Well for years Ive seen these funky
and common 5 speeds in volvo cars
and wondered if they where a good
option for an a series being small
strong, compact and cheap.
I then a few years later found some
old ads for volvo gearboxes to suit
A series setup speedway midgets and
recently spoke to a dude who used
to do them for some of the racers.
He no longer has any of the adaptor
plates but its interesting to hear
they used a volvo gearbox as it was
bullet proof, easy to get and cheap.
This guy is gonna get back to me to
see if anyone has the adaptor plate
to suit as there where quite a few
of them and the only issue is that
they are a 4 speed with electric
overdrive but an easy setup with
a button or switch to engage the
overdrive unit so you have another
set of taller ratios for the freeway
or for going backwards efficiently :)

I hope I can get such an adaptor
otherwise I will pursue the bw T5.

Have you seen whitesedans' jig he used for adapting a S15 6 speed to a L series bellhousing? it's brilliant looks to be easily made up.

Is there a link of the jig you can post up?

Id be interested in that jig for a 71 series 5 speed
but not for a heavy 6 speed though same bolt patterns
On a similar note.....
I weighed the reco stumpy box with the custom alloy
sandwhich plate install from a 71b series 2 box and
it was only 31kg spot on compared to 38+kg for the
71b S2 so theres is some gain to be had there.
71C box is over 40kg from what Ive read.
The 6 speed is much heavier again over 45kg.

after going through hard times, I've recently gotten a reasonable enough job that I'm back on my feet. I plan to tackle a 71 series conversion for the A-series.

It won't be an adapter plate. For a couple of reasons - namely it would space the box back further and require a sandwich plate to space the flywheel back further (or at least it 'might' need it) and secondly because placing it more rearward (even say 1 inch, for a modest adapter plate thickness) will mean the already tight fit (compared to a 'regular' a eeries gearbox) trans tunnel is even more likely to need to be cut/enlarged.

TO that end, I've at least worked out what to do (and no doubt many others have, and to be fair I have spoken with a couple of people here about it). I've had experience with adapting torqueflite auto bellhousings to suit non torqueflite patterned hemi 6 blocks.

Anyhoo, the process would be a type of 'cut n shut' to alter the existing 71 series bell to suit. Rather than cutting the front inch off it, I've got an idea of using solid alloy sleeves welded into the bellhousing to relocate the bolt holes as needed, and 'tabs' (thick plate section welded up to main bell) to 'locate' the gearbox (the dowels or whatver you call them). To finallise the idea (I believe that the input shaft spigot 'finger-tip' has to be machined down too - in a lathe - but I don't have one here to compare it to) to suit the a series spigot bush/hole.

Additionally, it would need a 'sacrifice' std gearbox, so that the starter motor mouting point/bulge can be grafted onto the 71 series bellhousing and locate the starter to suit the a series flywheel.

The clutch has been mentioned before. My personal take on it (as discussed about a year back) would be to use the 'medium' sized clutch plate for an L series (apparently they have one the same diameter as the a12 stock gearbox plate, then they have one bigger than that (which will still fit in the a series flywheel) and then one too big to fit on an a-series flywheel.

So obviously the 'easiest' go would be to run that itermediate sized clutch disc and pressure plate and have the a series flywheel drilled/tapped/dowelled to accpt this larger clutch plate. With the extra diameter, it should provide a handy increase in the amount of grip, resistance to slippage on high powered engines

When you've figured it all out you can make me one I've given it fleeting thoughts and even wondered about using composite materials. Some extra vibration damping never goes astray. The main thing with a composite would be choosing a resin that is suitable for the temperatures, <100 C. Sorry, wandering off topic. Just give me a SLS direct digital manufacturing machine and anything's possible.....

Daves' post on PF about it :

http://www.performanceforums.com/foru ... 741-6-speed-for-the-datto

Good idea on the tabs and sleeves instead of cut and shut.

Just to add another interesting idea, today went to PAP again
in the rain and found someone adapted a floor shift gearbox
from an early 1600 onto a J15 donk which was originally a
column shift. I just uses a 5mm steel plate with dowels and
threads to bolt both sides of the box and back of motor.
The plate was cut where the starter was so it has the correct
distance for engaging and Bobs your Auntie!
I dont know who did it but it looks well made and cause its
all painted with the engine block it eluded me the first time
I lay eyes on it, confused me the second time and after some
web search for the box type, I finally worked out its beauty.
5mm plate is cheap and strong with no welding required.

The biggest issue is the locating device.

That was an interesting job the cut and shut job on the 6 speed bell housing. If anyone's interested in doing something similar, using a backing stip on the world would stop the "dripping" he talked about. For alloy plain old steel or even that 25mm wide galv strip roll stuff I rembmer seeing in Dad's shed, never knew what it was for, something to do with carpentry I guess....

You're quite right about the spigot end of the input being too large. When I used a donor 63L short series box to replenish my completely fisted 63A, we had to turn down and shorten the spigot end of the input. The factory L series spigot OD, is bigger than the OD of the factory A series spigot bush. Turing it down however was challenging. If you hold the input shaft in you hand, you'll see that there isn't much to hold it by. Mine had to be held by forcing the tapered synchro ring journal, into a tapered socket in a mandrel to it could be turned.
Although i supose if you had a big enough lathe chuck, maybe you could tighten the jaws up and leave the gear part of the shaft on the chuck side of the jaws. depending also on how deep the jaws themselves were, and if you could make the shaft itself run true when holding it on the splines.
As for the clutch situation, the plate for a 63A box should fit with nthe standrd cover. BUt I'm a huge proponent of the 200mm flywheel modification. (Plus I get mine done for free )
I would imagine that relocating the starter motor could be quite a mission to get the starter pinion to mesh correctly. What about grabbing a billet of steel, and making a copy of the L series flywheel, only with the A series crank bolt pattern? Then the L series ring gear could be reused. (And you could drill it for any clutch patern desired)
I don't know what steel costs nowdays, but back in Late '98, I got a billet of steel to make a 13B flywheel for about $40.