Hello All,

I am tossing around the idea of welding the steel mid-mount plate into the firewall. My thought was to cut out the firewall to follow the shape of the plate and then weld it to make it a structural member. Tie it into the frame and cage for fore and aft movement wherever possible. I will have a removable trans tunnel and even though the trans will still have to come out from under it will have enough room to slide back since I have removed the factory trans crossmember and fabbed a new tubular one. I Have a 68 Dart w/a 512/400 block so other than obviously limiting the engines to big block Mopar is there other downsides? I have centered the centerline of the crank and trans output as well as the pinion. I would like to get the engine as far back as possible while not actually having it in the drivers compartment. Also, with the Magnum Force front suspension and the BCR main girdle, I could lower the engine a bit to gain some hood clearance. Thoughts or suggestions please and if others have done this, pictures would be appreciated.

Thanks, Paul

Sounds like a good idea. Should really help with torsional twisting. I have never run a mid plate, but I am seriously thinking about it with my new build. I am using a Quicktime scattershield and want to mount from some extra tabs on the trans flange. This way, I can remove the engine or trans without having to support the other. Plus, like you mentioned, add limiters to stop forward/aft shifting around instead of an engine limiter.

Its really not gonna change a thing being welded
in... I have bolted in ones.. the plate still
acts as a structural member as does the engine..
the shorter the span from the engine/trans to the
verticals that it ties into the stronger it is..
less flex... and spread the bolts a good bit apart
(dont put them close together)... a true chassis
car the body is along for the ride

A mid plate just hanging out in the breeze, with a couple tabs welded on the chassis is useless, for anything more than holding up the motor or trans when you take the other out. Now, you take that same mid plate and make it an integral part of the chassis, by welding it into the firewall or attaching it to tubing that is part of main chassis structure, you are actually DOING something to stiffen the car.

The pic is a stock firewall car. You sink a piece of tubing in the firewall between snout bars and tie mid-plate in like this and the car will be really ridged in the middle.......that's good

Be careful on how far back you set the motor. Two reasons I figure I moved my engine back too far; hard to work on the motor, too high of a percentage on the rear tires. The second part made mine a wheel stand monster when I had the power to run 9.0s to high 8s.

That's what I have in mind Monte. I will run a tube from side to side on the inside of the firewall off of the front support bars and follow the outline of the mount plate down to the front frame rails. It will almost end up as an X-brace in the middle of the car. I have test fit the motor in place and this modification will only move the motor back about 1" from where it would sit without doing this. I have planned on keeping the top of the carb level but may change that to a degree or two of an angle. The car should not end up with much rake at all.

Greg, how far back did you move your motor? Is it in the drivers compartment? Any pictures?

Thanks for the feedback guys. I haven't really heard anything negative yet about the idea so I think it might be worth doing.

Happy Memorial Day.

I have the same tubes as Monte show but the sheetmeatal
isnt welded in... at the time of the cert on this it
certed to 7.50
EDIT
I have 2" between the verticals and the engine/trans on
the race car.. I have 2" on the pass side and 3"on the
drivers side on the Rampage.. I moved the engine to the
right a little for added foot room.. and 2" across the top
to the cross bar

The angle of the carb doesn't matter. Point the tailshaft directly at the pinion and the driveline angle is what it is.

I will add, don't depend on the Mid Plate for lateral motion control. You'd be surprised how far that will bend if you have a hard launching car. put lateral supports from the chassis to the block as well

I run limiters so the engine/trans stay in place.. with
just a couple of inches with .090 steel it helps.. and
a 3/8"front plate... the car leaves nice and level with
a 1.19 60'.. thats with a 405ci

Hi Mike, are you talking about Fore/Aft limiters?

I have Andy's front plate, and put in the Fore/aft limiters that you suggested, and was also thing of having a Mid Plate or a mid/support that would attach to the the top of the Lakewood ears.

On a stock firewall/frame b-body, there is not much room, and with the headers in the way it seems difficult.

I like Monte's firewall a lot, but that would require a lot of firewall mods...

BR, Mark

Yes I'm talking fore and aft limiters