Engine Power verses motor mounts

[ViperMan]

Well I feel like I'm already in the dog house for askin' a lotta question, but at least I've got MEK to hang out with!

I just wanted to bounce something I heard from someone else off of you guys and see what kind of reactions I got.

A guy I worked with at Goodyear kept telling me that I need to build all kinds of brackets or chains or what-not to hold a 500hp 440 in the engine bay of the 'Cuda because a high power motor will rip out of it's motor mounts and pop up through my hood.

Whereas this created some hilarious (yet not funny in the long run) imagery in my mind, I always wondered how much truth there was to it.

What are the factory motor mounts capable of (and yes I know I need to change mine from a small block to a big block setup) and what methods are commonly used for higher power (and I don't mean power I'm looking to generate - just high power in general) engine applications?

Now I feel like I need to explain myself too much. 

Jeff

[nivvy]

Not in no dog house.....

I would run moroso SOLID motor mounts for about $30 bucks.... makes the car shake more..... 

and I also run a schumaker torques strap for about $85 also,,, the whole car just shakes at idle like a pro stocker.........   

Eventully a motor plate will go in for me........... 

[ViperMan]

Do you have pics?  Where does the strap mount to?  where would a plate mount to - both engine and engine bay points?  What about like a polyurethane motor mount that's much stronger than rubber but not quite as hard as a solid?  Or is that what a "solid" is?

Jeff

[matt63]

I use the Schumacher torque strap but also bought the Magnum motor mounts from Mancini Racing.  They interlock so they cannot come apart.  The Schumacher unit bolts to the K frame and has an adjustable rod that connects to the engine block ear.  You can check out their websites for pics.

[nivvy]

Do you have pics?  Where does the strap mount to?  where would a plate mount to - both engine and engine bay points?  What about like a polyurethane motor mount that's much stronger than rubber but not quite as hard as a solid?  Or is that what a "solid" is?

Jeff

solid mounts are all metal as there is not type of insulator...  the torque strap is a direct bolt in off the k member to the block in front of the drivers side head....

[nivvy]

  This is one cool Iron headed setup.... i miss it 

[ViperMan]

THIS little thing holds high power engines???



 

I mean - I'll say it again - if they say it works, I'll believe it, but I sure don't wanna!!

Jeff

[nivvy]

thats more solid than it looks.... motor plate is the ultimate....... the ea spotin the schumaer setup is the braket that ties from the rod to the block,,,

rubber type motor mounts and motor plate. its inbetween the waterpump an block and ties the frame rails together... water pump must be machined down the thickness of the plate to make all pulleys line up correctly....

[NoMope Greg]

THIS little thing holds high power engines???



 

I mean - I'll say it again - if they say it works, I'll believe it, but I sure don't wanna!!

Jeff

Jeff, some of the buses we have use a similar (larger) torque strap with two motor mounts to hold 12 liter diesels capable of 1500 lb-ft of torque.  I think, in concert with interlocking motor-mounts, that will do fine for the roughly 600 lb-ft your engine will make.

[matt63]

THIS little thing holds high power engines???

I mean - I'll say it again - if they say it works, I'll believe it, but I sure don't wanna!!

Jeff

You have to remember that the engine is torquing against the passenger side mount.  The torque strap is not taking all of the engines torque. Most of the torque is being delivered to the diff (hopefully).

[LAA66]

 Split two of the factory engine mounts on the driver side with my little 340 4-speed. Now I run a solid one just on that side. It would be nice to have more insulation though. If there is a set up that can reduce the vibration yet provide the support, that would be the ticket. 

[BB73Challenger]

Schumacher makes good stuff.
Even just at 400 horses my motor would tear up regular rubber mounts in just a couple of years.

You may not flop your motor through the hood, but when that fan goes tearing through your shroud you'll be bummin'. 

[Changin Gears]

The torque that is applied to the motor mounts is the old "equal but in the opposite direction".  It is in reaction to the torque transmitted to the drive-shaft.  Remeber the torque going through the drive shaft is the engine torque multiplied by the transmition gear ratio.  In the case of a four speed in 1st - 500 ft/lbs X 2.65 = 1325 ft/lbs.

This equal but opposite holds true at the other end of the drive-shaft also, twisting up the passenger side of the rear axle. Which is why a non sure-grip rear spins the right wheel, it is pulling the right tire up and the left down.  Super-Stock springs are designed to counter-act this with the right spring having those half leaves going forward.

I put my torque limiting chain on the back side of the motor attached to the head.  This puts it close to the firewall which is more capable of controling the force being applied.

[Chryco Psycho]

virtually every engine I build ends up with either a solid mount on the left side or a steel band bolted from the K frame across the rubber mount to the block , the steel strap is virtually undetectable but keeps the mount togther , the 3rd option is the Poly lock mounts that interlock that Mancini sells

[GoodysGotaCuda]

my 318 ripped stock replacements in a couple days, i just put a solid moroso drivers mount and ran it since