adampage
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 posted on 7/10/16 at 08:12 AM |
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Tricky little gearbox puzzle for you......:)
OK, i'm appealing to the collection of brainpower that is LB!
I think I might have a new eng/box sorted, but if that doesn't work, can I make my existing stuff work.
I have:
- K series engine from a Caterham
- Mazda RX8 box, which is now popular as a Type 9 replacement
- An adapter plate to mate the 2 together, which all bolts up fine
All sorted then? No.....
We discovered too late that the input shaft on an RX8 box is quite short. So the eng & box bolt up lovely, the little spigot adapter fits fine to
support the nose of the input shaft, all good, but the clutch is not reaching the splines on the input shaft.
I imagine it's the same issue if you try to mount a 'short input shaft' Type 9. So that's why the 'long input
shaft' type 9 works perfectly.
We've racked our brains on how to fix it? Push the flywheel out on a spacer? No... Make a 'spline extension' instead of the spigot
adapter? No... Chop an inch off the whole bellhousing to make it sit closer? No...
The only thing I can possibly think is if there's another similar box / model of box (e.g. Honda S2000? MX5? Lexus IS200?) which has a similar
size input shaft but is an inch or so longer, we're in luck, but what are the chances of that!?
SO MY QUESTION IS - Am I missing something obvious? Is there another way to make it work? To bridge the gap between the splines on a short input
shaft and the clutch?
Or do I need to scrap it all and start again.....? (Which i'm thinking I need to do so have nearly got a new eng/box)
Thanks!
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SPYDER
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| posted on 7/10/16 at 10:09 AM |
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Hi there. I had a similar issue ( twice) when mounting boxes to my Toyota Celica 3SGE engine. First time round was with a T50 box then latterly with
an AZ6 unit from an IS200.
On both occasions the end of input shaft fell short of the end of the crank by 10mm.
The T50 bellhousing soon found its way onto the milling machine at work and was quickly shortened.
By the time I converted to the AZ6, however, I no longer had such an easy remedy so I did it manually, so to speak.
Scriber, air hacksaw, file, emery...
Cutting an inch off though as your post suggests, wouldn't be practical.
FYI The end of the input shaft on an un-modified IS200 box is 10mm below the mounting face.
The start of the spline is 35mm below the mounting face.
Spigot is 12mm dia.
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adampage
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| posted on 7/10/16 at 10:54 AM |
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Thanks
OK good, no obvious simple things we've missed then....
I'll have a look at the position of the input shaft on ours just to see if that's any different, but it's a long shot!
Thanks for the idea
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steve m
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| posted on 7/10/16 at 12:02 PM |
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Is there no way of effectively moving the spigot bearing nearer the gearbox, by locating it in the flywheel
steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
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owelly
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| posted on 7/10/16 at 02:44 PM |
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If I've read this right (I've been awake for 37hrs so correct me if I'm wrong...) the shaft is the correct length as it's in
the spigot bearing, but the splined section isn't in the friction plate splines?
http://www.ppcmag.co.uk
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dmac
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| posted on 7/10/16 at 03:38 PM |
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quote:
Originally posted by owelly
If I've read this right (I've been awake for 37hrs so correct me if I'm wrong...) the shaft is the correct length as it's in
the spigot bearing, but the splined section isn't in the friction plate splines?
That's how I read it, only thing I can think of is that there is an offset friction plate available somewhere to put the splines in the right
place on the shaft.
dmac
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owelly
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| posted on 7/10/16 at 03:48 PM |
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If it's just the splines that are not marrying, then I'm sure CG Motorsport will make you a friction plate with a longer splined section.
http://www.ppcmag.co.uk
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adampage
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| posted on 7/10/16 at 03:54 PM |
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Thanks all...
On the last 3 points.
- Steve - I don't think the spigot bearing has to move, as the adaptor plugs that gap, it's more that where the spigot adapter is needs to
be more splines rather than just a support to help locate the end of the shaft
- Owelly - yeah that would work, if the splines continued an inch further down the shaft right to the end (rather than going to a smooth inch at the
end) then it would be fine
- dmac - Yeah, that would be good, if the clutch plate was offset an inch, or just had an inch longer collar to accept the splines nearer to the
gearbox, then it would work. But i'm assuming that doesn't exist!
I'm getting a complete xFlow eng/box combo now which will sort it, and i'll have a big sale of all the parts soon as I can't see a
clever fix.
I'll put things on here (k series eng & all ancillaries, exhaust manifold & can, the RX8 box, but also I have a duratec bellhousing, a
spare prop, some spare dials, a spare open diff & shafts, some spare uprights etc), and that will pay for the new gear.
Thanks again all!
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owelly
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| posted on 7/10/16 at 03:57 PM |
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See my post above your last one...... CG Motorsport can make you a bespoke friction plate with a longer splined section.
http://www.clutch-specialists.co.uk/
[Edited on 7/10/16 by owelly]
http://www.ppcmag.co.uk
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adampage
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| posted on 7/10/16 at 06:29 PM |
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Hmmmm, can they indeed.....
Well, I didn't know that.
I'll have a think!
Thanks
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