OK so I am building up my b16a for a new turbo setup and I picked up an extra b16a head for dirt cheap today and I was wondering a few things. I already bought Rev Springs, Rev Retainers, Ferrera Valves, GSR Cams, and GSR Cam Gears. Should I go with a 3 or 5 degree angle job. Only problem is that I am not sure what changing the angle really does or how it benefits me in any way? What is the angle set at stock? If you are needing a quick low down on what I am shooting for it is 450whp and reving anywhere from 9000-9800 depending on where the turbo stops making power.....Any help would be appreciated.

 

 

It's not a 3 degree or 5 degree angle valve job. It's a 3 angle or 5 angle valve job. This references how smooth of a surface the air will have to flow over immediately before entering the combustion chamber. Naturally it has to be machined flat for proper a proper seal so it's machined in various angles. The 3 angle valve job gives you three separate machined angles so that the air can smoothly flow with less resistance. The 5 angle valve job is the same thing but with less resistance due to the fact that there are five machined angles, making it smoother.

Imagine a skateboard trying to roll from the ground onto a wall. If you have a ramp with only one angle at 45 degrees then it's possible to roll up onto the wall, but would be very hard. If the ramp had three separate angles at maybe 23, 45, and 67 degrees, then it would be easier, and if the ramp had five angles at 15, 30, 45, 60, and 75 degrees, then you would have a nice, even rolling surface to roll up onto the wall.

Very simple concept of airflow and interference, but kind of hard to explain.

If you only plan on shooting for 350 to 400 horses, then a good 3 angle job should be fine.

 

The stock angles on Honda heads work real well with stock ports.With out acsess to a flow bench,most changes hurt flow.More angles don't always help.I had good results on one port with many angles,tried it on a similar port and hurt flow badly.Some people call the stock vale job five angle(30,45,60 on head and 45,35 backcut on valve),and cheap valve job a three angle(45,30 on head and 45 on valve).Ask who ever does the work his definition.
Glenn

 

I am not porting/polishing the head just leaving the valve sizes the same....so should I just run stock and save the money?

 

dc231 is correct it is about the number of angles put on the seat the more the less turbulent the transfer of air from the port to the chamber.I don't know why people refer to a valve job w/3 seat angles and a backcut valve to be a 5 angle valve job,it is no more so than a your 5sp being called a 6sp because it has a rev gear,I have no idea where it started but probably because it's **** to tell people you have a 5 angle valve job.Unless you go w/bigger valves it's hard to get more than 3 angles on the seat.Turbo motors usually respond to bigger valves really well,so I would recommend them for getting the most from your application.

 

A good 3 angle valve job is sufficient but you will get better flow with a five angle you all are right but using to many backcuts on a valve is a little overkill one is enuf on exh two is ideal for intake. Really deciding the other two cuts on the seat is more than just sayin30 32 45 52 60. other dude is on the right track use a flow bench but how many seats can you go thru getting it right. what im trying to say is you have to know exactly your bore size deck height your head cc's what gas youll run all of this is compiled into an equasion to get you your other 2 angles or evn changing all 5, and to othr dude its not hard to fit five angles unless you have bigger valves ive seen 7 u cant do this with stones, you need to find some one with a sekuri machine. i.e. dan paramore @ dprracing.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mysi92 &raquo;</TD></TR><TR><TD CLASS="quote">A good 3 angle valve job is sufficient but you will get better flow with a five angle you all are right but using to many backcuts on a valve is a little overkill one is enuf on exh two is ideal for intake. Really deciding the other two cuts on the seat is more than just sayin30 32 45 52 60. other dude is on the right track use a flow bench but how many seats can you go thru getting it right. what im trying to say is you have to know exactly your bore size deck height your head cc's what gas youll run all of this is compiled into an equasion to get you your other 2 angles or evn changing all 5, and to othr dude its not hard to fit five angles unless you have bigger valves ive seen 7 u cant do this with stones, you need to find some one with a sekuri machine. i.e. dan paramore @ dprracing.com </TD></TR></TABLE>
you don't want a backcut on a tuliped exhaust valve- it will cause the air to stick to the stem of the valve, not ideal. Your bore size, deck height, and any equation is not going to help in figuring out valve angles, when we look for angles we are looking for what the head likes- as in flow, and what RPM the motor is going to be ran at, which is also dictated by the cams, and if it's a NOS, turbo, or a NA application. Just so you know the machine you are talking about is called a Serdi seat and guide machine. If Jesus Christ himself were to come down and use this machine, even in all his mighty-ness and miricle happening ways could he make 7 angles go on a stock sized seat unless it wasn't ment to actually run on a motor, or maybe that's were the miracle would happen

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HEAD &raquo;</TD></TR><TR><TD CLASS="quote"> Your bore size, deck height, and any equation is not going to help in figuring out valve angles, when we look for angles we are looking for what the head likes- as in flow, and what RPM the motor is going to be ran at, which is also dictated by the cams, and if it's a NOS, turbo, or a NA application. Just so you know the machine you are talking about is called a Serdi seat and guide machine. If Jesus Christ himself were to come down and use this machine, even in all his mighty-ness and miricle happening ways could he make 7 angles go on a stock sized seat unless it wasn't ment to actually run on a motor, or maybe that's were the miracle would happen </TD></TR></TABLE>Thank you for some sanity Dave.<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mysi92 &raquo;</TD></TR><TR><TD CLASS="quote"> and to othr dude its not hard to fit five angles unless you have bigger valves ive seen 7 u cant do this with stones, you need to find some one with a sekuri machine. i.e. dan paramore @ dprracing.com </TD></TR></TABLE>Hey this is the other dude,and I don't need DPR to do my valve jobs.I have a Sunnen SGM 1500 and not stones,and am VERY capable of doing just as many angles as DPR,don't worry.As for getting 7 angles on a stock valve and seat honda,can I ask how wide each angle was...like maybe 25 thous??More angles only work when the sizing of the angles is perfect and not the amount of them.