BRONZE not brass

Ok ok.. so what about Bronze valve guides? Because of the work I do and because of a conversation I once had with Faye Butler.. I now question everything till its a tired, blue in the face, and tested subject. I have also been lucky enough to see how much the slightest differences can impact a certain products longevity and durability.

So I have been searching the internet for some time and thought to myself... Could people possibly be hurting their engines or effecting its longevity just by choosing the wrong guides? We all know that high RPM and heat destroys valve guides. Symptoms such as increased ovalness of the inside of the guide due to wear/tear, sticking, or guides cracking? Symptoms such as oil consumption due to the ovalness at higher RPM's because of the overall vacuum?

The question here is... Silicon, Phosphor, Manganese? This just might be a question for a career Metallurgist but its something my simple brain ponders from time to time. Pro's and Con's per our application?

I have seen companies that make them both for the same price range but can not see the reason for one or the other at this time.

Any educated input would be very helpful.

 

Do you mean bronze valve guides? What do you mean Silicon or Manganese? That's not really a question. What are you asking about them? As an alloying element or by themselves?

 

Yes Bronze. Silicon or Manganese is my question because of the elemental breakdown. Your actually the guy I think might have the best answer after reading a few of your right ups. I will be high revving alot with my new application.

 

Should we be using the Silicon or Manganese in your opinion? Or because of our applications does it not matter at all?

Through searching I see that JUN makes one in phosphor bronze

 

well if youre a metalugist (kick *** job by the way) you wanna look into the characteristics of the metals themselves and decide. maybe you have a cheat sheet or something. i know every time i mention replacing the valve guides to someone on here, someone else says "no dont waste your money" etc. personally in this shop i have them replaced with every valve job and head gasket repair. i just dont trust any other way. there are a few who will agree with replacing them but mostly not. i have never asked the machine shop what they are made of though. good luck on your question. please post up your conclusions if you dont mind so that i may know myself what is best for performance and what is best for durrability. also i believe the oil will affect the life of these parts too but thats gonna start a whole world of debate LOL

 

Anyone care to chime in on this?

 

so do they make bronze valve guides? i never asked the machine shop what a regular valve guide is made from. but yesterday i was in the steel warehouse and i seen the bronze melting point at like 1700 degrees F. it was actually bronze shot. everything is in there...copper bars, lead shot, billit aluminum, all kinds of steels and plate, lead sheeting, aluminum ingots, zinc ingots, aluminum bar stock-absolutely anything metal for manufacturing metal products. but i wonder if made my own bronze valve guides would they work and last longer?

 

yes, Ferrea makes bronze valve guides and they have a new guide made of copper alloy. i have the bronze guides in my head and after discussing them with the guy who built my engine, they're not really necessary. factory honda guides are made of aluminum (i think), and although bronze is a better conductor of heat, the aftermarket stuff just isn't manufactured as well as oem honda parts. also, since the head and the guides are made of the same material, they'll have the same expansion rates and you won't get into any possible failures. that's just my theoretical brain speaking.

overall, i think these are just products that companies make just so they can make money, and doesn't really add to the strength or durability of your engine.

 

you make a good point

 

I believe (correct me if I am wrong) that the OEM guides are cast iron. So that would throw out the whole expansion rate theory. Although you are correct by saying we should have something in the same ball park when it comes to expansion.

The idea of using a bronze valve guide is to help prevent galling to the stem of the valve as well as giving a better seal without making the valves sticky. Which can sometimes happen when we use some aftermarket valvetrains and high rev the living **** out of our motors. I have also read on a few forums that I have brought this topic to that there are still some of you that do not change your guides when rebuilding. In my book this is a big no no.

In my opinion you should ALWAYS expect to change your valve guides when rebuilding your cylinder heads. Your valve guides are consistently working at every RPM fighting the friction between the the guide itself and the stem. There is also what is known as side force on the stem due to something as simple as changing the geometry of the camshaft lobes.

