titanium pistons?

[snowmobilesrme]

okay, so ive done a search on titanium pistons, and came up with nothing.

the thought came up in my head, as i was reading the "dont buy a sled from twsandrew" thread.

someone mentioned something about 27lbs being alot of boost, which yeah, thats alot. said something about it also probly melting the pistons a little...

i know it would be super expensive to make titanium pistons, but what would be the pros and cons of titanium pistons? what are the posibilities? or would it be the worst thing thought of for a sled?

 

[winter brew]

I believe aluminum alloys have better characteristics for a piston...heat transfer, lighter weight, cost, easy to machine...and it needs to be somewhat sacrificial so it fails before more expensive components.

 

[POLZIN]

send me a 2K Deposit and a sample or drawing and I will make you a set of billet TI pistons

 

[milehighassassin]

I believe titanium is very strong but also fragile.

 

[tdblakes]

I would say the two largest reasons would be failure mode and rotating weight. Also cost and manufactuability would play a part in it.

 

[LRD]

The holy grail as far as pistons go so far is Carbon Carbon pistons
http://www.techbriefs.com/content/view/2258/32/

Good Luck

 

[Dam Dave]

There are some ceramic pistons out there, FI cars and Moto GP bikes get all the trick stuff

 

[mattymac]

they used to run ti rods or pistons in NHRA top fuelers and funny cars a couple years back (pretty sure it was rods)

they asked austin coil (john forces crew chief) what he thought, he said "it just makes an even more expensive part shoot off really cool lookin sparks when it lets go"

 

[milehighassassin]

All that trick stuff in race cars and what not, are on motors that are torn down after every race if not after ever run.

 

[POLZIN]

Im faily certain Ti would be a horrible material for pistons . Its is strong and very elastic ( not Brittle ) however it has a high coefficient of thermal expasion, creates tons of heat and a wicked light show when friction is applied.

Sparks and a case full of air /fuel mix could be bad!

 

[ttyR2]

Titanium is also very notch-sensitive, meaning scratches make a part likely to break. It also galls on other metals where movement is involved.

 

[turbo800]

Ti connecting rods have definitely been done. Tons of rotating weight to be had there. I know some shops hate to machine Ti, but with the right tooling (we do Grade 5), its a heck of alot better than 304, 316, or 17-4 Stainless. When Ti is being ground it puts off a wicked cool white spark light show as Polzin mentioned. For pistons, the aluminum is blended (I know it has silicon) and isn't pure alloy.

http://en.wikipedia.org/wiki/Hypereutectic_piston

Interesting tidbit from Wiki:
"Titanium alone is a strong, light metal. It is as strong as steel, but 45% lighter. It is also twice as strong as aluminium but only 60% heavier. Titanium is not easily corroded by sea water, and thus is used in propeller shafts, rigging and other parts of boats that are exposed to sea water. Titanium and its alloys are used in airplanes, missiles and rockets where strength, low weight and resistance to high temperatures are important. Further, since titanium does not react within the human body, it and its alloys are used to create artificial hips, pins for setting bones, and for other biological implants."

 

[snowmobilesrme]

i used to tear apart navy ships with my stepdads company and we would get these huge titanuim discs out of these heat exchanger type things or whatever you call it, so i figured what if?

and does TI expand with heat as much as aluminum does? if not, would it be a safe piston for snowmobile motors? thats if snowmobile motors dont get as hot as nitro fuel cars... just a thought... and with heavier pistons or rods or a heavier crankshaft, does more rotating weight in the motor mean more torque??


one time i was about 17 and took a cutting torch to ome of those discs and it turned red for a bit then went POW! with a bunch of white shiny stuff its fun to grind too Ingersol Rand has TI pnumatic impact wrenches those things are badass.

and whats 17-4 stainless? ive delt with plenty of 316, but is 17-4 an even higher grade?

we dont want to even mention 410 thats a swear word.

by the way, i believe Monel does better against salt water than titanuim but i could be wrong though. they use mostly monel and 70/30 for valve pieces on these ships. cause it doesnt corrode in water. same for the fresh water holding tanks. no one wants rusty water...

 

[Dam Dave]

i used to tear apart navy ships with my stepdads company and we would get these huge titanuim discs out of these heat exchanger type things or whatever you call it, so i figured what if?

..

That was probably ZINK, its used as a sacrificial metal to save the heat exchangers from salt water corrosion

 

[snowmobilesrme]

That was probably ZINK, its used as a sacrificial metal to save the heat exchangers from salt water corrosion

No this stuff was definitely TI cause of the way it acted when we took a grinder to it.

what about titanium turbo's? yay or nay?

 

[turbo800]

No this stuff was definitely TI cause of the way it acted when we took a grinder to it.

what about titanium turbo's? yay or nay?

The Ti housings are nice to loose some weight, but their expensive. Not sure if they do Ti turbine wheels or not. I imagine it would only help spool up time being 45% lighter.... Standard turbine wheels are usually Inconel.


Oh ya, 17-4 SS is up there with Inconel as far as poor machinability.