mk1-forum.net

A friendly international forum for people interested in the tuning & modification of classic BMC vehicles
It is currently Tue Jul 23, 2019 9:04 am

All times are UTC [ DST ]




Post new topic Reply to topic  [ 28 posts ]  Go to page Previous  1, 2, 3
Author Message
PostPosted: Sun Jul 16, 2017 9:44 am 
Offline

Joined: Wed Sep 09, 2015 11:22 pm
Posts: 248
It's a 2.76 with the overdrive primary and first motion input gears fitted.

I've got a NOS Rover boxed od primary somewhere.


Top
 Profile  
 
PostPosted: Tue Jul 18, 2017 2:14 pm 
Offline

Joined: Sun Sep 22, 2013 1:47 pm
Posts: 714
Location: Coastal VA USA
Yes I run a 2.76 with two (O/D) drop gears. I find the (O/D) first motion shaft input gear in core trannys. The Primary gear does not stay with the tranny till I get them. I have three in service now and a fourth about ready to return to the road. Using the really wide ratio tranny allows good acceleration in all gears. Fourth gear is fairly useless under 50 mph. Third gear carries the same ratio as a 3.44 FD. The 1000 rpm drop between gears requires a engine with some torque.

I'm about to pull the 1360 Cooper S with this gear box and replace with a 998 with 3.1 CWP. Son Alex (age 17) and his sister Lizzy (age 16) are becoming drivers. Alex got his drivers and Lizzy got her learners the same day last week. I bought my first mini roughly 50 years ago. Son Alex is 50 years younger than I am, while not as excited about minis as I was it has been his and my only transportation since he was born.

Getting back on topic, I'm beginning to think of the 3.44 as the new 4.1. I drove a 4.1 for two years of college. My autocross car had a 4.35 and looking at my chart there is a 30 mph difference at 3000 rpm between the 2.56 and the 4.35 CWP. With (O/D) drops and so many CWPs there should be a ratio that works for most. Steve (CTR)


Top
 Profile  
 
PostPosted: Thu Nov 08, 2018 5:25 pm 
Offline
User avatar

Joined: Sat Mar 07, 2015 8:40 pm
Posts: 369
Update...

Been on the rollers at SMMC (thanks guys) and it’s official my car is a screamer!!

All the readings pointing to a 4.1 diff... no wonder my ears were bleeding on the A34 going up!!!

Now it’s a case of how looow to go :D

_________________
Cheers

Kevin


Top
 Profile  
 
PostPosted: Thu Nov 08, 2018 7:53 pm 
Offline

Joined: Fri Mar 20, 2015 5:25 pm
Posts: 1565
I've two 1293cc Cooper S cars both with these final drives. The 3.44 is nice and smooth for a road car. The 3.65 is nice for town work even with an upgraded camshaft :D :D

Alan


Top
 Profile  
 
PostPosted: Wed Jan 23, 2019 10:10 pm 
Offline
User avatar

Joined: Sat Mar 07, 2015 8:40 pm
Posts: 369
Update.... going for 3.4 will let you know what it’s like next week ;)

_________________
Cheers

Kevin


Top
 Profile  
 
PostPosted: Mon Feb 25, 2019 10:12 pm 
Offline

Joined: Tue Nov 20, 2012 10:39 pm
Posts: 79
ive got a 3.44 in my mk1 mg 1100 engine and its perfect much prefer the drive over my 1293 mg metro engine that i had ive got in my first mini, keeps up with traffic well and get some looks off afew audi/bmw drivers while flying down outside lane on m1

Liam


Top
 Profile  
 
PostPosted: Tue Feb 26, 2019 10:02 am 
Offline
User avatar

Joined: Sat Mar 07, 2015 8:40 pm
Posts: 369
Ok. So all done. Fitted the 3.4 and I'm really pleased... takes the edge off the noise at 60mph but doesn't seem to have affected the performance at all.

Also overhauled some other parts and what I did learn was most baulk rings are pants! Blued a few sets up and it's amazing how poor the contact area is... Fitted Guessworks ones in the end and it's transformed the down shifts... the mini spares evo ones also came up really good.

All ready for a busy year now :)

_________________
Cheers

Kevin


Top
 Profile  
 
PostPosted: Tue Feb 26, 2019 3:23 pm 
Offline

Joined: Sun Sep 22, 2013 1:47 pm
Posts: 714
Location: Coastal VA USA
Nick, we run a 2.76 CWP with both OD drops primary and first motion input drop gear. I also use te French / 998 Metro wide ratio tranny gear set. With a 4 to 1 first gear I had to go from 145s to 165s to avoid wheel spin in first two gears. The only issue is the 1000 RPM drop with each gear change. Large engine built for torque helps. 70 mph is at 3000 RPM, 4000 is about 96 MPH. I see 70 every day going to the shop. I have seen 96 on my GPS even with windows closed the wind noise is too much for comfort. And there is the chance of getting a big ticket. I have three of these running for several years. Steve (CTR)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 28 posts ]  Go to page Previous  1, 2, 3

All times are UTC [ DST ]


Who is online

Users browsing this forum: rich080487 and 22 guests


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® Forum Software © phpBB Group
Localized by Maël Soucaze © 2010 phpBB.fr