Montjuic/Alpino valve shims

A

AndyB_11

Full member
Location
Bedford
So who?s the best person to contact to get my grubby little paws on shims?

I need to fit new needle roller bearings and get some threaded rod to pull the caps down properly before taking final sizes and ordering new shims but I?d sooner shim it while the head is off and know that when I fit it and dial in the cams I?m only worrying about one thing.

The caps aren?t hard down but there?s at least 0.5mm of clearance under the cam lobes and it?s so much I?ve had to order a set of cranked feeler gauges to get an accurate reading because my normal 100mm long feelers are reluctant to bend enough  :)
 
You will find the valve clearances will close up when the timing chain is properly tensioned.

Reckon I can supply the full range of shims for the 500s.

piet
 
That?s worth knowing, I was expecting the clearances to stay close enough not to worry about with the chain off and I was essentially being lazy and trying to avoid splitting the chain once I?d timed the cams.

Do you think I?d get away with aiming for 0.25 and 0.30 and expect them to drop by about 0.05 once the chain was tensioned correctly?

I?ll get in contact once I know what I need because I?m getting bored with seeing the engine on the bench and now I?ve got a decent head fitted there?s light at the end of the tunnel  :)
 
Depends on how worn the cams are, and how much clearance the needle bearings afford.  You won't get around checking, and most probably re-adjusting, once the chain is fitted.

piet
 
Dont know if it helps but as I have Atlas valves and had the seats cut properly, me and my engine man made our own as the shims were outside the range that I already had, silver steel, heated up and dropped into oil to harden  them up, worked fine since the last rebuild and stayed within tolelrance - but I am still running Castrol R, it was good enough for the Ogier engine so its good enough for mine
 
Making new shims is my last resort. They?d probably be ok because at the bottom corner inside what the Laverda parts list calls the valve tappet the corner has an undercut radius so I could make them a good fit and rely on the surface tension of oil holding them in place but it?s a last resort.

Once I?ve got the sizes I?ll contact Piet and see what he can do and fortunately I?m back at work on Thursday having been stood down since late March so I?ve got access to a machine shop again.
 
That?s it, I?ve finally managed to check, check and check again until I?m happy with the shims I need so I?ve sent an email to Piet to see if he?s got them.

There wasn?t too much variation on the sizes I need so that?s always a good start when you?ve used old valves in a different head and I?ve aimed big on the clearances because I?ve no doubt they?re going to close up a bit after 500 miles.

Hopefully that?s it for the engine, once it?s boxed up I?ll put a mini report of the trauma involved in this little project so everyone can have a laugh.
 
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