B16 vs. GSR Competition Headwork

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MARCH TECH ARTICLE

Last month we talked about the flow characteristics of the B16 and GSR head. This month we look at how they respond to head work. Both heads received competition head work which includes port/polish and a competition valve job. Both were given a fair chance with different valve job configurations to see which one worked best.

Once again its interesting to see that the B16 out performed the GSR at high lifts once again. Remember, in stock trim the B16 also out performed the GSR at high lifts. What gives??? What I have noticed is that the B16 head has a different bowl shape to it. If shaped correctly you see really good high lift CFM gains. If you don’t well…. Lets just say you gave someone money to just make it look pretty while over looking this area. Over the years many porters and head shops say bowls are for low lift, short side for mid lift and runner for high lift. This is were you target to change the flow charecteristics at certain lifts. I am sure this applies to many heads but it just goes to show you that Honda heads are finicky. Were you think something shouldn’t work actually works!

One more thing that I have noticed is that on a lot of production multi valve heads, high ports seem to flows better in low to mid lift numbers while ports with a tighter radius tend to flow better at high lifts. I noticed this a lot with motorcycle heads also. They don’t lift very high. On the average they see about .300-.350 of valve lift only. A high port would work extremely well on this type of lift.

I would also like to comment that all of this testing was done a Superflow flow bench. There was no guess work done hear or “I don’t need a flow bench to tell me I’m correct” type attitude. I hope this will educate the consumer further regarding these heads.

Some last words…….. This is not the bible. This applies to Honda heads and other types of heads I have flow tested. A BRODIX, DART, AFR, or your head (Fiat, example only) is a different story.

Joe Alaniz