Chevy LS motors.

>>15629111
The two valves are big as fuck. More valves lets slightly more air for the same size of head, but mostly lets you rev higher and faster.

>>15629111
It would be a lot of engineering / cost and you'd be better off putting that into the intake and exhaust manifolds for better breathing

>>15629111
Having a single pushrod and lifter open up two valves (i.e. compress two springs) would probably destroy the roller on the lifter and eat the camshaft. I think any performance benefit of additional airflow from a 4 valve like that would not be worth the extra valvetrain complexity and strain. Buy a coyote engine.

>>15629123
Would the extra revs have much benefit?These motors seem to peak mid range anyway.

File: IMG_20160813_141142.jpg (857KB, 3072x1728px) Image search: [Google]

857KB, 3072x1728px

>>15629150
Pushrods can't rev as high because of the inertia of the pushrod. But the compactness allows for more displacement where their power comes from.

>>15629111
It's called rocker bridges. Duramax, Cummins and Powerstrokes run them for 4v iirc.

>>15629111
Get mercury marine 4v heads

Or just build a coyote master race

File: SB4-Port_RM.jpg (4MB, 3260x2893px) Image search: [Google]

4MB, 3260x2893px

>>15629111
Mercury Marine is working on a 4 valve, hemi, DOHC conversion head for them. They call it the SB4

>>15629540
nice

https://en.wikipedia.org/wiki/Nissan_VK_engine#VK56VD

>>15629111
there are allot of 8 valve to 16 valve conversions out there
http://theoldmotor.com/?p=110870
some even re use a push rod block but with a dohc head run from the inblock cam drive
>>15629339
what about push rod flex ?
I recall something about rocker ratios meaning the more mild cam in use to limit flex is not a problem

>>15629540
Like 99% of engines are "hemi" including an ls