Just a friendly caution or two.. A cam is part of a package that needs to have
compatible intake manifold, exhaust manifold, heads and carb for maximum
performance. For instance, a cam that develops most of its power in the 3000 to
6000 rpm range probably needs exhaust headers and an intake manifold that can
flow well up through 6000. Any cam recommendation needs to be gotten along with
what mainifolds, heads, and carb are being used.
If Art is still running the stock heads, hopefully he has installed screw-in
rocker arm studs in place of the original pressed in version. (And with heads
off, will be putting in hardened valve seats for unleaded gas...) Also, the
original valve springs may have relaxed a bit over the years. They should be
tested and replaced if necessary to get full performance out of a new cam.
If he ends up picking from a catalog, and does not have fly cut pistons, there
is some guidance in the old "Performance Tuning The Tiger" book on page 41
regarding cams. It says the maximum lift should be 0.440 inch and maximum
overlap should be 56 degrees. It also says elsewhere that the slightly higher
lift LAT 20 gets away with that because the maximum overlap is not exceeded.
Obviously actually checking the valve to piston clearance by hand with modeling
clay, as described in the book is a must do when installing any new cam is a
must do. The book mentions 0.125 is desired with .080 minimum.
In addition to looking at Comp Cams, Crane and Lunati are very worthy of
consideration.
Just my thoughts, hopefully of some value.
Gene
----- Original Message -----
From: Carmods@aol.com
To: tigers@autox.team.net
Cc: BJBAAUW1@aol.com
Sent: Saturday, February 2, 2013 9:28:42 AM
Subject: [Tigers] 260 CID Cam
Art Bonsignore, owner of a 260 Tiger that has a Shelby American camshaft
that was installed in his Tiger in 1968. It was described as a High
Performance solid lifter cam with 0.450" valve lift and 272 deg duration. He
wants
to replace it with a slightly more aggressive hydraulic version. Do you
have a suggestion I can pass on to him?
John Logan
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