MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - preselector on an Xpag engine

Hello,

Has anyone ever heard of a preselector gearbox on an Xpag engine?

I intend to built a special with a preselector gearbox and would like to hear of similar experiences.

Thank you

Erik
Erik vanHardeveld

I am familiar with the "Wilson" pre-selector gearbox. As I remember, it uses vacuum and solenoids to shift the gears. A small shift lever would be placed in the desired gear and would engage when the clutch was depressed. This unit was used on the Cord in 1936-37 as the transmission was ahead of the engine and mechanical linkage would have been a nightmare. I'm not sure if it required a special transmission, or if it could be adapted to any manual trans. I have never heard of one being used behind an XPAG engine. As it is vacuum operated, a vacuum pump might be needed to get the desired vacuum.

John Masters

Eric,

If you're contemplating installing the preselector gearbox from one of the earlier SOHC MGs of the 1930's, stop and think about torque requirements. The ENV and Wilson boxes were used on the 746 cc MG engines as found on the K-type, Q-type and R-type engines producing I would guess, around 50 to 60 lb-feet of torque.

A tuned XPAG will almost certainly produce that much or more, making these boxes marginal.

Armstrong-Sidley made their own for their 6 cyl car and there is one out here where I live. It is physically bigger and will take more torque, but it almost certainly will present mounting problems.

BTW, Porsche offer a preselector for the their racing GT3. There is no doubt that the preselector is fast and smooth. I have driven an old Hudson with one and it was quite a delight. The preselector box has one big advantage over today's paddle-shift sequential box, and that is, that a preselector box can skip a gear (driver choice) whereas with a sequential box, one is always obliged to go to the next gear (up or down) without skipping.

I suggest you contact the Triple M Register and solicit their help.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

Upon further checking, The "Wilson" patent gearbox was used in the MG Magnette. Pictures and instructions are in the "Blower" MG Manual, page 159 in my issue. Apparently was not a manual trans as we know it. This gearbox is planetary, like an automatic with a manual shifter. Can't tell if it would mate up with an XPAG or not. The MG unit appears to be entirely mechanical and not controlled by solenoids.
John Masters

Check out this one I saw posted on the midget forum.

http://www.youtube.com/watch?v=5p_jEjjeDYo&NR=1
LED DOWNEY

The Wilson preselector as (also) used on the pre-war MMM MG's was (I think) the planetary unit.

Gord,
The blown 1100cc 6 cylinder K3 also used this gearbox in racing conditions, so a hot XPAG should pose no problems at all?

Erik, the trick is to get a suitable preselector gearbox in the first place? After that, in a special, mating it to the XPAG will be easy in comparisment?
Willem van der Veer

Willem,

While you are right about the prewar MGs using the Wilson box - specifically the K-Series (but not the K3 Magnette) and a few J-Series, I believe the K3 Magnette used the ENV box which was uniquely developed for the supercharged K3 Magnette and I would guess they are probably quite hard to come by.

In fact there were several iterations of pre-selector gearboxes - some with clutches, some with no clutches, some with automatic clutches and some operated by vacuum, and MG tried most of them at one time or another!

That is why I suggested trying to find an Armstrong-Sidley one.

While your idea is certainly with merit, make sure you have a good source of parts and expertise before you dive into this one!

Gord Clark
Rockburn, Qué.
Gordon A. Clark

Nice video. Be still my quivering heart. Reminds me of my Lotus 6 (MG-ZA 1500 powered) and the MT Equinox hill climbs. Nothing like a solo event where you don't have to watch your mirrors and at the end you pull the grass and weeds out of the wing mountings.

Safety Fast

Paul
Paul Gaynor

Got any idea what kind of gearbox is in it Paul?
LED DOWNEY

Could be most anything in a Lotus 7, even Series 1, in the UK. Originally they were fitted with anything from Ford Consul, BMC Series B (A, B, Midget, etc.), Cosworth and on up to Coventry Climax engines, with Ford, BMC and Hewland boxes. I think I know who the driver, or the videoist may be and will try to find out.

Paul
Paul Gaynor

Thanks Paul. I always get a queezy feeling in my stomach when I see the spectators lining the road. Particularly in the rallye events. Look like easy targets should the driver error ever so slightly. We have a local company selling the Lotus offspring here (Westlake I believe). I'd love to have one but theres no place around here you can do whats in the video.

