On Wed, 9 Dec 1998 20:17:55 EST
Rikrock@aol.com
Wrote: Subject: TR6 S-4 cam??
Hello,
Can anyone tell me the specs on this cam?
Thanks.
Rich Rock
64 TR4
65 TR4A-IRS
67 TR4A...parts
70 TVR VIXEN
71 TVR VIXEN 2500
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And on Wed, 09 Dec 1998 20:48:14 -0800
Hugh Barber <piglet@earthlink.net>
Wrote: Subject: Re: TR6 S-4 cam??
Rich,
According to the Competition Preparation Manual, the S-4 cam has the
following specs:
SPECIFICATIONS FOR S-4 CAMSHAFT V-579
Inlet opens 42 deg BTDC
Inlet closes 71 deg ABDC
Exhaust opens 71 deg BBDC
Exhaust closes 42 deg ATDC
Duration 290 deg
Lift at Valve .410"
Checking clearance at camshaft .013"
Operating clearance at valve hot .020"
Hope this helps,
Hugh Barber
San Jose, CA
'73 TR6
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That is curious because:
My reference material shows:
S4 Camshaft (data from Ted Schumacher)
Lift .410"
Duration 293 degrees
Power Range 4200-6500 RPM
nb. marginal for street
S4 Camshaft (37 67 73 31). (data from Gareth Thomas Tuning book-out of print)
Lift .465"
Duration 290 degrees
Power Range 3500-6500 RPM
BHP/L (in 2498cc engine) 185 BHP
Valve Clearances: Inlet 12 thou' & Exhaust 13 thou'
Curiously as you can see, the figures for the S4 vary ?
I do not know which ones are the true figures, but AFAIK, I have a BL ST USA
'S4' Camshaft in my Vitesse, and therefore would like to know the correct
figures!!!
(My Camshaft was made as one of a set of 10 ordered from Messrs Holbay back in
1985/6.)
Leon F Guyot
London, England
'63-date Vitesse 2L Convertible (triple webers etc)
'69 GT6+ (stock)(arriving Spring '99)
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