4 replies to this topic

[SKIDDERWOLF]

Ive been reading Vizards yellow book regarding cylinder head work in which there is reference to 'Bullet head valve guides' Could someone more experienced help me understand what these actually are please. I understand the porting aspects but I dont understand why the std valve cannot be used? 

[1968andyf]

To improve flow in the port by lessoning the restriction of the guide. The guide is usually tapered from where it protrudes into the port,some modifiers also use a valve with a 6mm stem

[SKIDDERWOLF]

Cheers Andy.

[Turbo Phil]

This YouTube short explains it all: https://youtube.com/...5ELx3xGzfJFFJny

Phil.

[SKIDDERWOLF]

Thanks Phil, watched a few of your videos yesterday really helped me understand. Cheers