LaVerne
LED DOWNEY

Erik,

From time to time I have thought about fitting an ENV 75 preselector to a T type. ENV Gears made preselector gearboxes based on Mr. Wilson's patents in several sizes to accommodate various power ranges. The 75 (as used on the K3 race cars and also in K type saloons and open cars would be the one to use. It is the right size for a T type. There would be a number of engineering issues, such as a bellhousing, but the biggest issue would be the cost of the gearbox itself. ENV 75s have become quite rare and are VERY expensive these days - maybe 3000 Pounds just for the gearbox. But if cost is no object and you have access to good engineering help, then have a go. You certainly would have a very unique T type.

Reed Yates
'54 MG TF
Reed Yates

Erik

No one has really answered your question yet. So what you need to do is contact Andy King in the UK. Tel/fax 01949 860519, www.mgsparesandrestorations.com

He has built a few Q-type look-alikes using a TA chassis, Q body and a blown XPAG with a pre-selector.

He would definitely be the first person I would talk to about a project like this.

Peter Gregory may have built some as well, but he was quite ill when we were at Silverstone, so not sure what to say about that.

Mike Francks
TC 8332
Mike Francks

Okay, I can't resist. I watched the YouTube and saw a car "shifting itself", didn't I? What exactly am I seeing?
Ed

PS: LED - try Hwy 92 from Crawford to Blue Mesa damn! Drove it last weekend. What a dream trip for your TD, especially with the blower! Just be careful!!
efh Ed

Ed, Thats what I thought I saw originally, but I think it's actually a paddle shift on the steering wheel. Watch his hands closely during the drive. Notice the gear indicator on the dash? Either way it's impressive. I've been on that road Ed and your right. I've got a closer one here thats a good test and lots of fun although slow speed limit. I took the TF over the Colorado National Monument loop last week and what a difference the blower makes. Shifting down to third only because of the tight corners. Heading to Denver tomorrow for the Colorado Conclave. The Saturday tour was the most fun for us last year and the Sunday Car show was huge.

LaVerne

LaVerne

Hi,

Thank you all for all your input.

I just returned from Beaulieu, and Barry Walker offered a preselector for 2500 pounds!
As is and without a bellhouse!!
Have decided to start building the car first.

I can fit the TC box that I bought in Beaulieu for a start, and perhaps another solution comes up in the meantime.

Thanks again

Erik
Erik vanHardeveld

I picked up an 'old' book at Bronte on the weekend...'MG - The Workshop Manual' (1952). It has a full chapter and schematics on the preselector gearbox...whew... complicated to work on and complicated to drive ... a lot of 'under no circumstances' .... 'when changing down extreme care should be......' etc. etc.
There is a full page on how to operate it... sometimes the clutch is fully pressed, sometimes half pressed...

Anyway... more then my brain could handle....!!!!
gblawson(gordon)

"WHY" One of the great pleasures in driving our cars is the ART of control. Changing the gears to make best use of the motor is a major part of the ART. Knowing when to shift up or down is something a driver acquires as he [or she] has acquired a sense of feel for what the car can do under many conditions. There is no doubt that a "T" with a preselector transmission would be quite novel, I think some part of the "T" experience would be missing. My car talks to me, and I like to keep the conversation going on a personal level.
George Raham
TD 4224
G. L. Raham

I would get really confused changing the position of the stick at any other time then when you are actually changing gears.... judging from the instructions you still have to select each gear...just it doesn't change until you put the clutch in and let it out.... Certainly not like a 'sequential' box?
gblawson(gordon)

G.L.. you still change gears manually with a pre-selector gearbox. It is not automatic. You simply select the gear before depressing the clutch rather than doing them simultaneously. I've driven a Wilson pre-selector and it was fabulous! Unfortunately they are very inefficient and therefore rob a lot of power.
Steve Simmons

Yes... I read over the instructions... am afraid I would stomp on the clutch when trying to move the gear lever... just an old dog not able to learn new tricks!
gblawson(gordon)

This thread was discussed between 09/09/2008 and 03/10/2008

MG TD TF 1500 index

This thread is from the archive. The Live MG TD TF 1500 BBS is active now.