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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
I have two breathers. One on the timing cover and one on the rocker cover. Though I have some crancase gas, not too much at all.
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Sun Aug 22, 2010 1:10 pm |
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the other Tim
The Terrible Tims
Joined: Sat Sep 29, 2007 12:23 pm Posts: 487 Location: suffolk GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
400 kms is not that far, i would have thought 1600 kms to run in a rebored engine.
6500-6800 is probably realistic for the cam.
There are much more modern single wound springs available these days that would do a better job than the old skool double springs and be kinder to the cam.
_________________ I'm not a complete idiot, parts of me are missing!!!!!
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Sun Aug 22, 2010 1:39 pm |
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West
Admin, and Coupe Nutter
Joined: Fri Sep 14, 2007 10:34 pm Posts: 1762 Location: In the workshop GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
Try coming down to 1.3 bar front 1.6 bar rear, but do this change only nothing else to see how it feels.
You might find this works better. It is close to what I run and simular to what stuart runs [turbocox]. I know It made a huge differance on mine reducing the fronts to this level made the car less nervous. It will make the steering a little heavier, but you will get use to it.
Neil
_________________ IF wile e coyote had a GTM he would have one with Nitrous too! watch out road runner! The First GTM into the 11s then the 10s, PB 10.87 @ 125.5 Mph on A048 tyres, and fully road legal at Santa Pod
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Sun Aug 22, 2010 1:48 pm |
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SportsLibre
Part built GTM
Joined: Sat Nov 22, 2008 10:24 pm Posts: 77 Location: englandshire GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
CamelotR wrote: The car holds the line firm, though it is not willing to get back to straight. It has no oversteer, no bumpsteer. But it fast corners, when I step on the accelerator, it becomes uneven. Not much, but I can feel. It is "nervous".
Have you removed all of the rubber from the rear, any rubber bushes left are likely to deform and steer from the rear on power.
_________________ Gtm Coupe, Jeffery J5, Mini Italian Job, Radical Clubsport and a road (tow) car
Last edited by SportsLibre on Mon Aug 23, 2010 10:01 pm, edited 1 time in total.
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Mon Aug 23, 2010 8:27 pm |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
Maybe. If I do not succeed with the tyre pressure/toe-in changes, I will search in the suspension.
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Mon Aug 23, 2010 9:35 pm |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
I have rechecked the suspension throughly, and it turned out that after the castor adjustment, the front suspension has developed some bump steer (I thought that the castor was right, but it wasnt, soo slightly missplaced the rack). Is there any known solution to cure it? I have toe-in on bump (soo have to raise the track rod end somehow).
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Tue Sep 07, 2010 7:54 pm |
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minitici
Looking like a GTM
Joined: Sat Jul 26, 2008 9:45 am Posts: 189 Location: Scotland [GTMOC 1190] GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
The original Cox GTM mounted the steering rack on the front bulkhead. Later GTMs mounted the rack on the back of the front subframe on special brackets.
_________________ 1967 Cox GTM; 1970 GTM Coupe, Lancia GTM Spaceframe , 1997 Rossa Mk2 (Two is never enough!)
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Wed Sep 08, 2010 11:04 pm |
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Alex Gibson (AXLE)
Part built GTM
Joined: Fri Nov 23, 2007 11:06 pm Posts: 130 Location: North Perthshire, Scotland (1141) GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
You will need to lift the steering arms. This is what you do on the racing minis for bumpsteer.
Alex
_________________ (Gulf) GTM Coupe
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Thu Sep 09, 2010 8:00 am |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
I have my steering fborlted to the subframe as I wanted to get the steering arms inline with the rack.
Lifting the arm? How? Simply by fitting spacers? Sounds a bit hard...
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Thu Sep 09, 2010 11:13 am |
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Alex Gibson (AXLE)
Part built GTM
Joined: Fri Nov 23, 2007 11:06 pm Posts: 130 Location: North Perthshire, Scotland (1141) GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
Its corrected with spacers under the steering arms. If you do a search on the mini marcos forum you will see what i am talking about! Mini Marcos Forum > Sport > Class win
And e-mail John Dickens Iam sure he did it on his coupe
Alex
_________________ (Gulf) GTM Coupe
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Thu Sep 09, 2010 5:03 pm |
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Ken555
On the Road
Joined: Fri Sep 28, 2007 7:39 pm Posts: 573 Location: Aberdeenshire GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
_________________ Member No 1185
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Thu Sep 09, 2010 7:26 pm |
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Alex Gibson (AXLE)
Part built GTM
Joined: Fri Nov 23, 2007 11:06 pm Posts: 130 Location: North Perthshire, Scotland (1141) GTM: Cox/Coupe
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Re: Cox GTM ('67-'68)
Cheers Ken!
_________________ (Gulf) GTM Coupe
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Thu Sep 09, 2010 7:59 pm |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
Great thanks! I have ended up doing this with rather minimal modification to steering arm gave good results. ... I am still unable to upload a pic ... Soo I have angle skimmed steering arm to raise the end about 10mms. Now my bumpsteer is about 1mm on the whole suspension travell, and 0.5mms on the "normal travell". I think it should be ok for the road. Or?
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Thu Sep 09, 2010 9:16 pm |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
By the way, I have fitted the front windscreen today. It was a great pain in the back as we did not checked it while making the chassis, but it turned out to be not that bad fitting. Just one part was awfull: the lower corners, especialy the left hand side. Did any of You experienced the same?
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Thu Sep 09, 2010 9:23 pm |
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CamelotR
Ready for SVA
Joined: Mon Aug 04, 2008 8:22 pm Posts: 425
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Re: Cox GTM ('67-'68)
I have corrected the suspension geometry, but the ride is still not perfect. I think the rear steering arm pickup point on the subframe is a bit weak and flexing. How was it done on later GTMs?
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Fri Sep 17, 2010 5:49 am |
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