ok so i've been reading dilligently through the archives about vlave guides and weather or not to replace them and weather or not to replace them with OEM or bronze. I'm getting ready to pull the head in January for a p&p along with a 3 angle valve job to go with the new valves. the only problem is that for every post i see that says OEM i find a post that says use Bronze so what gives? Any one have any solid info on the wearing characturistics of both? this will be my daily driver but i figured while the head is off i might as well go ahead and replace whatever is in there. Any thoughts?




Modified by B16b-EJ8 at 9:10 AM 12/8/2006

 

No one has any input

 

I've also been reading up on this....

My interpretation is that Bronze will allow for tighter tolerances and sheds heat better, but they wear faster. They're generally good for track cars or for someone that doesn't mind pulling their head more often to replace them.

OEM are harder, don't shed heat well, but last longer...

:shrugs:

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C_EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">I've also been reading up on this....

My interpretation is that Bronze will allow for tighter tolerances and sheds heat better, but they wear faster. They're generally good for track cars or for someone that doesn't mind pulling their head more often to replace them.

OEM are harder, don't shed heat well, but last longer...

:shrugs:

</TD></TR></TABLE>

Yeah thats pretty much the general idea i have gotten. My feelings on it are what a pain in the *** to pull them or even the head for that matter so i may opt for OEM.

But i would really like to hear more perhaps form someone with experience with both on street and or track motors.

 

How do you know that the close grain beryllium impregnated Honda OEM guide doesn't shed heat well?

Maybe it's well accepted rule that grey colored metal doesn't conduct heat as well as gold colored metal. That must be it.

 

I have no idea... As I stated previously, I was only stating what I had read....

 

Very cool, then.

There are some advantages to a good bronze guide over an OE guide. One of them being cost. Ask your pro cyl. head expert about the other benefits of bronze guides. One question would be. Bronze guides are less likely to _________ than OE guides. If you get a good answer your head guy has some good insight.

 

or if you ever happen to drop a valve on OEM guides you can kiss your head and motor goodbye!!

the broze guides are softer so when a valve drops its going to dampen the blow a bit.. as to the regular guide shattering destroying your head and cyl. wall

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Bronze guides are less likely to _________ than OE guides</TD></TR></TABLE>

Seize?

 

manikGSR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by manikGSR. &raquo;</TD></TR><TR><TD CLASS="quote">or if you ever happen to drop a valve on OEM guides you can kiss your head and motor goodbye!!

the broze guides are softer so when a valve drops its going to dampen the blow a bit.. as to the regular guide shattering destroying your head and cyl. wall</TD></TR></TABLE>

Not sure how this works...maybe im missing something but when you drop a valve it comes loose from the retainer correct?...then falls through the valve guide....and Blamo motor is all messed up. So how does a bronze valve guide prevent that? and how does the guide mess up the walls wouldnt it be the valve itself? or am i just totally off

 

depending on which alloy of bronze they have different properties, and also the coefficient of friction between the sliding parts are two main concerns...glass like surfaces can last forever...and driving habits as well...hehe

 

The valves i will be using have a nitride coating on them to reduce friction. What im really interested in knowing is for a daily driven car would OEM be reccomended oer Bronze?

 

well oem guides i believe use a cast iron of some sort so the nitride will help but iron wont dissipate heat like bronze so if u keep heat out friction and wear will be down as well...theyre all related

(non ferrous alloys dissipate heat much better than ferrous but are not stronger)

 

So really you can only have one or the other...assuming that bronze wont last as long but disipate heat better...where as OEM does not disipate heat but will last longer. However with my valves having a nitride coating it will reduce friction thus reducing heat correct? How important is it to disipate the heat from the valves and valve guides? what would be the negative outcome from this since im sure not everyone uses bronze valve guides in their builds.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B16b-EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">Not sure how this works...maybe im missing something but when you drop a valve it comes loose from the retainer correct?...then falls through the valve guide....and Blamo motor is all messed up. So how does a bronze valve guide prevent that? and how does the guide mess up the walls wouldnt it be the valve itself? or am i just totally off</TD></TR></TABLE>a bronze guide prevents more damage by locking the valve into the guide most times when it hits a piston/bends and keeps it from dropping into the cyl and bouncing around in there.I have seen many heads that have come off of race motors that had this and it just takes new guides and a valve job usually to repair

