Rick----Either I'm not reading your reply to Nick right, or we see
things differently on how spark is transferred.
First, the distributor rotor runs in a CCW direction, as you qustioned.
This is critical to what follows. If the tip is barely at the
distributor cap tower posts at idle, the bulk of the rotor mass will be
trailing. As the timing is advanced centrifugally, the spark then tries
to jump sooner. This puts the whole rotor mass somewhere between two
towers, and we don't want that.
There is an illusion that the rotor move farther clockwise as timing
advances, when viewed with a timing light (thru a hole in the cap). I
don't think the rotor itself speeds up, but rather the spark timing
does, and thus "moves" the rotor backward.
My position on this is as follows:
Set the static timing to where the center of the rotor tip is in the
center of the tower post, using #1 @ TDC, (or 10deg. BTDC)
Now, as the timing advances, there is still the bulk of the rotor tip
mass still under the proper tower.
While the timing may advance centrifugally between 20 and 32 deg. this
is in crankshaft degrees. At the distributor it is only half of this, so
the location of the rotor tip is not so critical when viewed this way.
I like your idea of the Dremel tool to make a viewing inside the cap.
This is much better than drilling round holes, as I have.
If I'm all wet about any of the above, please straighten me out!
Dck Taylor
From: patton@suscom-maine.net(Rick) Date: Sat, Jul 31, 2004, 1:49pm
(PDT+3) To: 6pack@autox.team.net (6pack) Subject: RE: Hi Energy
Ignitions?
Hi Nick,
......The TR cap is rather small but it can handle the job. I found the
best way to set it up was by drilling as large a hole as possible in the
cap. Using a Dremel tool you are not limited to a small round hole. If I
remember correctly (better check) the TR distributor turns clockwise.
Static timing should have the rotor lined up with number one so only
about a sixteenth of in inch of the rotor's contact is next to the dist
post. Most of the rotor will be PAST the post. This is very important
because when the engine advances 32 degrees it will still be aligned
with the correct post. Using a timing light connected to the post next
to your viewing port, you can actually watch the rotor and make
necessary adjustments. Improperly aligned, it will fire to the nearest
post which may not be the one you were hoping for.
Running all that power with the original cap it would be wise to add a
cap and rotor to the spares in your trunk.
There are some photos of the Crane system on my web site. Unfortunately
the site is down while the server is being relocated but it expected to
be back up within a day or so. Check out:
http://topshamautoparts.com/tr6/engine.htm
Rick Patton
75 EFI TR6
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