Jerry,
About 30 years ago I jumped an upper
chain and spent $25 or $30 replacing
damaged valves, a head gasket, and
timing chains. It costs a few dollars
more today to do that same job.
I jumped that chain because I was
running the timing at about 12.5 degrees
advanced timing with a stock smog curve
distributor. I learned that about a
year ago reading postings on this list.
Others may correct me, but with a
NON-SMOG dizzy I think you run the
timing about 7.5 degrees advanced. If
you have a stock dizzy you NEED to run
the timing at 0 degrees. If you need a
better dizzy, or maybe a recurve kit,
Gary Boone has the best you will find.
http://www.nowroc.com/Webpages/Techtips/
ElDizzy.htm
Running the timing like you are doing
right now does produce a lot of power
(great for beating Chevy's, V8 Mustangs,
and BMW 2002's back then), but it also
places a great deal of additional strain
on the timing chains, which causes
stretching and I suspect increases gear
wear too. If you are hearing any
knocking sound, especially when you
start the car for the first time each
day, you have a chain that is hitting
the L on the upper chain guide (assuming
you still have the L), and you are due
for at least a new upper chain now.
Gordon Glasgow has an article about the
Evil L that you should read and
understand. His web URL is:
http://www.gordon-glasgow.org
There is a LOT of good information about
your car here, but you need to be
careful with the chains in part because
of their cost, and other damage that
could occur if one should fail.
A better answer for quick acceleration
is to set the timing correctly for your
distributor and change the differential
from a 2.70 2000 rear-end to a 2.90 1600
rear end. Someone has done this to my
car and I like the performance increase
(my daughter has found she can beat
Honda & Acura pocket rockets in short
distance races). Performance seems
better than I remember all those years
ago. Higher ratios are also available
if you want to experiment with them.
Tom
69 2000 "Mr. Hyde"
Portland, Oregon
http://www.acmehomesales.com/datsun
-----Original Message-----
From: jerry thompson
[mailto:jwt101@actionnet.net]
Sent: Thursday, April 08, 2004 9:20 PM
To: datsun-roadsters@autox.team.net
Subject: a couple quick questions about
the U20 engine
First of all, I would like to thank all
of you for your help It is greatly
appreciated.
I have a 69 2000 that diesel's all the
time with no avail trying to fix,
timing is 15 before, recent plugs,
points, ect. I have tried leaning the
carbs
all the way, and turning them to full
rich with no change, The car seems to
run great down the road, lot of power,
good mileage 20-24 mpg. This is with
the carbs at full lean as they were when
I bought the car.
The other thing I would like to know is
how many miles it generally takes to
wear out the upper chain on these? This
car has had it changed 3 times that I
know of and it seems like it is loose to
me when I checked it today. It has
about 5-6000 miles since last change,
but maybe all the dieseling has streched
it. Thanks Jerry
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