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Valve lash questions B230F

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weslee

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Sep 14, 2009
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I re-shimed my H cam a few weeks ago. Removed the valve husher's/silencers for precision. I spent the time to get each clearance's to as close to .3500mm as possible. My friend allowed me to use his shop, $800 miyamoto micrometer, his resurfacing machine, and a precision set of metric feeler gauges.

After everything was done there is no noise from the valve train until the car reached operating temperature. No big deal just I just have to wait for the new set of valve hushers to arrive. My friend being a perfectionist wonders if I could have shimmed it to .34, .33, or even .32mm? He aslo is wondering why the spec is the same for intake and exhaust?

I still have to replace the hushers, so does anybody know for certain how tight I can go and still have the valves seal? It takes less than a minute on his machine to resurface and demagnetise a shim.
 
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On a big cam like the H cam you should set the lash out farther like 0.019 inch, (0.05 mm) not 0.035 mm, that is way too tight. Spec is 0.0160 inch, NOT 0.0138.

It will rev more freey when opened up a little when set cold. The H cam has such big overlap that the valve lash should be set exactly at the back of the lobe, so find each lobe TDC and rotate the crank and set each lash one at a time, intake 1,2,3,4 exhaust 1,2,3,4.
Don't use the Volvo procedure of setting two valves when one is TDC and the other is close, because for an H cam they are not.

Also, if you really want to get it right and have a precision lapping tool, make each shim to be zero tolerance, that is go/no-go with the feeler gage in 0.0005" increments, take three measurements across the face and center, not in one spot, average it, then keep lapping the shim until you have them the same. If you do this your B230F will run much better, greater vacuum, faster rev's, and better mileage.
Takes about 4 hrs to get it right.
 
I have access to a Volvo manual for a B230F/T/. It says the lash on my year motor should be between .35-.40mm (that's .1378" - .1575 in american) cold. .019" is .4826mm, would that not be .0826mm out of spec?

Why would the valve lash change with a different cam? The gap is still there when each lobe is TDC?

To tell you the truth the car has never run better. There is just a little bit of valve train noise when the motor is hot but there is no husher in the car right now. i'm pretty sure the noise will go away once the new hushers are installed.
 
I have access to a Volvo manual for a B230F/T/. It says the lash on my year motor should be between .35-.40mm (that's .1378" - .1575 in american) cold. .019" is .4826mm, would that not be .0826mm out of spec?

Why would the valve lash change with a different cam? The gap is still there when each lobe is TDC?

To tell you the truth the car has never run better. There is just a little bit of valve train noise when the motor is hot but there is no husher in the car right now. i'm pretty sure the noise will go away once the new hushers are installed.
 
weslee said:
I have access to a Volvo manual for a B230F/T/. It says the lash on my year motor should be between .35-.40mm (that's .1378" - .1575 in american) cold. .019" is .4826mm, would that not be .0826mm out of spec?

Why would the valve lash change with a different cam? The gap is still there when each lobe is TDC?

To tell you the truth the car has never run better. There is just a little bit of valve train noise when the motor is hot but there is no husher in the car right now. i'm pretty sure the noise will go away once the new hushers are installed.
Click to expand...


The acceptable range for a stock lash adjustment is 0.016 inch; check and adjust if exceeding 0,002 in. (0.014 to 0.018 inch) When adjusting you should set to 0.016 in, not 0.014 in.
When a new cam (and when seating an old replacment cam) and valve train wears in, the valve lash decreases as the valve seats get hammered into the head. It is foolish (and dangerous) to adjust to the low end of the spec range and could prematurely wear your cam out.

Also there is NO, absouletly NO performance gain by setting the valve lash toward the low end of the tolerance. Trust me the car will run smoother, better if you adjust as I said above. Performance cams I adjust to 0.02 inch, 0.5 mm.

You should hear the valve tappets even with the hushers. If you don't it means that you adjusted too tight.

One other point, if you want to rely on your measurements from the feeler gage, don't remove the cam to take the hushers out. There can easily be 0.002 inch of difference in the cam location from before to after replacing the cam. Find the 'feel' of metal to metal when measuring the lash, as opposed to metal to rubber (hushers), and leave the cam installed.
 
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The valves beat themselves into the head with use, shortening the distance between the cam and the valves themselves, therefore they get tighter.
 
And the shims don't wear much at all, they're very hard, and the base circle on the cam (where the gap is set) doesn't wear much either.
 
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