Titanium Valves

[BlueRidgePanther]

I was wondering if anyone had put the valves from the Raptor in their MZ, or if anyone had used any other titanium valves in their 660. Any ideas?

[Bill Jurgenson]

where do you get the idea that the Raptor has Ti valves? The 5 valve version certainly do not and the valves from the new 4 valve engine are not the same size even if they were made of Ti.
I did some homework while continuing development of my racing engine and here is nothing readily available that fits. The simplest way to go is replacing the guides for the different shaft dia and making new retaining plates for the springs to match the cotter that fit the valves. What I found had either 5-5.5mm or 7mm (car size). The larger is easier, cause the valve stem can be turned down at the top to accept the spring retainer from the 6mm valve and use the cotters that go with that. A lot of weight is not saved, however.
In all cases, the valve must be turned to size to match the seat.
All this is not cheap and it is no justifiable either is such a low revving engine. You'll have to change a whole lot of other things before Ti valves are even reasonable, let alone an improvement.
Face it, those 5 small valves are not what's keeping your engine from revving beyond 9000 which is a reasonable ceiling for the thing as such. How long is your list of modifications to get there?
new crank, best one-off and extremely carefully balanced together with conrod and piston
Carillo,
propriety hand fit forged piston (I don't mean JE tho they are good) in a Nikalsil cylinder
billet cam with RD or Kibblewhite springs and Ti retainers
lightened polished rocker arms with Ti screws and lock nuts
Roller timing chain and manual tensioner
lighten flywheel assemble, if racing none at all.
gone with the counterbalance or replaced with a lighter one and solid gears in that case.
If racing a suitable cluster
head work changing and enlargening the ports, welding up the intake side and remilling to make it symmetric and to fit twin Keihins with suitable long intake manifolds.

like this

c594_1.JPG (13.55 KiB) Viewed 1812 times

ceramic bearings, "diamond like carbon coating" of cam, valves, piston skirt...
etc etc and you still haven't gotten to a necessity of Ti valves.

how much of this have you invested in?
nuf said

[BlueRidgePanther]

where do you get the idea that the Raptor has Ti valves?

I just rebuilt an '03 Raptor engine for a friend and it was equipped with titanium valves. I asked him then if he had put them in there and he said he believed the engine was stock, though the previous owner could have put them in there.

[phlat65]

I also was under the impression that the raptor 660 had Ti valves, only on 1 side.