PDA

View Full Version : Oversized valves ?


Sick0
10-22-2002, 06:24 PM
How good are oversized valves and what are the benifits of having them done. Plus would they work with a stage two hot cam and head work?
jaspurx
10-22-2002, 07:25 PM
i would ask four stroke tech , mickey dunlap would have a real answer with no guessing or maybe`s. that is where i get the info to bank on!!
ridered86
10-22-2002, 07:31 PM
WHEN YOU GET OVER SIZED VALVES TRHEY INCREASE THE PORTS THUS ALLOWING MORE UNRESTRICTED FLOW...I THINK:o
oynot400
10-22-2002, 07:41 PM
Oversized valve will increase air/fuel flow resulting in more power. :D
Not sure what it would cost to get done. I am sure that it will not be cheap, but I am sure it will be worth it. I will know later this winter! :devil
danney f
10-22-2002, 10:01 PM
About $400 from Curtis Sparks
YZROOSTINYA
10-23-2002, 04:35 AM
you only need it on a 416 or higher with a high com piston, otherwise you really wont reap the benifts of larger valves. a stage 2 cam is a good choice with a large valve setup
OCCRA288
10-23-2002, 07:34 AM
Big valves kill torque.
danney f
10-23-2002, 09:56 AM
That is one reason (loss in torque) that if you get a enlarged valve job to go with the higher compression piston, bottom end cam and maybe change the sprokets to get the torque back. And YZROOSTINYA is right, unless it has a bigger bore on the 400ex you don't need larger valves. Now as for the 300ex that is a totally differant "?".
Sick0
10-23-2002, 03:26 PM
Well I plan on going to a hight compression piston and a 416. And maybe a 39fcr carb. I don't know. Any place I could get real good info.
ChadEXer
10-24-2002, 12:41 PM
Well i have a 505 and TC stresses that larger valves or new springs are not needed!!
330exracer122
10-24-2002, 01:22 PM
an thats y ur motor went to ****
ChadEXer
10-24-2002, 01:36 PM
My motor didnt go anywhere:rolleyes: I blew a head gasket because I had the thing not even feeding enough gas for a riding lawn mower!!
330exracer122
10-24-2002, 01:40 PM
lol