Lotus Elan

+2 Dual circuit master options

PostPost by: mikealdren » Sun Nov 07, 2021 9:12 am

berni29 wrote:Hi

Do you think its for front rear bias? I thought it would be criss cross. I will have to ask the PO.

Thank you for pointing that out!

Berni


By Criss Cross do you mean LHF/RHR and RHF/LHR? This would be more difficult, you would need two brake lines to the rear of the car. Also diagonal braking in the event of a failure would be worrying.

As I understand it, proportioning valves are generally used to prevent rear lock up by reducing the rear pressure above a threshold rather than reducing the pressure across the full pressure range. They generally give the same pressure front and rear below the threshold. A balance bar with twin cylinders allows true proportioning as well as providing secondary braking in the event of a hydraulic failure.
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PostPost by: mbell » Mon Nov 15, 2021 11:10 pm

To update this thread I recently bought another different Spitfire Tandem master. The spitfire tandem master comes in two variants:
1) Pre 1975, "Large Cap"
2) 1975-1980, "Small cap"

Previously I'd bought 2) and that master is too long to fit the +2 RHD as previously mentioned. However 1) is a shorter master, it however has a wider offset reservoir that will not fit along side the clutch master. With the reservoir removed it appears the master will fit with enough room for banjo bolts.

The reservoir on 1) is fitted via flat flange and some screws. So it is possible to replace the reservoir but adapters are required. With (a lot of) assistance of Chuck Nukem we've designed/machined some adapter that will allow fitting of reservoir with 7/16-20 fitting or Tilton ones(https://tiltonracing.com/product/master ... eservoirs/).

I still need to get the reservoirs/banjo for it and will be a few months until I get chance to fit it to the car and confirm its good.

Its not quite a bolt on solution as needs the adapters but a possible solution.
Attachments
IMG_20211113_103647.jpg and
Res + adapter
IMG_20211114_124209.jpg and
Master
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: nwbaxter66 » Tue Nov 30, 2021 1:27 am

I think that you might have a runaway Xmas retail success if you decide to put together a production run of these, count me in.
Inspired thinking
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1969 Plus 2 (UK) - sold
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PostPost by: mbell » Tue Nov 30, 2021 6:44 pm

nwbaxter66 wrote:if you decide to put together a production run of these, count me in.


That is one for ChuckNukem not me to decide. I suspect it would need a reasonable sized group buy for it to happen, as while the material costs aren't particularly high I think some extra tools are required and there is quite a bit of setup time to produce them.

I suspect this setup would also work on LHD +2 and RHD Elans and maybe quite a few other cars (e.g. europas). I don't think it would fit LHD Elans but the Datsun master should work for those.

First I need to get the other bits and get it fitted to the car to confirm it is a viable solution. If so I probably post a separate write up.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: nwbaxter66 » Tue Nov 30, 2021 7:38 pm

Thanks.
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1969 Plus 2 (UK) - sold
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PostPost by: mbell » Sat Jan 08, 2022 3:59 am

Currently got the engine and gearbox out, which gives good access to the brake lines. So decided it was a good time to try the new dual master out.

Initial test fit on the pedal box shows it fits and should be able to connect the brake lines. Should even be able to use the push rod that comes with it by adding a small spacer.
Attachments
IMG_20220107_164932_compress14.jpg and
Master on pedal box
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: mbell » Sat Jan 15, 2022 1:48 am

This week I've bought the various fittings and bits and pieces for the master. Now assembled and ready for fitting.
Attachments
IMG_20220114_193917_compress81.jpg and
Assembled and ready to fit.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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