GTD Flywheel - Need help

Dear All,
I am a new owner of a GTD40 from 1989. Putting down the alpine gearbox (UNI5) to replace a broken and leaking Crankshaft seal (rear) and the clutch, I noticed that the flywheel and the dented ring had some severely damaged tooth.
The tooth ring is a 121 tooth , that seems very uncommon. I cannot find which car it comes from originaly and where to find one. ( for information, the starter is a Tilton Super starter ref 98-073 with a 9 tooth wheel)
Could anyone of you help me on that.
Many many thanks in advance
Best Regards to you all
I remember that early GTDs used modified Ford Essex V6 flywheels with Renault transaxles. I had a new steel flywheel made with a ring gear off an Essex v6 for my car because I didn`t like re-drilling an old iron flywheel having seen one fail in competition. It was mid 1980s when they were doing that and might still have been doing it when your car was made
Thanks for your infos. Do you know how many tooth the flywheel had? any idea where to find Ford Essex V6 flywheels ? If I am correct Ford Essex was the UK name, it was also known as Ford Capri. Is this correct ?

Ian Anderson

Lifetime Supporter
Try Burton Power

they also do steel flywheels and would probably also drill to fit the 302 and clutch.

Many thanks Ian. With Kev previous info I could trace to Burton UK and identified this 121 tooth ring gear. I dropped them an email for confirmation and dimension but I am optimistic.
Again Many thanks for your help both Kev and Ian

Mike Pass

As Kev says the early GTD set up was a Ford Essex 3l V6 flywheel and an adaptor plate to the Renault gearbox. Burton Power should be able to supply the ring gear for about £80.
To remove the old ring gear place a sharp cold chisel between two of the ring gear teeth and hit it with a large hammer to split it. The ring gear is bigger than the flywheel so to fit the new ring gear it will need to be heated very hot. It will expand to be bigger than the flywheel. Pick it up with a couple of pairs of pliers and drop it over the cold flywheelI. You will only get one shot at this as once it cools to the flywheel temperature it is very tightly in place.
I had issues with clutch slip with the original Renault clutch so upgraded to the AP Racing clutch from Mick Sollis at Southern GT and an uprated release bearing and carrier from Chris Cole. Mick also does lighter steel flywheels. Your flywheel is most likely 28oz balance.
Many thanks Mike. I have ordered the Ring gear from Burton as I am convinced now it is the right one. When I get it, I will get the mounting on the flywheel done by a specialist.
Interesting to ear you mention the clutch slip as Lortec France who actually tuned the engine injection mentioned it when reaching peaks of torque.
I am not yet familiar with all the names you mention, could you give me more details on the AP Racing Clutch you recommend as well as release bearing and carrier. I have been advised by an Renault alpine racer to mount the AP2606. Is it the one you have in mind ? On the other hand I have also been advised not to put this setting as it will be extremely difficult to use on "normal roads". What is your experience of these stronger AP clutch.

I agree that the flywheel is externaly balanced and 28 oz or 50 oz was what I was expecting. Great you confirm the 28 oz.
Many thanks for your help Mike, I do really appreciate as I am neither an expert nor a familiar to GTD40 yet. I had the car for only 1,5 months and only ride it for 700 km.

Mike Pass

Hi Laurent,

I got the AP Racing clutch parts from Mick Sollis at Southern GT

The uprated release bearing and carrier I got from Chris Cole. Chris does not do internet stuff so phone him on 01952416051. He also does the sleeved down slave cylinder which I use with the AP clutch.

Clutch parts
Pressure Plate- CP2394-14
Driven Plate- CP2346-42 (For R2 T - 21 Spline)

The original Renault clutch was always slipping. I checked and the best uprated one from Helix Motorsport was only rated at 280 ft.lbs torque so not good enough. The AP Racing clutch is rated at 340 ft.lbs. but will take much more. It has worked OK with cars with 400+.

I have sent you a message - see top right of page.


Howard Jones

Be aware of the flywheel balance question. The original capri V6 flywheel is not balanced to suit a SBF. Either the 289 or a 302 (28 and 50 oz) just and having it drilled to suit the crank bolt holes will more than likely result in a out of balance rotating assembly. You can use your old flywheel as a example to "mirror" balance the new one and this is a OK way to do it without disassembling the engine. You can get as close as the quality of the machinist so pick a good one that does this quite a lot. Or as I said you can rebalance the rotating assembly with the new flywheel. Correct way but more involved.

One way or the other you need to insure that the one flywheel is the same as the old one as far as balance goes or you can really damage your engine.
Many thanks Howard for your advice. I agree with the high caution to be taken if I change the flywheel.
From my reading of today and search on the net I found the 121 tooth dented ring at Burton. So I will play it safe and get the ring changed on the original flywheel. This way it won't change the balance fine tuning of the flywheel.
You should probably think about getting the flywheel resurfaced also since you said it was slipping so it's probably been overheated.