[Roadsters] 1,200 miles, 5,000 feet; now where do I set me SU's?

[Tom @ Datsun2000]

Sad to say, the Iron Bottom has seen it's last run.  There is another run
coming up in Northern California called RUN FOREST RUN.  I have links to
that run on nowroc.org and datsun2000.com.  It is not intended to replace
the Iron Bottom, but people I have met from the area tell me it is likely to
be a great multi-day outing with each day starting in Arcata and exploring a
different part of the territory.

Keith Williams has told me that the damper design of the SU carburetor is
self compensating for altitude, which is one of the advantages of this
carburetor design.  I have never noticed any power differences due to
mixture adjustment changes when going from 16' above sea level where I live
to around 5000 feet.

I would strongly suggest going with a breakerless ignition system.  The best
and most reliable is the updated dizzy Dave Brisco is offering, but there
are others you can choose if you prefer.

Make sure you have your timing adjusted correctly for your dizzy advance
springs.  A smog dizzy should be set for 0 degrees advance (more is hard on
your upper chain - BTDT), and a pre-smog set of advance springs allows for a
setting the timing up to -16 degrees BTDC.

Tom
69 2000 - Mr. Hyde
Portland
http://www.datsun2000.com
http://www.nowroc.org


-----Original Message-----
From: datsun-roadsters-bounces+tom=datsun2000.com at autox.team.net
[mailto:datsun-roadsters-bounces+tom=datsun2000.com at autox.team.net]On
Behalf Of Nathaniel Leeds
Sent: Sunday, August 17, 2008 10:08 PM
To: datsun-roadsters at autox.team.net
Subject: [Roadsters] 1,200 miles, 5,000 feet; now where do I set me
SU's?


All,

First, I'd like to thank everyone for encouraging me to try the cross
country trip. The roadster performed admirably, or that was after I cured
some pinging with a generous treatment of octane boost, and a mysterious
non-idle, no-start, with some new points in Ely, NV. (Next iron-bottom, I'm
bringing a timing light and dwell meter)

Now I'm finally at sea level. I'm giddy with the promise of more power.
Unfortunately the first low altitude runs have been noisy messy affairs: the
car smells like a refinery and backfires like Chinese new year until the
engine gets well above normal operating temperature. Some of these problems
might be other maintenance that I'll need to do after the long, heavy
driving, but I'll get to that once I get the setting right.

I had a decent scheme for the timing and carbs at 5000 feet, but I thought
I'd ask the list where people set their sea-level SU's, timing, and what
octane everyone likes.

Here's some information: '69 2000, no air pump, SU's, w/ the Solex cam,
headers with aggressive exhaust.

Nathaniel Leeds