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leroysch

Flywheel TDC Markings

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I've never been able to see the "D" or "S" on the flywheel of my 2004 V11, but have instead relied on the ability to spin both pushrods on the cylinder I'm working on to establish TDC before checking clearances. Well, today I got to the point where both pushrods rotated freely and I decided to have a look for these elusive letters. Didn't find them, but I did discover a faint but well formed engraved arrow on the flywheel pointing in the forward direction when I had the RH cylinder at TDC (pushrods easily spun about). I'm curious if anyone else has seen this, or is this some other artifact defining a different relationship unrelated to adjusting the valves?

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Iirc one of the letters appears just after that arrow crops up.  My eyes are quite good still, but it can be a struggle to see these markings for sure.  Especially if the bike isn’t raised up!  When i’m tackling the job I find myself on hands and knees, torch in gob, spit dribbling down my chin, squinting like James finlayson and cursing as I glimpse the letter scooting past the window again.

If you’ve located the arrow, try going ever so slowly onward and hopefully you’ll spy the letter.

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I bought a TDC indicator after the intake valve closed indicator pushed TDC. 30 bucks or so on Amazon.

 

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28 minutes ago, Colorobo said:

I bought a TDC indicator after the intake valve closed indicator pushed TDC. 30 bucks or so on Amazon.

 

I seem to recall that the markings are further forward than I expect.

Pretty sure TomChri's TDC indicator comes in shy of thirty bucks . .

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I thought they'd done away with TDC markings by the time the V11 came out? I mean what would be the point of any sort of timing marks? The spark, along with the injection pulse signal, is governed by the phase sensor and phonic wheel and its input is non adjustable although how it is interpreted and how the ECU processes the information is adjustable in the map.

For setting the valve lash just turn the motor by hand until you see the inlet valve close and then pull it round until the piston is very close to TDC. This can be established by the drinking straw method or simply by feel once you have the hang of it.

The piston doesn't need to be *Exactly* at top dead to set the valves. As long as the tappets are on the base circle of the cam lobes that's all you need. Clearances are 4 & 6 thou.

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My March 2000 build Sport has the "D" and "S". Perhaps later V11, like leroysch's '04 do not? :huh2:

All this time I thought 4 and 6 thou (0.004" intake/ 0.006" exhaust) were US specs more for noise and emissions and "world clearances" were 6 and 8 thou? "Raceco" lash: 8 and 10 ? (And Meinolf'sMap clearances even greater and same I/E . . .)

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17 hours ago, leroysch said:

...but I did discover a faint but well formed engraved arrow on the flywheel pointing in the forward direction when I had the RH cylinder at TDC (pushrods easily spun about). I'm curious if anyone else has seen this, or is this some other artifact defining a different relationship unrelated to adjusting the valves?

That arrow is used to line up the clutch pressure plate to get the springs properly seated.

 

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4 hours ago, pete roper said:

I thought they'd done away with TDC markings by the time the V11 came out? I mean what would be the point of any sort of timing marks? The spark, along with the injection pulse signal, is governed by the phase sensor and phonic wheel and its input is non adjustable although how it is interpreted and how the ECU processes the information is adjustable in the map.

For setting the valve lash just turn the motor by hand until you see the inlet valve close and then pull it round until the piston is very close to TDC. This can be established by the drinking straw method or simply by feel once you have the hang of it.

The piston doesn't need to be *Exactly* at top dead to set the valves. As long as the tappets are on the base circle of the cam lobes that's all you need. Clearances are 4 & 6 thou.

Thank you Pete for clarifying the clearances. Searching the forum led to a number of different values..I was having some problem sorting them out and didn't write down what I used previously. (Oh..and now I remember why I have what looks like shish-ka-bob sticks in my toolbox....)

3 hours ago, docc said:

My March 2000 build Sport has the "D" and "S". Perhaps later V11, like leroysch's '04 do not? :huh2:

All this time I thought 4 and 6 thou (0.004" intake/ 0.006" exhaust) were US specs more for noise and emissions and "world clearances" were 6 and 8 thou? "Raceco" lash: 8 and 10 ? (And Meinolf'sMap clearances even greater and same I/E . . .)

Now that I can (barely) make out that arrow, let me try to be more meticulous in my letter search. If unsuccessful, I'll live with the pain of the extra mg's.

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2 & 4 thou we're the ridiculously tight specs for the US market to try and get past noise regs. It was t really necessary in the end. As for using the bigger clearances? Why? Why would you want to reduce lift and duration on an old 2 valve dunger like the Ditcpump?

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My Sport sure seems to idle more reliably with the looser valves i the high ambient temps and traffic of the US south, especially on this crap ethanol fuel.

Do not looser valves cool better from staying closed that wee bit longer? Or one of those theoretical things that just doesn't make a significant difference?

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It can get pretty hot here and even in traffic I've never had any issues with 4 & 6 thou clearances on any Squarefin motor. Roundfins need a thou or two more due to their cast iron/HCS rocker supports but even their 8 & 8 are absurd, I run 5 & 7 with them. The early Hi-Cams I don't have enough experience with to know the subtle nuances of necessary valve clearances but the 'Nuovo 8V' works fine with 4 & 6 and in fact the gaps actually open up with heat. It's very sensitive to changes in valve lash though. Sensitive enough to run poorly if they are wrong and you're running an open loop map.

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Mine has D (Dis-side) and S (Snot-dis-side) markings.  I find it much easier to take a marker to the alternator and mark it at midnight, then it's 3 o'clock for the other side.

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23 hours ago, docc said:

My March 2000 build Sport has the "D" and "S". Perhaps later V11, like leroysch's '04 do not? :huh2:

All this time I thought 4 and 6 thou (0.004" intake/ 0.006" exhaust) were US specs more for noise and emissions and "world clearances" were 6 and 8 thou? "Raceco" lash: 8 and 10 ? (And Meinolf'sMap clearances even greater and same I/E . . .)

I'm with you docc,I thought the tight clearances were .004/.006 and the loose were .006/.008. Oh well, I do know that it makes a difference to the starting and idle running though, which surprised me.Such sensitivity to valve clearances. Dont know about running them wider than that though,you would get to the point where the opening/closing ramps became ineffective and valve seat wear became an issue. It would be interesting to see what effect valve clearance had on actual dyno numbers though so we could see the differences between starting,idling,valve noise and outright running performance then choose the compromise we wanted to make. I'd chip in for the extra hour of dyno time after someone does a dyno tune to find that out.

Ciao    

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Off the top of my head, I don't recall what the clearances actually were, but I ran the Raceco spec on my Cal Vin for a while a couple of summers ago, the fueling on the bike is lean anyways, it didn't seem to help, still ran a bit ragged.

I went back to .004/.006, my impression was it may have ran a little better, but improved substantially when I did the TPS and balanced the TB's fwiw 

Kelly

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