Setting cam timing with bolt-snout cams

[billd]

Is there an easy way to set cam timing with bolt-snout cams? With the old-style cams I could put the special wrench on the cam, remove the dowel pin, rotate the cam to the correct lift, and then reinsert the dowl pin. With the new style cams, there seems to be no way to grab hold of the cam to rotate it while at TDC with the intake valve opening.

I managed to set the timing by backing off to where there was no lift, pulling the dowel, then rotating the crankshaft a bit and reinserting the dowel. But there has to be an easier approach.

[MBEngineering]

HI billd put the engine on TDC and the cams with the dots to the top and fit the timing gear and pins, fit the inlet rocker on No 1 and set the clearance, fit the exhaust rocker and set the clearance, put the Z holder on and the DTI and set to zero, turn the engine over to TDC and check the reading and where TDC is , if the cam IS reading the cam timing setting ok take the reading past slightly (0.2mm) stop and take out the bolt, back off the tension on the pin and remove , then turn to TDC and refit the pin and bolt, and then fit the No4 inlet rocker and set the clearance, fit the exhaust rocker and set the clearance, turn over to TDC on No1 and check the DTI is at "0" and turn over to check the timing again, if ok then torque the bolt and check , swap the Z holder on to the No4 and repeat, if the timing is NOT coming up to spec' on TDC then go past TDC to the cam spec" reading , pull the pin and turn back slightly past TDC and then bring back up to TDC and fit the pin, fit the bolt and turn over to TDC and check the DTI is on "0" and re check the setting, torque up the bolt if ok, Because you have both rockers fitted when you pull the pin out the cam should hold it's self there while you adjust the crank to TDC . I hope I have not over complicated things or made it to simple that it is not clear.

regards mike

[billd]

Thanks much. I didn't have the exhaust rocker in, so the cam would turn if I removed the pin when there was any load on the intake valve. Next time I'll try it with both rockers in place and see if the cam stays put.

[MBEngineering]

HI if you just put the exhaust rockers in on No 1&4 thay should hold the cam while you make the adjustment OK .

regards mike

[Vin-barrett]

Originally posted by MBEngineering
if the cam IS reading the cam timing setting ok take the reading past slightly (0.2mm) stop and take out the bolt, back off the tension on the pin and remove , then turn to TDC and refit the pin and bolt

Hi Mike
I found this post helpful, thanks
quick question on this part as I am not sure if I am reading this correctly.
Does this mean there is .2mm of "springback" (not sure how to say it) so to set it .2mm advanced to compensate for this?

Thanks
vin

[MBEngineering]

HI Vin if you take the reading slightly past and then remove the cam bolt and try to remove the timing pin , it will be under tension , so back the crank to let the pin come out is approx the 0.2 mm and when you go to TDC and re fit the pin , if you then turn the crank you will see slight movement between the sprocket and the cam gear(app 0.2mm) which you have already allowed for when you went past your setting, so when you do a full turn to check the timing you have already allowed for the movement in the pin and the cam timing should come up to your setting, if the cam setting is not in the pin hole you have and the next is to far forward/back, then take off the tensioner and the cam gear and turn the gear only 90 Deg and re-fit , this will put the pin location in a better setting for adjustment, if the timing is still not playing ball , then I would change the chain gear for a different one. is this one as clear as mud also, as it is easer to show you than to explain , I just wish I could pop round show you what I am trying to explain hear .

regards mike

[MBEngineering]

HI just a bump for viejopatron , as I do not know how to hyper link the thread, Gary have a read of this and see if it helps.

regards mike