Guide boss shaping

[BradH]

Heads without any type of wing behind the guide, need a wing behind the guide.

Hmmm... every intake bowl of these heads has what I presume is a wet fuel trail behind the guide. Click on image to see larger size for more details...

Unfortunately, the as-cast heads don't provide any material to develop a wing behind the guide.
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BBM Victor fuel trail behind guide.jpg

[camaro/holland]

Some very interesting information in here, thanks all.

Just wondering if anyone tested the position ie direction of the rear wing in relation to the center of the cylinder. Did you notice any improvement after directing the charge away from the wall and towards the center?

[ptuomov]

Found this ancient paper on exhaust valve guide boss shape and size and the exhaust valve temperature:

https://digital.library.unt.edu/ark:/67 ... 1931/m1/8/

Bigger boss can be designed without reducing flow and the bigger boss reduces exhaust valve temperature by 70F degrees.

Of course, this might also be dated info or obvious.