MDA GT40 Rebuild.

Just a quick question, does anyone know how easy it is to fit the Porsche Cayman box to the 302? Currently running the UN1 box with Quaiffe internals however i thought if i am to upgrade now is the time.
 

Boxster and Cayman use the same transmission.
 

Andy Sheldon

Tornado Sports Cars
GT40s Sponsor
Jack

If you stick with the UN1 I would consider upgrading the bellhousing, flywheel, clutch and starter set up.

Thanks

Andy
 

Ian Anderson

Lifetime Supporter
Supporter
Speak to Mark Sibley, he owned MDA and still sells adaptors etc for mid engined cars. he will know what will work and fit

I believe he goes as Gtracingno1 on e bay and has a few transaxle son there at present.

ian
 

Andy Sheldon

Tornado Sports Cars
GT40s Sponsor
Ian

Mark does not sell full sized bell housings that will take a full size Ford 302 flywheel, clutch and starter motor.

All of the plate type conversions have to use a small flywheel , clutch and starter leading to the obvious problems.

Only Tornado has the full size bell housings available.

Thanks

Andy
 
Jack

If you stick with the UN1 I would consider upgrading the bellhousing, flywheel, clutch and starter set up.

Thanks

Andy
Hi Andy

The motor has had a lot of work done to it but there are no receipts showing a new clutch, bell housing or flywheel which seems strange considering the extent pf word done on the motor. I was also told the gearbox has Quaiffe internals, what these consist of I do not know. Would you have an idea?

Would you suggest the Porsche box or stick with the UN1?

Cheers
 

Andy Green

Supporter
Ian

Mark does not sell full sized bell housings that will take a full size Ford 302 flywheel, clutch and starter motor.
All of the plate type conversions have to use a small flywheel , clutch and starter leading to the obvious problems.
Only Tornado has the full size bell housings available.
Thanks
Andy
Hi Jack,
Mark Sibley may not sell full sized bellhousing, but Chris Cole (who specialises in UN-1 transmissions) does and adapter plates for full size flywheels are readily available from Mick Sollis at Southern GT. I've build '40's with both these options.
The Quaife internals are likely to be a LSD and a raised 5th gear ratio, which makes cruising more relaxed. Looking at your engine spec and assuming your an empathetic driver towards your powertrain, the UN-1 will be OK. Changing to an alternative g/box is not a 5 minute job requiring new mounts, driveshafts, gearshift and potentially exhaust changes. However an upgraded gear reduction starter motor would be a good investment
Regards,
Andy
(currently building a MDA 40)
 

Morten

Mortified GT Asylum
Supporter
Hi Andy:
I don't know what the problem with the small flywheel and clutch assembly is, if it's done correctly. After all, the originals used small flywheel and small bell housings.

There is no problem whatsoever fitting a small flywheel and clutch on a Renault UN1 gearbox with suitable adaptor plate and a geared starter motor.

Even an Audi O1X or O1E use small flywheel and adaptor plate to suit.

There are no problems with running a small flywheel as you state!

Kind Regards
Morten
 

Andy Green

Supporter
Hi Morten,
I never stated there was an issue in running the smaller flywheel. The only issue I've seen on taking this route is when we've had to machine a 302 flywheel to fit the ford V6 ring-gear as the ring gear fits where the balancing holes were leaving voids in the area of the interference fit. A few tack welds before re-balancing reduced the risk of it coming off
Regards,
Andy
 

Morten

Mortified GT Asylum
Supporter
Hello Andy Green,
My comment was meant for Mr. Sheldon, not yourself.
I can see there would be issues trying to machine down a 302 flywheel.
 

Andy Sheldon

Tornado Sports Cars
GT40s Sponsor
Morten

We have been building GT40s for 31 years now and I have seen lots of problems with the smaller stuff over the years.

Thanks

Andy
 

Mike Pass

Supporter
My GTD has a UN1 and uses an adaptor plate. I use an single plate AP clutch, one of Chris Cole’s uprated release bearing assemblies and sleeved master cylinder. It has done two runs to Le Mans and done the track time twice. It has been run at Donnington, Oulton etc. It was fastest GT40 on the Manx Classic in 2007. All is well after 20 years. There is also a twin plate AP clutch which can be fitted which is rated at 600 ft.lbs. and gives a lighter clutch pedal.
Cheers
Mike
 
Thanks for all the useful info. Andy what would be the reason for the gear reduction starter motor?
I’ve been busy trying to create nice shapes from aluminium. I am rolling the inside edges on the sill panels to mimic the centre tunnel. I’ve also decided that in the front area I am going to replicate the curved panel as is in the originals. I believe this is where the spare wheel was. The hours you can lose in a build like this is unreal.
I couldn’t decide if I wanted a straight through pipe or slightly silenced. Luckily I have a talented pal who made me up one of each. Cannot wait to bolt it on the block.
does anyone have any recommendations on the shifter for the UN1 box? The current unit looks utter shite. Fancy something with shorter throw and a little firmer. It’s pretty sloppy but that’s in the stick etc.
 

Attachments

Michael

Supporter
Beautiful work Jack, but I would be concerned about the position of the O2 bung, should be raised at least 10 degrees above horizontal to prevent moisture from destroying the sensor.
 
Beautiful work Jack, but I would be concerned about the position of the O2 bung, should be raised at least 10 degrees above horizontal to prevent moisture from destroying the sensor.
Thanks Michael! the sensor is in the same position as the original one. I shall keep an eye on it though.
 

Andy Green

Supporter
Hi Jack,
Sensor in proposed position will be fine, Mine’s in exactly the same position and has now done 10,000 miles and still works fine. The heater element in the sensor are sensitive to moisture, so the installation needs to prevent condensation building up in the unit.

Also regarding the starter motor, modern gear reduction motors, have a higher torque capacity, can spin the engine faster and are generally lighter

Regards,
Andy
 
Hi Jack,
Sensor in proposed position will be fine, Mine’s in exactly the same position and has now done 10,000 miles and still works fine. The heater element in the sensor are sensitive to moisture, so the installation needs to prevent condensation building up in the unit.

Also regarding the starter motor, modern gear reduction motors, have a higher torque capacity, can spin the engine faster and are generally lighter

Regards,
Andy
Cheers Andy
 
As you’re all aware I am currently forming the aluminium panels around the chassis. The front section is definitely a frustrating part. I want to create a similar look to what the original car had with the spare wheel section but the steering column is proving this to be difficult. I also plan to leave the remainder of the front open instead of closing it in like it was before.
Have anyone made any differences to the front and if so do you have any pictures to share?
 
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