Datsun Roadster Forum-311s.org

I'm contemplating a transmission upgrade since my factory 4 speed is giving a few problems.
Can someone draw a template of the rear of the G15 engine block trans. mount bolt pattern or the bell housing of the SP310 4 speed so I can start scoping what may or may not be a possibility?
I have an R30 Skyline "stumpy" 5 speed in my collection which would be a sweet upgrade if I could swing it
TIA

Following...

The bolt pattern is the same as the R16, U20 and H20. If you get an R16 main case, and a 510 4 speed, I am told that you can stuff the 510 stuff into the case and use the tailshaft and end up with an all synchro 4 speed. I have also heard that if you take a 2000 5 speed and switch the shifter, it comes fairly close to the stock shifter hole. I have a stock 1500 4 speed that I would give you if you were closer...

Thanks for that info.
Unfortunately, those engines are very scarce to us here in Oz which is why I am asking for some help.
I am just hoping someone with the appropriate hardware sitting around can trace the mating surfaces for me.
Do you happen to know if the L series trans have the same bolt pattern as the G/R/H/U engines?
Knowing Datsun/Nissan they are likely to be!
Clocking of the trans would be different however since the L engines lean to the RHS.

At least some of the L trans will bolt up to a U20 5-speed bell housing, but the L-series bell will not bolt up to a G/R/H/U engine AND the starter is on the wrong side too..unfortunately those transmissions are too long for the roadster. Which is why Sid mentioned removing the insides and building a hybrid. That isn't for the roadster novice. Some folks resort to truck diesel transmissions too.

If you really if you really want the roadster bell housing pattern, the easiest thing to find and/or ship is the spacer plate that goes between the engine and trans. I would not rely on a tracing to make an adapter or modify a bellhousing because if something is off by a fraction of a mm, it isnt going to fit or line-up. (input shaft must align perfectly with the crankshaft too)

Have you checked with Lou Mondello? Lots of 1500's in the states wind up with 1600 4-speeds since the fit is good and they have a fully synchronized 1st gear.

Trying to make some other transmission fit is going to be way harder than finding a roadster transmission.

Yes, you're right in all the critical places.
I was dreaming of a 5 speed since my little G15 really buzzes at 120KpH

Plan to cut the tunnel for a 5 speed.

JT, you say the L trans is too long, long as in not lining up with the trans mount, frame or transmission tunnel?

Cheers
Ian

Been a while since i looked at them, but most (all?) z 5's used a longer rear mainshaft, so everything turns out long if I recall. Others can certainly chime in. The z trans (at least some of them) will bolt up to a roadster 5-speed bellhousing, but yes, the shifter and mount locations probably would require some modification. Probably a shorter drive shaft too.

As Sid mentioned, even with a 2000 5-speed, you have to modify the tunnel a little bit, so the same probably applies.

I think a roadster 4 or 5 speed will be By FAR your most reasonable solution even if difficult to source.

Another route might be to swap the complete 2000 rear axle assembly in. I've done that on 1600's, but not 15's, but it would likely bolt in. I could be wrong, not having actually done it. The 3.7 would make 1st gear more useful and drop the freeway rpms a bit. Pretty sure you can't just swap the diff as I think they are different sizes. Again, I really don't play with 1500's anymore, so I could be in error. Its a nice mod for 1600/4. ( you can just switch the diff in a 1600)

Yes, different rear end in the 1500s. I have a car with a swapped rear end.

I have the shield that goes between the engine and tranny I’d sell you for cheap dunno how bad shipping is from the states.

That sounds great!
Could you get a quote to Australia, Post Code 5162 please?
Time is not critical.

Yes I will get a quote and let you know

Woodcroft, 5162, Australia
is this the correct destination?
Fed ex shipping economy is $195

I'm actually at Morphett Vale but same Post Code.
Sorry, I can't do the deal for the plate.
However, if you could do a cardboard tracing of the outline and mounting holes, roll it up and post it in a tube, that would be the ducks guts