[Tigers] Stock 260 Camshafts' Limits

[Jim McLaughlin]

Robert:
Fly cutting the intake pistons is just one item in performance options for a tiger.  If you have flat top pistons and you wish some horsepower evaluate and consider the following:
1.    For almost any high lift cam you will have to fly cut flat top pistons.  Your engine builder (or You) will have to check clearance BEFORE you run the engine anyway, and then fly cut the piston tops.
2.    The rocker arm studs on the 260 were pressed in, if you are strengthening the engine switch to threaded rocker arm studs, this is a must do or you will wreck the engine.
3.    Obtain the old book Performance Tuning your Sunbeam Tiger, it contains the information you need to be successful.
 
My ’66 Tiger has around 300 horses, 9.5-1 compression ratio, threaded rocker studs with roller rocker arms, high performance cam with racing hydraulic lifters, so it can work for you.  I installed other mods to help with cooling etc. But I retained dual point distributor and standard ignition.  The car starts like it is fuel injected.
 
Jim McLaughlin
B382000175LRXFE
 
From: Tigers [mailto:tigers-bounces at autox.team.net] On Behalf Of Robert D. Hogan via Tigers
Sent: Thursday, June 18, 2015 5:16 PM
To: LIST TIGER
Subject: [Tigers] Stock 260 Camshafts' Limits
 
I plan to reassemble & reinstall my 260 C.I. engine after 45 years of storage to simplify sorting and usage of the Tiger's fuel, ignition and various other systems.  Improving the engine's valve train with better hydraulic lifters, screw in studs, stronger valve springs and a higher performance cam seems cost and performance effective.
 
The Clymer book (page 41) lists the maximum camshaft lift at 0.440" & maximum overlap at 56 degrees.
 
Does anyone have experience with installing a higher than 0.440 lift cam in the stock 260 with standard flat top pistons and 260 cylinder heads?  I will be putting a test assembly together to check for interference but asking may guide from going for a Summit Racing cam that is risky.
 
Just as a note, there is apparently no off the shelf fly cut 260 pistons available anywhere that will increase the compression ratio approaching 10:1 without ordering a special set at high cost.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/tigers/attachments/20150619/f8adb226/attachment-0001.html>