VFRBert Posted November 25, 2013 Share Posted November 25, 2013 Maybe i have a solution: I put the part number in Google and the same valve is used in the VTR 250 until 1990 and is still available at webshops in the US and Europe. http://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDgQFjAB&url=http%3A%2F%2Fwww.bike-parts-honda.com%2Fmicrofiches-recherche_piece-14721-KM3-000.html&ei=9y2TUtb4IKKN0AXdoIGoAg&usg=AFQjCNGH2eeuxZwO_3TE9sFzUPOKzPM8og http://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=7&cad=rja&ved=0CF8QFjAG&url=http%3A%2F%2Fwww.gearhead.com%2Fhonda-14721-km3-000.html&ei=9y2TUtb4IKKN0AXdoIGoAg&usg=AFQjCNGFdX29B1US-zyUrxDXxXJxnizjFw http://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&ved=0CG0QFjAI&url=http%3A%2F%2Fwww.2wheelpros.com%2Foem-parts%2Fhonda-valve-ex-14721-km3-000-part.html&ei=9y2TUtb4IKKN0AXdoIGoAg&usg=AFQjCNHJ7TzZ9VlhVtW569cUTrEK8-N_Vw&cad=rja Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted November 25, 2013 Author Member Contributer Share Posted November 25, 2013 Maybe i have a solution: I put the part number in Google and the same valve is used in the VTR 250 until 1990 and is still available at webshops in the US and Europe. That was my original plan. To use the spare 86 engine as parts for my VTR and 85 VF engine rebuild. I am looking at options between parting out both engines and buying a third one, or rebuilding all three engines and selling the spare. I tried to buy from CMSNL. They have a few springs and valves but not a full set of intake or exhaust. They may look like they do but they don't, or at least they ddn't in May this year when I ordered from them, even though their website suggested they did. They told me they were unobtainium too. they are pricey, but if you want to spend the money, you could try these people. I was told that they did have the parts for the 500, but you will have to ask them. If I was doing a serious rebuild and had the money, I would seriously consider rebuilding my head with their parts. If they don't have them, maybe enough would want to rebuild their VF500 engines that the cost would be their normal levels. http://valvetrain.kpmivalvetrain.com/category/honda-cbr-600-f2-f3-1991-to-1996 Link to comment Share on other sites More sharing options...
jeremyr62 Posted November 25, 2013 Share Posted November 25, 2013 When I priced up the valves and springs and all the other bits and bobs, I decided it wasn't worth it and just kept on the look out on Ebay UK for a second hand engine. I found one eventually with 3,000 miles. Valves and cams look pristine. They are out there, you just have to be patient. Link to comment Share on other sites More sharing options...
Member Contributer JamieDaugherty Posted November 28, 2013 Member Contributer Share Posted November 28, 2013 Unfortunately, all too common. The only way to prevent dropped valves on 500's is to keep those revs down. Observe a 9000rpm maximum engine speed and you'll enjoy a long life out of your VF500. Each time you exceed that you are one step closer to problems. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 28, 2013 Member Contributer Share Posted November 28, 2013 I forget were these engines unleaded gas or leaded gas only motors . Link to comment Share on other sites More sharing options...
VFRBert Posted November 28, 2013 Share Posted November 28, 2013 Unleaded, Japan was one of the first country's to introduce unleaded gas. Link to comment Share on other sites More sharing options...
Member Contributer JamieDaugherty Posted November 29, 2013 Member Contributer Share Posted November 29, 2013 I forget were these engines unleaded gas or leaded gas only motors . I'm curious: why do you ask this question? Link to comment Share on other sites More sharing options...
Member Contributer YoshiHNS Posted November 29, 2013 Author Member Contributer Share Posted November 29, 2013 Unfortunately, all too common. The only way to prevent dropped valves on 500's is to keep those revs down. Observe a 9000rpm maximum engine speed and you'll enjoy a long life out of your VF500. Each time you exceed that you are one step closer to problems. So that does sound like an issue with springs. I don't really have a need for a high performance mini V4, so not a worry. The 250 might be another story. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 29, 2013 Member Contributer Share Posted November 29, 2013 I forget were these engines unleaded gas or leaded gas only motors . I'm curious: why do you ask this question? The primary use of lead in gas was for valve cushioning .. Link to comment Share on other sites More sharing options...
