Vince Posted January 2, 2015 Report Share Posted January 2, 2015 Please, dont bring MX engines to the conversation. They are not even close to the beating that speedway engines are having. In same rpm range speedway engines would also go for many many many hours. But speedway engines wont see these rpms after warming up at the pits. Here is a helmet cam from Ryan Villopoto racing in Unadilla. https://www.youtube.com/watch?v=t2fuUeDqATM A 450 MX engine will rev to around 13500 rpm before the rev limiter kicks in so pretty similar to a Speedway engine. If you think a Speedway engine takes a beating go to any deep sand track and see what a MX bike goes through. At some of the beach races they will be absolutely flat on a big straight for as long as some entire Speedway races. There are differences such as in the weight of the crankshaft assembly that badly affect reliability but not to the extent that they are so much less reliable. That is down to design and build quality, If I get chance over the weekend I will photograph a Yamaha and Jawa cylinder head together and even in a photo you will see the difference in the quality of the castings. If I can find it I have a drawing of the oil system on a Yamaha as well, it's more complicated than an entire Speedway engine! Quote Link to comment Share on other sites More sharing options...
THE DEAN MACHINE Posted January 2, 2015 Report Share Posted January 2, 2015 (edited) [quote name="theknow 2" post="2561348" timestamp="1420193801 Competion with more engine makers should bring the cost downThe main issue is the GM engine is not a good product from the factory it should bring the price down but it won't and the GM microlight engines are pretty much the same in design although not in size and I don't see them falling from the skies ,to be honest I never really had reliability problems with my GMs but I never really tried to get every last bit of speed out of them, a company who I do work for are a motox family and when I was still racing they were having more blow ups than me and I was riding more often Edited January 2, 2015 by THE DEAN MACHINE 1 Quote Link to comment Share on other sites More sharing options...
theknow 2 Posted January 2, 2015 Report Share Posted January 2, 2015 (edited) it should bring the price down but it won't and the GM microlight engines are pretty much the same in design although not in size and I don't see them falling from the skies ,to be honest I never really had reliability problems with my GMs but I never really tried to get every last bit of speed out of them Aero engines have very strict service guidlines, 50/100 hour checks. They are run at very low HP for there size. My lycoming has a TBO time of 2000 hrs. It is however 5.5 lites producing 180hp. very basic design but made to last not produce HP. I would not fly a plane with a GM engine, Period !!!! Or micolight with any engine Edited January 2, 2015 by theknow 2 Quote Link to comment Share on other sites More sharing options...
Bream Posted January 2, 2015 Report Share Posted January 2, 2015 A 450 MX engine will rev to around 13500 rpm before the rev limiter kicks in so pretty similar to a Speedway engine. If you think a Speedway engine takes a beating go to any deep sand track and see what a MX bike goes through. At some of the beach races they will be absolutely flat on a big straight for as long as some entire Speedway races. There are differences such as in the weight of the crankshaft assembly that badly affect reliability but not to the extent that they are so much less reliable. That is down to design and build quality, If I get chance over the weekend I will photograph a Yamaha and Jawa cylinder head together and even in a photo you will see the difference in the quality of the castings. If I can find it I have a drawing of the oil system on a Yamaha as well, it's more complicated than an entire Speedway engine! Yeap, you cant really put KTM, Yamaha, Kawi cylinder heads on the table next to Jawa or even GM. I just love the way new KTM´s are built. Very easy to maintain etc. But hardly ever 450mx engines are ran on the rpm peak. Like the vid I posted where RV rides in Unadilla. Ryan´s Kawi doesnt peak at all. Mainly because they look for easy handling, traction and keeping the momentum going forward. Gearbox, water cooling and computer adjusted fuel injection system are things that keeps these bikes going like they do. When they work like they should they will never go lean, rich, overheat.. Oh, and for those who dont know who is Ryan Villopoto? Guy is one of the best active motocross and supercross riders in the world at the moment. Quote Link to comment Share on other sites More sharing options...
theknow 2 Posted January 2, 2015 Report Share Posted January 2, 2015 Yeap, you cant really put KTM, Yamaha, Kawi cylinder heads on the table next to Jawa or even GM. I just love the way new KTM´s are built. Very easy to maintain etc. But hardly ever 450mx engines are ran on the rpm peak. Like the vid I posted where RV rides in Unadilla. Ryan´s Kawi doesnt peak at all. Mainly because they look for easy handling, traction and keeping the momentum going forward. Gearbox, water cooling and computer adjusted fuel injection system are things that keeps these bikes going like they do. When they work like they should they will never go lean, rich, overheat.. Oh, and for those who dont know who is Ryan Villopoto? Guy is one of the best active motocross and supercross riders in the world at the moment. Indeed he is. be good to see how he gets on in MX1. Quote Link to comment Share on other sites More sharing options...
