As a result of this thread:

http://datsun1200.com/modules/newbb/v ... hp?topic_id=48443&forum=2

I've decided to post this in the main forum, since it might be of interest (probably most of you already know it but just in case.

Basically I'm embarking on tig welding a cut n shut front section of an a series bellousing onto a 5 speed casing from an L series (probably out of a bluebird, since they are the most common/easy to get)

http://datsun1200.com/uploads/photos/22568.jpg



Here's pics of an old a15 flywheel (if you can see it under the surface rust) with an L series clutch disc (albeit a race oriented one, but the diameter is the thing we are concerned with initially)

http://datsun1200.com/uploads/photos/22570.jpg



Additionally here's a comparison of an L series clutch disc (again a race oriented one, not a stock one, since it's the only one I have from an L series (technically it's Datsandy's and you'll note the icy pole sticks keeping the clutch lining away from the rusted flywheel!) which shows the difference in diameter of them when both sat on a level surface. The overall difference in radius is of course half that (if anyone wants to do some back of the envelop quick maths to work out the increase in grip/force)

http://datsun1200.com/uploads/photos/22569.jpg



then there is a pic to show the L series pressure plate. The flywheel would need the dowel holes redrilled/located and new bolt holes cut and tapped, but the important thing is that the L series pressure plate _does_ fit on there as far as the diameter goes. it has a few mm to spare - not a lot of extra room, but definitely doable and safe.

So the only other thing to be done would be the spigot bush might need to be made to suit (not sure on the diameter vs the L series and a series 4/5 speeds) and the clutch linkage (though I dare say they'd be the easy bits)

I reckon the drilling for the pressure plate, if done VERY carefully could actually be done by anyone with access to a lathe to enable a couple of hubs to be machined up to properly centre an a series flywheel on top of an l series flywheel then drilling/tapping as required straight through the l series flywheel. A bit like how brake discs are redrilled in this thread:

http://www.performanceforums.com/foru ... 7257992&highlight=redrill

The only possible spanner in the works here - and I honestly don't know this - are the intput splines on the 4 speeds different to the 5 speeds as far as L series boxes go? The clutch/p plate I have upload were from an l16 with 4 speed. it was in the rally car Andy has started to part out. It had a rear diff out of a 200b - so I'm not sure if the box itself is out of that, or an early bluebird or what. I'm hoping they are interchangeable, as that would result in a fairly easy swap (definitely cheaper than a toyota t50 conversion bellhousing, and for that matter getting a good t50 cheaply is getting hard. In contrast, people are practically giving away the bluey 5 speeds.

Only slight downside is that each conversion would have to 'sacrifice' a 56 series 4 speed to get the front bellhousing section to graft onto the bluey/L series 5 speed

EDIT:

http://datsun1200.com/uploads/photos/22571.jpg



here's a pic of the std a series clutch disc on an l series pressure plate, gives a better idea of the extra diameter/leverage/grip available with a larger diameter clutch disc, even if clamping force and friction lining was identical) Sorry about the angle of the shot not being directly overhead, I couldn't get the light to stop glaring otherwise.

i think lagwagon has done something similar already with sikyne,and D was looking into it.

I think Lags has one running in his 1k too, or was palnning on it. check his build thread maybe.

There is a factory clutch cover and disk for this.

Disc: 180cm L-series/A-series disk for 63A-series transmissions.

NISMO 30100-NR260 Disc Clutch 180 Ø 25x24T Ceramic A 30210-RS100

* 30100-K0500 ASSY-DISC,CLUTCH 5-SPEED(COUPE) B210 USA, JDM $66.07 USD superceded 30100-H5801
* 30210-N1600 ASSY-COVER,CLUTCH 5-SPEED(COUPE) B210

Something else to throw into the mix John,is that the "A" series automatic transmission has an un-boltable bell housing.....been tossing this about for ages but too busy.
Cheers

Mmm this is very interesting stuff, Look after that clutch john its my ticket to retirement.

my concern would be the L series pressure plate fitting inside the A series bit of the bellhousing you are grafting to the L series part

L series boxes all have the same input shaft, same with everything else that runs 71 series boxes
dont have to use a bluey box, can use anything 71 series as all the bellhousings are interchangable. so Z series CA, SR FJ, VG...pretty such endless supply once you have the bellhousing sorted

but as DD said there is a stock clutch that does the job, think the only L series vehicle to run the really small size were 1600s or something like that, then pretty much every over 4 cylinder(apart from 720s and Z18et) ran the 200mm clutch, then 6s ran 225mm

I believe the L13 and maybe L14 ran a smaller diametre clutch (same as A series) than L16+.

Use a bearing in the flywheel for the spigot... not the brass bush in the crank

Wow, interesting work Jmac!

I'm interested to see how this frankenstein gearbox will affect or compare to the A-Series gearbox prices. Might be worthwhile pairing up with Simon or Jason and pumping out some new-version A-Series 5 speeds gearboxes. I know I'd have some difficulty finding someone willing to do this one-off job for a reasonable price (welding & machining costs).

Cheers.

The only problem is the length of the L series or ca boxes
it would be better to use the stumpy of C series Stumpy
unless you can get hold of easily the Stanza gearboxes