timmythecop Posted November 29, 2013 Share Posted November 29, 2013 I forget were these engines unleaded gas or leaded gas only motors . I'm curious: why do you ask this question? The primary use of lead in gas was for valve cushioning .. yes, but to benefit the valve seats. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 29, 2013 Member Contributer Share Posted November 29, 2013 I forget were these engines unleaded gas or leaded gas only motors . I'm curious: why do you ask this question? The primary use of lead in gas was for valve cushioning .. yes, but to benefit the valve seats. Hmmm I wonder what the seats were being hammered by ? I know the valves !!!!!! Link to comment Share on other sites More sharing options...
GazVF500 Posted November 29, 2013 Share Posted November 29, 2013 No the lead in fuel was to stop valve seat recession caused by micro-welding on soft materials for valve seats - e.g. soft cast iron heads. See your local BMC mini or MG B for details. The lead works as a lubricant. As the Hondas have aluminium heads, Honda fitted hardened ferrous (iron-based) exhaust valve seats so that enable the bikes to run on Unleaded - because the materials used meant that valve seat recession was not an issue. Dropped valves are usually caused by valve spring weakening, allowing the valve to bounce against the seat, weakening the narrowest part - the stem. Does anyone if this is more or less likely in engines that have sat in the same position for a while (says he who owns a VF that was last registered on the road in 1994....) - an anecdotal story says that privateers with formula 1 engines used to have to turn the engines to a different position every day to avoid valve spring "set". Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 29, 2013 Member Contributer Share Posted November 29, 2013 Tetramethyl lead was added to gas to help make a cushion and seal between the valves and the valve seat ... Use to be a SAE auto mechanic in the 80's, it was question on the test and I missed it, I answered octane booster... Link to comment Share on other sites More sharing options...
Guest Posted November 29, 2013 Share Posted November 29, 2013 how many miles were on the engine? and how were you riding when it ate itself??? the valves look dark ---rich like dirty air filter bad gas etc-- they should have a brown look to them those plugs never lie---- Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 29, 2013 Member Contributer Share Posted November 29, 2013 I not saying this is what caused Yoshi valve to unhead itself .. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 Unleaded, Japan was one of the first country's to introduce unleaded gas I think it was the late 70's or early 80's, just could not remember .. Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 Unfortunately, all too common. The only way to prevent dropped valves on 500's is to keep those revs down. Observe a 9000rpm maximum engine speed and you'll enjoy a long life out of your VF500. Each time you exceed that you are one step closer to problems. I enjoyed a long life in my 500 Belt-0-Ceptor and I exceeded 9K on just about every ride... You're looking at 98,755 miles not in moderation... Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 The primary use of lead in gas was for valve cushioning .. Negative... primary use of tetraethyl lead was for knock or detonation control... The story how lead got into our fuels started with high compression aircraft engines back in 1921... a young engineer fresh out of college named Charles Kettering started Dayton Engineering Labs Company or Delco... he invented the first battery ignition systems for aircraft engines... when protagonists in the field of aviation widely blamed his battery ignition systems on knock or detonation Kettering commanded his young assistant Thomas A. Midgley on a investigation of detonation. motivated as much by a desire to protect Delco's reputation as by scientific altruism. Midgley worked for months over his single cylinder engine and famous "bouncing pin" which was devised to measure differences in detonation pressures. and he soon determined that detonation depended on both fuel grade and engine compression ratio. Thinking at first that fuel color influenced knock. Midgley added iodine to his fuel theorizing a dark-colored fuel would absorb more heat energy and vaporize more quickly. When the knock diminished he smelled success, but it did not come in the form . he suspected. Further experiments forced him to discard the fuel color idea but led in turn to a long. frustrating line of trial anti-knock additives. GM. parent company of Delco. encouraged Midgley and his assistant T. A. Boyd. who in a vigorous program, individually tested more than 30,000 compounds and their discouragement mounted with the list. On December 9, 1921. a chilly Friday. Midgley and Boyd were anticipating the weekend's respite from their series of relentless, routine tests when suddenly the engine was not behaving the same at all. Jolted into disbelief, Midgley had quite literally stumbled onto the remarkable antiknock properties of an obscure substance called tetraethyl lead. This proved to be without doubt the greatest single discovery in the development of aviation fuels; not only did this additive make higher power possible. it enabled the aircraft to fly farther on a given amount of fuel- it gave aircraft range and in turn enabled the successful engines that dominated aviation until the advent of gas turbines. Thomas Midgley Charles Kettering Link to comment Share on other sites More sharing options...
