The Triumph Dolomite Club - Discussion Forum

The Number One Club for owners of Triumph's range of small saloons from the 1960s and 1970s.
It is currently Mon May 25, 2020 2:35 pm

All times are UTC




Post new topic  Reply to topic  [ 13 posts ] 
Author Message
 Post subject: TR7 axle into dolomite?
PostPosted: Sat May 23, 2020 2:17 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Oct 26, 2008 7:26 am
Posts: 2123
Just an idle idea. Does the TR7 5 speed axle fit (with or without fettling) into a dolomite?
Looking at ratios, seems the TR7 5 speed has a wide range of ratios available, down to 2.84 and 3.08
My mind is wandering, thinking about jag v6 engines.......

_________________
Clive Senior
Brighton
Driving Toledo fitted with slant 4, sprint OD box and axle. Needs fettling!


Top
   
PostPosted: Sat May 23, 2020 3:54 pm 
Offline
TDC Member

Joined: Mon Dec 03, 2012 6:04 pm
Posts: 1162
I just had a look at this because the TR7 axle does look very like a Dolly Axle, i suppose not much of a surprise there. It appears to be 20cm wider than a Dolly axle, I suppose you could flare the wheels.

The other issue is the location of the tiebar mounts is different on the TR7 axle and whether the suspension arm mounts line up, no idea. Still he owns a welded and an angle grinder can get round such things.

It seems the diff is a 3.9:1 ratio.


Top
   
PostPosted: Sat May 23, 2020 5:58 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Oct 26, 2008 7:26 am
Posts: 2123
Ah, 20cm is a lot, I was hoping it would be a lot closer.
Maybe I was being hopeful....

_________________
Clive Senior
Brighton
Driving Toledo fitted with slant 4, sprint OD box and axle. Needs fettling!


Top
   
PostPosted: Sat May 23, 2020 6:14 pm 
Offline
TDC Shropshire Area Organiser

Joined: Sun Aug 21, 2011 4:12 pm
Posts: 5570
Location: Highley, Shropshire
I had a 7 axle till recently, couldn't give it away so it got binned when I lost the workshop.

I bought it to try in the Carledo before I found a scrap Sprint rolling shell and used that axle instead.

By my reckoning the error is more like 10cm (4") over the hub flanges and across the trailing arm mounts, near enough the same.

Still a bit dubious over whether you'd need arch extensions, but it'd certainly help you fill them!

The axle I had had a 3.63 in it but there are several more advantageous choices. the upper tie bars would convert easily, you might even get away with 7 upper tie bars, I had those too but think they met a similar fate!

Steve

_________________
2 door '73 Toledo with Vauxhall Carlton 2.0 8v engine OWF 797M (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine EGP 247T (The Dolomega)
'91 Cavalier 2ltr 8v auto
'95 Cavalier 2ltr 16v auto
Spectrum Auto Services, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 45 years and home of Maverick Triumph.PM for more info or quotes.


Top
   
PostPosted: Sat May 23, 2020 11:02 pm 
Offline
TDC Member

Joined: Mon Dec 03, 2012 6:04 pm
Posts: 1162
Quote:
I had a 7 axle till recently, couldn't give it away so it got binned when I lost the workshop.

I bought it to try in the Carledo before I found a scrap Sprint rolling shell and used that axle instead.

By my reckoning the error is more like 10cm (4") over the hub flanges and across the trailing arm mounts, near enough the same.

Still a bit dubious over whether you'd need arch extensions, but it'd certainly help you fill them!

The axle I had had a 3.63 in it but there are several more advantageous choices. the upper tie bars would convert easily, you might even get away with 7 upper tie bars, I had those too but think they met a similar fate!

Steve
I was basing the different in width on measurements that people on the TR7 forum had taken and compared it to numbers on here. It is surprisingly difficult to get accurate specs on axle widths, I suppose you don't normally need those numbers.

The diff ratios came from here https://www.revingtontr.com/the-tr-seri ... nge-points, interestingly it seems later US spec TR7s got the same diff as the 6 cylinder SD1s. I don't know much about that engine but I assume it must have put out a decent amount of torque and the diff must be pretty tough.


Top
   
PostPosted: Sun May 24, 2020 2:17 am 
Offline
TDC Member
User avatar

Joined: Fri Oct 06, 2006 8:57 am
Posts: 599
Location: Auckland, New Zealand
But what can be made to fit is a Ford English axle from an Escort / Capri. That is about half an inch difference in width, drum face to drum face.

