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Group 2 Dolomite Sprint racers
Posted: Sun Oct 08, 2017 10:22 am
by GrahamFountain
Does anyone know what race series the group 2 Dolomite Sprints were being used in, in the 1970s? That's not the British Touring Championship race series, which was group 1 (series-production touring cars) 74 to 81. I also seem to remember something about some "Group 1 1/2" race cars, with HS8 carbs.
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Mon Oct 09, 2017 7:52 pm
by new to this
GrahamFountain wrote: ↑Sun Oct 08, 2017 10:22 am
Does anyone know what race series the group 2 Dolomite Sprints were being used in, in the 1970s? That's not the British Touring Championship race series, which was group 1 (series-production touring cars) 74 to 81. I also seem to remember something about some "Group 1 1/2" race cars, with HS8 carbs.
Graham
Graham
I have 2 inch cabs on mine HS8
Dave
Re: Group 2 Dolomite Sprint racers
Posted: Mon Oct 09, 2017 7:58 pm
by GrahamFountain
new to this wrote: ↑Mon Oct 09, 2017 7:52 pm
I have 2 inch cabs on mine HS8
Dave[/color]
I've a set in the garage on a manifold with linkage I've thought about fitting. How does it go?
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Mon Oct 09, 2017 8:11 pm
by new to this
GrahamFountain wrote: ↑Mon Oct 09, 2017 7:58 pm
new to this wrote: ↑Mon Oct 09, 2017 7:52 pm
I have 2 inch cabs on mine HS8
Dave[/color]
I've a set in the garage on a manifold with linkage I've thought about fitting. How does it go?
Graham
Graham
Don't know they were on the car when i bought it,but am making a new exhaust now so should go alright
Dave
Re: Group 2 Dolomite Sprint racers
Posted: Tue Oct 10, 2017 6:07 pm
by trackerjack
I had some 2" SU's on mine for a while before I went over to 45 Dellorto's. The SU's were better than the 1 3/4" ones that they replaced especially at higher revs. The car pulled well from low down too and I would say they are def worth fitting, however the standard manifold and rubber mounts are not up to the job and I had solid alloy mounts that I made myself and I also opened up the manifold to match.
A chain is as strong as the weakest link.
Re: Group 2 Dolomite Sprint racers
Posted: Wed Oct 11, 2017 5:18 pm
by GrahamFountain
I can see how the extra weight of the HS8 could be a problem for those mounts. So what problems can there be from the greater ridgidity, etc. of the metal ones?
Still hoping someone knows about the Group 2 racers. Was it just for rallies? And how did BL get away with alternative carbs (and brakes) in the Group 1 British Touring Cars - especailly after 1976 when the FIA/CSI tightend the rules on modifications?
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Wed Oct 11, 2017 11:41 pm
by soe8m
Creative homologation. The STR91 camshaft was part of a special emission kit. A bigger rad and oilcooler etc. were standard parts for some export countries. When you had on paper a certain number of production cars had those parts fitted it was a standard part so could be used in gp1.
After the rule change in 1976 there were only group 1 cars allowed. Triumph had almost nothing homologated. Ford did. It even didn't homologated the mk2 escort. In 1975 they just homologated a slightly change in bodywork of the escort and could continue.
Jeroen
Re: Group 2 Dolomite Sprint racers
Posted: Wed Oct 11, 2017 11:51 pm
by xvivalve
The club sell 2" aluminium mounts Graham
Re: Group 2 Dolomite Sprint racers
Posted: Thu Oct 12, 2017 9:41 pm
by new to this
Graham
Sorry to Hijack your thread,but on your 2inch carbs do they have a thread in them for where the air filter fits, or is it just a.nut and bolt
Dave
Re: Group 2 Dolomite Sprint racers
Posted: Fri Oct 13, 2017 7:58 am
by GrahamFountain
soe8m wrote: ↑Wed Oct 11, 2017 11:41 pm
Creative homologation. The STR91 camshaft was part of a special emission kit. A bigger rad and oilcooler etc. were standard parts for some export countries. When you had on paper a certain number of production cars had those parts fitted it was a standard part so could be used in gp1.
After the rule change in 1976 there were only group 1 cars allowed. Triumph had almost nothing homologated. Ford did. It even didn't homologated the mk2 escort. In 1975 they just homologated a slightly change in bodywork of the escort and could continue.
Jeroen
There are some mods listed for the Group 1 car in the homologation papers for the Dolomite, but only 3. The camshaft isn't one: it's claimed to have been within the limits of the tolerances allowed by the FIA on the production one.
