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Motor Mounts

10K views 58 replies 13 participants last post by  dennis111 
#1 ·
Just noticed the motor mount is broke on my 351W in my Falcon. My friends are telling me to go with solid mounts but Im afraid of vibration. On the other hand I dont want to be putting mounts in it often. Is there a compromise between a soilid and a traditional rubber mount? Something heavy duty.
 
#27 ·
I restored a 68 GTX 440/727 monster back in 2005 and they're soft.

They are a uni-body setup with an engine cradle and torsion bars, and being a body man like I am sometimes I can totally see how it can twist and deform the car.
Hey FE...Luther says Hi...

And once again....It was the passenger side that was breaking the mount DanH....Putting it on the left side wasn't going to stop anything...

And being referred to as KLUTZ is a far greater honor than anything that you might have achieved..PUTZ
 
#26 · (Edited)
Think of engine mounts with a polyurethane medium with built-in safety straps. That will reduce the vibarations to tolerable on the street. Dedicated strip cars need to be taken further.

Solid mounts on a street car will rattle your fillings loose. A safety strap @ the left mount will prevent most separation but the torque will then be transmitted to the unibody.
 
#31 · (Edited)
I thought Lakewood made some really good mounts that won't separate and have some rubber in them to cut down on vibration?
I'm surprised this discussion hasn't come up before.....I'd like to know more what needs to be done to the suspension. I've got frame connectors already but I'm sure I'll need more later.
 
#32 ·
Lakewood does and frame connectors will cure alot......But..

Again we're talking street cars and not race cars...What happens in street cars is normally rust and the weak spots it leaves...Bad cowl,"A" pillars, firewall flex that lead to breakage..Or just too much torque, because like FE said, the motor is in a cradle and unibody cars just don't have the support system to back up the torque.

A racecar is normally stripped and then built back up..(or built from stratch)
But a street car or even street/strip car, you by-pass alot to keep the car looking it's best..

So...You're on the correct path, but it's still a crap shoot...If you rip something up, just be proud you built something that you broke..;)
 
#35 ·
What the OP needs is a set of Boss 302 mounts... they have metal bent at an angle so you get isolation with travel limit. the engine mounted portion nests in the frame mounted portion.. I've bought plain parts store mounts that have had this feature. I've always run a chain to the frame, but left it a little slack. If your car is making that much HP, the subframes ought to be tied anyways... JMHO


67 70 Ford Mustang Boss 302 289 Motor Mount | eBay
 
#36 · (Edited)
I have the 1965 solid rubber block type mounts. After breaking 3 brand new sets of mounts, spliting them apart, I took my brackets and mounts(bolted together) and had 5/8th's holes drilled through the bracket and mount. I then installed grade 8 bolts and nuts, left just a little play so as to not compress the rubber block any and loctited the nuts. I have not broken another motor mount. This is an old trick.

The next thing it started to do was peel the spot welds loose in the shock towers. I pulled the engine, tapped them back into position and welded 1 inch beads ever 2 or 3 inches all around the seams, ground them down and painted them. No more problems with mounts. They have just enough give so that the engine isn't bone rattling and shaking a lot.

This is a 289 car and I leave at 3800 on the foot brake. Converter flashes to around 4750. I am in the 1.60's 60 foot times with it. Still, no big deal. After every race week end, my driver door would make a kathunk noise for a couple days until it settled back down. I put in the sub frame connectors and convertible torque boxes and now it is straight. I can even jack the whole front end up under one subframe and it is straight with no tendency to crack the windshield.

I had some old fart at the machine shop tell me there was no way a 289 would bust motor mounts. I threw the last new set out on the table and invited him to look at my engine if he wanted to. He said he was busy. So much fracken ignorance around that it amazes me.

Ah forgot this one. I also have an aluminum turn buckle on the driver side that I tighten up for racing.
 
#40 · (Edited)
Could some of you all quit your personal verbal fencing and attacking and try to actually give some of your expert advise to the OP of this thread? That would be nice.

