another valve clearance question

[narfire]

Thought I'd try another post. I read Manoa's point about the gaskets settling after tourquing. I'm doing the clearances on a 1800 head right now(head is in a black and decker shop mate, great for doing this shimming) and am also wondering about what kind, if any, alowances one might make if the valves seat in after a bit of time, lessening the clearances? Should I add a thou or two and let the valves seat, bringing the clearances closer to the specs? Or just set to the higher end on the spec for the int. and ex. and be done with it.
Not sure what the guy did when he did the valves but I'm using I thought ,quite thick shims...4.65 and 4.60 mm on the ex side.
Thanks for any insight
Chris

[manoa matt]

I think I'd install the gaskets torque up the cam boxes and let it settle for a day or two. Then install the shims and get to the middle of the spec. The procedure calls for you to do the shimming on a fully warmed up engine, at that stage all the components have undergone thermal expansion and the clearances are at their tightest. Since you are doing it on a cold head, I'd adjust to a middle spec, so after its installed and warmed up the clearances will tighten up, and as things wear they will increase. There are a lot of guys running around with clearances in the .012 and .014 range. Most performance cam manufacturers list clearances around .016 Generaly speaking its better to run with tighter clearances than looser clearances. The important thing is to get the clearances even arcoss the intake or exhaust cam valves.

[narfire]

Thanks Matt,gonna have a Guiness and check the clearances again tonight.

[narfire]

Argh... Exhaust side #4 4.65 mm shim gives me .0200 clearance and 4.60 gives me .016 clearance to the best of my estimation. spec says .017-.019. The head has been torqued down and has sat for a week. it's cold sitting in a shop-mate table.
What would / should I do... .020 and hope the valve seats to .018 or go for the smaller clearance and end up with perhaps .015 or so. I have oversize valves, this is an 1800 head and the 2L block will have .3mm over HC pistons.
Thanks guys/gals

leaning to the 4.60 shim
Chris

[narfire]

Took a break (guiness) and went back. They all got to .016 exactly. Gonna leave them as is now. Tomorow check the intakes.

[So Cal Mark]

everythings better with Guiness, and you'll be just fine with that exhaust clearance

[baltobernie]

The procedure calls for you to do the shimming on a fully warmed up engine,

Are you sure about this, Matt? My manual says Cold, and I remember mechanics insisting on Overnite Cold.