Valve timing

[Jef Walker]

Hi everyone,
I am new to this forum, as I have recently bought a 1981 Jota and am trying to find out how to check my valve timing, in what position are the pistons supposed to be in when I put the camshafts back in after re-shimming?
Thanks

 

[The Sock]

This should cover it:

 

[Jef Walker]

Hi ,
Thanks for all that information, not. Sure I explained what I'm looking for exactly.
I want to know in what position do I install both camshafts when setting up the valve timing, and what position do the pistons have to be in.
Thanks again

 

[markQLD]

The factory manual can be downloaded from the forum library.

 

[Jef Walker]

Thank you.

 

[The Sock]

Hi ,
Thanks for all that information, not. Sure I explained what I'm looking for exactly.
I want to know in what position do I install both camshafts when setting up the valve timing, and what position do the pistons have to be in.
Thanks again

Apologies, I missed a page:

 

[Schurminater]

Hi Jeff,yes download the manual if you can which will help you no end,.
Be also aware that when you are trying to connect the cam chain one of the camshafts will be under valve spring tension and will need to be rotated and turned with a spanner in order for you to fit the joining link.

This can be a little tricky and if you are not careful the sprung camshaft can flick back and fire the chain down the tunnel for you to then fish out again!

 

[Jota Rob]

Hi Jef
Not to dissuade your efforts.
Absolutely set it according to the manual but this doesnt guarantee that its correct.
Various reasons discussed on this forum over the years. The most common is cam wheels that are marked for 1 cam type, used on a different cam. More common than you'd believe.

Using a degree wheel and dti ensures that your cam timing is in spec and it is the only way to be sure.

Rob

 

[Jef Walker]

Thanks for all your help.

 

[Pauls]

I expect you have already worked it out, but you don't need to remove the generator flywheel to set the valve clearances.

 

[Jef Walker]

I expect you have already worked it out, but you don't need to remove the generator flywheel to set the valve clearances.

Thanks for the info, I'll keep that in mind.

 

[motoddrob]

#1 piston TDC, after splitting the cam chain you'll find the inlet cam in a lazy position and exhaust under load. You will need to retard the exh cam until it's also in a lazy position. Before retarding it using a spanner on the chain wheel I usually drop the piston slightly so there is no contact with valve/piston when retarding it. Best not to undo the the exhaust cam under load. On reassembly turn the cam back to align the marks, put the piston back on TDC and reconnect the chain.

 

[IAG]

You'll find this helpful: https://laverdaforum.com/resources/degree-disc-markings-4c-a11-cams.100/