd motor mounts have a metal strap around them, in design its probably there to limit the upward movement of the engine, in practice it holds the engine in the car after the mount fails
mike
mike
