on your standard angle its 30/45/60*
what angle on multi angle valve jobs?
what angles are they cutting your seats to?
Im sure the angles get sharper as the go into the head but what degree do they start at and what degree to they end at?
Just wondering
thanks
Im sure the angles get sharper as the go into the head but what degree do they start at and what degree to they end at?
Just wondering
thanks
1 - 7 of 7 Posts
so the angle of the valve is 30* and it gets consitently sharper with every cut?
What is the reasoning behind the 5 angle jobs. Do the not get as sharp as fast or do they get sharper?
Thanks
What is the reasoning behind the 5 angle jobs. Do the not get as sharp as fast or do they get sharper?
Thanks
Its all about contouring the seat so it flows better, especially at the lower lift #'s.
When the valve is wide open the angles dont really do much, but when the valve is barely off the seat and starts to flow, certain angles will help to get a head start on filling the cylinder.
There are 3, 4, and 5 angle valve jobs. 5 is tough because theres not enough alot of room to cut that many angles in. 3 is standard, and Id say 4 is probably the the most common on a performance valve job on these heads.
See the more angles you cut into the seat, the smaller and smaller sealing angle you are able to cut and have. The smaller the sealing angle the better the flow but you get into a situation that the sealing portion of the seat wears out faster due to less contact area. Also, the less contact area means less heat can be absorbed through the seat, one of its important jobs...
Theres probably a good diagram somewhere floating around the web that would illistrate the angle and give you a good visual on what we're saying.
good question though.....
When the valve is wide open the angles dont really do much, but when the valve is barely off the seat and starts to flow, certain angles will help to get a head start on filling the cylinder.
There are 3, 4, and 5 angle valve jobs. 5 is tough because theres not enough alot of room to cut that many angles in. 3 is standard, and Id say 4 is probably the the most common on a performance valve job on these heads.
See the more angles you cut into the seat, the smaller and smaller sealing angle you are able to cut and have. The smaller the sealing angle the better the flow but you get into a situation that the sealing portion of the seat wears out faster due to less contact area. Also, the less contact area means less heat can be absorbed through the seat, one of its important jobs...
Theres probably a good diagram somewhere floating around the web that would illistrate the angle and give you a good visual on what we're saying.
good question though.....
so the angle of the valve is 30* and it gets consitently sharper with every cut?
What is the reasoning behind the 5 angle jobs. Do the not get as sharp as fast or do they get sharper?
Thanks[/b]
your standard valve angle is 45* there are three on the seat, and the 45* angle on the seat is the one your 45* angle valve touches! its not sharp or gets sharper, its flat to flat. does that make sense? you normaly will always have a 45* valve, the 5 angle just puts 2 angles on each side of the 45* valve seat and is supposed to give it better flow at lower lifts.
thanks for the great info guys
for clearity 2 angles are basically cut in combustion chamber then the actually seat then 2 more in the head?
Im on the hunt for some cross sections now
thanks
for clearity 2 angles are basically cut in combustion chamber then the actually seat then 2 more in the head?
Im on the hunt for some cross sections now
thanks
yes basically, but they are all cut on the seat itself! no problem helping you out eitherthanks for the great info guys
for clearity 2 angles are basically cut in combustion chamber then the actually seat then 2 more in the head?
Im on the hunt for some cross sections now
thanks[/b]
1 - 7 of 7 Posts
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