Valve timing

[drifter]

Disclaimer: I have searched but not found anything specific...

I am rebuilding my 2.25P engine - its only timing mark is a fitting that goes on the outside of the timing chain cover - so - not a part of this discussion.

Crankshaft and camshaft are in - I am now agonising over the timing chain setup...

Crankshaft locating keyway is at the top and I have verified that piston #1 is at TDC.

Looking at the business end of the camshaft and the camshaft gear, I have located the slot marked 'P' and slid the gear onto the shaft, lining the keyway up with the 'P'

I then rotated the camshaft until the 'P' mark on the outer edge of the cam gear was pointing at the tapped bolt hole on the block, as per the manual.

There is no way the chain will sit cleanly on the 2 sprockets with no slack on the driven side of the chain. The chain becomes firm with the cam sprocket slightly back from the alignment hole - or slightly past the hole.

I am concerned that this will become the root of future problems.

Looking down the cam follower holes (head is not on yet) it would appear that the inlet valve has just closed and the exhaust valve is about to open (if not already opening - dependent on whether I am before the tapped bolt hole on the block or after it). I have heard too many "I was one sprocket out" stories to just press on with out addressing this.

Thoughts?

[Blknight.aus]

ummm inlet closing and exhaust opening? thats not right....

exhaust closing and inlet opening is more like what you are after.

from memory the inlet valve starts to open one tooth before TDC.

[drifter]

#1 valve is exhaust ? (it is the smaller and dirtier of the 2 and lines up with the exhaust mainfold)

Looking down the follower hole, the lobe on #1 is about to open the valve (rotation = CW and the lobe is to the right of the cam centerline looking down the hole from the front of the engine)

[chazza]

Looking down the follower hole, the lobe on #1 is about to open the valve (rotation = CCW and the lobe is to the right of the cam centerline looking down the hole from the front of the engine)

This may be of no use at all and perhaps I have misunderstood your abbreviation.
As I understand it:
Looking from the front of the engine the crankshaft when running will be turning clockwise; therefore the camshaft will also be turning clockwise, which means (if I have got it right) that the lifter you are looking at will be going down i.e. closing the valve.

I would be tempted to install the head and valves and set up a dial indicator on the valve stem, so I knew exactly what it was doing and borrow a timing-wheel from an engine re-conditioner, so that the valve timing could be accurately set.

Alternatively you could mark TDC on the flywheel and follow the procedure for setting the timing on the earlier engines as detailed in the manual.

Guesstimating the centre of a threaded hole as the manual advises, seems to me to be too imprecise,

Cheers Charlie

[drifter]

That'll teach me not to proofread

Sorry

CW not CCW - I would blame it on this crap filled keyboard - but it is my responsibility to proofread...

Thanks - I'll press on and do the dial gauge bit once the head and all are on.