I'll toss this out to the Triumphs list. It's a bit beyond my area of
expertise.
Anyone out there care to help Doug on this one?
- --Andy
On Sun, 8 Jun 1997, Doug Bell wrote:
> I have a 1500 Spitfire engine that I warmed up with 10:1 CR, headers, dual
>SUs/1296 intake manifold, and a modified cam. I'm using a Delco
distributor D-204, an emission controlled item from a Mk3 Spitfire. I
get knock under 3000 rpm when ignition timing is set at 6 BTDC. Looking
at the specs for this distributor, it is obvious the mechanical advance
curve is set way up compared to its non-emission controlled counterpart
from the UK market. The book notes the advance curve is very steep in
order to meet emission control targets. That's fine, but clearly I do
not have such an engine anymore! This extra advance is responsible for
the knock at low rpms.
>
> My options seem to be get a different distributor or recurve the one I
have. Regarding a different unit, I suppose I could try Rimmer Bros
and get a UK-spec model. If I got a Mallory unit, I wouldn't have a
drive for the mechanical tachometer. Either replacement is a guaranteed
$200+
investment. Hence the interest in recurving the one I have. Do you
know a) how to do> it, b) where to find out how to do it, or c) who can
do it?
>
> Thanks,
>
>
> Doug Bell
Doug,
Go down to any good NAPA store and they have lots and lots of
distributor
springs, many times a good number of selections in little "kits". You
can mix and match to you heart's content to find what will work. The
down side is you'll have to do just that--try each out to see if it
works on your engine. If someone you knew had a distributor machine
they could re-curve it the way you wanted, but my guess is you don't
know at this point what type of curve you need. The NAPA route is easy
on the pocketbook and if you're (note proper use of the contraction of
you and are) in good with the counter person, he/she may let you keep
swapping
until you find what you need that works. If you're getting too much
advance too soon, try a heavier/stiffer spring that doesn't allow your
weights to move out until a higher rpm is reached. It's (note proper
use
the contraction it and is) worth the try to keep its (the distributor)
tach drive. Hope this helps some.
Bill Wood
1973 TR6
1979 TR8 Coupe
1981 TR8 F.I.
Greensboro, N.C.
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