I have been giving the darling wife driving lessons in the austin, however it is clear she is not going to master the three speed box. The biggest dificulty she has is getting it out of gear, we have nearly got into reverse from 1st on a number of occasions, and I thought she had split the gear box when she put it in first at about 20mph!.

Thinking out loud, If I fit a later coil engine, with 4 speed box, with the shorter nosecone and fan assembly and later starter, will I have to do any butchery to make it fit my RL. I'm thinking in terms of floor modifications or longer propshaft.

Hedd

See Malcolm's article on the Cornwall Club site

http://www.austin7.org/gearbox_conversion.htm

Steve

Hedd,

Dave Mann fitted a 4 speed box in one of his RN saloons by cutting the middle out of the top of the gear box and rotating it 180 degrees to offset the gearstick to the right then welded it back together. He then joggled the stick inside the gearbox to make it all line up. An incredible feat indeed!!! Bit of luck he may be able to post some pictures

Regards

Rob

My conversion is not a weekend job and was done during a body off refurbishment, it involved:
1) Shortening the prop shaft
2) Machining an adaptor for the speedo drive housing so the cable runs vertically to avoid having to hack the chassis or tunnel about.
3)Fit 3 speed speedo gears to 4 speed box.
4)Offsetting the gear lever as Rob describes to clear the starter-I’ll have to photograph it for you.
5)Moving the handbrake lever back to clear the fabric coupling, this car has no cross shaft because it has hydraulic brakes.
6)Altering the 3 speed clutch to take 4 speed levers and mousetrap springs to mate with the 4 speed clutch release bearing
7)Screw the 4 speed oil filler plug in tight and cut the square off so as to avoid cutting the floor. Check oil level and fill box through the top.
8)Reverse the body mount by the gearbox oil filler.
9)It was during this conversion that I found out that a 4 speed box is 7/8” longer than a 3 speed.
10)I can’t claim to be the originator of this method, I first saw it on Dave Wortley’s Ulster on Malcolm Parker’s 1997 Pennine Run.
11)It is a close ratio 4 speed (not as close as a nippy-that’s too close for a heavy saloon) box with gears supplied by Andrew Bird.
12)Finally Sue doesn’t like it and prefers to drive the 3-speed car.
I think the easier solution is to fit a 4 speed high frame engine with short nosecone and fan assembly as Hedd says. You will also need a 4 speed cranked accelerator cross shaft to clear the flywheel cover and carry out mods 7 and 8. Also do something to correct the speedo such as mod 3 or a separate gearbox as described in one of the recent A7CA mags. It may be easier to put a stop on the 3 speed gearbox top to prevent inadvertent engagement of reverse.
Good luck Dave

Hedd,

The article referred to by Steve Martin was my first 4 speed conversion which was in an RL/RM. It meant I had to move the engine mounting holes in the chassis 3/4" further forward. The method I used kept the inboard starter.

My latest car an RK saloon has a 4 speed box but I also swapped the crankcase for a later version (RP )where the feet are 3/4" further back which means you do not have to drill new holes in the chassis. However the starter motor will now be under the bonnet. I perfer this as I run a 12v car and putting 12v through the bacon slicer starter seemed just a little too much.

The only mods you need to do to the bodywork is to adjust the lefthand body mount and cut a notch in the floor to gain access to the oil filler plug. You will possibly need to add material to the floor plate that fixes in front of the gearbox. The only other change may be the gear lever may have to be bent and/or shortened to suit your needs, plus the speedo gearing ( I us an additional gearbox in the cable to change the ratio )

A 4 speed box in a short wheelbase car is an absolute dream,

Malcolm

Having welded all the holes up in my chassis and body one, I intend not to make any more!.
A later engine sounds the simplest soloution. However the oil filler on the gearbox seems to be the largest problem. I will obtain a crankcase and gearbox and play next time the engine is out.

Hedd,
I think you will be making the right decision with later engine and gearbox. I did it with my RN with very few mods required. As far as I can remember I needed a Ruby type cast iron top fan pulley assembly to stop the fan hitting the rad and the 5/16" BSF screw on the reverse gear shaft flange sticking out of the rear of the gearbox needed changing to countersink rather than hex head in order to allow clearance between this screw and the front chassis crossmember.The body to chassis bracket on the gearbox filler side needed moving and a small cutout was required in the floor to allow access to the gearbox oil filler. None of thes mods are irreversible and the car is much more useable around the hills of the Peak district.I also did a 4 speed gearbox to early coil crankcase mod using the direct rearward facing starter motor to fit my Ulster replica. This involved much cutting and carving and welding of the gearbox top and the gearlever before I got it right but it has been fine since I did the mod in 1993. I have to admit that I used 3 gearbox tops and 2 gearlevers before it would fit properly.Dave Mann did a much more professional job on his RN.
Regards,
Dave.

Thanks Dave I'd forgotton that using the 3 speed engine the 4 speed layshaft needs thinning to clear the front cross member. Dave

I appreciate that the problem is your wife's gear changing in a 3 spd my suggestion wont help that, but rather than go to all the hassle of modification you can really improve the 3 spd box by having an ANDES gear fitted I have one in my RM. Vince leek designed it for our Argentina trip basically it gives you another 8mph in second allowing you catch the torque of the engine when going into top it does not alter first gear but as far as I am concerned it is so good I won't even consider the hassle in putting in a 4 spd now.
Chris

Ive never been convinced about a 'close ratio box', I regularly find steep little hills in wales that she wont pull in top, but will in middle. Very rarely I need bottom, once I had to terf the current wife out to get up 'happy valley' in bottom cog. As far as I can make out a higher middle gear would mean more bottom gear work. I appreciate that on the longer more gradual hills a higher middle gear would be of benefit, but with the driving I do I have more short steep hills than gentle long ones.

I actually prefer too the 3 speed to the 4, but I also want the wife to drive the car.