Chris Coker wrote:
>Howdy Bill,
>
>I'm in the process of rebuilding the carbs in my GP Roadster, and I was
>wondering if you had any suggestions for jets and needles. The intake and
>head seem to be pretty stock, so I'm thinking about running with the
>standard 1600 jets, although the previous owner had complained about it
>running out of top end. I know we may not be able to make an 'apples to
>apples' comparison, but any tips or blind alleys to avoid would be most
>appreciated!
>
>Regards,
>--
>Chris Coker
>69 1600 SPL311-24529
>66 1600 G Production Racer
>Royal Oak, MI
Chris, sorry not to get back to you sooner but.....
Use the stock jet with some 0.100 needles.
In Haynes SU Carburettors, ISBN 0-85696-299-6 is an appendix at the back
with needle charts. You want the thinnest (richest) needle you can get.
Stock needles for the roadsters were all 0.090 series. About the richest
you can get of those is the M87 (16354-H6000), M70 (16354-A7710) or M66
(16354-22011 SSS) (chart in How to modify your Nissan/Datsun OHC Engine,
ISBN 0 89586-353-7).
Sharp recommended using the RH needles, ("rich needles for TR2-4",
according to the Haynes book). In my old car I used some RF needles, which
are richer still. These worked well with my Racer Brown STX-16 cam (old
Nissan Comp,) Arias pistons and comp valves. In my new car, Hauser told me
he hand tapered the needles himself. I'll have to check what kind of
profile they have. (They work fine though).
Hope this helps....
Bill Wessel
Madison, WI
'68 1600 and
GP race car
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