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fkned &raquo;</TD></TR><TR><TD CLASS="quote">a bronze guide prevents more damage by locking the valve into the guide most times when it hits a piston/bends and keeps it from dropping into the cyl and bouncing around in there.I have seen many heads that have come off of race motors that had this and it just takes new guides and a valve job usually to repair </TD></TR></TABLE>

Interesting...so if the valve guide holds the valve in wouldnt that create mass friction and heat since the valve is experiencing resistance from the guide by holding it in place?

 

no,what I said was when the valve bends from whatever the cause then it will have a much higher chance of becoming caught in the guide and not dropping into the cyl and doing more damage.
The benefits of having broze guides far out weigh the cost of replacing the stock set.You can run tighter guide clearences-which lead to the possiblites of longer lasting valve jobs as well as better flowing thinner seats.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Fkned &raquo;</TD></TR><TR><TD CLASS="quote">no,what I said was when the valve bends from whatever the cause then it will have a much higher chance of becoming caught in the guide and not dropping into the cyl and doing more damage.
The benefits of having broze guides far out weigh the cost of replacing the stock set.You can run tighter guide clearences-which lead to the possiblites of longer lasting valve jobs as well as better flowing thinner seats.</TD></TR></TABLE>

So what about longevity of the the bronze valve guides on a daily driver? Are we talking 6 months 1year 2years 3? Is there any guestimated time frame?

 

I found these supposedly they are good also.

http://www.nipponpower.com/product.phtml?p=904

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lude98SH &raquo;</TD></TR><TR><TD CLASS="quote">I found these supposedly they are good also.

http://www.nipponpower.com/product.phtml?p=904
</TD></TR></TABLE>

Huh...they dont mention them being used for NA I wonder why that is? So now we have OEM, bonze, and Copper alloy. So which is gooing to be best for a dd.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B16b-EJ8 &raquo;</TD></TR><TR><TD CLASS="quote">

Huh...they dont mention them being used for NA I wonder why that is? So now we have OEM, bonze, and Copper alloy. So which is gooing to be best for a dd.</TD></TR></TABLE>

i dont know much but it seems like whenever this question is asked the answer is almost always OEM

 

imo it comes down to this.
If your running stock cams and dont plan on beating the **** out of it and dont want the best valve job around then stay with stock.Hell you probably dont even have to replace the ones you already have.
But:
If you plan on having a high lift cam or you will be beating the **** out of it or want a very good valve job then most likely your going to need bronze guides.

Bronze guides allow tighter fits and better lubricity to help control the valve better at high lift or high rpm situations,along with better heat dissapation(usually)and stronger material(less brittle).

Ok so what does this mean?

Well the stronger material means that as said in other posts that when the valve gets bent it will usually wedge itselt into the guide and not drop into the cyl and do more damage.Also broken guide tops wont fall into the motor either.

Tighter fits mean better valve control and valve job seals,and longer valve job life,as per required use.

Better lubricity means if the valve happens to rub the guide wall from either lack of oil or deflection,it will ride the wall better and have a much less chance of galling or sticking.

Now having said that I cannot answer the question about if the stock guides will last longer in the same use as bronze.Factory guides usually have to large guide to stem clearence to begin with for my preference,so I replace them with bronze liners or guides to get what I like to have.

 

besides longevity etc..

i use magnease bronze guides..

not silicon..

research it a little..

 

Most bronze has small amounts of silicon. The silicon is a hardening agent in bronze (analogous to carbon's function in steel.) The silicon adds stress to the atomic lattice structure thus making the bronze alloy harder.