Ti valve questions

[Swiss]

Hey Guys,
I have several questions on the Ti valves used in the 250 and 450 engines. I would like to build a small database of the valve specs for the different engines and need to get the basic specs for the different model valves. Head diameters and stem diameters would be basic, the lengths would be a help also. Have any one manufacturers Ti valves shown to be tougher than the rest? How much spring pressure is needed for the Ti valves and how do the numbers compare to the pressures needed for the heavier SS valves?
I have heard of Ti valve springs, but don't know if they are proving to be reliable?

Thanks in advance for any help you can contribute.

Swiss

 

[Rich Rohrich]

Thanks in advance for any help you can contribute.

Swiss

Swiss the Kibblewhite Master Catalog has a ton of dimensional information on the popular engine valve gear.

Link to catalog PDF ==> http://www.blackdiamondvalves.com/pdfs/KPMI_Catalog.pdf

The Kibblewhite Tensilite Ti valves and the Xceldyne Ti valves have both proven to be incredibly well made and much tougher than the inexpensive OEM valves. Matching them to the correct seat materials obviously helps longevity as well.

My experience with Kibblewhite Ampco45 seats has proven them to be an outstanding match for the Ti valves from both companies.

Matching valve spring pressure and spring material properties to valve weight is a fairly serious science, one that I'm only marginally comfortable with at present. Professor Blair has an amazing spring design program built into his Four-Stroke Head software, but as it has been for me, the cost might be prohibitive. :)

Luckily guys like Mike Perry (Kibblewhite R&D) and the tech guys at Xceledyne are well versed in helping their customers clear the spring design hurdle and are a good resource to tap.

Titanium spring discussion is out of my depth so I'll leave that to the experts in that area.

Both companies do custom work so it's worth the effort to contact their tech support people and work with them on your application.

I hope this helps.

I see you pop up on Micheal Moore's frame builder list now and then, and it's good to see you on DRN again.

 

[Swiss]

Thanks Rich,
Of course we don't think of the obvious sources even though I have been to Kiblewhite several times before. Their online catalog doesn't show the Ti valves available for all of the newer models, and I didn't see any info on the seats but I will dig further into the site and when I need to I will call them directly.

What we are looking at is the problem of running the older Honda XL350 engines in race bikes (flattrack and MX Vintage) and the source of rocker arms (Honda) is getting slim and some of the really high lift cams like the 2790 Megacycle put a lot of stress on the rockers. So there has been some rocker breakage. The options are to design and engineer a limited production run of stronger rockers that would hopefully not be even heavier than the factory pieces, but they would of course be limited in market value so you could say Expensive! I am looking at it from a different direction and that is reducing the stress on the rockers because of the high rpm 50+ hp engines, but running lighter valves and a lighter spring pack. I understand that there is still some increase in replacement costs because they aren't going to last as long as a good set of Stainless valves (as long as neither of them are bouncing in valve float).

AND I understand that given the higher rpm control that the lighter Ti valves and matched springs would allow, there MAY be some racers that further raise the Redline and still raise the stress levels back up to marginal conditions. But they would be running even faster than they are now!!! HA!HA!

I have kept tabs on many of the posts in DRN on a regular basis Rich, but I don't get involved unless I have something constructive to contribute. I really enjoyed the "Blair" days and I learned a lot during those lengthy posts. One of the most important things that I learned is that regardless of the accomplishments of anyone in the "hobby"/business, no one has tried everything. Not even the engineers in the major Japanese corps. have an unlimited budget and unlimited time to research every option in their search for performance.

I was browsing the Tech posts the other day and saw an old group of posts on "no-jet" carbs that was long ago retired. Enjoyed the read and the marketing "hype" that was evident that you sliced through so accurately. I do sales work for advertising, but I try not to "fool" my customers with unrealistic claims for our print product. I also talked with Jerry Branch of Branch Flowmetrics years ago and he called the Posa-Fuel (actually based on the English Gardner design) a poorly controlled leak! HA!HA! I do know that the machining and designs have come a long ways with these carbs, but they did much of that by adapting designs from conventional carbs to work with idling circuits etc...

Now we will play with FI for the next 10 years, looking for more and more performance which seems to be a never ending goal!

Swiss

 

[Rich Rohrich]

Swiss - Here is some additional info on the Xceldyne stuff. CV products is the parent company :

http://www.cvproducts.com/cv/products/brands.aspx?brandID=137

 

[Swiss]

Rich,
Thanks for the links.

The Xceldyne stuff looks kind of big for the 5.5mm stem size, but possibly some custom machined pieces?. I thought about possibly dropping the stem size to 5mm for the extra flow.
I spend a lot of my time helping Geoff put together information for the Vintage XL Honda site at
http://www.oldrice.com/xl_page.htm

We still have a lot of info to put up for the smaller vintage Hondas.

We just lost much of our good list work due to Aimoo redoing their servers. No one likes the new format. Geoff is working at moving things to a new host, but it is a lot of extra work for a working man.

Swiss