A heavy duty suspension is listed for exoprt cars in 74. I've not read the 1974 version of appendix J, so that may be different, but there wasn't a rule in Appendix J 1975 for export options in Groups 1 and 3, only groups 2 and 4 - a production of 5000 was needed for a group 1 mod, and 1000 for group 3. However, it does look like the RAC/FIA/SCI were a bit slapdash over mods pre 76, also approving the HD axle for the group 3 TR7 as an export model in 75. It does look like there was a change in how the rules were applied about 77-78, when Jean-Marie Balestre tookover the CSI/FISA, but it is said he had been in the French SS during the war (as a spy for the resistance, of course). BL re-homologated that HD axle again in 1978, when production of 5-speed TR7s exceeded the 1000 car requirement for group 3.
As to the Escort RS 1800 , there's a long list of mods for the group 2 RS1800 from 75 on in its papers (FIA RN 1605). As far as I can make out, they made 58 cars for that, but don't forget, the 100-off rule applied in 1975, and cars (and parts) approved using it were allowed to continue to be rallied in group 2 (and 4) untill the end of 1977. The Mk II shell is homologated in ammendment 18, for the 4th evolution, dated 1/5/75. Ford also got a separate new homologation of it for group 4, with the 2 ltr version of the BDA engine (BDG?) in 77 (FIA RN 650). They seem to have got that on only another 50 cars as a modification to the RS1600/1800 - the cars marked with X0 on the chassis plates - not the 400 required for a simple new homologation into Group 4. However, there at least one other similar instance at about that time where homologations of new a car that was actually modified from exiting approved car was approved on very many fewer than 400 <150 at most.
As to there only being group 1 cars after 76, there's references on the web for the Group one and a half Dolomites in 77-8, at least one saying they had Webber 48s and bigger front brakes, which was not allowed by the FIA in Group 1 under the rules for 76 or 78. There're also references to the group 2 race car engines in some of Graham Robson's books, clearly separate from the Group 2 rally cars, and that goes into 77-8 too.
But I still cant find any reference to where the Gp 2 Doly racers were used, or how the got to modify away from gp 1 for the BTC without listing those changes in the recognition form - however they got approval.
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Fri Oct 13, 2017 7:59 am
by GrahamFountain
new to this wrote: ↑Thu Oct 12, 2017 9:41 pm
Graham
Sorry to Hijack your thread,but on your 2inch carbs do they have a thread in them for where the air filter fits, or is it just a.nut and bolt
Dave
I'll go look tonite.
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Fri Oct 13, 2017 10:34 am
by soe8m
GrahamFountain wrote: ↑Fri Oct 13, 2017 7:58 am
soe8m wrote: ↑Wed Oct 11, 2017 11:41 pm
Creative homologation. The STR91 camshaft was part of a special emission kit. A bigger rad and oilcooler etc. were standard parts for some export countries. When you had on paper a certain number of production cars had those parts fitted it was a standard part so could be used in gp1.
After the rule change in 1976 there were only group 1 cars allowed. Triumph had almost nothing homologated. Ford did. It even didn't homologated the mk2 escort. In 1975 they just homologated a slightly change in bodywork of the escort and could continue.
Jeroen
There are some mods listed for the Group 1 car in the homologation papers for the Dolomite, but only 3. The camshaft isn't one: it's claimed to have been within the limits of the tolerances allowed by the FIA on the production one.
A heavy duty suspension is listed for exoprt cars in 74. I've not read the 1974 version of appendix J, so that may be different, but there wasn't a rule in Appendix J 1975 for export options in Groups 1 and 3, only groups 2 and 4 - a production of 5000 was needed for a group 1 mod, and 1000 for group 3. However, it does look like the RAC/FIA/SCI were a bit slapdash over mods pre 76, also approving the HD axle for the group 3 TR7 as an export model in 75. It does look like there was a change in how the rules were applied about 77-78, when Jean-Marie Balestre tookover the CSI/FISA, but it is said he had been in the French SS during the war (as a spy for the resistance, of course). BL re-homologated that HD axle again in 1978, when production of 5-speed TR7s exceeded the 1000 car requirement for group 3.
