Rocker arm side to side play
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Rocker arm side to side play
Posted: Mon Jan 09, 2023 9:43 pm
by Bryan Cotton
When a cylinder is at TDC, I sometimes have this play. Normal or do I need more shims?
Re: Rocker arm side to side play
Posted: Tue Jan 10, 2023 10:53 am
by Area 51%
The amount of slop you have on the exhaust rocker isn’t particularly worrisome, but the fact that you have none on the intake might indicate you have that adjuster too tight, the shim is incorrect, or you’re not really at TDC.
Re: Rocker arm side to side play
Posted: Wed Jan 11, 2023 12:00 am
by karmarepair
Gap should be .005" according to references I can find. The assembly manual is silent on this point.
And I probably should replace my hairpin springs and wavy washers (provided with my 2001 AeroVee kit) with a solid shaft kit, as currently provided with AeroVee kits. We are running higher than stock lift, and, I suspect, stronger than stock springs, which can lead to busting the hairspring clips, with bad results.
Re: Rocker arm side to side play
Posted: Thu Jan 12, 2023 9:46 am
by GraemeSmith
I would say you want to eliminate it. Or at least hit the 5thou that karmarepair suggests.
Otherwise you are not controlling the slightly off-center contact patch called for in the assembly manual to ensure valves rotate.
Re: Rocker arm side to side play
Posted: Mon May 08, 2023 3:01 pm
by Bryan Cotton
For followup - I bought some EMPI 0.010" shims and by inspection/trial and error ended up with a couple per side. Those were the thinnest I could find. That play is largely gone, everything is still free, and the rockers are aligned as per the Aerovee manual. I have done a ground run plus 2.7 hours of flight and it seems good.
Re: Rocker arm side to side play
Posted: Tue May 09, 2023 12:11 am
by karmarepair
karmarepair wrote:Gap should be .005" according to references I can find. The assembly manual is silent on this point.
And I probably should replace my hairpin springs and wavy washers (provided with my 2001 AeroVee kit) with a solid shaft kit, as currently provided with AeroVee kits. We are running higher than stock lift, and, I suspect, stronger than stock springs, which can lead to busting the hairspring clips, with bad results.
I did do just that. The rocker shaft kit I got from CB Performance also came with the “Hoover Mod” grooves in to increase oiling, and I fitted my rockers, similarly modified to increase oiling, and Elephant foot adjusters. I got the clearances as tight as I could get them will still retaining free movement of the rockers. It took some trial and error with the supplied shims.