Ok I know they say the biggest you should go on stock heads are the 2.00 and 1.56 sized valves. I was just wondering.....with the stock size being 1.94 and 1.50, what kinda gains would you actually get from going up so little and why.

thanks

 

anybody?????

 

Depends. If you can get the same flow numbers with good valve pocket work, you'd probably be better off with stockers because the smaller valves should provide more cylinder packing velocity.JMHO

I went with the larger valves just because I wasn't convinced of the ability of the porter to get the max out of my stockers.JMHO

 

I would like to know as well, I'm just satisfied with the answer "it's better than stock"

 

Okay good then...because I did my own P&P work (49 hours ). And I definately aint a good porter, so I'm sure I didn't get the max outta it.

John you meathead... You talked me into getting those 200 bucks worth of valves for nothing!! Nah just kidding man. I figure ...doing the whole port and plish thing why stop there. I wish Phil or Lloyds server was working so they could give us the deal. I do remember reading something from Phil about 2.00 and 1.56 is the biggest he would recommend for stock heads. Just wondering why.

 

Something about the larger valves and how they sit on the seat...... I'll let one of them explain it, I just buy what I'm told!!

 

Larger valves will flow more only if your motor needs it, If you have minor mods (stock heads, medium cam) you don't need them, With a big cam or larger cubic inches, they will help. Larger valves in a mild motor will hurt your torque, and torque is what a street car needs.


Brian

 

I'm going w/ a 383, ported heads, larger cam etc., I think I would benefit from the larger valves?

If ya do a search it's been explained, somthing about the valve sitting on the seat on the back of the face and not on the seat where it should be...

My question:

Ferrea 6000 vs. Manley Race Flos vs. SI Valves

???

 

I went with Manley's.

 

A reputable porter told me that with bigger valves the heads could possible flow as much as 10CFM more.

I decided it wasn't worth the extra to do it. I couldn't find proof either way.

 

It depends entirely on the app IMO... however effective valve area/curtain area is a nice thing .

For some it wont matter & for some itll make all the difference. Killer valvejobs are where it's at.

SI stuff I've seen in the past has looked more like stock replacement stuff than anything else. The manley's I don't use if I don't have to as I've had quality issues with them in the past. For my $, I'll just keep buying Ferrea stuff when I can. Rev is a decent valve too for the $, but I'd still stick with Ferrea.

 

With the bigger valves you will pick up more at the top end.