81' CJ-7 engine mount placement for a V8 GM 400 small block

jeep

#1

getting ready to weld the engine mounts from Novak for my GM 400 sm blk. how much distance should there be from the fire wall to the engine. also bought a conversion Radiator from Raceway parts. How much space for optimal performance, for cooling and breathing should the radiator need to be from the engine fan??
should the braces that gets welded to the frame that hold the engine mounts be at a certain degree??
also any other tips and such before all this happens??


#2

You need to find a jeep forum with lots of conversion discussions to find out how to come up with those dimensions. The mount maker doesn’t know?


#3

ive been searching a lot of forums online and kept running into dead ends.but yeah ill keep lookin!
thanks!


#4

One could write a book detailing answers to your questions. In short, at a bare minimum, you don’t want anything touching the body under worst case conditions. Hard mounts can have less clearance than rubber since they don’t deflect under load. You should be mocking up the entire drive train and setting positions to minimize the drive line angles.

The engine fan should be coupled to the radiator by a shroud. The shroud will usually ensure youre not too close but again you must not be so close it will hit under worst case conditions. The fan should extend into the shroud but not all the way. No one size fits all declaration but 2/3 in is a decent starting point. Look at OEM setups to get an idea…


#5

@TwinTurbo pretty much has all the bases covered here. I used to build V8 Vegas back in the day and my first build taught me a lot. I experimented a lot and the only problem that I encountered was getting enough radiator in the little car to keep the engine cool. I found a good radiator shop that fixed my problem by adding a couple of extra cores to my radiator. I didn’t use a shroud because there was no room for a fan on my engine. I just used a large electric fan in front of the radiator which worked perfectly.


#6

A lot of people have put Chevy SB 350’s in these so I know there should be some good info out there.


#7

How about using electric fan(s) instead of trying to get the shroud correct?


#8

i was actually gonna leave the shroud off. Now my question is… when gettin ready to place the frame bracket for my engine mounts… what angle, degree and off set do i need and how far from the fire wall?? 81’ CJ-7 converting to a GM 400 w/ TH400 turbo tranny


#9

If the GM small block has a carburetor intake manifold on it, the carb mounting plate should be level with the frame line. This will put the proper rake on the engine. However, for a trail truck, this may not need to be critical. You want the engine to be lined up with the centerline of the frame and centered between the frame rails.