Black91Z28

just what the subject asks, because when i look into getting some new heads, there are angle plug and straight plug heads...and i was just wondering!

Thanks

aklim

When I got my AFRs I believe we had straight heads. I think angle heads are better for header clearance or something. Can't remember. Call AFR and ask.

Black91Z28

I'll definitely call them when I get serious, but ya, i believe i remember when i put in my plugs that they were straight....

MRZ28HO

OEMs are straight plug style. You can get which ever you want, but be cautious as some headers will not work with angle plug heads. The reason for angling the plug is to get the spark closer to the exhaust valve ... I forget the reasoning. Maybe a better burn.

2IROC

Yup

Black91Z28

and let me ask u this.....is 68cc better than 72cc??? i would think so but im not sure

MRZ28HO

Depends on what the application is and what the target compression ratio is. But for OEM, yes the smaller the chamber size the better ... to a point. The smaller combustion chambers also cause shrouding as the valve opens. 68cc is good, you can go as far down as 60cc on a 4.00" bore IMHO.

Black91Z28

causes shrouding as the valve opens? is that good?

82355

LOL No valve shrouding is bad. It is when something (ie. the bore or the combustion chamber) is close to the valve and blocking airflow. Therefore limiting power. You want the most airflow you can get out of a head without loosing velocity.

Vavle shrouding = BAD

Martin

ZZ430RS

You need to have at least 3/16" from the valve to the edge of the chamber for good flow, any closer will cause shrouding.