Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) Flat Rad Morgan 5 Speed Conversions

Bill,

Firstly your Moss Box and elektron bell housing are extremely valuable items, so if you do end up making the conversion, then please preserve them very carefully , or sell to a very hungry market and get full value for yourself.

Secondly there are a number of 5 speed conversions available, but not all are commercially available off the shelf. The Ford Sierra box (sorry I don't know the designation , is it a T5?) is certainly one of the more common, and there is a fair choice of ratios for it. In Australia a Toyota Supra has been used and there are undoubtedly others as well. However you need to ensure you get one with a ratio of less than 1:1 in 5th gear , or you will be back where you started.
I think I am correct in saying that both of these conversions involve moving the gearbox cross-member , so you have now changed the car irreversibly.

The Moss overdrive option might seem a better option but even here there are issues that you should approach with both eyes wide open.
Firstly the only overdrive unit that bolts straight onto a Morgan Moss Box comes from a Humber Super Snipe , and those really are like rocking horse manure these days. Because the overdrive unit bolts on the back of the box it is now much longer so the bell housing must be cut and shut, no easy job that as welding magnesium allow is not a common skill these days, and you have now destroyed any value in this component. Secondly again you are forced to move back the gearbox crossmember, and thirdly you have to rig up some sort of fore-and-aft linkage because the whole unit moves drastically under braking (don't ask how I know)

Unless you have a very powerful uprated engine, the aerodynamics of the flat rad will limit your cruising speed to about 75/80 mph , at which the engine will be turing over at about 4,000 rpm. As others have said , I think it would be much easier to change the ratio in the back axle BUT as yours is likely to be a 3HA unit I am not sure that there are any new crown wheel and pinion spares available for axles of this vintage.

Good luck and let us know what you decide to do.

Hi Martyn - Thanks for the link to JB Sports Engineering. Maybe a different crown & pinion for the rear axle is the way to go. It might make the Mog slower off the line, but I just tractor about anyway.

Bill, I have not heard of an adaptor kit to mount a Ford Sierra Type 9 5 speed box / bell housing to the engine you have. The only adaptor kit I know of is the Milton Racing UK version which enables you to mount the Sierra T9 box to the Ford X Flow engine retaining your original 4 speed clutch mechanism and bell housing.

Here is a link to the Morgan Spares of New England 5-speed conversion. There is no photo, but there is a photo on the instructions PDF.

http://www.morgan-spares.com/mm5/merchant.mvc?Screen=PROD&Product_Code=305-100

Here is the instruction PDF with a photo:

http://www.morgan-spares.com/images/tech/5speedmanualPDF.pdf

-Bill in Tehachapi, California

Here's a couple of links to Ford gearbox conversions, the Revington Ford conversion is based upon a UK design (possibly the one in the next link, and I think that their Toyota conversion is Australian.

http://www.revingtontr.com/shop/collection_display.asp?cartype=tr3&cid=969

http://hi-gearengineering.co.uk/

Both are intended for the TR range so would involve some frame surgery which is the main reason I decided to leave mine as it is!

Similar comments apply to the overdrive option but the links on GoMog are helpful in deciphering Moss boxes and compatability.

I had a link to what looked like a very nice T5 conversion which I can't find right now but it appeared to retain the bell housing and torque tube and just replace the Moss box with a T5 which I understand is something that Jaguar owners sometimes do.

Yes: There is a Toyota conversion. Talk to Mike Anthony. I have a Laycock OD in My +4-4Str. Hardly use it. Try to stay off the Interstate Hiways. Difficult to put this mod. into a 2 str unless seats are changed. Don't think I would modify a '53 Flat Rad. Put your money into making the engine run smoother (balancing).

Button