Engine Offset

[hjc74260Z]

I searched this topic and came up dry. I have an early 70s LT-1 350, factory bellhousing and four speed Muncie mounted in my '74 260Z. I'm using all the JTR mounting hardware. The bell housing is right up against the passenger side of the tunnel near the firewall. I measured the engine offset at the front crank pulley ( to frame rails) and it looks to be 1.5" to the passenger side. The JTR manual indicates that it should be 0.75" and that the original offset was 0.75". It does not say if the offsets add. My question is, should it be 1.5" or 0.75"?

 

Also, what is the ideal measurement for the transmission output shaft relative to the tunnel in the horizontal plane? I measured the Datsun transmission before pulling the engine and the output shaft it appeared to be centered in the tunnel. The JTR transmission mount is offset by 1" to the passenger side, not 0.75" or 1.5". Won't the engine/trans centerline be at an angle to the centerline of the car and presumably the differential.

 

Thanks

[blueovalz]

I cannot speak directly toward the JTR mounting, but the differential propeller shaft is offset toward the passenger side of the car's centerline due to the differential's design. On my 240 (using the R200) it comes out close to 1", again toward the passenger side.

 

Do I understand your post to say that the offset at the front of the engine is slightly different than the offset at the transmission mount? If so, (and this is a question to all) is the output shaft centerline supposed to line up with the mounting of the transmission? I could also see that it would be entirely possible for the input and output shafts of the tranny to be on completely different axis' being they are separate shafts. Perhaps I'm confusing the matter more than it needs be.

[Brad-ManQ45]

JTR offset is 3/4" to passenger side - same as stock engine location.

[hjc74260Z]

Thanks BlueOvalZ (nice car, by the way). The differential offset explains the transmission mount offset at 1". The axes of the respective shafts can be different as long as they're nearly parallel. My concern is that the engine/transmission axis is not parallel to the diff.

 

I double checked to ensure that the engine mount spacers are correctly installed (2.25" on driver side, 1.25" at passenger side). I can't see where I may have screwed that up.

 

I guess I will need to modify the tunnel at the firewall so that the bellhousing clears. I'm using a unilite distributor and it is within about 0.5" of the firewall so the engine is well back and this may be why I have interference at the bellhousing. Time for the 4# hammer.