Vince Posted January 3, 2015 Report Share Posted January 3, 2015 Yeap, you cant really put KTM, Yamaha, Kawi cylinder heads on the table next to Jawa or even GM. I just love the way new KTM´s are built. Very easy to maintain etc. But hardly ever 450mx engines are ran on the rpm peak. Like the vid I posted where RV rides in Unadilla. Ryan´s Kawi doesnt peak at all. Mainly because they look for easy handling, traction and keeping the momentum going forward. Gearbox, water cooling and computer adjusted fuel injection system are things that keeps these bikes going like they do. When they work like they should they will never go lean, rich, overheat.. Oh, and for those who dont know who is Ryan Villopoto? Guy is one of the best active motocross and supercross riders in the world at the moment. I'd disagree strongly with the idea that MX engines don't run at peak rpm. Villopoto is riding a hard pack track that has obviously seen rain because it is heavily rutted in that video, therefore he won't be screaming the bike. Even so that bike is running pretty hard at times and even hits the limiter now and again in the air and his limiter will be a good chunk higher than on a stock bike. Find a video of somebody like Herlings in the sand or Barcia anywhere and you'll hear a bike scream! Water cooling is a major part of reliability on a mx bike but only because it runs for a long time. A Speedway bike running on methanol for a couple of minutes should be no problem with an efficient oil system. Fuel injection may help performance and emissions but bikes were no less reliable on carbs. To me the difference is the design and build quality, if one of the major Japanese manufacturers built a Speedway engine it would be many times more reliable than the current offerings. Can see Villipoto winning races in the GP but Cairoli getting the better of him simply because he knows the tracks and is used to the GP system. If he stays for a second year I could see Villipoto winning the Championship. Quote Link to comment Share on other sites More sharing options...
KN1 Posted January 3, 2015 Report Share Posted January 3, 2015 and throw in the fact that mx uses petrol (oil based fuel), and speedway uses methanol (oil washing fuel). not sure about the rev limiters though vince, asked some of the boys that used them and they were a bit inconsistent on the speedway tracks, giving a false indication of what the engine was doing in the turns. Quote Link to comment Share on other sites More sharing options...
foamfence Posted January 3, 2015 Report Share Posted January 3, 2015 I'd disagree strongly with the idea that MX engines don't run at peak rpm. Villopoto is riding a hard pack track that has obviously seen rain because it is heavily rutted in that video, therefore he won't be screaming the bike. Even so that bike is running pretty hard at times and even hits the limiter now and again in the air and his limiter will be a good chunk higher than on a stock bike. Find a video of somebody like Herlings in the sand or Barcia anywhere and you'll hear a bike scream! Water cooling is a major part of reliability on a mx bike but only because it runs for a long time. A Speedway bike running on methanol for a couple of minutes should be no problem with an efficient oil system. Fuel injection may help performance and emissions but bikes were no less reliable on carbs. To me the difference is the design and build quality, if one of the major Japanese manufacturers built a Speedway engine it would be many times more reliable than the current offerings. Can see Villipoto winning races in the GP but Cairoli getting the better of him simply because he knows the tracks and is used to the GP system. If he stays for a second year I could see Villipoto winning the Championship. Does anyone give a stuff about Villipoto (whoever he is)? 1 Quote Link to comment Share on other sites More sharing options...
Vince Posted January 3, 2015 Report Share Posted January 3, 2015 Clearly at least 3 of us are interested! 2 Quote Link to comment Share on other sites More sharing options...
Bream Posted January 3, 2015 Report Share Posted January 3, 2015 (edited) Does anyone give a stuff about Villipoto (whoever he is)? My point was to say that this rider in the video isnt some sunday guy but the very top of the sport taking the bike on the limit. And yes, there is lots of helmet cam material from the top guys like James Stewart, Barcia, Roczen, Ken de Dycker.. nobody goes to the rev limiter while riding with 450, maybe on a panic rev in the air. There is no point because these engines arent made for it. Not even in Lommel. Cairolli on his 350 goes pretty close but he rides it like a chubby 250. In AMA and GP, 250s goes to the limit, but they are rebuilt after every race with every trick part in the basket so no point of talking about reliability there. Lower classes are going towards 125cc two strokes because 250f:s are too expensive (and rumor says "killing the sport!") Figure out the exhaust noise problem and speedway engines will live longer. These exhaust that we are using now are able to melt ice racing engines ffs.. Ken De Dycker, MXON 2013: https://www.youtube.com/watch?v=7Z08a4jvZUw Freddy: https://www.youtube.com/watch?v=-zN0ZINukDY Edited January 3, 2015 by Bream Quote Link to comment Share on other sites More sharing options...
mac101 Posted January 3, 2015 Report Share Posted January 3, 2015 The difference with the mx bike is that it has a gearbox to keep the bike at high revs Quote Link to comment Share on other sites More sharing options...
