New RB to 240z engine and trans mount (71c transmission)

[winstonusmc]

Decided to move the engine back 2 inches to make more room in the front for accessory belts. I also am tired of the shifter hitting the center console and not being centered in the hole. I originally used the R32 mounts for the RB25 and factory transmission mount on the 71C RB transmission (RB20/25DE). For those who dont know, the stock mounts move the engine pretty far forward, so far that the power steering belt wouldnt clear the fans. I put these pics on my build thread for those who have seen them already.

First step was to build a jig with the old R32 mounts. The jig was designed to allow the bottom to be shifted 2 or 2.5 inches.



Then mock them up in CAD (cardboard aided design)



Left Mount:



Right Mount:





Then Transfer to metal, 3/16 plate steel:











A comparison in between the 240z mount and the partially fabbed new mount. Note the drop is greater to correct the pinion angle.







Done and painted



Here is how everything sits now. The head is about 2 1/4 inches from the firewall.

[jacky4566]

So what did you do about the drive shaft? Had to get it shortened?

[winstonusmc]

Yeah, the drive shaft was shortened 2.5 inches, which is compatible with both sets of holes.

[Neverdone]

Pardon my ignorance, but couldn't you just put the driveside R32 mount on the passenger side and vice versa?

 

Or would that move it even further forward?

[winstonusmc]

The passenger mount is longer to tilt the engine 10 degrees to the left. If you flip them, it will tilt the other way. And the bolt holes are not in a regular pattern, they are "keyed" so they can't be simply turn them around, the bolt holes wouldn't line up.