Winter Projects

[Cliff Ryan]

Originally Posted by ascona i2000

In post hist (pre74) the original carbs and carb size must be retained, Mexico 40's, please correct me if i'm wrong. However in grp1 carbs are free providing the original number of chokes are retained. In short if you run in both you would have to use 40,s. If you ran solely in grp 1 you can choose your carbs. Dave

[SAMD]

By 40s I presume you mean 2 X twin choke side draughts with a 40mm venturi. ie 4 chokes. I always thought the Mexico was produced with a single twin choke downdraught?

[Robyn Slater]

Originally Posted by SAMD

By 40s I presume you mean 2 X twin choke side draughts with a 40mm venturi. ie 4 chokes. I always thought the Mexico was produced with a single twin choke downdraught?

Thats what i was thinking,,

How can post historic run twin 40 dcoe?
Is it just CRTCC regs?

[ascona i2000]

Originally Posted by Robyn Slater

Thats what i was thinking,,

How can post historic run twin 40 dcoe?
Is it just CRTCC regs?

Oh sorry, i believe there is a waiver for mk1 mexico to run twin carbs.

[delta]

This is getting more complecated by the hour. Mike have i got to run a mechanical pump. Im thinking of going back to my original idea and running the 32/36.

[ascona i2000]

Originally Posted by delta

This is getting more complecated by the hour. Mike have i got to run a mechanical pump. Im thinking of going back to my original idea and running the 32/36.

Do you not have a specific set of regs you are building your car to.

[Mike Bell]

Originally Posted by delta

This is getting more complecated by the hour. Mike have i got to run a mechanical pump. Im thinking of going back to my original idea and running the 32/36.

No, electric fuel pump can be substituted for mechanical nowadays. Original Gp1 regs do not mention it at all, which suggests it couldn't be changed back then.

The cost of new set of Webbers of whatever type is a big lump of engine build cost- but if you get it going with 32/36 can always upgrade later!

[Mike Bell]

Originally Posted by Robyn Slater

Thats what i was thinking,,

How can post historic run twin 40 dcoe?
Is it just CRTCC regs?

Robyn, it depends if Mex was homologated with twin carbs. I don't think it was, but havn't got the papers to check for certain. For modern Gp1 it is easy to allow dispensation if all agree, and in historic rallying they are allowed twin 40s. (But it isn't strictly Gp1 again!)

[Mike Bell]

Just checked Mexico homologation papers (5455) and it only shows 32/36 Weber, so any Gp1 car wishing to run in period spec would have to use that. Don't forget Ford were not really interested in Mex for competition- they had RS1600 for Gp2 and bit later on RS2000 for Gp1. World Cup Rally, where works cars used pushrod crossflow, came before Mex production started.

Allowing twin sidedraft nowadays a good way of making car more competitive against Avengers etc. Incidentally, no vented front discs homologated either, but CTCRC seem quite free with braking regs.

[Cliff Ryan]

Originally Posted by Robyn Slater

Thats what i was thinking,,

How can post historic run twin 40 dcoe?
Is it just CRTCC regs?

Mike's right as CTCRC regs specifically allow twin 40s on Mexico and CSCC are OK with them too which is why we fitted them as the Mexico isn't competitive without them.

[Peter Mallett]

Bear in mind the BTCC (BSCC as it was), only ran to the Grp 1 regs (pre 75) for a year. The CTCRC in my opinion, has merely axpanded the pre 74 regs to allow for more cars and bring the regs into line with the mods that were developing in the early Gp1 year. 1975 onwards the BSCC ran to Group 1.5 and I think the regs rteflect that quite well, at the same time they allow the cars to be competitive in the pre 83 Gp1 (1.5) thereby giving the drivers the chance to enter two races at one event.

[SAMD]

Originally Posted by Mike Bell

Just checked Mexico homologation papers (5455) and it only shows 32/36 Weber, so any Gp1 car wishing to run in period spec would have to use that.

Allowing twin sidedraft nowadays a good way of making car more competitive against Avengers etc. Incidentally, no vented front discs homologated either, but CTCRC seem quite free with braking regs.

I thought as much, 'cos I well remember Plum Tyndall racing his Mexico in Gp1 and it had a blue printed engine etc. to try and keep up with the Boyd's Capri's and the Hunter GLS and stuff, but still ran on a 32/36.
I did my driving test in a Holbay Hunter (it had 40s standard) so I was reasonably familiar with what could be done in those days. at 17yo you tend to be into that. My Dad has bigger carbs than your Dad sort of thing.

I remember an article in CCC called, 'The Hunter they all chased' 'cos the Holbay engine came with a big cam, and webers etc. IIRC it was advertised as 'The Wolf in Sheeps clothing'
They went ok for a mid 70s car.

[Mike Bell]

Originally Posted by SAMD

I remember an article in CCC called, 'The Hunter they all chased' 'cos the Holbay engine came with a big cam, and webers etc. IIRC it was advertised as 'The Wolf in Sheeps clothing'
They went ok for a mid 70s car.

IMHO the Hunter and Rapier H120 with Holbay engine were very under rated cars. Talking of Rootes Group, my Mum had an Avenger Tiger- one of the first ones with magnesium Minilites. After one winter they looked very sorry for themselves!

[ascona i2000]

Originally Posted by Mike Bell

Just found this period pic on my pc of a Gp1 RS2000 engine- as homologated.

