Triple cam cover removal

paulincayman said:
I once had to rotate a v8 marine engine 64 times to get everything where it was supposed to be . Memory is a bit dodgy at the mo but was definitely a lot for cranking by hand.
Click to expand...

I've spent many happy shed moments winding Laverda triples over to line up the marks and the joining link. I'm also a curious (tedious) git, and I wondered how many it was. The chain has 102 links and the crank sprocket has 15 teeth, presumably there's a mathematical description for it, but basically 102 and 15 both need to be an equal product of a whole number. 102x5=510 and 15x34=510.

So you need to turn the crank up to 34 times to find that dastardly point where everything aligns. The chain does 5 laps. So you can all sleep at night again knowing this! :ROFLMAO:

It's better than the Velocette I'm working on which needs something like 98 turns due to the 'hunting tooth' on the idler. Even then, in a fit of old-pommy-bike-industry weirdness, when the crank and idler marks align, the idler and cam marks are maybe 15deg of crank rotation from aligning. The hunting tooth has a sensible engineering basis (even wear) but I've no idea why in 50-odd years of building the same poxy design, they could not make all the marks line up at once at any engine position!
 
breganzane said:
I've spent many happy shed moments winding Laverda triples over to line up the marks and the joining link. I'm also a curious (tedious) git, and I wondered how many it was. The chain has 102 links and the crank sprocket has 15 teeth, presumably there's a mathematical description for it, but basically 102 and 15 both need to be an equal product of a whole number. 102x5=510 and 15x34=510.

So you need to turn the crank up to 34 times to find that dastardly point where everything aligns. The chain does 5 laps. So you can all sleep at night again knowing this! :ROFLMAO:

It's better than the Velocette I'm working on which needs something like 98 turns due to the 'hunting tooth' on the idler. Even then, in a fit of old-pommy-bike-industry weirdness, when the crank and idler marks align, the idler and cam marks are maybe 15deg of crank rotation from aligning. The hunting tooth has a sensible engineering basis (even wear) but I've no idea why in 50-odd years of building the same poxy design, they could not make all the marks line up at once at any engine position!
Click to expand...
Brilliant! I laughed out loud. I knew there’d be a mathematical calculation for this and hoped that someone had bothered to do it. Well, now I know I have to connect it up and rotate it a maximum of 34 times whilst at the same time ensuring the pistons will miss the valves to allow me to do it!

Thanks, you’ve made my evening! 😂
 
You could just remove the cams and have a round bar or something above he head for the chain to slide over as you rotate the motor - don't have to think about valves and pistons then.
 
Thread drift. I hold the dubious distinction of having dropped 1) A washer and 2) the chain down the tunnel four times over the last year, despite taking (obviously inadequate) precautions. Mind, these were my first times removing stuff off an OHC engine. I had to buy a fancy borescope to find the washer after which I attached a magnetic to the end of the scope to get the washer and now have a fine collection of magnetic pickup tools. I am now unfazed by dropping the cam chain down the tunnel, as I've taught myself how to "walk" the thing back up by alternating two magnetic rods, one over the next.

Yes, I've learned my lesson. Only took four times.
 
ksoholm said:
Thread drift. I hold the dubious distinction of having dropped 1) A washer and 2) the chain down the tunnel four times over the last year, despite taking (obviously inadequate) precautions. Mind, these were my first times removing stuff off an OHC engine. I had to buy a fancy borescope to find the washer after which I attached a magnetic to the end of the scope to get the washer and now have a fine collection of magnetic pickup tools. I am now unfazed by dropping the cam chain down the tunnel, as I've taught myself how to "walk" the thing back up by alternating two magnetic rods, one over the next.

Yes, I've learned my lesson. Only took four times.
Click to expand...
I can only imagine the level your heart sank to the first time that happened! Now, you're clearly impervious to the potential pain caused by the dark vortex that is the chain run, and you have a swanky new tool. Bonus!
 
All done and a lesson learnt for next time. I definitely made it harder for myself, but objective achieved in the end. Clearances now almost perfect, so should last me for a while. Thanks to all for your help and suggestions. Next stop Redax ignition :oops::oops:
 

Attachments

  • Jota Cam Timing 100222.JPG
    Jota Cam Timing 100222.JPG
    122.7 KB · Views: 25
  • Jota Vv. Clearance 100222.JPG
    Jota Vv. Clearance 100222.JPG
    105.4 KB · Views: 25
You must log in or register to reply here.
Back
Top