Solid Motor Mounts?

[PNJSNAK]

Should I be using solid motor mounts? What is everyone else using on their 351W motors or other engines? I have about 325+ H.P. and when I get on it a bit, it really torques to the right. Causing the side pipes to hit the body. I have 1/2" clearance and would like to keep it that way.
I am presently using the Napa 351W mounts with the rubber between the plates.
If others have gone to solid mounts, what would be the disadvatages if any?
Where and what part numbers would I use to fit in the place of the Napa units without having to add or change anything else?
Any help would be appreciated, Thanks.
Jim

[Venom S]

Jim

Solid motor mounts might cure your problem, but you will feel a lot of vibration tranmitted from the engine.

Try Energy Suspension mounts. They use zinc-plated steel and Polyurethane. Their website is www.energysuspension.com

Venom_S

[dalola]

Jim,
You may also want to look into a torque rod, like that from Competition Engineering. It will control engine torque rotation without the harshness of solid mounts. On a street car, solid mounts can shake your car(and you!) apart in no time! I would avoid that for sure.
Dave

[JAM1775]

I used the solid motor mounts by Moroso. I have had them for 3700 miles and I like them very much. The motor simply does not torque. I have been in many Cobras and only a few seem to have less vibration than I feel in my own. Once you give a powerful Cobra some throttle.....well...it does not feel like the family car !! I am sure there is vibration which I take up by torqing bolts during maintenance. IMO I would not go with rubber mounts. Poly is probably the most vote getter...or solid.

[427sharpe]

The best of both worlds I think...
Forget the solid motor mounts, too much vibration transferred to the chassis and the driver. Take a regular motor mount and drill a 1/2' hole thru the mount perpendicular to the motor. Install a grade 8 1/2" bolt thru the hole with heavy gage fender washers on both sides and secure with a nylock. Leave about 1/2" or so of play in the bolt. The motor will now torque that far and stop. This gives you a solid mount when you're heavy, but a good insulator when cruising or idling. I went thru motor mounts too quickly when I started, and this has eliminated the problem of tearing the mounts apart while keeping chassis vibration to a minimum. Very unobtrusive as well.

[JT]

I couldn't ask for a more well-timed post. I'm pacing the floor with this one myself. My position is: If flexible mounts are used, wont the engine torque, through the sidepipes et al tend to twist the sidepipes apart? Given the hundreds of times the car will get shifted, might this tend to tear the sidepipes apart over time? Am I thinking this through too much, here?
I'm not intending for this to be a luxury car, so......where do I find solid mounts? Any input from urethane owners??

[Bob Putnam]

"If flexible mounts are used, won't the engine torque, through the sidepipes et al tend to twist the sidepipes apart?"

JT,

It depends upon how the side pipes connect to the primaries. A solid connection (flange-to-flange) will eventually break something. The original-style side pipes that most people use are a tube-in-tube slip fit, with tabs to keep everything from coming apart. Just enough freedom to prevent fractures, although there is a small amount of leakage.

[JAM1775]

Solid Mounts ?

Moroso:

www.jegs.com
www.summit.com

[flipper35]

I have seen some of the older big block muscle cars that have a square spring clamp around the mount on the drivers side. Looks kind of like the letter c in block letters. Made out of a heavy guage steel. They may not work for your setup depending on the shape of your mounts but it would allow no movement from torque and still have less vibration. Might be similar to what daola mentioned.

[cob289]

go and ask David, they have stong mountings of own production line for FE engines !


Fritz

[niles]

427 Sharp:

I sent you an email with additional question.

Second though do you put the retraining bolts in both mounts or just the left side?
gn

[Jack21]

Forget rubber mounts!

Had same concerns about sidepipes moving around and eventually cracking, body clearance, etc.

Using Energy Suspension polyurethane motor and trans mounts and they work GREAT! The car (instead of just the engine) rocks a little at idle, but no vibrations. The engine is planted good and solid and does not move. No rotational stresses on sidepipes, no air cleaner hitting the inside of the hood. Night & day difference! Have digital shots if interested.

Easy if your frame mounts are OEM '84 up. FFR's that use all late 5.0 parts should be an easy substitution.

I've got a CR and had to fabricate frame mounts. CR frame mounts used MII 302 motor mounts. Most of the professional builders, DV, Don Scott, have newer frame mounts to use the ES mounts.

