Adam:
Aside from mechanical compatibility, the differences center
around:
1. Whether equipped with a vacuum advance
2. Whether equipped with a vacuum retard
3. Maximum mechanical advance
4. Shape of the advance curve.
The PI distributor is mechanical advance ONLY.
You can remove the vacuum capsule if you want a mechanical only
dizzy, and you
can trim the bob weight stop inside the dizzy if you want more total
advance. You can
also change the bob weight springs to adjust the shape of the advance
curve. Vacuum advance
would be in addition to any mechanical advance, and is highly desirable
for fuel economy.
Also, the mechanical advance is added to the base timing, which for our
motors is 10-12
degrees when stock.
Normally, you want in the vicinity of 25-27 degrees total
advance for a naturally
aspirated gas engine, and that should be all in by about 3,500 RPM. The
actual numbers
depend on octane, camshaft, combustion chamber, fuel mixture, etc. It
really takes a
dyno or lots of experimentation to optimize the advance curve. This is
why people like
to do a swap, so they can get a proven combination. Trouble is, that
combination may
not work well for their motor, depending on the modifications....
Cheers,
Vance
P.S. Here is the data from the NZ triumph web page. You can see
the numbers
vary a LOT.
(rpm quoted is distributor not crankshaft)
Model From engine # Distributor Part # Max advance
------------------------------------------------------------------------
-----------
2000 Mk1 high compression Lucas 25D6 Lucas 40967
11-13 degrees @2100rpm
low compression Lucas 40975
15 degrees @2500rpm
2.5 PI Mk1 Lucas 25D6 Lucas 41236 11
degrees @3000rpm
2000 Mk2 ME1 Lucas 25D6 Lucas 41314
13 degrees @2500rpm
ME50001 Lucas 25D6 Lucas 41378
9 degrees @1800rpm
ME92301 Lucas 45D6 Lucas 41452
9 degrees @1800rpm
ML20001 Lucas 45D6 Lucas 41621
11 degrees @2300rpm
2.5 PI Mk2 MG1 Lucas 25D6 Lucas 41236
11 degrees @3000rpm
MG75001 Lucas 25D6 Lucas 41502
13.5 degrees @1400rpm
MG82007 Lucas 25D6 Lucas 41543
13 degrees @1500rpm
MG83620 Lucas 43D6 Lucas 41582
13 degrees @1500rpm
2500 TC Pre '74 engines Lucas 25D6
14 degrees @2300rpm
MM45 Lucas 45D6 Lucas 41536
10 degrees@1400rpm
MM20001 Lucas 45D6 Lucas 41624
7 degrees @1400rpm
Australian Lucas 45D6 Part 41654
11 degrees @2000rpm
-----Original Message-----
From: owner-6pack@autox.team.net [mailto:owner-6pack@autox.team.net] On
Behalf Of Adam C Beasley
Sent: Wednesday, August 25, 2004 3:00 PM
To: 'The 6 Pack List'
Subject: Distributors... and lucas part numbers
What's the difference between the different distributors for the TR6? I
read on the web that you want Part number 41219 if you are doing a PI
conversion and want max power. I found a distributor with part number
41352
that I'm considering. what would be the difference between the two?
Would
part number 41352 work in my 73 TR6? I don't have the existing part
number
of my distributor yet.
Thanks,
Adam
73 TR6
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