On my 848 head the intake valves are nearly flush with the deck... which makes sense why the stock cam for 848 heads waits till 1° after top center before opening intake valve.

'59 valve timing

However, the 261 cam is listed as opening the intake 11° before top center... so it sounds like a recipe for disaster when used with an 848 head.
I'll assume that the 261 head has a more recessed intake valve?


So now I'm confused:
There are several stories of performance builds using fabled 261 block, with 848 head, or the corvettes using the 261 cam in a 235.
Are these just myths, or is it common to cut intake valve reliefs in the pistons?
Attachments
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valve timing.png (79.11 KB, 177 downloads)

Last edited by Ott3r; 03/25/2020 6:59 PM.
'59 Chevy Suburban, NAPCO