Landracing Forum
Tech Information => Technical Discussion => Topic started by: russ jensen on October 16, 2006, 08:30:04 PM
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:?: Is anybody out there expermenting w/ titanium pistons{cept my budy}?
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been done! ceramic, carbon, all been done before! ask noonan he's dah piston guy.
kr
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ya been done but what results. the magneesium one didn't work out to well
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ya been done but what results. the magneesium one didn't work out to well
Yeah, but it sure gave off a pretty bright light for a little while, didn't it?
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talk to Noonan.
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Actually magnesium pistons have been built and run with some success. Not nearly as expensive as titanium. We have run titanium pistons in some military high altitude aircraft with multi-stage turbos running at fairly high pressure ratios. You just need to have the $$ and will to develop whats needed. You don't just drop them in and go. If you search a bit you will find many people who can help you if you really need it.
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Actually magnesium pistons have been built and run with some success. Not nearly as expensive as titanium. We have run titanium pistons in some military high altitude aircraft with multi-stage turbos running at fairly high pressure ratios. You just need to have the $$ and will to develop whats needed. You don't just drop them in and go. If you search a bit you will find many people who can help you if you really need it.
8) I make myown pistons and am interested in any quirks that might be assoicated with titatium. IE gauling problems- looks like clearence could be tighter than al as expansion rate is less than iron, was interested because of the aprox 3000 melt vs 1100 for al, buddy seems to have trouble in his app - thinks it is because of to rapid heat transfer??? in your aircraft engs do you know if same cam grind as al?? clearence dif?? ring grove clearences??? oil heating problems?? pressure oied wrist pins??just trying to be a jump ahead of problems if possible. {Titanium isn't all that expensive if it can be found in bone yards, bout same as good al}Al works OK but looking for something to take more abuse.
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Check me if I'm wrong , but doesn't Titanium have very little or no growth when Hot, just my experience from running Titanium Valves, the tappet clearance seamed to be less once heated, or is it the head expanding at a much greater rate than the valves''???? (Over Head cam motor,,)
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Check me if I'm wrong , but doesn't Titanium have very little or no growth when Hot, just my experience from running Titanium Valves, the tappet clearance seamed to be less once heated, or is it the head expanding at a much greater rate than the valves''???? (Over Head cam motor,,)
: :? right on steel roughly .000006x al .0000124 titanium .000004xpure don't know about alloys but probably close.
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ya been done but what results. the magneesium one didn't work out to well
Yeah, but it sure gave off a pretty bright light for a little while, didn't it?
:lol: Bright light is least of mags problems, its brittle and has no strength and alky turns it to ash, doesn't burn that good, caught bandsaw on fire, just smolders & fills shop w/ white smoke. titanium seems to produce that bright light when the shavings come off lathe if I get in a big hurry,makes me wonder if pistons could catch fire in eng??? Was told how dangerous mag was to melt & cast{ only ones doing were making MX missle parts around here} one day when done pouring al I threw mag in pot with out any inert gas to see what would happen - it melted like al with o glow on surface, poured a slug in oil can, burned on sfc so put foot on top of can to stop oxygen supply, = nice slug & only lost aprox .030 cleanup on slug to get perfict billet.
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some interesting points re Titanium, My experience from Valves, And Found we had a few failures on the Dy no, bedding brand new stuff, and Failures were during warm up and idles, later found that some solvent have an adverse affect on titanium,
this is from my drag racing days, titanium valves have never melted, when lean outs have accrued melted pistons , ie a fuel supply line gets skwished during reassembley and leans a cylinder out,
good set of pistons will run at .002 but titanium must b . 0002
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ti has a molecule transfer problem..
this causes it to gaul when in close proximity to sliding and rotating surfaces.
this is why we have had to have the connecting rods metal sprayed on the sides , so the two rods would not stick together and or burn out the thrust surfaces (end play) on crank cheeks.
pistons have been made before but required lots of buttons or actually a "band" of a wear material in the skirts to keep from siezing.
...rings do not remain able to float and turn....
the very small model airplane type engines have been doing this for years, but some have had failures too...
heat transfer has a problem in comparison with conventional (aluminum alloy types) to dissapate heat.
I am certainally not saying that it cannot be done in todays world, especially if new thoughts on coatings could be worked in....
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galling and material transfer issues on ti valves apparently respond very well to the diamond like coatings like casidium.
Perhaps that could be used on a Ti piston to avoid problems with the rings and cylinder wall?
Larry
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I thought Formula 1 where running Titanium pistons in a Nicklesil Bore.
Would a Bronze liner stand up to the job,
Top Fuel Pistons have a PTFE type coating,
The Expense may not out way the performance advantage, is most likely why big $ teams don't run them
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:roll: Thanks for the info on my post = most helpful & save lots of misadventures on my part. thanks again.
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Russ,
Did you receive my PM?
J
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Russ,
Did you receive my PM?
J
yes-kato had info I was looking for thanks.
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F1 does not use Ti for pistons, it is because of the added weight and the heat transfer. Ti. is 60% heavier than alum. so if you make a Ti piston it would need to be 60%thinner in every area which could really be hard with Ti as it has some machining challenges. If you made Ti piston the could get them to even only 25% heavier than aluminum the extra weight would require heavier wrist pins and also stronger rods, as the largest load that a "normal" rod sees is the force generated at high rpms to pull, accelerate, the piston back from TDC and the mode of rod failure is tension, i.e. the rod is pulled apart and of course if you are trying to run 19,000 rpm as F1 does that extra weight makes for additional weight needing to be added to the crank and block to hold everything together. So if you are trying to make a V8 engine that only weights 80 kilos you go with aluminum pistons, not that they don't have piston troubles, ask Micheal Schumacher. (I define a "Normal" engine as one that is not on big percentages of nitro as these engines typically fail rods in compression or they push the piston pin down through the rod!)
Ti is also a very poor bearing so you need to give it some type of coating to get it to live if it is rubbing against something. F1 is using lots of DLC, Diamond Like Carbon, coatings on Ti to get a living bearing surface. Also Ti doesn't like to transfer heat, which makes it a great brake caliper piston but a poor selection for engines.
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:lol: 2 stroke rods don't have the yank the piston back from flying out to space{ or through the head} unless the motor is used for brake- since there arn't supposed to be any corners in lsr a little extra piston wt can actually be a plus as to help on compression. but as in katos post ti has other problems.