When guides are worn you will no longer have a tight seal between the guide itself and the stem of the valve. This should be a topic looked into for those who have just done a rebuild of a higher mileage head and are experiencing mysterious oil loss. I am sure this can be a problem for both the intake and exhaust sides but I would say even more so with the intake side due to the massive engine vacuum.

I have been researching the different properties of these guides to put a finger on which guide specific (Intake & Exhaust) would be ideal for my All Motor build up. So the qualities I seek are as such.. Resistance to wear and scuffing, performance enhancement (If any at all), thermal conductivity and heat transfer, corrosion resistance, tensile strength, and of course the cost and workability of the different metal alloys.

This is still a topic in the works for me so if anyone has real hands on experience with the making of these guides and not just hearsay from their machinists it would be a real help if they were to chime in. Maybe your machinist could log on and give me some examples of the metal casting he has done in the past or what he or she has experienced with seeing these guides installed, removed, and after a few thousand miles of beating.

Also, I am in no way trying to recreate the wheel. I am just simply trying to put a tire on it.

I will post more findings as soon as I can do more tests and gather more information.

 

i agree with you 100 percent MVM. i asked my machinist for all the standard re-builds i do and they use iron guides for replacements...which is basically oem replacement parts. i have another machinist for performance build motors like 13:1 compression all motor honda builds who i will ask this question to about which valve guides he recommends. i ususally just tell him the specs and he just produces it for about 3500 bucks for just the motor.

i also agree that valve guides should be re-placed whenever the head is in the machine shop-even for a valve job with a head gasket replacement. in my shop every head gasket repair gets a valve job and new valve guides. this is non negotiable for customers in my shop. at 6 bucks per valve guide which includes the extra machine shop labor and the part its not a big deal on price but its a big deal in a quality repair. i dont even mark it up-which people accuse me of doing. but there are many on these forums that dis-agree. i'm sure you have read posts where people are doing head gasket repairs without doing any machine work-or at least having the head inspected by a machine shop. many people just think the standard straight edge is just a basic level or something similar thats laying around in their garage. but a machinists straight edge is calibrated to be accurate to a .00005-inch tolerance. i know many people dont have one this accurate. i onc did but i traded it to my machine shop for some work because almost every head needed machine work so i figured every head will go to the machine shop for a valve job (and new guides) with every head gasket repair.

i'll let you know what my peformance machine shop says on the guides that he recommends

 

I agree that the guides should be replaced with a proper valve job and that most guys on this forum don't do it. Or most machine shops for that matter. You can also have them knurled which will bring them back to proper dimensions and has the benefit of possible better oil retention.

I see tons of post on here regarding oil consumption where people think that throwing valve stem seals on a car that is consuming oil is going to cure the problem. Then when the seals get wiped out by a rocking valve they blame it on the quality of the seals, etc. In my experience most 'professional' machinist out there have no idea how an engine works they just know how to operate the machines.

PS: I love the "I'm not trying to reinvent the wheel I'm just trying to put a tire on it" quote. I'm gonna steal it. ;-)

 

Lets not forget another function that bronze valve guides can provide. Compared to a stock OEM cast iron valve guide bronze guides have superior heat transfer and dissipation. Most bronze guides are resistant to seizing and can handle tighter tolerances then the stock OEM cast guides can.

But still brings me to my big question.. which bronze is the bronze for my build? lmao I will post more findings soon enough.

PS: You can use that quote for anything it applies to.. haha

 

No, you don't want to knurl the guide, that's bad practice. Knurling just basically wrinkles the material to look like the surface of a Ruffles potato chip. The high ridges may be within spec, but the low ridges are still too loose. The high ridges are weak, and wear away quickly, dumping those metal particles into the engine and in no time, you're right back where you started, usually even worse.

A MUCH better option is to use a K-liner, which is basically a bronze sleeve. You ream out the old guide to get it round again, then fit the smaller sleeve in there (usually a press fit), and broach it to lock it in. Some people even hone it after that. I'm pretty sure they have sizes for Honda valves.

