i was looking up the retainers and i was wondering if cracks are found in an f20c can the retainers be replaced with f22c retainers. Also are the f22c retainers stronger or weaker than the f20c.

 

I think you can use the F22C ones but I don't think there is any reason to.

 

billman reports that the ap2 retainers are heavier than ap1 ones. It seems reasonable to assume they are stronger. On the downside, heavier retainers mean less overspeed margin to valve float.

I don't know how big these effects are. Probably if you never overrev, your valves will never float, and any extra strength will help prevent cracking under normal speeds.

 

The small weight factor will not be an issue.

If you mechanically over-rev beyond a RPM that will crack the AP1 retainers, but under the RPM that bends the valves, the AP2 retainers may indeed save you.

 

It took me a while feeling them out by hand to see if the AP2 is heavier, but I'm not 100% sure. They are near identical in weight. I need a gram scale to be sure. If I can remember, I'll bring them to tech day next week where the host has a gram scale.

They are indeed redesigned, and stronger.

 

so did you find out if ap2 retainers are indeed heavier then ap1's?

 

This is an interesting question, did anyone every weigh them? I've got a friend changing out ap1 retainers on his 02 and want to know if I should recommend ap2's.

Any idea what the approx. RPM limit is for the ap1, ap2 retainers, and then valve float? Just curious.

 

Just picked up some AP2 retainers today, I'll campare weight and design via pics and share once finished.

 

I've got a few AP1s running AP2 retainers.

 

Cool, I'll be switching mine over this weekend hopefully. Any issues or concerns yet?