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Old 09-09-2006, 10:40 PM   #33
FuJi K
Scooby Guru
Member#: 3687
Join Date: Jan 2001
Chapter/Region: MWSOC
Location: St. Paul, MN
MY99 GF4 JDM 6spd
NF Performance


Originally Posted by Matt Monson View Post
Fuji K,
I suggest you stop arguing with Steve as he is right. Last year about this time a bunch of us measured head ports on various heads. I measured DOHC Ej25 heads at 54mm x 38mm and Steve measured his v6 ports at 57mm x 48mm. I am going to go with his gutt instinct on this and suggest you are dealing with small port v7 heads, and your friend, expert or not, doesn't know what he actually has there...
What disinguishes a BIG PORT and a "small port?" Is it the PORT ENTRY where the intake manifold bolts onto, or is it the port runner to the valve seat?

From looking at the 3 heads altogether, WRX, STi Ver7, 2.5L DOHC....BOTH the 2.5L DOHC port runners and STi Ver7 where the same. The WRX port runners where ROUND to the port and much smaller port runners. BOTH Ver7 Heads and 2.5L DOHC port runners where D-shaped at the port entry then gets round to the valve whereas the WRX are round from air splitter to valve.

NOW when we were comparing the PORT ENTRY of the 2.5L DOHC and STi Ver7, yes, the INJECTOR tongue and PORT shape is slightly different (possibly due to casting styles then and now), BUT WHAT WE FOUND TO BE THE SAME, was the port runner all the way to the valve. The VALVES where of the same size too when put up against each other.

I should have took pictures of the 3 heads when we were comparing them.. . . . . ..Well.....I'll stop arguing and let you believe what you WANT to believe..... Yes, my friend did comfirm that his Ver7 Heads are the "big ports" that you speak of.

BUT REALLY what I was trying to figure out was which heads had the better port runner to the valve. LOTS suggested WRX heads, I've SEEN WRX heads as well as the USDM STi heads (Legacy Liberty heads w/ AVCS) and the port runner is just small. I had purchased these 2.5L DOHC heads BEFORE I started comparing head ports. Then I came back to desiding if I wanted to KEEP these 2.5L DOHC heads or go for WRX heads. AFTER researching and finding pics of 'said' heads, I decided to make this thread. LATER I asked my friend to bring his set of heads out for a comparison. We compared and he was impressed by the PHASE1 2.5L DOHC heads. The difference was the INJECTOR TONGUE shape & intake manifold bolt pattern.

but oh well...whatever.... (yes it's hard to believe the person on the otherside of the internet)
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