dino ferrana Posted June 6, 2002 Share Posted June 6, 2002 So assuming money no object (wouldn't it be nice). How much weight would you save by having your running gear made in Titanium? If the Gearbox, Driveshafts, Diff and Propshaft were all titanium was % lighter is it and who could make it? Also I am assuming Titanium pistons, con rods and Crankshaft are possible for a K-Series but who could make them and or how much would it cost? Presumably there would be a longevity benefit in ths as well? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 6, 2002 Share Posted June 6, 2002 Guess what. It isn't as simple as that so I am going to disabuse you of the notion that engineering is just about money and is something to do with compromises. Titanium is lighter (and in most grades) weaker than alloy steel. So you need more of it to do the same job. It has very good fatigue characteristics. It is approx double the density of aluminium. The weight advantages usually come in when you can substitute a fabricated or precision die cast or forged component for a sand cast component. So you could make gearbox casings and uprights from titanium - indeed Formula 1 and top end GT1 sees titanium uprights used and they are things of beauty, weighing nothing. Pistons are already aluminium and most crucial that weight is minimised. Conrods can be made in titanium and various people advertise - buy a copy of Racecar Engineering. Valevtrain components are another possibility, but you need different valve seats (ceramic?) and guides to prevent the valves from welding themselves to the metal components they come into contact with. Titanium spring caps are available from Piper. Crankshafts are steel for a reason, but if you take the counterweights off them they can weigh very little and last a lot less. In other words: the compromise is about material suitability rather than just cost. Carbon driveshafts have much more promise, but I wouldn't want to pick up a stone chip in one and have it explode alongside my legs. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
dino ferrana Posted June 6, 2002 Author Share Posted June 6, 2002 Guess I would have to go seriously exotic for better materials. I know there are different grades and alloys of titanium each part presumably has different weight versus strength ratios. Is Drop forged titanium stronger than drop forged steel (assume most suitable alloy) I assume it is a little lighter? Link to comment Share on other sites More sharing options...
Peter Carmichael Posted June 6, 2002 Share Posted June 6, 2002 Density is down to atomic mass and metallic structure. Alloys don't change the density much because most strengthening/hardening effects are achieved by small percentage additions distorting the regular metal structure by taking up interstitial positions. Metallurgy also gets into crystal structures with Martensite and Austenite etc. crystal forms possible just as the basics of heat treated carbon steels. What I am saying is that the base metal is just the start and mechanical properties can be varied greatly through alloying and heat treatment. You have to work hard to get anything in titanium stronger than easily attainable steel properties. Then there is the question of which physical property you want to optimise for: ultimate tensile strength? yield strength? surface hardness? fatigue? elasticity? brittleness? Usually failure begins with yield rather than ultimate tensile failure. Elasticity and surface hardness is the other main concern - you want components to be strong and stiff. Most components are made from particular materials for a reason - in production car engineering it is a matter of spotting the cost compromises in order to find the opportunities for improving the material spec. Take a conrod for instance - a cast conrod is cheap and may be fine for 6500rpm, but for 9000rpm you need forged conrods and special rod bolts - these are still steel (same bulk atomic composition), but the material bears no resemblance to the original ( a casting steel vs. a forging steel) and it is used because it is most appropriate. Peterid=teal> 253 BHP K-seriesteeth.gif, no gearboxbum.gifid=red> Link to comment Share on other sites More sharing options...
Graham Perry Posted June 6, 2002 Share Posted June 6, 2002 Correct me if I am wrong but doesn't titanium have other drawbacks. ie shouldn't be left uncoated as it can be attacked and damaged by quite 'ordinary' day to day domestic chemicals. I seem to recall they avoid it on airplanes if possible for this reason Link to comment Share on other sites More sharing options...
sjwb Posted June 6, 2002 Share Posted June 6, 2002 If they avoid it on aircraft, there are a lot of Harriers in trouble! Steve B Link to comment Share on other sites More sharing options...