Keep in mind, we aren't dealing with thunder bolts and 440 magnums. These are cars that were designed to handle a 110 horsepower straight 6. It is relatively easy now to build an engine making 3 to 4 times the horsepower these were designed for. It will require some enhancements to have these things handle this much extra horsepower and torque. OP just would like to know what they can do.
 
#42 · (Edited)
You just answered the whole enchilada, proper preparation. To hence-

Keep in mind, we aren't dealing with thunder bolts and 440 magnums. These are cars that were designed to handle a 110 horsepower straight 6.

It is relatively easy now to build an engine making 3 to 4 times the horsepower these were designed for. It will require some enhancements to have these things handle this much extra horsepower and torque. OP just would like to know what they can do.
As posted, breaking the factory spot welds and a continuous weld all over the apron rails, tower brace bars and a Monte Carlo style bar (not OEM junk but adjustable tubular, proper cage and connectors. Even the rails @ the rear need to be reinforced. Follow what OEM did to both the THUNDERBOLT and CJ MUSTANG (heavy reinforcement).

There has to be texts full of info out there as they have been raced since the early sixties.
 
#52 ·
Where you been? They hold a big pow-wow up on the reservation? Get your feathers shook out?

You all pass the peace pipe with that wacky-weed peyote in it?
 
#53 ·
Back on topic klutz , Motor Mounts and the secondary topic straps/chains .

how do you explain oldgator damaging the GTX 440 roof ?
there was no chain or strap , yet the damage was done .
why the damage klutz ?
A chain or strap be the blame even when one wasnt installed ?
 
#54 ·
Uni-bodies can twist, with or without a tie-down.

If you are going to try and chain one down, you need to think what path that torque is going to take. It ain't rocket science.
 
#57 ·
I got poly mounts on my 03 Mustang. Honestly, the increase in vibration is only marginal so it is very bearable. If you can get poly mounts, this would be a good route to go. Alternatively, to prevent the stock rubber mounts from failing again, you can take steps to avoid excessive deflection. For example, rather than using a rigid strap, you can use a heavy duty spring to tie the top part of the engine to a place which can take the force (someplace by where the engine mounts or a suspension pick-up point). I myself will do this when I put new mounts in my F-150 as the I6 makes enough torque, and the mounts are old enough, that the shifter stick makes for an accurate load gauge now (0 being vertical, 100 being the ash tray). Alternatively, rather than a spring, a rigid mount can be used but fabed like a suspension arm (both ends bushed). This way, whether spring or with a bushed link, torque is absorbed by more pieces, thereby limiting the amount of deflection on each individual component. The bolt trick discussed is also a good one, though it will not offset the excessive deflection for the mount in compression so that mount will take the force not absorbed by the mount in tension.
 
#59 · (Edited)
OK, its the early type mounts 3 pc stud mounts.

This is how I strengthen the stud mounts for the car in my signature:

Modifying the engine mounts

It works with my 4 speed car at the track with slicks. After doing this I quit breaking mounts, but then started bending the metal of the mounts. To help stop this, I added I added a chain type torque strap from the head to the driver's side sway bar mount. You should be able to make something similar if you continue to have mount problems after beefing them up:





If the chain is not made absolutely taunt, you will not have a noticeable vibration.

I do not know of a direct replacement HD stud motor mount. If you upgrade to the 66' and later 2 piece "through bolt" motor mounts you have more options, such as the poly ones. The through bolt MM's will raise the motor higher in the engine bay and may cause clearance issues with the hood.

The 66'-70' mounts use a different shock tower frame bracket, similar to this:



Another good option is the Ron Morris mount and it totally replaces the existing motor mount:



There is an optional one that allows you to move the motor up/down and fore/aft of the factory location. I had Accufab header tube clearance issues when I tried this mount.

Here is more info on the Ron Morris mounts:

http://www.mustangmonthly.com/techa...install_adjustable_engine_mounts/viewall.html
 
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