pistons and valves contact

[alanr]

As an addendum to my last post..
Remember that before the engine will run you will almost certainly, unless you are very lucky, need to start from scratch and re-do the ignition timing after you have done camshaft timing and before the engine will run correcftly. Do this by removing and refitting the distributor to get ignition co-ordination with the camshaft timing.

Alan.

[checkrail]

Hi Alan, I 've everything set up but the crank will not turn a fraction , whereas before it would rotate half a turn before locking up.

Thanks John

[Craven]

Not in gear by any chance?

[alanr]

Hi Alan, I 've everything set up but the crank will not turn a fraction , whereas before it would rotate half a turn before locking up.

Thanks John

Hi John,
Clarification needed please.
Is this with the cylinder head on, cam shaft sprocket marks all positioned and lined up and with crankshaft pulley mark at TDC?
Or are you now saying you cannot turn the crankshaft with the cylinder head off?

Alan

[checkrail]

Yes Alan to your first question , but I've just removed the cams, hooked the chain up and the crank rotates easily.

Thanks for your patience
John

[Europa88]

John,

How are you shimming the tappets? Are they all at the correct clearances? Inlets and exhaust?

Cheers
Neil

[checkrail]

Neil,
I've shimmed them on the generous side. Not a good idea?

John

[alanr]

John,
You need to go back to basic first principles with the cylinder head on the bench, cams out and start from scratch as per the procedure I spent considerable time typing out this morning.
Sorry to say this but currently you are just thrashing around..
Tappet clearance unless you have got them wildly out is unlikely to be the issue.
I strongly suspect that you now have either one or more bent valves.
If you follow what I sent you this morning it will lead you to the answer to your problem.

Alan.

[HCA]

Please, please, get some physical help. This is all becoming a tad silly.

You ‘have removed both cams and hooked up the chain’ to what have you hooked the chain up to?? You. Have ‘shimmed up the tappets generously’ what does this mean?

I hate to say it, but you are not listening to anyone. There are couple of really knowledgable people who tried to give you help but you just ignore them.

[checkrail]

HCA I'm sorry but I don't care for your comments, I am takeing notice what people tell me and I appreciate that they are taking the trouble to advise me.

John

[rgh0]

Given the the engine turns freely with the cams removed there is nothing jamming the crank and pistons. Before you remove the head again I would do the following

1. With both cams removed turn the engine so all the pistons are in the middle of the stroke i.e. 90 degrees before or after the TPC mark on the crank pully. This is required so the valves dont hit the pistons during steps 2 and 3 when they open

2. Install only one of the cams and see if you can turn it 2 full turns via the sprocket bolt

3. Remove that cam and install the other and see if you can turn it via the sproket bolt

This will verfiy if one or both of the cams or the valves are jamming for some reason.

If both cams can be turned then you problem is how you are setting up the engine timing so that the valves and pistons are meeting each other at some point in the cycle.

regards
Rohan

[Europa88]

Neil,
I've shimmed them on the generous side. Not a good idea?

John

Hi John

As alanr has said unless the tappets are wildly out it shouldn’t be a problem. If you have mistakenly got a very thick shim in one, in theory the valve could open to maximum and the cam could bind!

Seriously follow step by step what Rohan has said and report back

Cheers
Neil

[alan.barker]

Please, please, get some physical help. This is all becoming a tad silly.

You ‘have removed both cams and hooked up the chain’ to what have you hooked the chain up to?? You. Have ‘shimmed up the tappets generously’ what does this mean?

I hate to say it, but you are not listening to anyone. There are couple of really knowledgable people who tried to give you help but you just ignore them.

+1
Alan

[checkrail]

I have followed Rohan's instructions and the problem is the ex. cam, it will not turn one full revolution,
Its no.3 valve, the lobe on the cam is trying to open it, thats where the jam is.
The inlet cam will revolve fine., So the head will have to come off again

John

[rgh0]

Before removing the head, I would lift off the exhaust cam and the followers and shims and examine the No3 ex valve to see if it is sitting in the same position at the other 3 exhaust valves and that the retainer and collets are properly in place and nothing can be seen that may be jamming it.

Potentially the valve is bent but it is unusual for a bent valve to jam totally, it normally just sits partially open and can be opened further by the cam and does not stop the cam rotation. Does the No3 valve move at all or is it jammed in the closed postion or does it jam as it is opened, if so how far does it open

cheers
Rohan