[Jimmy Clarke]

Hey guys,

My Fatman mustang II IFS has been final welded in and I’m trying to get all the information I can before deciding which SBC (LT-1) motor mounts to use, and where to weld them. If given a choice, I’d prefer to use the stock motor mounts. My last project truck, I use the L shaped aftermarket SBC mounts, and although they utilized round rubber insulators, there was still more vibration than I would like to have had. I’m gonna have to do a fair amount of fabrication to secure the bottom part of a stock mount to make it work, but if I can position the engine in such a way as not to interfere with my rack and pinion connections, I feel I can make it happen. I need some input from you fellas concerning engine-positioning parameters. The lower firewall in my truck has been cut out, and will be custom fabricated after the eng/trans mounts are in place Here’s my questions: What is a “ballpark” horizontal distance between the oil pan “hump”, and cross member? What is the highest and lowest vertical distance that you would want to mount a SBC, relative to your mustang II cross member? Any, and all feedback related to engine mounting location will be appreciated! Thanks Jimmy

 

[CptKaos]

What kinda truck are you putting this in? I am working on my 50 Chev and could give you dimensions if yours is an AD truck. The way we figured the mount location was to put the frame at its ride attitude then with the engine and trans lowered into position we located the trans cross member and tacked it in place then raised the engine until the carb mounting surface on the intake was level then tacked the motor mounts into place, this gives the entire drivetrain about a 3 degree down angle. Mine is a RAT motor but the motor mount dimensions would be the same.

Larry

 

[Henry Highrise]

Your gonna have to do like CptKaos did and mock up your set up. Don't rely on someones measurements...what if they were wrong?

 

[powerrodsmike]

If I am not fighting floor pans, firewalls, etc, then on most pre 1960s hot rods and trucks I like to put the centerline of the crank (at the balancer) level with the frame rail top or lower. Go as low as you can with the motor without getting the oil pan too close to the ground. I get nervous if I can't see 4" between the floor and pan..

If I can get the motor to set down further in the rails then I like to keep at least 3/4" between the pan and crossmember. I have notched the crossmember to get a motor to sit lower if I was doing a ford motor (even with using a rear sump pan)

Once the front is set, raise or lower the rear of the trans until the carburetor mounting flange is within 1 degree of level.

That should get the motor sitting at about 4 degrees front up.

I like 66 chevelle motor mounts. They are small and cheap and look good in a hot rod. :thumbup:

Hope this helps,
Mikey

 

[Sixguns]

Along with what others have said, don't overlook the position of the rear end. if your not carefull you can set the engine too low in the chassis making it below the diff,that would multiply the Driveline u joint angles as the suspension works. be sure the driveline is going down hill to the rearend.

 

[Jimmy Clarke]

thanks guys...keep the suggestions comming.....

The truck is a '37 Studebaker. Right now there is no trans crossmember, just a frame, mustang II, and a cab shell. As I said, I'd like to use stock LT-1 mounts, but their kinda "bulky" and I 'm concerned about clearance for my rack and pinion to column steering shafts. If I could get an idea of how far back the oil pan "hump" is in relationship to my mustang II crossmember, I could start there. All suggestions welcome........Thanks, Jimmy

 

[powerrodsmike]

You really need to start mocking stuff up on your truck.

You need your radiator and grill in place as well before you start to place the motor.
If you are going to build a firewall and floor you should make sure that you will not set the motor too far back in the cab that you run out of room for people.



Mikey

 

[Jimmy Clarke]

I'm flexible there also...can locate the rad anywhere I want. Approx distance measured (front-to-back) between oil pan hump, and back of crossmember (4" wide crossmember located at front axle centerline). That's one of the measurements I'm looking for??....Jimmy