ordered two rear sprockets for the little ninja. stock is 45, i think, and the kids kept hitying the rev limiter. so i put on a 44 and tbeyre still hitting the rev limiter making records doing it, but if they can reach 14600 rpm then they need smaller sprockets. so i bought a 43 and a 42, which should let them go from 109 mph to maybe 112 or so. well see. need a spare chain too
In the 80s and 90s there was a bloke up in Hull who ran a company called Racecraft - Peter Cook. (Not that one ). I don't think he charged enough for his work and couldn't maintain the business so went back to teaching. He may still be around, I don't know. He had some strange ideas about Triumph and Norton twins. But those who had the money (about 3 grand) would get their bikes sorted by him. He apparently could engineer them to pull all the way to 8000 rpm and claimed top speeds of 140mph! I believe he used the T140 750 engines and were test ridden by Classic Bike over 100mph in 4th gear (the rider didn't have the bottle for any more around the local roads to Hull.) Quoting the relevant bits from the magazine - He designed cams by trying them out on test bikes - I've no idea on profiles but his timing sequence was INLET opening at 52 degrees BEFORE TDC and closes 107 degrees AFTER TDC. EXHAUST opens 116 BEFORE TDC and closes 60 degrees AFTER TDC. Normally they are 35-55 and 55-35. No larger valves but engine is fed by 36mm Amal MKIIs but proposed 40mm. He had to alter the inlet stubs to allow the gradual taper to the ports. He also only used 8 bolts on T140 heads by filling the additional ones with weld as he reckoned that the more holes there were the weaker the head would be. He didn't like high compression (his were rated at 8:1 in this article but in the one below they are rated at 13:1) or twin sparkplugs "It may be worthwhile on other engines, but not this one" he said. Lengthy experimentation led him to a redesigned exhaust system which is a two into one with the pipes not of equal length that terminate in a tapered silencer that he called a 'pulse chamber'. There is a marked lip inside it's gently tapered end. He engineered a breather that ran from the timing cover to the vented frame top tube. This is a similar article about Peter Cook on TOMCC's website that may also be of interest (you can see the zorsts set up and the longer carb inlet) pdf Thrashing a T140 BBM Aug 1995.pdf (2699kB) Geoff Walton, 22 Nov 2020 If that doesn't work look down the list here for the above title http://watoc.info/Library Just thought this may be of some interest, no good asking me about any of this, I can't even get the latest one not to wet sump let alone actually run properly (I'm now thinking it's the crank ) Here's his wife and her Triton that they built together - note the long carb inlet taper into the head
the cams i use are mwgacycles 510-x2, stock is supposedly: 45.5/71 73.5/43 measured at 0.020. but i actually dont set them that way, i just position them on lobe centers. they recommend 103/105 lobe febters but i retard them to 106/109, so add 3 and 4 degrees to those timing numvers. shitfire theres a lot in your links. im trying to read them on my telephone. i think hes wro g about twin plugs tho. i run 9.5 to1 on my morgo with 87 octane and twin plugs. cheap and easy
lol my typoes are too amusin g to correct off to the shop now to put a 43 tooth sprocket on the little ninja, and cut the new DID chain for the triumph. the triumph last ran 17 inch wheels, which meant that 21/39 gave me the right rpm for record attempts. if im running a stock triumph 43 or 46 rear sprocket with the huge 18-inch rear wheel and tire, ill have to have a longer chain. but it came in the mail from the most excellent bonneville shop, so we re good to go. puctures coming.
yes, it is. a cold windy day for the pretty lady, it appears. ml recieved a 42-tooth sprocket, okay . . . then recieved another 42- tooth sprocket . . . i wanted a 42 and a 43 to be able to gear up the little ninja from its current 44. a lesson in not drinking mezcal while ordering in eBay. but then, a 43 showed up as well. so all is good, and i have mostly just been humbled. miving on . . .
