MEEEEEEGA MOTOR MOUNT.
 

After braking another new stock motor mount (drivers side) im looking at other options. I dont want a 100 dollar magic bolt MightyMount. I have read that solids are a rough ride and can break a block in higher horsepower apps.

I was thinking about fabbing up my own for the drivers side. I would keep the stock passenger side and make a semi solid drivers side that uses pourable urethane. it also will utilize as many of the mounting bolts holes in the block as i can.

my question is the mounting hole in the block that is up higher than the 4 along the bottom edge of the block. Is that one a safe one to use along with 3 of the bottom ones? Im afraid i might pop it out of the water jacket.

http://www.highperformancepontiac.co.../photo_06.html

i know it overkill but i want to do this once and forget about it. im tired of chewing up fan shrouds lol

Regular Pontiac LEFT Motor Mount with a Link Chain and Eye-lets has held many engines making 1000+ hp and does not stress the block or allow the mount to fail.

One eye-let goes to the head, the other eye-let goes to the frame.
Typically one eye-let will have a provision to lengthen or shorten the chain.

Everyone always wants to invent something new. Try that vs designing up a whole new mount that may or may not work.

Tom Vaught

I use a 3/8 " turnbuckle, infinitely adjustable and about 3-5 dollar investment. It also looks more finished than a chain. Pretty easy to install too.

Do you think it would be a problem with aluminum heads ?

You can make a 3 bolt plate that will spread the load across the aluminum head bolt threads in the head and have an "ear" that connects to the chain or Turn-buckle mentioned by Sirrotica.

Tom Vaught

How about a picture of your turnbuckle and chain set-up???

I made a plate up and secured it too the head on drives side,,and then to the frame.. no issues so far..

The Might Mounts are just regular mounts with two flush bolts installed in each one.. that's the way the mounts were for our 68 Firebird..

Charles

Chains the head to the frame? Is a custom fit bolt on kit? Thats available in billet right? Color wont clash with my powder coated block and polished pump? LOL (8-)

The Chevy factorys solution to the 396 trying to jump out from under the hood was a very simple, clean, elegant tie wire of 1/4" aircraft cable and looped ends from frame to head. Hardly noticeable.
Never tried the chain deal myself, I always took a big hammer to the drivers side stock mount and bent the tabs over so it couldnt come apart. That worked ok for me. I dont know if it would work on the later model big flat mounts?
Anything with big power better have some kind of solid mount on drivers side IMO

Bmans deal is clean, easy to do. seen it on a 1000 cars.

Nice Picture, Bart, and totally understandable. That engine is going no where.

Tom Vaught

Back when I was racing turbo Buicks we used a small tie down that is used for like motorcycles and it worked great. We had several cars with 1,000+ hp and no failures. The webbing material isolated any vibrations. It was adjustable so worked on a lot of different combos.

Question. If you use a 3 bolt plate on the end of a head and use a stock mid 60's alternator bracket, does the bracket have to be machined down for the thickness of the new plate? My new motor is going together right now and not to this point quite yet.

Look in the picture where Bart's cylinder head bolt is, I used the studded head bolt that the ground cable usually bolts to and attached my turnbuckle to it. Also using a bolt with a stud on it you can use the front, middle or rear of the head to attach it to, my 69 GP worked better in the middle of the head due to the extreme setback of the engine, the upper A frame and shaft are in the way to mount it to the front of the engine. Of course if your using a studded block that wouldn't work out. I welded a 3/8' bolt to the frame and your done.

Mine was on my oval track car for 3 years and when I junked the car and pulled the engine the mounts were like new. I had broken brand new ones back in the late 70s when they weren't made in China, Korea, or Indonesia. My car was a 69 GP, and the left mount didn't have the limiters on it as the A bodies, etc. do. Actually those style mounts are interchangeable from left to right, one number fits both sides. That's how I did it when I didn't want solid mounts and thought I could find a better device than chain, the choice is yours....good luck with whatever you decide....:)

the only problem i have is room. i have an alternator, PS pump and stock exhaust logs facing backwards so they dump out the front of the motor in my turbo setup. i was thinking maybe the plate for the back of the drivers side head but there isnt much room there either.

In my case I needed to space the alternator bracket forward by 3/8" because of the use of an early style '64 alternator bracket on a '74 455 engine with the later style front cover, balancer and water pump pulley setup.

In your case you can mill the back of the accessory bracket down. Do this only after making sure that after removing the material needed for the thickness of the engine tiedown bracket the accessory bracket still has the structural integrity it needs.

You can use 1/4" steel plate and it will be plenty strong, keeping the amount milled off the back of the accessory bracket to a minimum. Also you might consider just milling down only some of the backside of the bracket leaving part of it intact, using only the 2 outer bolts instead of all 3 bolts to secure the tiedown bracket to the head.

Read post #13 if you haven't already, and I addressed an alternate way to mount it, unless you have a block with studs instead of head bolts.

Vic,

Perhaps you can make up a longer more elaborate tiedown bracket out of 5/16" or 3/8" steel plate (depending on bracket length) attached behind the accessory bracket on the front of the cylinder head that will reach over and past any obstacles, like the front-dumping exhaust manifold.

Mill down the accessory bracket on the backside to match the new bracket material thickness. You can then attach a chain or turnbuckle to the frame. I used a long 3/8-16 Grade 8 bolt and drilled through both walls of the frame to attach the bottom link of the chain.

Get out some heavy cardboard and start making a bracket template.

Good luck, Bart

You could go strait vertical from the frame to the extra holes in the block allowing some movement to cushion the hit with the original mount. My engine straightend the safety catches out the metal is not near as thick as original mounts.

I had thought of that set up but became concerned about the torque applied to the front of the head. I figure that a 6 to 8 inch lever plus the torque of the motor at full squirt, 10 pounds of boost etc would/could cause some problems with the head lifting, twisting or distorting? i dont know, am i being too much of a puss here? am i over reacting on the forces at work here?

There is another mod where you weld a piece of steel rod across the tab interlock. It allows about .03-.06" travel and then it is basically a solid mount. i found a pic of it once upon a time, very inconspicuous and simple.