I used one in the Sprint I raced for at least ten years after the original Sprint item destroyed itself. We had to gas axe the four mounting points off the Sprint axle and weld them to a cleaned up Capri 3L axle. Chose the Capri as it comes with 9” rear drums, so same size as Sprint. Had the welding professionally done and with careful measuring it was surprisingly easy. Handbrake and hydraulic pipework was simple to adapt to the Ford axle.

We drilled the hubs (and drum) to the Sprint PCD. Alternatively if we had wanted to change wheels we could have retained the rear Ford PCD and bought a front hub conversion to use that all round. That would have opened up a wider variety of secondhand wheels. I did use uprated studs all round and spacers to position the wider tyres (195) central to the Sprint wheel arches.

The front flange on the Capri diff bolted straight to the Sprint prop.

Advantages of the Ford axle are
1) the huge variety of diff ratios available both new and secondhand.
2) The fact the whole diff head can be removed from the diff housing (still in the car) and changed as one unit.
3) LSDs and parts to rebuild them are more readily available and usually cheaper
4) Thicker diameter halfshafts are available off the shelf which are better when racing and no drums full of diff oil as Sprint ones are prone.

Just a thought...

Geoff


Top
   
PostPosted: Sun May 24, 2020 5:45 am 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Oct 26, 2008 7:26 am
Posts: 2123
I was just thinking about jag aj30 engines. Seemingly popular in certain circles, Rocketeer are using them in MX5's and others in kitcars.
240 bhp std, easily tickled up towards 300, and good for more if wallet is heavy.

Downside is the std manual gearbox has top gear as straight through. So hopeless unless a very long ratio diff, something around 2.8 would be needed I reckon.
Rocketeer use the MX5 box, however, that needs a custom flywheel to fit.
Other alternatives are the RX8 box via an adaptor plate, and then the flywheel from a mondeo st200, which are near-impossible to find.

Bearing in mind my thoughts are a bit of a "budget" build, things could easily get out of hand! So it looks like a simpler 4 pot engine is a safer bet if the car is ever to actually reach the road with a new engine. I keep looking at the st170 engine I have in the garage.... so same as in my spitfire. At least I know (more or less!) what I am doing with that :wink:

Cheers All

and I am especially surprised that triumph props have the same pcd as ford. NOBODY has ever mentioned that before.

Clive

_________________
Clive Senior
Brighton
Driving Toledo fitted with slant 4, sprint OD box and axle. Needs fettling!


Top
   
PostPosted: Sun May 24, 2020 6:10 am 
Offline
TDC Member
User avatar

Joined: Wed Oct 04, 2006 8:49 pm
Posts: 717
Location: Sutton,Surrey.
Are those AJ engines heavy around 200kgs and wide at the top.

Would they even go into a Dolomite engine bay without mods.

I’ll go ST170 it’s lighter and I’ll bet more fun when done.

_________________
2005 Mercedes C Class V6 Diesel Turbo Daily Driver.
1980 Dolomite Sprint with a touch of BLT
Balanced Lightened and Tweaked 13B Rotary.
Rebuilding the Sprint time now spent 72Hrs 24/03/2020
80Hrs 08/05/2020.

Member TDC no 0471


Top
   
PostPosted: Sun May 24, 2020 10:05 am 
Offline
TDC Member

Joined: Mon Dec 03, 2012 6:04 pm
Posts: 1162
Quote:
But what can be made to fit is a Ford English axle from an Escort / Capri. That is about half an inch difference in width, drum face to drum face.

I used one in the Sprint I raced for at least ten years after the original Sprint item destroyed itself. We had to gas axe the four mounting points off the Sprint axle and weld them to a cleaned up Capri 3L axle. Chose the Capri as it comes with 9” rear drums, so same size as Sprint. Had the welding professionally done and with careful measuring it was surprisingly easy. Handbrake and hydraulic pipework was simple to adapt to the Ford axle.

We drilled the hubs (and drum) to the Sprint PCD. Alternatively if we had wanted to change wheels we could have retained the rear Ford PCD and bought a front hub conversion to use that all round. That would have opened up a wider variety of secondhand wheels. I did use uprated studs all round and spacers to position the wider tyres (195) central to the Sprint wheel arches.

The front flange on the Capri diff bolted straight to the Sprint prop.

Advantages of the Ford axle are
1) the huge variety of diff ratios available both new and secondhand.
2) The fact the whole diff head can be removed from the diff housing (still in the car) and changed as one unit.
3) LSDs and parts to rebuild them are more readily available and usually cheaper
4) Thicker diameter halfshafts are available off the shelf which are better when racing and no drums full of diff oil as Sprint ones are prone.

Just a thought...

Geoff
it is an interesting idea, the only problem I can see is ford bits seem to go for silly money these days.


