Measuring Piston to Valve Clearance

[Roundy]

easy way is to set the cam shafts at the tdc lifter rise as you would set up your cams .when you have done that then care fully take cam belt off the top cam pulleys and with dial indicator measure how much further you can move the inlet cam towards the exhaust and if you have more than 80thou before the valve hits the piston you will be safe any less then you would need to fly cut the valve reliefs more

I am confused with this

How exactly is this measuring it? I can't figure it out.

Sorry for the dumb question

[Celica RA45]

most cams or aftermarket cams have 2 set ups lobe center and lift at tdc lifter rise ,
on the tdc lifter rise you need to bring no 1 cyl about 80% before tdc set up magnetic base and dial indicator and set this up so it is on no 4 cyl .on the inlet preset the dial indiactor so its 300 thou into the bucket and clearing the cam .now turn the dial so it sits on 0 .now start moving the crank and keep watching the dial until its starts moving { as lobe starts to go down the bucket } keep a eye on the tdc mark and count how much the dial indicator moves from 0 until you are at tdc if it has moved 150 thou thats what you have at tdc
if the card says 165thou at tdc then you would need adjustable cam pulleys to get it in its place
once you have set them up and thats both and use a black texta to mark pulleys and belt
gently slide the belt of at tdc and then try to move the inlet cam towards the exhaust and keep track how much movement there is till it stops if you have 80 thou after or more you are ok but if you only have say 20 thou you will have to fly cut the pistons
this set up needs the spark plugs out as well so it will turn easy as well
on the exhaust to set up take it to tdc on no 1 then do the same with the dial indicator preset it agian at 100 thou and see when you turn the crank down to the bottom to bdc see how much its moves till it stops moving and that will be how much it is at tdc for the exhaust

[Cuzzo]

So if i drop from a 2mm gasket to a 1mm gasket what will change?

Have to run less boost? Can i run 25psi like i was going to with the 2mm one?

What sorta ratio difference will there be?

[Celica RA45]

with out checking anything you wont know ,but 2 things higher comp and most likely valve will be closer to piston

[Cuzzo]

Ok i have tried to get my head around it and i really want to make 100% sure before i put it all back together.

Now when i install the playdoh WITHOUT a HG the playdoh gets cut in half by the valves moving into the piston fly cuts.

Ok so now if i add a 1mm hg this well then give me 1mm clearance. Is this enough?

Im trying to understand what you describe "celica ra45" however me being the noob at this its not easy.

I'll keep at it though. Maybe i should throw up some pics of my findings

[Billzilla]

0.060" or 1.5mm with the headgasket in place is good.