Member Contributer BusyLittleShop Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 Dearly beloved... we are gather here to pay our last respects to the passing of this sweet little VF500 engine... Link to comment Share on other sites More sharing options...
Member Contributer Mohawk Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 I had a VF500 for 10 years, it got abused all the time, BUT I had a great maintenance regime. Fresh oil every 2500 miles, valve clearances every 5000 miles & it always needed it, plus oil & filter. It had over 65k miles when I sold it. I suspect all these valve failures are due to loose valve clearances, allowing the valves to slam closed at high rpm, thus wearing the valve head. Or alternately over revving with worn or poorly maintained cam chains ! On the valve clearance issue, the screw wears from new to an angle & if you then adjust it, there is much less material in contact with the valve stem, so it wears much quicker after adjustment ! Buy a spare set of tappet screws & swap them when you do a valve adjustment, then face the old ones flat for reuse next time ! Valve adjustment stays good for longer ! Also lever the Y rocker up at its centre when measuring the clearances, to avoid any excess clearance from rock on the rocker shaft. Good luck with the rebuild. Link to comment Share on other sites More sharing options...
Guest Posted November 30, 2013 Share Posted November 30, 2013 On a side note, Thomas Midgley contracted lead poisoning as a result of experimenting with TEL, and although debilitated, not die from it. He contracted polio at age 51 and was severely disabled as a result. He rigged a rope and pulley contraption over his bed to help lift him, got tangled up in the ropes one day and died of strangulation. Link to comment Share on other sites More sharing options...
Member Contributer Switchblade Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 The primary use of lead in gas was for valve cushioning .. Negative... primary use of tetraethyl lead was for knock or detonation control... The story how lead got into our fuels started with high compression aircraft engines back in 1921... a young engineer fresh out of college named Charles Kettering started Dayton Engineering Labs Company or Delco... he invented the first battery ignition systems for aircraft engines... when protagonists in the field of aviation widely blamed his battery ignition systems on knock or detonation Kettering commanded his young assistant Thomas A. Midgley on a investigation of detonation. motivated as much by a desire to protect Delco's reputation as by scientific altruism. Midgley worked for months over his single cylinder engine and famous "bouncing pin" which was devised to measure differences in detonation pressures. and he soon determined that detonation depended on both fuel grade and engine compression ratio. Thinking at first that fuel color influenced knock. Midgley added iodine to his fuel theorizing a dark-colored fuel would absorb more heat energy and vaporize more quickly. When the knock diminished he smelled success, but it did not come in the form . he suspected. Further experiments forced him to discard the fuel color idea but led in turn to a long. frustrating line of trial anti-knock additives. GM. parent company of Delco. encouraged Midgley and his assistant T. A. Boyd. who in a vigorous program, individually tested more than 30,000 compounds and their discouragement mounted with the list. On December 9, 1921. a chilly Friday. Midgley and Boyd were anticipating the weekend's respite from their series of relentless, routine tests when suddenly the engine was not behaving the same at all. Jolted into disbelief, Midgley had quite literally stumbled onto the remarkable antiknock properties of an obscure substance called tetraethyl lead. This proved to be without doubt the greatest single discovery in the development of aviation fuels; not only did this additive make higher power possible. it enabled the aircraft to fly farther on a given amount of fuel- it gave aircraft range and in turn enabled the successful engines that dominated aviation until the advent of gas turbines. Thomas Midgley Charles Kettering Double negative !!! Tetraethyllead From Wikipedia, the free encyclopedia Tetraethyllead IUPAC name[hide] Tetraethylplumbane Other names[hide] Lead tetraethyl Tetraethyl leadTetra-ethyl lead Identifiers Abbreviations TEL CAS number 78-00-2PubChem 6511 ChemSpider 6265UNII 13426ZWT6AEC number 201-075-4 UN number 1649 MeSH Tetraethyl+lead ChEBI CHEBI:30182RTECS number TP4550000 Beilstein Reference 3903146 Gmelin Reference 68951 Jmol-3D images Image 1 SMILES [show] InChI [show] Properties Molecular formula C8H20Pb Molar mass 323.44 g mol−1 Appearance Colorless liquid Density 1.653 g cm−3Melting point−136 °C, 137 K, -213 °F Boiling point84-85 °C, 357-358 K, 183-185 °F (15 mmHg) Refractive index (nD) 1.5198 Structure Molecular shape Tetrahedral Dipole moment 0 D Hazards EU classification T+ N R-phrases R61, R26/27/28, R33, R50/53,R62 S-phrases S53, S45, S60, S61 NFPA 704 2 3 3 Flash point 73 °C Related compounds Related compounds Tetraethylgermanium Tetraethyltin (verify) (what is: /?)Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox references Tetraethyllead (common name tetraethyl lead), abbreviated TEL, is an organolead compound with the formula (CH3CH2)4Pb. It was mixed with gasoline (petrol) beginning in the 1920s as an inexpensive octane booster which allowed engine compression to be raised substantially, which in turn increased vehicle performance and fuel economy.[1][2] TEL was phased out starting in the US in the mid-1970s because of its neurotoxicity and its damaging effect on catalytic converters. It is still used as an additive in some grades ofaviation gasoline and automotive racing fuels. Innospec is the last firm still making TEL. Contents [hide] 1 In motor fuel 1.1 Valve wear preventative 1.2 Antiknock agent 1.3 Phaseout and ban 1.3.1 In race vehicles 1.3.2 Aviation gasoline 1.3.3 Alternative antiknock agents 2 Synthesis and properties 3 Reactions 4 Formulation of ethyl fluid 5 Toxicity 6 History 6.1 History of TEL in fuels 6.2 History of controversy and phase-out 7 In literature 8 See also 9 References 10 External links In motor fuel[edit]Tetraethyl lead was extensively used as an additive to gasoline, wherein it served as an effective antiknock agent and prevented exhaust valve and seat wear. Valve wear preventative[edit]Tetraethyl lead works as a buffer against microwelds forming between the hot exhaust valves and their seats.[3] Once these valves reopen, the microwelds pull apart and leave the valves with a rough surface that would abrade the seats, leading to valve recession. When lead began to be phased out of motor fuel, the automotive industry began specifying hardened valve seats and upgraded exhaust valve materials to prevent valve recession without lead.[4] Antiknock agent[edit]A gasoline-fueled reciprocating engine requires fuel of sufficient octane rating to prevent uncontrolled combustion known as engine knocking ("knock" or "ping").[5] Antiknock agents allow the use of higher compression ratios for greater efficiency[6] and peak power. Adding varying amounts of TEL to gasoline allowed easy, inexpensive control of octane ratings; aviation spirits used in WWII reached 150 octane to enable supercharged engines such as the Rolls-Royce Merlin and Griffon to produce 1500 HP at altitude.[7] In military aviation, TEL manipulation allowed a range of different fuels to be tailored for particular flight conditions, and ease and safety of handling Wikipedia is ALWAYS right . http://en.wikipedia.org/wiki/Tetraethyllead Link to comment Share on other sites More sharing options...
Guest Posted November 30, 2013 Share Posted November 30, 2013 Cushioning? Or prevents valve and seat burning by reducing microwelds? I read it on the interwebs so it must be true! Link to comment Share on other sites More sharing options...
VFRBert Posted November 30, 2013 Share Posted November 30, 2013 The vf500f is built for unleaded fuel, so that should not be a point of discussion. 1 thing is having my attention at al the pictures from broken pistons and cilinder heads. No black soot in the damaged cilinder, the cilinder and valves are burnt clean and have the browm color of rusted iron. I think that cilinder was running on a very lean mixture, maybe caused by a leaking insulator. I have sean pics of cimilar damage on cbx550's, valve stressed to much by overheating, breaking and the we have an other serie of pics from a damaged engine. Link to comment Share on other sites More sharing options...
Member Contributer gll429 Posted November 30, 2013 Member Contributer Share Posted November 30, 2013 i remember getting scolded in class because i said it was a fitting end for a man who caused so much death and suffering. but like others have said.. have fun on the rebuild.. however. rebuild a non blown up motor. Link to comment Share on other sites More sharing options...
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