as the title says, what does that mean and what would they do? how many "angles" are there?

 

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Noah ***** &raquo;</TD></TR><TR><TD CLASS="quote"> </TD></TR></TABLE>


i guess that means he doesnt know, try to answer his question instead of flame.

 

I can't remember the 'exacts' about it but you can have upto a 5 angle valve job if you want. Someone correct me if I'm wrong.

Anyway, the more angles (I think) has to do with the actual flow and sealing of the valve itself. I believe you can't just do a 3 or 5 angle valve job without some other head work. I don't think that it will help.

Correct me if I'm wrong, I have a book about but I can't find it..

 

i always wanted to know this too

 

In a 3 angle valve job there is a 30 to 35 degree top cut, a 45 degree seat angle that also matches the angle on the valve, this is the angle the valve job seals up on, the you have a 58 to 62 degree bottom cut. sometimes they put a throught cut that would be a 70 degree angle and put a 35 degree backcut on the back of the valve and you have 5 angles. I hope I explained it well enough

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HEAD &raquo;</TD></TR><TR><TD CLASS="quote">In a 3 angle valve job there is a 30 to 35 degree top cut, a 45 degree seat angle that also matches the angle on the valve, this is the angle the valve job seals up on, the you have a 58 to 62 degree bottom cut. sometimes they put a throught cut that would be a 70 degree angle and put a 35 degree backcut on the back of the valve and you have 5 angles. I hope I explained it well enough</TD></TR></TABLE>


what???

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HEAD &raquo;</TD></TR><TR><TD CLASS="quote">In a 3 angle valve job there is a 30 to 35 degree top cut, a 45 degree seat angle that also matches the angle on the valve, this is the angle the valve job seals up on, the you have a 58 to 62 degree bottom cut. sometimes they put a throught cut that would be a 70 degree angle and put a 35 degree backcut on the back of the valve and you have 5 angles. I hope I explained it well enough</TD></TR></TABLE>

I think you explained it too well. Any way you can dumb it down for us who don't know every single aspect of an engine?

Chris

 

were are you confused I will try to clear it up-sorry guys!

 

I kind of understood it.

 

A picture is worth a thousand words...

From the Helms.



--
Tom

 

that is a really good pic so you can see what I am talking about a little easier, when I tried to explain it before I gave the ranges that some head porters use for the different cuts to get the desired airflow effects, some cylinder heads just like different angles. the one shown is a preety common factory valve job.

 

but why is there more than one angle... when the valve closes shouldnt it only touch on one of those faces? how can it make contact in more than one place?

 

The valve has 3 angle cut, and 3 angle cut provides better airflow, by smoothing the direction teh air takes

a 5 angle cut provides even better flow thorugh teh smoother transition of air though the valve port as the vlave is less of a restriction

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JonnyCoupe &raquo;</TD></TR><TR><TD CLASS="quote">The valve has 3 angle cut, and 3 angle cut provides better airflow, by smoothing the direction teh air takes

a 5 angle cut provides even better flow thorugh teh smoother transition of air though the valve port as the vlave is less of a restriction</TD></TR></TABLE>

also if you have a 3 or 5 angle cut on the valve you will also have to have a 3or 5 angle cut on the valve seal in order for it to seal right. When the valve enters its closed position it doesn't just touch one surface, it touches all 3 or 5(depending on how many angles are cut) to make for a better seal.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Redlineracer &raquo;</TD></TR><TR><TD CLASS="quote">

also if you have a 3 or 5 angle cut on the valve you will also have to have a 3or 5 angle cut on the valve seal in order for it to seal right. When the valve enters its closed position it doesn't just touch one surface, it touches all 3 or 5(depending on how many angles are cut) to make for a better seal. </TD></TR></TABLE>

you don't need to put 5 angles on a valve and the backcut on the valve wouldn't be the same as the valve job angles except for the top cut(30) the 45 seat angle is the angle in which the valve seals on.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by real9999 &raquo;</TD></TR><TR><TD CLASS="quote">A picture is worth a thousand words...

From the Helms.



--
Tom</TD></TR></TABLE>

This is the best way to explain 3 angle cut.. the top and bottom radius cut are designed for air flow purpose. the mid cut is what so the sealing. all Honda's expect for some of the k20 engines have a 3 angle valve seat cut the RSX has a four angle cut for a better the air flow. When a head shop talks about valve angle they are talking about the radius cut on the seats. The reason most head shop do 5 angle cut is for better flow. Now, when they preform a valve back cut this is done to import high rpm flow; for, for the valve stays open a smaller mount of time compare at lower rpm.

a valve cut is a 30 degree cut made after the 45 degree cut on the valve..

the 30 degree cut widen the gap between the valve and the seat for an import air flow. a 3 angle on a b-series head are 30, 45, and 60. the valve it self has a 45 degree - well after the 45 degree on valve - I believe it 40? just a guess i really never check but I'll use it as an example. throat cut is 60 if the angle after the 45 is 42 or 40 if we cut it to a 30 degree - we just opened up the gap.

i hope this was some help

 

I got a radial valve job on a B16 head. No angles. Suposedly helps the air roll past the seat.

 

head, thanks for the correction

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HONDADNA &raquo;</TD></TR><TR><TD CLASS="quote">

This is the best way to explain 3 angle cut.. the top and bottom radius cut are designed for air flow purpose. the mid cut is what so the sealing. all Honda's expect for some of the k20 engines have a 3 angle valve seat cut the RSX has a four angle cut for a better the air flow. When a head shop talks about valve angle they are talking about the radius cut on the seats.The reason most head shop do 5 angle cut is for better flow. Now, when they preform a valve back cut this is done to import high rpm flow; for, for the valve stays open a smaller mount of time compare at lower rpm.

a valve cut is a 30 degree cut made after the 45 degree cut on the valve..

the 30 degree cut widen the gap between the valve and the seat for an import air flow. a 3 angle on a b-series head are 30, 45, and 60. the valve it self has a 45 degree - well after the 45 degree on valve - I believe it 40? just a guess i really never check but I'll use it as an example. throat cut is 60 if the angle after the 45 is 42 or 40 if we cut it to a 30 degree - we just opened up the gap.

i hope this was some help</TD></TR></TABLE>


Radius cuts on valve seats really dont have an angle anymore.What this does is makes the seat more round kinda like the way a velocity stack is.There will be one cut angle for the valve to seat and seal on and thats usually the 45 degree cut,the 30 and 60 degree cuts would actually disappear and actually be blended in with the combustion chamber,ports and the 45 degree cut.

 

Posts likes this always separate the respectful enthusiasts from the ricers.

 

A five angle valve job is really not worth the extra money because it get knocked down to three angles the first time the motor is started. so i would just stick with the three angel.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 01accordv6 &raquo;</TD></TR><TR><TD CLASS="quote">A five angle valve job is really not worth the extra money because it get knocked down to three angles the first time the motor is started. so i would just stick with the three angel.</TD></TR></TABLE>

I really dont see how a 5 angle valve job will be broken down when the car is started up as long as it is done right.Having a five angle job done to the seats is almost the same concept of making the seats radiused instaed of having the sharp angles,if you think about it,the more angles on the valve seat,the more rounder it would almost be....like a velocity stack.

 

radius style valve cut is bad for long term durability. over time the valve will bed itself into the seats or you'll get leakage.

not worth it for a long term motor.

 

If you guys really want a detailed explanation of this stuff, you should pick up a copy of the "Honda Builders Handbook." It explains all of this in great detail. Well worth the $24.