Titanium for crankshaft?

[Sixtysixdeuce]

Hi all, haven't posted in awhile, been busy with non-model engine projects. One of those has been making custom muzzle brakes and compensators out of 6/4 gr. 5 Ti, of which I have a decent amount, and it occurred to me that it might be kinda interesting to use it for crank and rod in a small one-lunger, was curious if anyone ever had. The stuff is certainly a pain to work with, but I've become pretty adept at dealing with it's properties, two of which are sort of at odds with each other; abrasion resistant, yet galls. As such, I'm not sure how well it'd do in this role, although I think with proper lubrication, it should be alright.

Just screwing around in a quiet shot today, made this little guy out of some 3/4" (no plans, just wingin' it). The material I have does not deform when cut off-center like some steels, remained true. The rod journal was done with a 1/8" 4 fl carbide cutter on a rotary indexer with 4 jaw chuck

 

[1dbweldor]

I've made a lot of engine parts using 6AL4v Ti through the years and one thing I discovered quite quickly was the use of bronze on the turning journals. If you run a roller bearing against the Ti it will rollover the Ti and knock the bearing out real quick. So you will have to run with a hardened sleeve. The best I found is a bronze sleeve or bushing will eliminate the gall factor. Keep in mind on your Ti parts about the elongation factor of the Ti. I don't have the ratios in front of me right now but if you need info on this I will look it up and post later today.
Good luck on your parts I hope this helps.