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TR6 TR6 twist from John Twist

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TRclassic3

TRclassic3

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I was surfing through Youtube the other day and was watching a few of the Unversity Motors videos. In this particular one, Mr Twist was working on a TR6, and a couple of comments caught my interest. First, he suggests disconnecting the vacuum retard and plugging. Then set the timing to 32 degrees BTDC at max advance (3 to 4K RPM). Anybody running this way? How does one know when at max advance?

He also uses 80/90 gear oil in ZS dashpots. (maybe SUs also). He guarantees it will give better acceleration. Now I know that there are a multitude of opinions on dash pot oil, but this is the first time I've heard it suggested to use this weight. Any thoughts. Anyone running this way?
 
Using a heavy oil would slow the piston from moving upward and result in a richer mixture for a few seconds. Does that really help acceleration. Don't know that you could measure the improvement if there is an improvement. Personally I don't like the idea. If the carbs are in good shape and you use the recomended oil in the dash pots I'd think you'd get the best acceleration too. The engineers knew what they doing when specifying the whole system.
 
Both suggestions make sense to me; though I don't have a 6-pot to try them on. Easiest way to be sure you're at max advance is to keep increasing rpm until the advance quits moving. Note that you may have to reset the linkage to the float bowl vent on each carb after disconnecting the vacuum retard, in order to get the idle down to something reasonable. Oh, and disconnecting the retard may technically be against federal law (which prohibits "tampering" of any pollution controlled vehicle regardless of model year).

It is worth nothing, perhaps, that gear oil is rated according to a different system than motor oil, so 80W90 gear oil is about like 20W50 motor oil. I prefer straight 20 weight, but it is getting hard to find for some reason. gear oil.JPG
 
I haven't used distr vac on a TR6 in years. Just set it by ear and test drive/reset until I like it. I've used motor oil ( same that's in the engine) for the dash pots. Its getting harder to get a good idle with worn carbs and the gas we have nowadays.

Marv
 
On my 73 TR6 I use automatic transmission oil for the dashpots. I found a big improvement on the get up and go on the zs carbs!
 
Disconnected the retard, set the timing by finding maximum vacuum then backed it off 1 1/2, using 20w oil....real happy with the way my '73 performs.
 
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