[427sharpe]

Niles---
I put bolts thru both of mine. Also, I went out and looked and I have about a 1/4" of play to the bolt. My motor doesn't torque over at all, and I have never broken anything @ the sidepipes as BP mentioned (mine do mount to a solid flange, no tubes and no leaks!). Just drill the holes as close to center as you can so there will be enough meat around the hole and you will be fine. Niles, I also said perpendicular to the block--I meant to the mount. Just drill straight thru in the best location you can find.

[Double Venom]

Crawling out of the woodwork for this one. Bob of course is right. If your headers to sidepipes are flanged and bolted tight, something is going to go. Usually the #3 header pipe first.

This is only caused if you bolt the tail end of the sidepipe "rigidly" to the frame...this combo is a definate no-no.

Use a large rubber "block" between the hanger and the pipe. Absolutely no problems.

Dalola, has the simplest, safest solution, in my opinion. Remember if you go to solid motor mounts, you should also use a solid tranny mount!

No solids for us...Hundreds of 5,200 RPM launches with slicks and nothing broke yet....except rear ends!

DV

[anil]

Had similar problems with my 302, but feared polyurethanes and really feared solids. Ended up using the Mustang convertible mounts which are made of really high-durometer rubber and are very close to polyurethanes. Love 'em!

I do get a bit of torque flex, but MUCH less, and if I ever thought it was a problem, I'd add a torque link instead of changing the mounts.

Cheers,
-Neil.

[Howard Bosworth]

I sat the 351w (1974 block) on today with solid mounts. Similar to those pictured in the cj pony catalog mine are id on the box M2287 602287 listed for 289/351w/351c 65-72 mustang.

The engine sits very low about 3 1/2 inch from oil pan to floor. What is an acceptable ground clearance?

I checked summit and jegs books for the PS Engineering but not sure what i'm looking for exactly. Can anyone help with what part number that will work with a 351w on a shell valley? Should I just check with my local napa? The ford part number D00Z-6038G from shell valley is rare according to my ford dealer.

Any help would be appreciated
thanks
Howard

[Jack21]

Howard,

Not sure how motor mounts bolt to frame on Shell Valley car. You might have to have a set of frame mounts fabricated. Welding shop here in NoVa thats pretty good at this.

3 1/2" a bit low for oil pan to ground clearance. 5" - 6" would be better. Mock it up so you have 3/4" - 1" clearance from the air cleaner to the hood with the hood closed.

My vote still goes to Energy Suspension polyurethane late SBF motor & trans mounts. Engine does not torque, but soaks up vibrations. Car, instead of just engine will rock a little when the engine is idling. Don't have part # but Summit does. There's only one.

Send e-mail to jwalsh21@ix.netcom.com and I'll return some shots of this.

[Shell Valley]

The only other part # I have that you may be able to cross over is Car Quest #31-2342. As far as I know the 351 w and 302 motor mounts should be the same, so the energy suspension mounts that summit lists for the 84-95 mustang should work (I think but don't know for sure ) Part # ENS-4-1124GX.
As far as the ground clearance, 3 1/2" does seem a little low (assuming you have your ride height set where you want) but should not be a problem. The main thing to consider, as Jack21 posted, is how much clearance you have between the air cleaner to the hood. You also need to look at clearences where the headers / sidepipes exit the body. If that all looks good you can shim the mounts up some or let me know and we can make you taller mounts. Either way one thing we like to do is, if you have an oil pan with the drain plug on the bottom, relocate it to the side. This will gain you a little more clearance and help protect it a little more.
Hope this helps
-Dana

[niles]

I liked 427Sharps idea of using regular rubber mounts, while limiting the deflection with a C8 bolts thru the middle of the mount.
I drilled mine through (3\8) but added an improvement; under the washer on the limiting bolt; I fabricated a tough reinforced rubber waher out of the side wall of a tire. Put these with less clearance; approx 1\8 in; now the mount and deflect an eight and not hit the bolt metal to metal; but rather bottom on the rubber washer.
gn

[Jack21]

Dana,

My hat's off to Shell Valley. Any manufacturer that scans these threads, and jumps in to offer assistance to a builder of one of their cars running into a snag deserves a pat on the back. Your efforts did not go unnoticed. Thanks!

The 302 & 351W use the same motor mounts. Where it gets tricky is that the 351W is taller and wider than the 302. The 351W then may require a slightly lower mounting height in the frame so the air cleaner clears the hood, yet provides sufficient ground clearance for the oil pan. The trans may need to be dropped a like amount or the sidepipes may not be level. We're only looking at 3/4" - 1" lower on the 351W.

Some manufacturers use different frame and trans mounts specific for the 302 and 351W or some shimming method to compensate for the install height difference.