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Re: Jack Knight Twin Cam Heads
Posted: Sun May 17, 2015 11:42 am
by rich@minispares.com
Spider wrote:Tupers wrote:Didn't most of them go to Japan? I'm sure there was a company doing JKD 5spd twin cam conversions over there.
Slightly OT here - the JKD 5 Speed Gearboxes were also fitted by Rover to I believe 60 Mini Coopers, there was an inital run of 50 somewhere in the mid 90's then the last 10 off the line also had them fitted.
they where rubbish as well, the fifth gear gets all chewed up and there are no spare parts.
we are always getting people ringing up at work in the vain hope that parts from the minispares five speed will fit!
Re: Jack Knight Twin Cam Heads
Posted: Mon May 18, 2015 9:17 pm
by Tim Harber
rich@minispares.com wrote:Spider wrote:Tupers wrote:Didn't most of them go to Japan? I'm sure there was a company doing JKD 5spd twin cam conversions over there.
Slightly OT here - the JKD 5 Speed Gearboxes were also fitted by Rover to I believe 60 Mini Coopers, there was an inital run of 50 somewhere in the mid 90's then the last 10 off the line also had them fitted.
they where rubbish as well, the fifth gear gets all chewed up and there are no spare parts.
we are always getting people ringing up at work in the vain hope that parts from the minispares five speed will fit!
We did sort a Jack Knight 5 speed box a while ago by getting a selector fork made, which wasn't cheap but it saved the box. I think one is supposed to advertise the fact if one is in business , but it seems to have missed me. We also sorted one of the prtotype ones that had no oil feed to the centre of the layshaft

Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 7:10 am
by bill773mini
rich@minispares.com wrote:Spider wrote:Tupers wrote:Didn't most of them go to Japan? I'm sure there was a company doing JKD 5spd twin cam conversions over there.
Slightly OT here - the JKD 5 Speed Gearboxes were also fitted by Rover to I believe 60 Mini Coopers, there was an inital run of 50 somewhere in the mid 90's then the last 10 off the line also had them fitted.
they where rubbish as well, the fifth gear gets all chewed up and there are no spare parts.
we are always getting people ringing up at work in the vain hope that parts from the minispares five speed will fit!
It's odd but I hear how terrible the JKD 5 speeder is all the time, can't be fixed, chews up 5th etc.
My SPI (the same one that's done Blyton now twice (I hope you'll agree not driven gently), the Italian Job and about 12k hard road miles mostly in 5th) has never given any grief despite a big chunk of torque going through it, the box it's self is a total joy, it's the nicest Mini box I've ever used.
Had the original 2 pin diff pop on the way back from the 2007 IJ, drove it slowly all the way home with a broken diff, pulled the box out and found it full of shrapnel and the diff cover cracked. Put a cross pin in from Rich and had the box rebuilt as a precaution as the diff was in such a mess. No problem with the rebuild and nothing at all damaged in the box, just new bearings etc as a matter of course.
Great box.

Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 7:18 am
by Spider
I don't know a real lot about the Boxes and haven't heard much about them either, but I did drive 998 a few years back that was fitted with one. I thought the shift was excellent, probably a tad better than the stock one and the ratios very well suited that engine (mind you, while it was a 998, it was a very refined Injected engine, pulled really well to the point that I could hardly believe it was only 998 cc). 850man has more details on the car, engine and gearbox, I think he recently overhauled the box in fact.
Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 8:48 am
by rich@minispares.com
bill
yours is the earlier straight cut one though......
its the later helical version that gives all the problems. they didn't make the fifth gear correctly and they just chew them selves to bits.
id guess that the big, heavy 13" rover wheels didn't help with the problem either
Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 9:58 am
by bill773mini
rich@minispares.com wrote:bill
yours is the earlier straight cut one though......
its the later helical version that gives all the problems. they didn't make the fifth gear correctly and they just chew them selves to bits.
id guess that the big, heavy 13" rover wheels didn't help with the problem either
Oh I didn't know that mine was an earlier version, it's from 96. Good news for me then!
I revise my statement, straight cut ones are brilliant, don't buy a helical one, they're rubbish! Better?

Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 11:37 am
by JohnA
Our S Works JK Speed box was replaced under warranty by John Cooper Garages after self destructing at 1500 miles. The new box was obviously fitted without cleaning the metal out of the engine as at 17,000 miles I had to strip and rebuild it, new oil pump, new camshaft and crank bearings. The replacement box has now covered 25,000 miles and is getting ready for some attention
Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 11:57 am
by Spider
Looks like this thread is also going the way of that damn cat,,,,,,,,,
Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 12:33 pm
by JohnA
Meow

Re: Jack Knight Twin Cam Heads
Posted: Tue May 19, 2015 12:39 pm
by Richspec
Does anyone know if the Twin Cam head bolted straight on or needed block work / supporting mods?
Re: Jack Knight Twin Cam Heads
Posted: Thu Jul 09, 2015 1:25 am
by FISH FINGER
The head bolts onto the standard head stud configuration, obviously block skimmed to get your desired CR as with any well built engine, although I cannot speak for the "road" kit which had about 120hp.
I am placing my whole car and spares in the sales section soon when I can get a chance to go through everything. well developed over time with more to come from engine , currently a rally car, it but would be better suited to track so it could stretch it's legs properly shall we say

Re: Jack Knight Twin Cam Heads
Posted: Thu Jul 09, 2015 5:39 am
by JC T ONE
rich@minispares.com wrote:
its the later helical version that gives all the problems. they didn't make the fifth gear correctly and they just chew them selves to bits.
id guess that the big, heavy 13" rover wheels didn't help with the problem either
I have a helical JKD 5 speeder, works nice, and havent noticed any additional metal on the oilplug, when i change oil.
Re: Jack Knight Twin Cam Heads
Posted: Thu Oct 15, 2015 12:24 am
by mab01uk
Just found this photo I took of the Jack Knight 16V Mini at Brands Hatch in the early 1990's. It went up against the 16V KAD Mini in 1994 for the 'Fastest Mini in the World Race". As said if I remember right it was a very close race between Peter Baldwin (JK) v Bill Sollis (KAD) and the KAD Mini won?
Re: Jack Knight Twin Cam Heads
Posted: Sat Sep 03, 2016 1:14 pm
by mab01uk
Re: Jack Knight Twin Cam Heads
Posted: Sat Sep 03, 2016 3:53 pm
by mini_surfari
Didn't paul wiltshire who used to work for mini world supposedly have one of those 6 speed box's on his 7 port mini?
Re: Jack Knight Twin Cam Heads
Posted: Mon Sep 05, 2016 10:06 am
by Richspec
He did, ultra rare, his face dropped when my mate said to him, 'yeah i have one of those as well'
(its in the metallic green 1275GT with the Turbo K head that was at MITP if anyone saw it).
Re: Jack Knight Twin Cam Heads
Posted: Mon Sep 05, 2016 12:35 pm
by mk1coopers
Such a pity they aren't the company they were anymore

Re: Jack Knight Twin Cam Heads
Posted: Mon Sep 05, 2016 8:10 pm
by Ministwo
I would like one.
image.jpg
Re: Jack Knight Twin Cam Heads
Posted: Tue Sep 06, 2016 12:01 am
by Richspec
Wouldn't we all!
thats a KAD though
Re: Jack Knight Twin Cam Heads
Posted: Fri Dec 16, 2016 11:57 am
by mab01uk