Technical Stuff

First, let me say that is not meant to be a comprehensive technical resource for all things Alpine. Such a thing already exists at team.net, on the Alpine page. There is quite a bit of technical information on the Tigers page that is applicable to the Alpine too.

This page is for technical information that I have discovered about my Series 3. It may be applicable to other Sunbeam models, and if I know this to be so, then I'll state it.
Read this disclaimer before you ring your lawyer.

• Correct carburettors for the Series 3 and some possible alternatives
• Water temperature sender unit
• Oil for gearboxes with overdrive
• Clutch
• Cooling System

The early Series 3 Alpines (prior to Oct 63) were fitted with a pair of downdraught Zenith carburettors, which changed to a single twin barrel Solex carb for later Series 3s. This article will concentrate on the early, Zenith-equipped cars.

The Roadster came with a pair of downdraught Zenith 36WIP-3 carbs fitted with small round air-cleaners on the top of each carby. The GT came with a pair of downdraught Zenith 36WIA-3 carbs fitted with a remote air filter, and a 'pancake' duct on top of the carbs. The body of the two carbs is the same. They have different jet sizes and the WIA model has an 'economy' valve which is blanked off in the WIP model.

Some say that the Roadster was fitted with the GT's air filter assembly when the cars were destined for dusty locations (eg. Australia), as the Roadster's air filters were not very tolerant of dust. I haven't been able to verify this yet. If this was the case, was it just the air filter which was changed or did these cars also get the GT's carbies?

• Later Series 3 Solex - not a well regarded carb, probably the worst option.

• Fit twin, single barrel, downdraught, Weber ICTs (from a VW) to original manifold. This weird fitment came from Bill Lewis

• Twin DCOE40 Webers. Some manifolds for this fitment were cast up a while back. Who knows when the next batch will be made. Can be jetted for the stock motor. Will stay with the motor through all stages of tune. Also the firewall brace on the car needs modified to clear the rear carb. Jarrid Gross suggests trying 29mm venturis and ~125 to 130 main jets as a starting point for a stock motor.

• Single sidedraught Weber. Lynx Australia makes a manifold to fit this carb to a Hillman Hunter. The cylinder head face of the manifold needs machined to make it fit on an Alpine. Russell Maddock has this setup on his Alpine. Also the firewall brace on the car needs modified to clear the carb.

• Twin, sidedraught, Zenith-Stromberg CD150s from a Series 5 Alpine. Correct model CD150s (150 CD without temperature compensationmodel 3023/4) are very rare according to Jarrid Gross, so different model CD150 carbs are the most likely option. Can use Series 5 inlet manifold and linkages.

• The gauge (and wiring) can be checked by connecting a resistor (about 60 - 70 ohms) in place of the sender unit. Turn on the ignition and the gauge will move to about half scale if it's OK (mine did). Don't directly earth the sender wire or you'll burn out the voltage regulator.

• Measure the resistance across the sender unit itself. Disconnect the wire from the sender, and measure resistance from the connector to the body of the sender. The sender unit should measure in the hundreds of ohms if the motor is cold. Here are the specs for the sender unit. Mine measured several million ohms, so it was suspect.

• I decided to check the wiring just the same. I removed the earth strap from the battery, then out came the temp gauge, and I disconnected the wires from it. I checked the continuity of the wire to the sender unit - OK. I temporarily reconnected the battery and checked the other wire - power was there. I checked the earth wire that runs between each gauge. It was burnt away but the gauge still moved when I substituted the resistor for the temp sender! There must be more than one earth path for the gauge, possibly through the sender unit itself. After replacing this wire I set off in search of a replacement sender unit.

A query to the Alpines list resulted in Curt from Classic Sunbeam sending me the original Smiths part number (TT4802/00). Curt had them in stock, but he's in the USA and I'm in Australia, it wasn't worth shipping one part if I could find a local source for them. A few phone calls later I was able to cross reference the part to a 1974 Jaguar XJ12. The part is made by VDO (P/N 320.045). It should be made of brass. Don't accept the steel part (P/N 320.046) as a substitute, it will corrode in the alloy thermostat housing. BTW - the same part (TT4802/00) is listed for Alpine series 3-5 and Tiger 1 & 1a.

Simple, non-detergent, non-friction modified, single weight, engine oil is not easy to come by nowadays. One suggestion is to go to a lawnmower shop as 4 stroke mowers use 30wt oil. Another suggestion is the specialist oil companies (eg Duckhams, Penrite) who make oil for older cars (but they are expensive). Yet another possible source is the racing fraternity, 30wt oil is used for running in some race motors, I'm told. Good luck.

I also found that The Green Bearing Company makes a roller-type throw-out bearing which can be used in these cars (PN: CB-2033-C). You need to use the throw-out lever from a later Alpine with the smaller diameter throw-out bearing. If you have the spring-type pressure plate, you will need to keep the original pedestal that the throw-out lever pivots on (this pedestal is different height for spring vs diaphragm pressure plates).

The bolts that secure the throw-out pedestal to the gearbox were very loose on my car. I used locktite when putting these bolts back in.

The radiator may be the same as the Singer Gazelle. At least my local radiator guy thinks so.

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