i got even more humbled. i sat down at a spreadsheet i wrote to check on speeds and gear ratios for the LSR machines, and i couldnt make the ninja come out right. i plugged in the 14 countershaft sprocket, the 44 rear sprocket, and 14600 rpm, and i kept getting 105 mph. shoot, i said. the kids were doing 108 and 109 with that setupp. so i looked at the bike and the "44" that i painted on the sprocket was still there, just like it was when i put it on. i knew they werent running 15000, and i measure the tire circumference. what could it be? my spreadsheet is usually fed accurate. anyway we put the new 42 sprocket on, fiddled a long time to get it all set, and then i had an aha moment. i said, wait. gimme that old one so i physically counted the teeth on the 44 sprocket, and it was a 43. oops. that made the spreadshee t come out correctly. but now we have two 43-tooth sprockets, in addition to two 42s, which is now on the bike. and a 45 that it came with. but we re right up against the air wall on this bike, and i think a 42 might be just enough to get to 110 before the rev limiter stops us
on thr ttiumph, im switching to oxygenated fuel, so ive ordered bigger jets to test. once the mixture is good, im going to retard the spark. stock is 38 btdc, im running 30 now, and i know people running as little as 24 advance. dont know what that bike needs, have to test.
yes. i will be interested as well. the C12 is a very good standard gasoline with an average RON/MON octane rating of 112. the Q16 is a methanol gasoline blend, i believe, and is rated at 116. my compression will be unchanged at 11.5 to 1, but i will be running significantly more fuel. they say to richen the jets as much as 7 sizes to start, and to expect 3 to 5 percent increase in power. that would just give me the jump from 135.289 to 139.226, i hope. the latter is the target, the fastest 650 triumph i am aware of. ive swapped from 21/46 to 20/43 in gearing, good for 138 at 7275 rpm. i can still switch to 21/46, but at 145 i think thats optimistic
I will be keeping my fingers crossed for you I did have a little experience of these fuels back in the late 80's when i was a mechanic in Formula Renault single seaters and we played around with one of the cars, we managed about a one mile and hour top end with just the fuel and adjusting the fuel regulator over our other car we gave up on that and had a better result buy modifying the bodywork to force air into the engine, that only lasted two races before the other teams caught on and we had to remove it as it was technically illegal lol.
lol anything is legal as long as nobody can see it. the biggest problem really is that im hitting tbe wall on aerodynamics. but im in a class with no aerodynamic aids allowed, although i could fair in the front of the rear wheel and install wheel discs. no time so far. i dont know how much more horsepower i can get with this motor, but i think at around 65 im mostly topped out. still, im very close to beating the fastest triumph ever. im already faster than any triumph in a production frame has ever gone without a fairing. once i get to 139.266, i have a full fairing to install-- a copy of dick manns old 111 bsa 650 unit. then. ill gear for 145 and see if i can get anywhere near it. not a lot of sprocket options for a 650 until you change wheels. i have 17-inchers for it, but i destroyed a wheel bearing and havent fixed it yet
Have a great time and when you think you have done all you can come up with another plan say like a sealed air box that is force fed air
its going to be busy. we show up late tuesdsy night, and then wednesday i drive north to pick up my fuel. theres a guy there in a yamaha shop with extensive experience with Q16, and i want to pick his brain. thursday i tune and help the kids, and friday and saturday i run the bike. i currently run 150 main jets in the 35mm FCR carbs, and ive bought every size up to 190, which is as high as they go. so ill start out two sizes up on the pilot, one or two notches down on the needle, and then start jetting the mains down from the top until it runs clean at WFO. then ill revisit the lower metering. the Q16 adds between 3 and 5 percent horsepower, they say, mostly in low and midrange. thats what i need, as the last gearing gave me 135 at around 7275. i dont want to spin it faster, so im hoping the torque from the fuel can get me up to 139 in the higher gearing without much more rpm. a 3 percent boost will do it. if i pass 139.266, i shut it down and drink beer from then on.
damn it. the guy i want to beat- at 139- apparently has gone 143 with a 660 in a stock frame. technically hes out of my 650 class and has to run 750, but i dont think 10cc is important. so now i have to somehow hit 143. thats next to impossible
well, every big record has a tailwind. the event where i threw a rod had a steady 12 mph tailwind for two days. i was crying, but the kids set records
ive thought about offset cranks, but eventually decided that it was getting too far ahead of my ability to understand the changes needed with cams and ignitions. the people who use them swear by them.