As to the Escort RS 1800 , there's a long list of mods for the group 2 RS1800 from 75 on in its papers (FIA RN 1605). As far as I can make out, they made 58 cars for that, but don't forget, the 100-off rule applied in 1975, and cars (and parts) approved using it were allowed to continue to be rallied in group 2 (and 4) untill the end of 1977. The Mk II shell is homologated in ammendment 18, for the 4th evolution, dated 1/5/75. Ford also got a separate new homologation of it for group 4, with the 2 ltr version of the BDA engine (BDG?) in 77 (FIA RN 650). They seem to have got that on only another 50 cars as a modification to the RS1600/1800 - the cars marked with X0 on the chassis plates - not the 400 required for a simple new homologation into Group 4. However, there at least one other similar instance at about that time where homologations of new a car that was actually modified from exiting approved car was approved on very many fewer than 400 <150 at most.
As to there only being group 1 cars after 76, there's references on the web for the Group one and a half Dolomites in 77-8, at least one saying they had Webber 48s and bigger front brakes, which was not allowed by the FIA in Group 1 under the rules for 76 or 78. There're also references to the group 2 race car engines in some of Graham Robson's books, clearly separate from the Group 2 rally cars, and that goes into 77-8 too.
But I still cant find any reference to where the Gp 2 Doly racers were used, or how the got to modify away from gp 1 for the BTC without listing those changes in the recognition form - however they got approval.
Graham
I will check the original complete homologation forms I have but I thought that webers and another camshafts are homologated in gp1 later in time. The later gp1 rallycars were almost as powerfull as the gp2 ones after the 1976 rule change. So the racecars can be gp1's with bigger carbs and other brakes and not gp2 cars but i have to check. There are many alterations/amendements in homologation papers through the years.
Jeroen
Re: Group 2 Dolomite Sprint racers
Posted: Fri Oct 13, 2017 1:13 pm
by Graham.Fountain
The Dolomites FIA form of recognition is available online at
http://historicdb.fia.com/sites/default ... roup_a.pdf. The bigger brakes are only approved for group 2 and there's no mention of different carbs. There is, however, an alternative exhaust manifold for group 1 approved in Novemeber 1979 - I didn't know it changed between early and later cars. I bet someone can work out when that changed and if there were 5000 cars with that mod before Novemeber 1979. That would shed some light on the issue.
However, there wouldn't be any group 2 approval for Webbers (or HS8s), because carbs and manifolds were entirely free for group 2; not even needing the 100-off rule like alternative heads and gearboxes, etc. But there was no such freedom for group 1 in Appendix J for 1975 on (they are also on line with the FIA somewhere) - I say thatm but there's a 1977 version I can't read 'cos "(Mais) je suis Anglaise. Je ne parle pas le Francais".
It's an interesting question whether the FAI/CIS/FISA were allowing mods for groups 1 and 3 on less than the stated numbers of production cars (5000 and 1000) - either before or after 76-7. However, it's irrelevant here, because none of these items are approved for the group 1 Doly anyway. So, if they were using webbers or HS8s and bigger brakes in the BTC, the scrutineers can't have been applying the group 1 homologation rules. How that comes about might be an interesting thing to know.
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Sat Oct 14, 2017 12:27 pm
by GrahamFountain
new to this wrote: ↑Thu Oct 12, 2017 9:41 pm
Graham
Sorry to Hijack your thread,but on your 2inch carbs do they have a thread in them for where the air filter fits, or is it just a.nut and bolt
Dave
I've looked, and mine are not threaded and look to be original.
Graham
Re: Group 2 Dolomite Sprint racers
Posted: Sat Oct 14, 2017 1:15 pm
by GrahamFountain
I had another look at the Dolomite's homologation papers in detail and the vented disks were homologated for group 1 in amendment 21 for the 12th variant, in January 1977, as part of a dual brake system. I can't tell whether it's just the disks or if the callipers are different too.
That amendment references article 258 of Appendix J, which about brakes says:
Brakes: Must be those provided by the manufacturer. The replacement of worn linings is authorised and their system of attachment is free,
provided the dimensions of inner friction surfaces remain unchanged (Art 252 m). Servo-assistance and pressure limiting valves are only permitted
when duly recognised by an homologation concerning a number of identical cars equal to that required for basic recognition.
If a servo-assistance is normally provided for on a car, the servo device may be disconnected.
It is permissible to fit a dual braking system on condition that it be of the same make as that of the hydraulic master cylinder or provided by the
manufacturer of the vehicle and that it has been recognised without minimum production.
The material and method of fixation of the brake linings are free.
As can be seen, these regulations don’t allow for different disks or callipers, just the dual circuit equipment. So, the use of vented disks from 77 in group 1 really was a bit of creative homologation. That still doesn't explain the different carbs though.