motor plate question

[knucklemeat]

we are currently building a yota 2wd with a 5.0 and have seen lots of pre runners with mid mount motor plates(between engine and trans)summit has an.090" steel one ,but i don't know if that would be heavy enough gauge for off road.the ones i have seen on rdc are usually thick (.250" maybe) made from aluminum.is there a source for these or are they all custom made? also would like to make it urethane bushing mounted so the other mounts cold be bushing style as well. j.webs race truck has been breaking after market mounts and i thought a mid mount would help this from happening on the yota. any thoughts or ideas are appreciated.

[partybarge_pilot]

Page 22 herehttp://www.chassisshop.com/pdf/fabrication.pdf

[ntsqd]

A midplate isn't going to do a lot for fore/aft dynamic locating. It will transmit torque to the chassis and stiffen the chassis at that point IF the chassis is designed to take advantage of the plate. Mounting the plate to the chassis with some method other than rigid won't do that. I would not mix rigid with bushed mounts, you will break something.

Are the mounts that are failing of the Autofab/TotalChaos type design or like stockers?

[Outcast]

You can get mid plates from just about any popular chassis manufacturer, Chassishop, Art Morrison, etc. I don't think using a mid-plate with urethane bushings will add much if any actual rigidity, it will just make swapping the tranny easier. Every mid-plate installation that I have seen was solid mounted and also used in conjunction with front plates (Also solid mounted). Along with front and mid plates, are often engine limiters, which are diagonal braces between the frame and engine to limit fore/aft movement, since the plate style mounts don't do a good job of that. The chassis may also need to be strengthened, particularly where the plates mount, to accept this kind of setup as well.

Some additional food for thought, are the mounts breaking from chassis flex or engine torque....or both? Adding a mid-plate and more rigid engine mounting might make the problem worse if the chassis, itself, is not strong enough. You will then be transmitting even more chassis flex into the engine block and transmission case that could easily damage them.

[knucklemeat]

thanks a bunch for the info guys.the mounts that are breaking are in a mini-stock 4.0 ranger and they are a brand name bushing type and appear very well built ,but we broke the first set after five or six races,and was informed that the second set needed welding at the nv 1000. must be all that bone stock v6 power! the motor plate setup i am thinking of for the yota would be more of an addition to a good set of urethane bushing type mounts(in the stock locations on motor and trans) with bolts going through the plate into bushings attached to down bars coming from the cowl/engine cage bars. would it need to have fore/aft locating capability with the regular mounts on the sides? thanks again.

[partybarge_pilot]

You don't need better motormounts, you need more suspension......

[Outcast]

...the motor plate setup i am thinking of for the yota would be more of an addition to a good set of urethane bushing type mounts(in the stock locations on motor and trans) with bolts going through the plate into bushings attached to down bars coming from the cowl/engine cage bars. would it need to have fore/aft locating capability with the regular mounts on the sides? thanks again.

I've seen similar types of deals on heavy trucks, where there's basically an extra set of "engine mounts" coming up from the frame rails to where the trans and engine block meet. However, those setups are more to help support the weight of extremely heavy transmissions, they are not necessarily adding any chassis rigidity. I'm still not sure you are going to gain any rigidity (which is the most common reason to use a mid-plate). You will have some extra support in terms of hanging the drivetrain but I don't know if that will make much difference if the current mount problem isn't related to engine torque. I would agree that a good suspension goes a long way towards isolating loads from the chassis. I would also add that a nice rigid chassis makes the suspension more effective ;).

[johnnyweb]

You don't need better motormounts, you need more suspension......
you can say that again!! however rules only allow so much to happen in that department.the mount we have been using are the auto fab. they are on the motor and on the trans.

[partybarge_pilot]

For the Autofab ones, Jon usually puts another bushing off the top of the bell housing if your having problems.

[johnnyweb]

For the Autofab ones, Jon usually puts another bushing off the top of the bell housing if your having problems.

ive talked to john about doing that to help support better and take a little stress of the other mounts.