Forum

[Martin]

Recently Norm had had a local friend fretting that he
may have reassembled a early 500 twin with the camshafts
arseabout. We identified the exhaust 332705 as pointed
profile and the inlet #32705 as rounded, these same cams
used on all the 500/700 twins anyway. Since am wondering
if I have made a similiar error too, have become quite
interested in the actual camschaft profile degrees, and
whilst can find no record on the Enfield twins, averaged
several other twins as inlet opening at 33 (degreees)before
TDC, and closing at 65 after BTC, whilst the exhaust opens
at 65 before BDC and closes at 32 after TDC. The Ariel KH
twin has similiar docile characteristics as the Enfield w/
inlet a late opening exhaust at of 51 before BDC, and a
early losing inlet at 56 after BDC. Simon speculated at the
time that using two exhaust camschafts in thye Enfield twin
to sport it up a tad, but this would be two camshafts open-
ing and closing with their pointed profiles as hapharzed.
Anyway, what would the motor do with camshafts incorrectly
fitted beyond doing calisthenics in the frame if it actually
ran at all? Thanks, lads, for any feedback.

[Martin]

In the interim DID stumble on the Meteor's valve timing
figures in Phil Irving's superb 'Automobile Tuning'
allegedly with inlet opening at 30 (degrees before TDC,
closing after 60 after BDC, and Exhaust opening at 75
before BDC, and closing at 35 after TDC for the record
which is average for the period anyway, 'cept doesn't
explain why the inlet cam is gently rounded,and the
exhaust cam so abruptly pointed, thus a presumable
shorter opening time. Still love to hear comments
though, Thank you, Gordon

[Mark M]

This may not help much but I can confirm that some models were fitted with 2 exhaust cams,and seemingly for performance reasons. They were some of the Indian badged twins, notably the Tomahawk and Chief and also the late 500cc Meteor Minor, the Sports Twin which was made from 61-63. The Indian models are clearly stamped 2X on the left side cases about where the exhaust cam tunnel is. This usually requires a different inlet cam sprocket stamped A, but I've never seen one!
REgards, Mark

[Martin]

Thanxs, Mark, your note is invaluable given my
current interest in twin cam profiling.You may
recall the motor had been assembled from a diverse
early Twin and later Tomahawk parts cache found in
a well. Belately realize I have a xeroxed 700cc
Indian Chief parts manual over the garage, and will
check for any mention of same, including the evasive
inlet cam sprocket that was used..one wonders how that
modified the set up. Meanwhile, have rigged up a
timing degree dicc and a dial indicator to discover
when the cams now installed are actually opening and
closing..anything to save stripping down the motor in
vain. Glad you responded, Mark.