I posted this in the prelude section, but no one seems to know. I saw that the Prelude Type S cylinder head has a 45 degree valve seat angle and all other H22a engines are 60 degree. What is the advantage of this? I don't know much about this type of subject, so any feedback will be appreciated.

Thanks,
Mark

 

Deviances in valve seat angle and power gains depend on wihch side og the head you are talking about. Changing the angle 15 degrees will do almost nothing for power. They are just specs and someone probably had nothing better to do one day than measure it.

In general, increasing the angle on the valve seat will increase flow through the cylinder head but at a risk of losing compression if the valve job is not performed correctly. Is it worth going out of your way to change the valve seat angle? No. Hope this answers your question.