Top
   
PostPosted: Sun May 24, 2020 6:29 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Oct 26, 2008 7:26 am
Posts: 2123
Quote:
Are those AJ engines heavy around 200kgs and wide at the top.

Would they even go into a Dolomite engine bay without mods.

I’ll go ST170 it’s lighter and I’ll bet more fun when done.
From the kitcar site I frequent I had the bare aj30 as approx 125 with flywheel. With of engine (no manifolds, but they are tucked away) as 530mm.


But the gearbox issue is a real stumbling block, plus the ST conversion is pretty straightforward for me. Still, will be 50-70bhp and a bunch of torque down. However, I suspect the sprint axle may be too stressed as well with the V6, but the st won't trouble it.

_________________
Clive Senior
Brighton
Driving Toledo fitted with slant 4, sprint OD box and axle. Needs fettling!


Top
   
PostPosted: Sun May 24, 2020 7:37 pm 
Offline
TDC Shropshire Area Organiser

Joined: Sun Aug 21, 2011 4:12 pm
Posts: 5570
Location: Highley, Shropshire
What about the Vauxhall V6? 217 bhp and bags of torque out of the box for the 3.2. Lots of tuning goodies now available for this engine and the gearbox is tough, short, light and 5th gear is overdriven. I saw a pic of a bare motor offered for sale which rekindled my interest recently as it looked rather narrower than i'd thought. I'm guessing its a 60 degree V6 with quad cams and 24 valves. Omega donor cars are cheap as chips ATM. I have the wiring diagrams to make it all work too!

I dropped the V6 as a plan as the Z20LET 2.0 turbo can put out similar bhp figures for less weight, i'm just undecided about forced induction, i'm an NA man at heart!

Steve

_________________
2 door '73 Toledo with Vauxhall Carlton 2.0 8v engine OWF 797M (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine EGP 247T (The Dolomega)
'91 Cavalier 2ltr 8v auto
'95 Cavalier 2ltr 16v auto
Spectrum Auto Services, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 45 years and home of Maverick Triumph.PM for more info or quotes.


Top
   
PostPosted: Sun May 24, 2020 9:24 pm 
Offline
Future Club member hopefully!
Future Club member hopefully!

Joined: Sun Oct 26, 2008 7:26 am
Posts: 2123
Quote:
What about the Vauxhall V6? 217 bhp and bags of torque out of the box for the 3.2. Lots of tuning goodies now available for this engine and the gearbox is tough, short, light and 5th gear is overdriven. I saw a pic of a bare motor offered for sale which rekindled my interest recently as it looked rather narrower than i'd thought. I'm guessing its a 60 degree V6 with quad cams and 24 valves. Omega donor cars are cheap as chips ATM. I have the wiring diagrams to make it all work too!

I dropped the V6 as a plan as the Z20LET 2.0 turbo can put out similar bhp figures for less weight, i'm just undecided about forced induction, i'm an NA man at heart!

Steve
ha, I don't see Omegas under 1K at all. Obviously wrong end of the country again. But after much deliberation, the ST is "the chosen one"

_________________
Clive Senior
Brighton
Driving Toledo fitted with slant 4, sprint OD box and axle. Needs fettling!


Top
   
 Post subject: Aye.....
PostPosted: Mon May 25, 2020 11:54 am 
Offline
TDC Member
User avatar

Joined: Thu Aug 09, 2007 12:22 pm
Posts: 6530
Location: Caithness, Scotland
Quote:
and I am especially surprised that triumph props have the same pcd as ford. NOBODY has ever mentioned that before.
You need to tread carefully here Clive.

Ford UK changed from imperial to metric in the early seventies (during the production of the mark 3 Cortina,
I am not sure when that corresponds to in the Capri production).
Triumph in the 70s used at two UJ sizes with corresponding flanges, so used two PCDs.

Dolomites use the smaller size. T2000 used the larger size for the driveshaft (and the smaller on the prop).

A Dolomite prop won't fit a Capri 2.8 diff. (I have just tried)
It is possible that a Dolomite prop could fit a mark 2 Cortina or mark one Escort diff though?
Therefore I am thinking it may be possible to use a mark 2 Cortina diff flange on a very early mark one Capri three litre differential?
Whether a Dolomite flange could fit the Capri diff is another question? I suspect yes.....


The thing is Clive, you are surely going to have a bespoke propshaft anyway?


thanks,
Ian

_________________
TDC Forum moderator
PLEASE help us to maintain a friendly forum,
either PM or use Report Post if you see anything you are unhappy with. Thanks.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 13 posts ] 

All times are UTC


Who is online

Users browsing this forum: Bing [Bot], Macleesh, marshman and 20 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:  
Powered by phpBB® Forum Software © phpBB Limited