It is currently Sat Apr 20, 2019 3:54 pm




Post new topic Reply to topic  [ 391 posts ]  Go to page Previous  1 ... 23, 24, 25, 26, 27  Next
Cox GTM ('67-'68) 
Author Message
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post 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.


Sun Aug 22, 2010 1:10 pm
Profile E-mail
The Terrible Tims
User avatar

Joined: Sat Sep 29, 2007 12:23 pm
Posts: 544
Location: suffolk
GTM: Cox/Coupe
Post 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!!!!!


Sun Aug 22, 2010 1:39 pm
Profile
Admin, and Coupe Nutter
User avatar

Joined: Fri Sep 14, 2007 10:34 pm
Posts: 1803
Location: In the workshop
GTM: Cox/Coupe
Post 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


Sun Aug 22, 2010 1:48 pm
Profile
Part built GTM

Joined: Sat Nov 22, 2008 10:24 pm
Posts: 98
Location: englandshire
GTM: Cox/Coupe
Post 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.

Mon Aug 23, 2010 8:27 pm
Profile E-mail
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post Re: Cox GTM ('67-'68)
Maybe. If I do not succeed with the tyre pressure/toe-in changes, I will search in the suspension.


Mon Aug 23, 2010 9:35 pm
Profile E-mail
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post 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).


Tue Sep 07, 2010 7:54 pm
Profile E-mail
Looking like a GTM
User avatar

Joined: Sat Jul 26, 2008 9:45 am
Posts: 206
Location: Scotland [GTMOC 1190]
GTM: Cox/Coupe
Post 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, GTM Spaceframe (Two is never enough!)


Wed Sep 08, 2010 11:04 pm
Profile E-mail
Looking like a GTM
User avatar

Joined: Fri Nov 23, 2007 11:06 pm
Posts: 159
Location: North Perthshire, Scotland (1141)
GTM: Cox/Coupe
Post 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


Thu Sep 09, 2010 8:00 am
Profile
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post 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...


Thu Sep 09, 2010 11:13 am
Profile E-mail
Looking like a GTM
User avatar

Joined: Fri Nov 23, 2007 11:06 pm
Posts: 159
Location: North Perthshire, Scotland (1141)
GTM: Cox/Coupe
Post 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


Thu Sep 09, 2010 5:03 pm
Profile
On the Road
User avatar

Joined: Fri Sep 28, 2007 7:39 pm
Posts: 590
Location: Aberdeenshire
GTM: Cox/Coupe
Post Re: Cox GTM ('67-'68)
http://www.minimarcos.org.uk/cgi-bin/forum/Blah.pl?b=SP,m=1191271779
Image

_________________
Member No 1185


Thu Sep 09, 2010 7:26 pm
Profile E-mail
Looking like a GTM
User avatar

Joined: Fri Nov 23, 2007 11:06 pm
Posts: 159
Location: North Perthshire, Scotland (1141)
GTM: Cox/Coupe
Post Re: Cox GTM ('67-'68)
Cheers Ken!

_________________
(Gulf) GTM Coupe


Thu Sep 09, 2010 7:59 pm
Profile
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post 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?


Thu Sep 09, 2010 9:16 pm
Profile E-mail
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post Re: Cox GTM ('67-'68)
By the way, I have fitted the front windscreen today. :mrgreen:

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?


Thu Sep 09, 2010 9:23 pm
Profile E-mail
Ready for SVA

Joined: Mon Aug 04, 2008 8:22 pm
Posts: 471
Post 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?


Fri Sep 17, 2010 5:49 am
Profile E-mail
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 391 posts ]  Go to page Previous  1 ... 23, 24, 25, 26, 27  Next


Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB © phpBB Group.
Designed by Vjacheslav Trushkin for Free Forums/DivisionCore.

phpBB SEO