Valve timing fine adjustment

#61
I'm starting to think that I need a DTI on the tappet to check when the inlet valve is fully open and a vernier on the crank damper. If the chain wheel is removed the cam can be turned to the exact position when the inlet valve is fully open and the crank angle can be set to 104btdc. The chain wheel can then be put back on with the help of the vernier.
 

redrover

Active Member
#62
I think that's a good way to go about it. Although there's so much slop in that valvetrain from the twin chains that it's only ever best guestimate. You could get it bob on under hard load, but at idle, it'll still wander well behind the times!
 

Dave3066

Well-Known Member
#63
I'm buggered if I'm taking mine off again to get what might be no more than a few tenths of a degree more accurate cam timing :D

Those top sprocket bolts are a bitch to get back in again whilst keeping the top chain tight :evil:

Mine is timed with the pin in the flywheel and the lock in the camshaft. I admire your endless search for perfection but at some stage you have to say "STOP". Is all that effort really worth the results (rhetorical question)? I guess Ranald's rolling road session will help.

Dave
 

redrover

Active Member
#64
Dave3066 said:
Is all that effort really worth the results (rhetorical question)? I guess Ranald's rolling road session will help.
You know me Dave, I'm just the type of person who can't even compute what that question is getting at!! ;-)

The easiest way I found to do the timing is to back the top chain wheel bolts out far enough that you can pull the centre section out of engagement with the wheel teeth (after circlip removed of course). After that just move cam or crank and push in hard on the left side of the chains as you push the centre section of the wheel back in to meshing. Nip up the bolts and clip and you're done. No need at all to touch the tensioner then because the chains never move anywhere.
 
#65
Hello.

I've been reading this thread over and over to try and make sense of it.

It would of been so easy for rover to put one locking hole at EP...... And be done with it!!!!! If only.

I have a 2200sc automatic and have replaced the head. I'm now need to time it up and I don't want to get it wrong.

I have located the EP tag on the flywheel and have inserted the locking pin. There is no pointer on the housing so I don't know if I'm correctly at EP. I just assume that as the locking pin goes fully in it must be correct !! My cam is locked at EP. Question...... I'm I ok to bolt everything back down?
 

sdibbers

Well-Known Member
#67
Because the crank rotates twice for every one revolution of the cam you want to be sure the cam is in the correct position. The cam has four slots on the sprocket flange, one of those four slots is slightly wider to accept the 'L' shaped key that's attached to the front camshaft bearing cap. You can lock the camshaft at it's EP point with the key. If the key fits the slot while still in its place on the bearing cap your timing is where it should be. If the key fits the slot but not the slot in the bearing cap, then your valve timing is off and should be adjusted.

Hopefully I've made sense and not made it worse for you.

Good luck,

Steven
 
#71
Thank you all very much for your responses.

I was hoping to find a pointer on the housing to be even more assured/accurate.

I've attached a photo of the EP tag on the flywheel.........(the locking pin is inserted, fixing the crank in this position). Question..... Does this look correct ?

Number 1 piston is positioned down the bore......... I assume where peak exhaust occurs.

I'll get on with the job!! Hopefully I'll be back on the road this weekend.

Cheers
 

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harveyp6

Well-Known Member
#72
I was hoping to find a pointer on the housing to be even more assured/accurate.
I think you'll find that the very earliest engines didn't have the timing marks on the front pulley, only on the flywheel viewable through that access window, and those engines had a pointer. After the marks went to the pulley the pointer at the back was deleted. If you can see the EP mark, and the pin is located in the flexplate then the crank is in the correct position.
 
#74
Hi fellas, just wanted to post a quick thank you for all the advice above. Have now sorted out the valve and ignition timing, balanced the carbs and set the mixtures on my recently acquired '74 2200tc. All were a loooong way off and obviously hadnt been done in years; now pulls like a train and smooth as. First time with a p6 having had 4s and 5 s before, but smiling now!

Best wishes

Nige
 
#75
Great thread. I've been chasing wwhat I thought might be a vacuum leak in my rebuilt SC Auto as I'm unable to seem to get it to idle smoothly (especially in gear). A few other things, no bottom end power but pulls nicely above 20 MPH. Also has a tinny noise when accelerating. The team that did the engine up specialise in old equipment but are not Rover experts. I'll check tomorrow
 
#76
Checked valve timing as per this thread (made sense of the instructions in the manual). It was spot on. Have noticed pooling of fuel in the carby body when I remove the air cleaner. Will now check the float setting.
 
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