Thoughts on Conical/Beehive valve springs kz440

Yes it has more preload on the seat but open pressure is actually a little less than the stock spring by about 10lbs.
I'll get pictures of the springs and the pressures.
That is the nice thing about conicals is the varying spring rate that most double springs just can't do and the weight reduction on the valve train allows you to actually get away with less pressure while still controlling the valve and it's harmonics.
I might just end up buying some 7mm titanium valves off of ebay and custom making them fit my application. I'm not really a lover of titanium stuff on street applications but what short riding season their is I don't think it will make much difference.

13bravo wrote: Yes it has more preload on the seat but open pressure is actually a little less than the stock spring by about 10lbs.
I'll get pictures of the springs and the pressures.
That is the nice thing about conicals is the varying spring rate that most double springs just can't do and the weight reduction on the valve train allows you to actually get away with less pressure while still controlling the valve and it's harmonics.
I might just end up buying some 7mm titanium valves off of ebay and custom making them fit my application. I'm not really a lover of titanium stuff on street applications but what short riding season their is I don't think it will make much difference.

Ti valves in a 440? Why? Ti is not as strong and durable as the stock steel valves. Honestly man, you are getting wrapped around the axle on this rebuild. Focus on putting the engine back to OEM specs. Get some new stock OEM Kawasaki valves if the stems are worn otherwise do a light facing and move on to the seats and valve guides. Sloppy valve guides should be tended to. The Kawasaki service limit is quite sloppy on most bikes so yo can improve on that by keeping the "wobble" clearance down to just a few thousands. Also make sure you have nice straight and round cylinder bores. That's where your bang for your buck will come from, not from modifying valve train parts.

I'm not really going to use Ti. valves in it, but I can't find a good replacement valve, the stems on the originals are too worn and valves are too thin for use.
I do know a lot about ti valves as I've had customers use them in their circle track dirt modifieds. Even with it being in an engine that comes apart yearly, I'm no huge fan of ti. valves.
The guides have already been changed to bronze, the ports have been lightly cleaned up and straightened a little bit. I really want to use a stainless valve because being a bit heavy for the bike is going to put more strain on the engine which leads to valve recession.
We do a 3 angle valve job as a standard valve job and this will more than likely get a 4 or 5 angle valve job as it's for ourselves not a customer.

Best to avoid heavy duty springs unless using a wild cam grind, the extra spring pressure increases valve train wear. IIRC Some megacycle cams need synthetic oil to combat these extreme cam lifter pressures.

One thing you may not have considered : mechanical resonance. The lighter springs will have a higher harmonic frequency, the bike engine might rev double the speed of a car engine. The reason two sets of valve springs (with differing fundamental frequencies) are used is to combat this resonance issue.

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www.physicsforums.com/threads/valve-spri...must-be-down.553482/