THE DEAN MACHINE Posted January 9, 2015 Report Share Posted January 9, 2015 Just been reading Guy Martins book , see how many engine blow ups he has had in the last 5 years and these engines are all made by the leading manufacturers, it doesn't matter if you fit a better oil pump or even an oil refinery to the engine ,race engines blow up and to claim an engine will last all season is pure fantasy Quote Link to comment Share on other sites More sharing options...
Ray Stadia Posted January 9, 2015 Report Share Posted January 9, 2015 Just been reading Guy Martins book , see how many engine blow ups he has had in the last 5 years and these engines are all made by the leading manufacturers, it doesn't matter if you fit a better oil pump or even an oil refinery to the engine ,race engines blow up and to claim an engine will last all season is pure fantasy I haven't read Guy Martin's book, but I imagine there are different degrees of a 'blow up'! i.e. con rod punching a whole through the crankcase or a burnt out valve! I haven't seen a speedway engine blow up for a while, but I did see a grass track rider blow up a Godden engine many years ago and it basically exploded! Quote Link to comment Share on other sites More sharing options...
Guest Posted January 9, 2015 Report Share Posted January 9, 2015 Does anyone give a stuff about Villipoto (whoever he is)? Here's some data on the man in question: http://en.wikipedia.org/wiki/Ryan_Villopoto Quote Link to comment Share on other sites More sharing options...
piston197 Posted January 9, 2015 Report Share Posted January 9, 2015 I haven't read Guy Martin's book, but I imagine there are different degrees of a 'blow up'! i.e. con rod punching a whole through the crankcase or a burnt out valve! I haven't seen a speedway engine blow up for a while, but I did see a grass track rider blow up a Godden engine many years ago and it basically exploded! Saw one years ago at Newport, think from memory it was Nicky Simmonds bike ?? 3 bikes left the line and one stayed still, the frame contained the cylinder and top half of the crankcases, the track staff were picking up bits of hot metal with a shovel and putting them still smoking into a bucket Quote Link to comment Share on other sites More sharing options...
Vince Posted January 12, 2015 Report Share Posted January 12, 2015 Just been reading Guy Martins book , see how many engine blow ups he has had in the last 5 years and these engines are all made by the leading manufacturers, it doesn't matter if you fit a better oil pump or even an oil refinery to the engine ,race engines blow up and to claim an engine will last all season is pure fantasy One lap of the TT course is much the same as the distance between services for a Speedway engine though. Of course engines will blow up sometimes but I can think of exactly none that are anywhere near to the time limits of Speedway engines. You've had Speedway engines apart same as I have and it's not hard to see that reliability could be doubled or trebled with better lubrication and build quality. Just seeing one next to a modern Japanese engine is like a trip back to the 60's. I can't believe that in the past 30 years the life expectations of most engines have increased out of all expectation despite producing more power yet Speedway engines have stayed much the same and can't be improved. 1 Quote Link to comment Share on other sites More sharing options...
theknow 2 Posted January 12, 2015 Report Share Posted January 12, 2015 Just been reading Guy Martins book , see how many engine blow ups he has had in the last 5 years and these engines are all made by the leading manufacturers, it doesn't matter if you fit a better oil pump or even an oil refinery to the engine ,race engines blow up and to claim an engine will last all season is pure fantasy Your Wrong Quote Link to comment Share on other sites More sharing options...
THE DEAN MACHINE Posted January 12, 2015 Report Share Posted January 12, 2015 Your Wrongreally ,I guess it's just speedway where engines blow up ? ALL motorsports suffer blow ups and regularly no matter who makes the engines or what oil pump they use, cut the revs if you want more reliability Quote Link to comment Share on other sites More sharing options...
theknow 2 Posted January 13, 2015 Report Share Posted January 13, 2015 really ,I guess it's just speedway where engines blow up ? ALL motorsports suffer blow ups and regularly no matter who makes the engines or what oil pump they use, cut the revs if you want more reliability Yes, look at motocross, supercross, F1, motogp, nascar, over the season how many blow ups do you see ???? Less than five percent and these are all long races with plenty a revs and a lot of HP. Speedway engines blow up as rubbish design and no oil pump !!!! Oh and NASCAR run methanol for 500 laps at 850 hp :-) Quote Link to comment Share on other sites More sharing options...
THE DEAN MACHINE Posted January 13, 2015 Report Share Posted January 13, 2015 (edited) Yes, look at motocross, supercross, F1, motogp, nascar, over the season how many blow ups do you see ???? Less than five percent and these are all long races with plenty a revs and a lot of HP. Speedway engines blow up as rubbish design and no oil pump !!!! Oh and NASCAR run methanol for 500 laps at 850 hp :-) yes spread over 4 cilinders with a Rev limiter and a gearbox, you put all that power into one pot with no Rev limiter it will blow , motox engines regularly blow up and at half the revs of a speedway engine Edited January 13, 2015 by THE DEAN MACHINE 1 Quote Link to comment Share on other sites More sharing options...
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