The Triumph Dolomite Club - Discussion Forum

My sprint engine needs some work. 5 years of abuse in my hands etc. First thing I intend to tackle is the rebuild of the SU's. Right away I hit a problem, seems they may have waxstats and been told to convert them to non waxstats. Discuss please

I think they've had a bad press.

All the cars I have run with them I have never found any issues.

If they have not been a problem, then don't change. However, waxstat jets are way more expensive if you intend replacing them. Or you can do the 2p conversion.....

I have found it is usually just the spindles that are worn. Moreso if the carbs use "normal" spings to close the throttle. The carbs with "radial" (not sure if that is the correct term, but the srings that are wound around he spindles) cause far less damage. Can be worth rplacing the butterflys if they have the poppet valves, or solder them up and cut off the sticky outy bits. Needles can wear as can jets, but inspect carefully before forking out!

They are more problematic on cars with non-crossflow heads, where the inlet manifold and carbs are directly above the exhaust manifold, and the heat affects the jets and vapourises the fuel in the float chambers. I have a Midget 1500 with this problem, so it will be getting fixed jets and a new heat-shield soon.

If you need new jets anyway, then I would go for fixed ones. Also, as has been said, change the throttle disc for the plain type.

As said previously, if the jets are OK I would do the 2p conversion.

If you want new jets then Burlen do a conversion kit. You have to buy two parts, the jet and the linkage. On my 1850 these worked out at just over £20.00 per carb. Not sure about HS6s but Burlen are very helpful if you give them a ring.

I have done it both ways with no problems but I wonder if it's needed given that the hot stuff is in the other side of the engine.

Ok I'll ask... whats the 2p thing?

Tony

You just replace the wax pellet with a penny which happens to be the right size. On the twin carb cars you need 2 pennies (one for each carb) hence the name.

Waxtstats are fine if they are kept clean. They can get covered in crud which makes them lean off too much as
they get too warm.

SU tuning guide on the dolly wiki.

If the holes are worn oval then new jets are needed, so it may be cheaper to get non waxstat ones.
Running wise it doesnt make a huge amount of difference.

Jonners

Toledo Man wrote:You just replace the wax pellet with a penny which happens to be the right size. On the twin carb cars you need 2 pennies (one for each carb) hence the name.

AH thanks, never heard of that

Tony

This was mentioned at last night's West Yorkshire meeting. The heat from the exhaust manifold on the OHV cars can throw the waxstat out causing uneven idling. This isn't so much of a problem on the OHC cars.