The OEMs have been using powdered metal guides for almost a decade now, and I'm pretty sure Honda is one of them. They're really tough to beat. They're hard, so they don't wear very much at all, but they're brittle as well. Ferrous metals are typically pretty abrasive too, so they tend to have a higher friction coefficient.

Silicon Bronze is basically the worst of the bronze guides. They were the first, and a lot of guys had problems. Then Phosphorous and Manganese Bronze guides came out, and are what you will find in 99% of aftermarket heads. Compared to iron/powdered metal, they have a lower friction coefficient so you can run the clearances much tighter, conduct heat a lot better so you can run tighter clearances, and they aren't as brittle, so if something bad happens they'll usually bend with the valve instead of explode into a bunch of pieces. However, they usually tend to wear quicker, so if you've worn out a set of powdered metal guides, you really want to fix the side-loading issue first. I guess with a OHC Honda head, you could use a longer valve or a hardened steel cap with a good press fit.

 

Using a simple Machinists Handbook I have gathered some useful information. Not everything I have gathered and certainly not as complete as it should be. But here are some examples.

*Phosphor Bronze Castings S.A.E. No 64
This alloy is excellent when anti-friction qualities are important and where resistance to wear and scuffing are desired.
-Commonly used for wrist pins, piston pins, valve cover rocker arm bushings, fuel and water pump bushings, steering knuckle bushings, aircraft control bushings.
-Tensile strength of --?-- lbs per square inch.

*Manganese Bronze Castings S.A.E. Standard No 43
This alloy is intended for castings requiring strength and toughness.
-Commonly used for such automotive parts as gear shifter forks, counters, spiders, brackets and similar fittings, parts for starting motors, landing gear and tail skid castings for airplanes.
-Tensile strength of 65,000 lbs per square inch.

*Hard Bronze Castings S.A.E. Standard No 62
This is a strong utility bronze suitable for severe working conditions and heavy pressures.
-Typical applications include gears, bearings, bushings for severe service, valve guides, valve tappet guides, camshaft bearings, fuel pumps, timer and distributor parts, connecting rod bushings, piston pins, rocker lever, steering sector and hinge, bushings, starting motor parts.
-Tensile strength of 30,000 lbs per square inch.

*Cast Aluminum Bronze No 68 (My personal favorite at this point)
This bronze is known for its strength, corrosion resistance, equal hardness to Manganese bronze, good bearing qualities.
-Commonly used for worm wheels, gears, valve guides, valve seats, and forgings.
-Tensile strength will depend on the grade.

Another reference site with useful knowledge... http://www.anchorbronze.com/newpdts7.htm

I would also like to create or find a pictorial display of each alloys surface texture. Sometimes its what we do not see that makes a difference. My goal is to find the best alloy for our application.

 

Found this picture on the internet in a random google search.

For those whom keep PM'ing me... This is a prime example of what is known as galling. Please note the marks across the stem of the valve. See how it started to pit the metal as well? This is a mild case compared to what I have seen in the past. As a matter of fact after reading more about this on (http://www.thecj2apage.com/forums/en...opic12175.html), I read that this valve was only used for 300 miles before it was removed. OUCH !!

 

I disagree with that statement. Knurled valve guides can last very long in service. Whether or not they are ideal for a performance build is debatable but for stock applications they are more than adequate. K liners are usually knurled into place and are a good repair. I think a solid valve guide made of the proper material for the valve being used is best for performance though.

 

mvm - i think it's cool that you're devoting a lot of time and effort to try to improve something, but what makes you think it needs or is worth improving? what potential gains are you hoping for?

if this was a response to my comment on what my engine builder told me, let me respond by saying this isn't just some guy who machines **** and never sees it again. he builds honda engines EVERY damn day for a living for high hp cars, and sees results 1st hand when he rips a motor back apart. he works at a shop which has been in business for 12 years, most of their business of which is dynoing and building. the reason i say all that is not to instigate a dispute, but just to inform you that the info i get from him is solid with years of REAL experience.

i just think you're putting too much effort into this topic, and i've never been the type to discourage.

