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  • #16
    Re: Brakes - Single or dual circuit?

    Originally posted by stevejgreen View Post
    Do you have such a thing as IVA in NZ?

    for a new build to be properly registered in the U.K., it’s mandatory. Once registered, you can do what you like, provided you don’t mind driving an illegally modified car, and are not caught.
    About 25 years ago when the NZ government was thinking about doing something like that the NZHRA (New Zealand Hot Rod Association) said - "we can do that"

    And the Government said "You're On"

    So we have a very very sensible set of standards and experienced "Hot Rodders" who run our certification system

    Comment


    • #17
      Re: Brakes - Single or dual circuit?

      As this thread seems to have lost it's purpose I though I would post what I have discovered by much Googling!

      The (non servo) tandem master cylinder seems to be a very rare beast. I have been unable to even find a picture of it! however what I have discovered is a few facts.
      Bore was 0.7" (Servo version 0.75")
      The mounting flanges are vertically in line (Servo version horizontally in line)
      Because of the angle of the pedal box the fluid reservoir is wedge shaped. The same for (I guess) both non servo, and servo versions.

      Anyway, what I have discovered is the GMC226 as used on later Spitfires. 0.7" bore, vertically aligned mounting flange and a wedge shaped reservoir.

      gmc226.jpg

      It's my best guess that it will do the job. I know that the Marina shared some of the gearbox internals with Triumph. Maybe that applies to the brake hydraulics as well....

      Cheers, Robin

      Comment


      • #18
        Re: Brakes - Single or dual circuit?

        Originally posted by martinclan56 View Post
        As this thread seems to have lost it's purpose I though I would post what I have discovered by much Googling!

        The (non servo) tandem master cylinder seems to be a very rare beast. I have been unable to even find a picture of it! however what I have discovered is a few facts.
        Bore was 0.7" (Servo version 0.75")
        The mounting flanges are vertically in line (Servo version horizontally in line)
        Because of the angle of the pedal box the fluid reservoir is wedge shaped. The same for (I guess) both non servo, and servo versions.

        Anyway, what I have discovered is the GMC226 as used on later Spitfires. 0.7" bore, vertically aligned mounting flange and a wedge shaped reservoir.

        [ATTACH=CONFIG]11877[/ATTACH]

        It's my best guess that it will do the job. I know that the Marina shared some of the gearbox internals with Triumph. Maybe that applies to the brake hydraulics as well....

        Cheers, Robin
        During the 70’s there was an awful lot of parts bin engineering going on BL parts were to be found both in Triumphs, MG/Austin/Marina/Ital and even in LandRovers.
        The Marina gearbox is essentially a Triumph clone with slightly different gear clusters but all the bearings, dog clutches and slip rings etc are essentially interchangeable. With all the small Triumph range.
        MOC member since 05/97
        1984 Marlin Roadster SWB.
        1800TC, Unleaded ported head, stage 2 cam. Ford Type 9 gearbox, Dolomite Sprint rear axle fitted with MGF disc brakes.
        Three core radiator, Renault Clio vented front discs.
        The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

        Loads of Marlin Reference can be found documents here or there.

        Comment


        • #19
          Re: Brakes - Single or dual circuit?

          Originally posted by chris_cussen View Post
          Robin is correct. However if you use dual cylinders and find the best ballance then weld the adjustment then it will pass as it won't be adjustable....
          Yes, but you don't have to go as far as welding them in place using a lock nut counts as well. This type of pedal box is commonly used in 7 type kits. The MoT inspector will be looking for an adjuster in the cabin that can be reached by the driver.
          Mk2 SWB Marina Roadster with a 2.0L Pinto built in 1986

          Comment


          • #20
            Re: Brakes - Single or dual circuit?

            Andy: IVA requires the brake ballance to be non-adjustable, i.e. welded. Your MOT tester may not be aware of the difference and you could probably get away with it.

            Comment


            • #21
              Re: Brakes - Single or dual circuit?

              It seems to be that the IVA testers probably are not requiring welding, that's probably offered as an example of how to meet the requirement, using lock nuts would achieve the same result...
              Mk2 SWB Marina Roadster with a 2.0L Pinto built in 1986

              Comment


              • #22
                Re: Brakes - Single or dual circuit?

                Adjustable brake bias. Look at https://www.gov.uk/government/public...-a-pass#brakes

                Comment


                • #23
                  Re: Brakes - Single or dual circuit?

