Subject: Camshaft Timing/New Data
Author: joe jump
Date: Sep 10, 2001, 7:05 AM
Post ID: 1708175833
Hello Loopers,
First off, I would like to thank you all for responding with so many
good recommendations. Great List!!
Well, I spent some time in the garage this weekend getting some data
with a degree wheel. I made up a timing plug, essentially a gutted spark
plug with a 3/8" bolt passing through the shell & protruding about an inch
beyond into the combustion chamber. Mounting the degree wheel to the alt.
rotor and using this "tool" as a piston stop, I located tdc on the R/H
cylinder in the usual way. First discovery was that the timing marks were
off on the r/h side by about 5-6 deg. The L/H side was almost dead nuts on.
So my first plan of action is to reset the timing, after I make a wrench to
loosten the distributor.
While I had the degree wheel mounted, I decided to measure the cam
timing. The following is the data I found (numbers in brackets are specs
from factory manual):
Right Hand Cylinder
Intake Opens 32� BTDC(40� BTDC)late 8�
Intake Closes 79� ABDC(70� ABDC)late 9�
Exhaust Opens 62� BBDC(63� BBDC)late 1�
Exhaust Closes 36� ATDC(29� ATDC)late 7�
Left Hand Cylinder
Intake Opens 32� BTDC(40� BTDC)late 8�
Intake Closes 78� ABDC(70� ABDC)late 8�
Exhaust Opens 56� BBDC(63� BBDC)late 7�
Exhaust Closes 34� ATDC(29� ATDC)late 5�
I used the procedure stipulated in the workshop manual, i.e., set valve lash
to .019", note crank position when valve starts to open. It looks as though
my cam is timed about 8 degrees late. The only figure that disputes this is
the opening of the r/h exhaust, but since most the other data points are in
sinc, I'm going to attribute the discrepency to manufacturing tolerances. My
next step will be to bump up the cam timing.
I find it quite interesting to hear all the testimonials on
re-installing the intake runners. That sure sounds like an easy one! I have
a set of stacks from an 850-T, and also a set from a V700 which are of the
more traditional "cone" shape. It would be easy to open the V700 set up to
30 mm from 29---"We have the technology!" Or should I use the standard
items? Maybe I'll try both!
These mods I will try one at a time, starting with the ignition timing,
then the intake stacks, and lastly the cam timing.
Next question: can the timing cover be removed from the engine (Tonti
frame) without first removing the engine from the frame?
Thanks!
Joe in St Louis
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