www.zxrworld.co.uk

Would appreciate any assistance regarding cams
There are no identification on these - other than (IN and EX) but they are adjustable. Am told they may be 'SP' type. If so does anyone have any data?
Opening/Closing degrees set at what amount of lift (1mm) ?
Many Thanks. Phil

they look very much like SP cams to me.

The info you seek MAY ( or may not) be found here

http://www.zxrworld.co.uk/zxr400/manual.html


However given that you seem to have acquired these cams and seem to know nothing about them or their history and the fact that ZXR400s have been around now for over 20 years your cams could have been considerably changed and re-profiled in that time.

Measure twice and cut once

The exhaust cam data seems very similar to that in the book both standard and race but the inlet cam bares no relation to anything? Very long duration, long overlap and lobe centre angle is very different. Don't think it's been reworked as the shim size seems normal (approx 3.00 mm) and is higher lift that the exhaust ? (This is with the cam gear marks lined up with the cam box joint) Phil

Hi mate I run both inlet and exhaust at 105 degrees cam lobe centres and it runs sweet. If you need any info about setting them up give me a shout.

regards steve

Thank you for your assistance
See attached data which is a comparison of data I have from the manaual both std and race also from the KENT website all compared with data from my own engine. Cams are set to the marks with the cam box half joint. My inlet cam opens earlier, closes later, much longer duration, higher lift and different lobe centre ?? Valves have good piston clearance.
I bought this bike a few years ago, raced it once but was unrideable due to suspension problems so its languished in the back of the shed. Now the suspension is rebuilt, some idiot left out some bits in the forks so it was on max compression damping!!! Rear Ohlins was very tired so that's been overhauled. Consequently have never really assessed the performance of the engine, seemed to go ok but nothing special.
Have re assembled the engine and is back in the frame. Will run it in the next few days
Any comments greatfully received Thank You Phil

This is the method I used to set mine http://www.muzzys.com/articles/lobe_centers.html