Blatman Posted June 6, 2002 Share Posted June 6, 2002 Er......I thought the SR71 Blackbird was all titanium skinned.......... Link to comment Share on other sites More sharing options...
tbhall777 Posted June 6, 2002 Share Posted June 6, 2002 titanium fasteners (6AL-4V). Titanium is 40%lighter than steel, yet is stronger than mild steel; it is more resistant to corrosion than stainless steel & has no adverse reactions when used with other metals. Edited by - tbhall777 on 6 Jun 2002 20:32:34 Link to comment Share on other sites More sharing options...
singlespeeder Posted June 6, 2002 Share Posted June 6, 2002 Titanium chassis,save weight,no corrosion,now how much Link to comment Share on other sites More sharing options...
tony pashley Posted June 6, 2002 Share Posted June 6, 2002 If you want wacky materials just for the hell of it, then the thing to seek out is a Polimotor. The earlier versions raced in America (somewhat different to the ones that made it to these shores) was made largely of a Torlon polymer - block, head, rods (I think) and some CF too. The later versions (an attempt at productionizing) had major bits from CF matting in moulded phenolic resin on an alloy 'armature', carbon sump, cam cover, plastic pulleys and bits and pieces. A bit too far ahead of its time really, and other developments have gone a long way to cancel out its weight advantage. Being broadly similar to a Hart, I'm assured it would have fitted a Seven (by someone who had actually ordered an engine for that purpose, before manufacture ceased prematurely). At least one has been hillclimbing in the recent past, in a couple of different cars. I tracked one down, but it wasn't for sale a sensible price and would be a hopelessly impractcal thing for me anyway. Interesting idea though. Have a stack of info on Polimotor if anyone's interested, but it'll take me some time to find it. Link to comment Share on other sites More sharing options...
Paul Ranson Posted June 6, 2002 Share Posted June 6, 2002 Car 115 entered at Loton Park this weekend has a Polimotor fitted. Paul Link to comment Share on other sites More sharing options...
tony pashley Posted June 6, 2002 Share Posted June 6, 2002 Paul - would that be John Chalmers? He ran one in an MP53(?) last year year, didn't he? Link to comment Share on other sites More sharing options...
ian balson Posted June 7, 2002 Share Posted June 7, 2002 Ti is used in the aircraft industry, that's where my seat rails came from smile.gif Ian Link to comment Share on other sites More sharing options...
dino ferrana Posted June 7, 2002 Author Share Posted June 7, 2002 I know that the A-10 Tank Buster has Titanium armour on the cockpit to protect the low flying pilots! It is an awesome material and I seem to have stirred up a hornets nest (always good to have some debate). Basicallly it is horses for courses and you just have to find the ultimate material for the part like they did with the McLarne F1 (that was the idea anyay). By the way that had titanium wheel nuts. Link to comment Share on other sites More sharing options...
John Posted June 7, 2002 Share Posted June 7, 2002 Ive heard of titanium crankshafts being made before. In fact it was Steve at Coventry Balancing (www.vibrationfree.co.uk)that made it. Didn't cost that much more than a billet stell crank either IIRC. John Link to comment Share on other sites More sharing options...
sjwb Posted June 7, 2002 Share Posted June 7, 2002 Personally, I always use unobtainium where ever possibleteeth.gif Steve B Link to comment Share on other sites More sharing options...
ECR Posted June 7, 2002 Share Posted June 7, 2002 Costalotium is far better........ Link to comment Share on other sites More sharing options...
oilyhands Posted June 7, 2002 Share Posted June 7, 2002 Didnt think Steve made cranks, although he is planning to... Oily Link to comment Share on other sites More sharing options...
Paul Ranson Posted June 7, 2002 Share Posted June 7, 2002 would that be John Chalmers? He ran one in an MP53(?) last year year, didn't he? The very same. It didn't run much, if at all, last year. Now on petrol and something sensible as management. Not a lot of power though. It's a weird looking engine, definitely plastic where you can touch.... Paul Edited by - Paul Ranson on 7 Jun 2002 11:48:48 Link to comment Share on other sites More sharing options...
John Posted June 7, 2002 Share Posted June 7, 2002 Oily, It was a one off for someone who was apparently very pleased with it and then wanted another as well. John Link to comment Share on other sites More sharing options...
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