Question- what are the 4 pipes running to or from the bottom of the carbs? It's not the fuel supply- that is from the mechanical fuel pump (remember those!)
They are vacuum pipes from the inlet tracks going down to some sort of collector

They are vacuum pipes coming from the inlet tracks down to some sort of collector

[Mike Bell]

Originally Posted by ascona i2000

They are vacuum pipes coming from the inlet tracks down to some sort of collector

For brake servo maybe?

[ascona i2000]

Originally Posted by Mike Bell

For brake servo maybe?

Ahh yeh, quite possibly.

[Al Weyman]

Originally Posted by terence bower

Carbs off of Ebay?? Fully refurbished? didn't think there was such a thing as a bargain [I was right,there wasn't! Be careful with what you buy,it could cost just as much as buying new]

If you were refering to my Holley purchase Terry, they are a very simple device and I have rebulit many of them usually for the cost of a repair kit around 25 quid. The only thing you have to watch is play in the spindles but even they can be rebushed. Any you uy off a race car will be nowhere near that stage and as most double pumpers would never be used on the street where a vacuum secondary model will work much better they are usually in very good condition. The one I recently bought for a 100 quid (£450 new) is mint.

[Al Weyman]

Originally Posted by Robyn Slater

Tell me,...what are the regs concerning carbs when running 1600 xflow,post historic and grp.1 ctcrc. Can i use dcoe 40's/45's for both classes?

Homolgated 40 DCOES in Post Historics, and the bigger ones in the Gp 1 but I think if the engine is a genuine 1600 or +60 40's will deliver and I would opt for those as on Daniel Ryans car.

[Al Weyman]

Originally Posted by SAMD

By 40s I presume you mean 2 X twin choke side draughts with a 40mm venturi. ie 4 chokes. I always thought the Mexico was produced with a single twin choke downdraught?

If, as I believe it was, homologated in period then fine, we are not a Production Saloon or Gp N championship. Or has been pointed out over a period of time it has been allowed. Its called leveling the playing field and although maybe not strictly for the purists works to get a wider variety of machine out, if not we would all be racing one type of car per class which no one wants!

Its for this reason in the stricter Road Saloons I started my circuit career in I opted for a genuine Sunbeam Talbot Ti which came standard with twin 40's and could certainly hold its own.

[terence]

Originally Posted by Al Weyman

If you were refering to my Holley purchase Terry, they are a very simple device and I have rebulit many of them usually for the cost of a repair kit around 25 quid. The only thing you have to watch is play in the spindles but even they can be rebushed. Any you uy off a race car will be nowhere near that stage and as most double pumpers would never be used on the street where a vacuum secondary model will work much better they are usually in very good condition. The one I recently bought for a 100 quid (£450 new) is mint.

When doe's Holley look like Webber Al?

[Robyn Slater]

If i can run twin 40's it will be half way competitive

Just that i cant find it mentioned in the regs.

[Mike Bell]

Porker Update-

Waiting for new water temp sender for the 924, but got new oil sensors so now have working pressure gauge and warning lamp, which is nice. Have decided to get another set of injectors as precaution then set engine up with them fitted.

In meantime have made alloy blanking plates for rear floor area to cover access holes for tank (to replace the original tank tape!) but need a big piece to do the spare wheel well. Will get supplier to cut exactly to size for me, so much easier with a guillotine.....

Side windows all fitted but need to get a slider kit for drivers. Was thinking of getting extractors for hatch 'glass' but have seen price of them so maybe not! Door mirrors also fitted so starting to look like a race car. While doing all the windows and mirrors the driver's door handle broke. Appears that it was common enough for Porsche to supply a repair kit (one small whitemetal part breaks!) but can only find on American ebay. Will have to go for a complete handle but of course they are handed. If get desperate will have to borrow one off the S, but don't really want to nick bits off it.

The rear hatch glass is polycarb or lexan or whatever and very scruffy. Anyone suggest a polish that would smarten it up a bit?

Was hoping to get a set of Minilites for the car but they can't do the correct offset from their blanks so having another set of 5 spoke Compos done in satin black. Need to see who can do me some cheap Yokos or Toyos to go on them!

Looks like first track day at Snet is beginning of March, so should be ready for that- as long as track is ready.

[ascona i2000]

Originally Posted by Robyn Slater

If i can run twin 40's it will be half way competitive

Just that i cant find it mentioned in the regs.

Its in their at the bottom under the vehicle weights. Waiver for avenger to run ford box. Mexico to run twin 40's. BMW CSL to run 152 wheels.

A very good and well pedalled class D car can be righ at the sharp as has been seen before.

[racedriver]

Having been reading about the exploits of PorkerDave and PorkerMax and the very readable Mr Bell, I'm beginning to think that I wish I'd built a 924 last year instead of the "new" Midget.

Anyway I rolled said race midget out of the garage today, and washed it.

End of winter project for me then!

Actually just waiting for the prognosis on the over-pressurising of the oil in last years engine to see whether we revert to an even older one or have the "new' last year's engine refurb'd.

Managed to also wash the road Midget AND get that started today, so that was better than expected.

Keep up the reading material, I'm learning so much!

A.

[Al Weyman]

Originally Posted by Robyn Slater

If i can run twin 40's it will be half way competitive

Just that i cant find it mentioned in the regs.

Foot of the page in the regs Robyn,

6 APPENDICES

6.3.2 Ford Escort Mexico may use 2 x 40DCOE Weber carburettors.

(Sorry Ascona Dave winner and hero of the Clarkson Video I missed your post )