                  Originally posted by chris_cussen View Post
                  That's definitely open to interpretation. I'll ask a couple of the guys who have got cars with adjustable bias how they got them through IVA.
                  Mk2 SWB Marina Roadster with a 2.0L Pinto built in 1986

                  Comment


                  • #24
                    Re: Brakes - Single or dual circuit?

                    Originally posted by andyf View Post
                    That's definitely open to interpretation. I'll ask a couple of the guys who have got cars with adjustable bias how they got them through IVA.
                    Conversions that are not based on M1 vehicles may comply with the applicable requirements of the original base vehicle. Documentary evidence of base or incomplete vehicle approvals will be deemed acceptable provided the maximum mass of the original approvals has not been exceeded.
                    MOC member since 05/97
                    1984 Marlin Roadster SWB.
                    1800TC, Unleaded ported head, stage 2 cam. Ford Type 9 gearbox, Dolomite Sprint rear axle fitted with MGF disc brakes.
                    Three core radiator, Renault Clio vented front discs.
                    The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

                    Loads of Marlin Reference can be found documents here or there.

                    Comment


                    • #25
                      Re: Brakes - Single or dual circuit?

                      'Car Builder Solutions' States that drilling and pinning is no longer acceptable, it must be welded!

                      Comment


                      • #26
                        Re: Brakes - Single or dual circuit?

                        Originally posted by HairyDave View Post
                        'Car Builder Solutions' States that drilling and pinning is no longer acceptable, it must be welded!
                        What you do to a vehicle after it has been IVA approved is up to the individual owner.
                        The legislation will be vague when an inappropriate modification is carried out, and the vehicle sold on without notifying the purchaser.
                        Buyer beware is not a satisfactory defence in the UK where the seller has a legal obligation to describe the condition of the vehicle accurately.
                        MOC member since 05/97
                        1984 Marlin Roadster SWB.
                        1800TC, Unleaded ported head, stage 2 cam. Ford Type 9 gearbox, Dolomite Sprint rear axle fitted with MGF disc brakes.
                        Three core radiator, Renault Clio vented front discs.
                        The reasonable man adapts himself to the world; the unreasonable one persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man.

                        Loads of Marlin Reference can be found documents here or there.

                        Comment


                        • #27
                          Re: Brakes - Single or dual circuit?

                          Originally posted by HairyDave View Post
                          'Car Builder Solutions' States that drilling and pinning is no longer acceptable, it must be welded!
                          Interesting, I wonder how the competition cars get around it. Optimum break bias it dependent on the surface conditions and adjustable from the cockpit. The problem is that professional teams will not be able to get away with something that is regarded as an infringement of the regulations for health and safety reasons!
                          Mk2 SWB Marina Roadster with a 2.0L Pinto built in 1986

                          Comment


                          • #28
                            Re: Brakes - Single or dual circuit?

                            The document says - must not be manually adjustable

                            That is usually taken to mean must "require tools" to be adjusted

                            Anything can be "adjusted" if you can use tools!

                            There are similar requirements on protecting people from high voltage - you need to have the cover bolted down "so that it needs tools" to take the cover off

                            The illustration has what looks like a hand nut that can be rotated by hand to adjust the bias

                            Comment


                            • #29
                              Re: Brakes - Single or dual circuit?

                              We are going a bit off topic, but ...
                              From https://assets.publishing.service.go...r-vehicles.pdf
                              Section 09B Service Brake Control / Mechanical Components

                              26.It must not be possible to manually adjust braking rates between axles see Notes 4and 5
                              27.Vehicles fitted with adjustable twin master cylinders that have been rendered inoperable by mechanical means to comply with RS 26 must have a label affixed on the master cylinder or the immediate vicinity with legible text as detailed in Note 6

                              Note 4: Hydraulic valves that only operate automatically and react to vehicle loading or braking forces are permitted (Load Sensing and Gravity valves) Manually adjusted valves (other than to permit pre-setting the automatic function of a valve) are not permitted to be fitted even if they are rendered un-adjustable.
                              Note 5: Bias bars and other mechanical adjusting devices fitted to twin master cylindersmust be rendered inoperable by mechanical means e.g. lock wiringof components.
                              Note 6: Adjusting front/rear brake bias may invalidate approval and breach Construction and Use requirements.

                              However if the vehicle was not subject to IVA in the first place.......

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