ABC valve guides

I need to replace a worn inlet guide and appreciate the groups views on whether it should be bronze or cast iron. The guide I have taken out is bronze. However the exhaust guide that I am not replacing and happy to leave loose, is cast iron. My general preference is towards a cast iron guide in a cast iron head for both expansion considerations and its self lubricating qualities. Your views appreciated.
Ian

Hi Ian,
I'm sure that all original Sopwith valve guides were of bronze, perhaps reflecting aircraft engine practice of the day, when valve cooling was as important as valve wear. Maybe reliability came into it too: the cast iron of 1920 was less predictable that the bronze. However, for 'guide replacement purposes (2021), I'd definitely go for cast iron, for the reasons you mention.

Paul,
Thank you for the guidance,
best wishes
Ian

Hi Paul and Ian
I have found that most Inlet guides are Bronze and Exhaust guides are Cast Iron. I have made a few guides but i also find that some heads are reamed where the guide fits and therefore require custom fitting.
Regards
Peter

Peter,
Interesting,thanks for your reply
Ian