 

i think hes putting in the time and effort for this topic because he's a metallurgist which means he studies the different characteristics of metals if you didnt know. so in short hes a doctor of metals still in a life long practice. personally i agree with putting the time in something that a person is really into and metallurgy may be over some of our heads and i only have a real basic crash course of it from my structural engineering and welding days but its a profession i respect, but if it helps us members think a bit more about valve guides then its good. i dont think his post you quoted was to you or your machinist personally though. i'm all for replacing valve guides with every valve job though and my customers and i sleep better knowing its done right and wont have any issues causing any questions about the valve guides

 

mvm - have you searched the Society of Automotive Engineers website (sae.org) for technical papers on valve guides?

 

Actually, I am a Millwright/Mechanic/Machinist for a well known company that produces aluminum soda cans that are distributed world wide. I work hands on with many fellow machinists, metallurgist, and mechanics on a daily basis. You probably drink from the cans I make every day and never thought about it till right at this moment. I work within the tightest of all tolerances where as if I am a millionth off it would most certainly mean disaster to the industry. These cans have to be structurally strong, extremely thin, display specific elongation properties, and tight tensile strength. I completely understand how important the slightest change in the metal composition can affect the life of my product. Hell, I make 5 million cans a day and they all pass vigorous and unbiased testing.

Either way metal structure and composition is a huge part of my work and I am lucky enough to be a car enthusiast at the same time. This allows me to combine the 10 plus years of my own experience working with Honda in particular and my daily grind. haha I have also had my fair share of years working in automotive machine shops and performance shops in my area.

The previous posts and comments were not directed or intended to offend you in anyway. You are not the only one who has given me the answer of "my machinist says this, my machinist says that". What I am trying to find out is if your machinist is on the correct path.

Maybe its just a natural instinct to question everything.. To see things with my own two eyes and actually understand how things are made and why they function like they do.

The way I see and can describe it is like this..... Consider your engines combustion chamber like you would your very own heart. We would all like to think that we all have the best health and our hearts pumping healthily but the reality is that most of us are WRONG. In fact most of us never pay attention to our hearts until it is far to late.. Just like the time some of us would have rebuild our engines. So at this point and time of a rebuild do you still go with what others tell you to do? Or do you search for the best doctors, procedures, surgeons, & rehab. The answer should always be that you want the best possible so that you can live the fullest and happiest life you can.

On that note.. How important is it that the valves of your heart are healthy?

You asked if I thought "If it needs or is worth improving? what potential gains are you hoping for? ". Well in just a few posts here we have already had a very broad view on how this one crucial part can be easily disregarded. We have also seen and heard of the many affects of what not replacing them or properly sizing them can do. Maybe something this crucial should be thought of with more then a grain of salt. Obvious gains have been made with bronze guides on certain applications. More so with leaded gasoline then unleaded.

My goal is to simply question everything and answer a question that nobody else can answer for me at this time. My goal is to simply find out which alloy in the end was better for me to use on my build. So far we are seeing that the industry has dropped certain materials over the years trying to find these improvements and what are the reason for dropping certain materials. Like we have read in posts earlier, companies have shunned from using the silicon and phosphorus.. So why now should I not question if manganese is the right choice or maybe if I would be better off using a aluminum bronze casting instead.

You are only limited to how far you are willing to go and question. I am sure you have all heard that knowledge is power.

 

Excellent, I will do so right now. Thanks

 

no MVM i didnt think any of your posts were for me LOL i was trying to explain to the member in the post above mine why you were going to the length you are in search of your answer LOL i still agree with you...with exception to my bad heart and health LOL in that sense i smoke, drink occasionally, eat lots of fast food with tons of unhealthy ingredients, hate that i cant get super size from mcdonalds anymore and have to settle for "large", drive way to fast sometimes, and chase heart pounding horse power in my mustang 5.0 with my little 200 shot of nitrous LOL. when i die its game over but the end of a great life i'm one of those guys that has no regrets in the way i live my life like tomorrow isnt gonna come for me. but i still agree with you in your quest for the best valve guides for your build

 

Haha.. Sorry wasnt meant for you. But I am grateful for the support!!

 

thats cool.