HBN lubricant, and methods for installing valve seats and guides

[modok]

Being a VW enthusiast, and auto-machinist, I've tried to collect and learn whatever I can about different methods for cylinder head repair, when I have the opportunity.
It never hurts to ask, and I think you can always find better and easier ways to do things. (opposed to....."I've been doing this for 20 years so and it works so it must be fine")

As with sealants, and oil, guys can get downright RELIGIOUS about the procedure they use and secret sauce they apply.
The secret sauce in some cases is.......nothing, and nothing does work fine, but on the other hand a lubricant could certainly help.
Lubricants commonly used, to lube valve seats for driving them in.
-nothing
-Engine oil
-locktite sleeve retainer
-"seal-lock fluid weld" (a water based ceramic stuff of secret ingredients)
-bearing assembly lube
-anti-seize (such as never-seize brand, or permatex silver grade)
-moly lube (arp lube)
-sunnen b200L press fit lube
http://speedtalk.com/forum/viewtopic.php?f=1&t=46410

In many apps, it is not necessary to heat the head to install seats, but IMO, it IS necessary to heat the head to 250-300 degrees F for aircooled aluminum heads to KNOW they have adequate press fit when the heads are hot. Freezing the seats with liquid nitrogen is said to work, but I don't have any of that. freezing with CO2 is good too, but alone it won't be a replacement for heating the head, especially with some higher nickel alloys.
With the head heated past 250F.......many of the above list won't work very well, or just become smoke instantly.
I've tried some different oils and the b200, and a few other things not worth mentioning, and didn't find them superior to nothing.
I do find ARP(moly) lube seems to work for me. Moly lube usually does seem to work well if one part is steel, but I didn't find it to work well on bronze guides.
One day I decided to look up the heat transference properties of ARP lube, graphite, ect, to see if one was better than another.............and what I found was .....there is a stuff called -hexagonal boron nitride-, which is a LOT like moly and graphite, but is white, and has 2-3x better heat transfer. It's sometimes called white moly. It is used in heat sink grease like between your computer chip and heat sink, it is used in some chain lubes because it looks less messy than moly. It is used in a LOT of things actually. It is most likely the majority ingredient in "fluid weld" compound from the list above. So, I decide, I'll find a high temp oil based HBN lube and try it on stuff.
So, I bought some Permatex #24125 ceramic brake parts lube
It is purple, and expensive, and nobody is really sure what to do with it. LOL

I tried it on seats, and IMO, it works as well as ARP lube
I tried it on guides, and IMO, it works as well as anti-sieze

So, it does not work better at reducing friction, but it works as well as what I was using, and it should AID heat transfer, so, maybe it is a great idea.

So now if I die tomorrow, I'll have no secrets.....well, maybe I'll put all relevant info I have on the subject in one place, but that's enough for today, and this HBN stuff certainly could be useful for many things, once we figure out what they are.

[raul arrese]

I use engine oil , but most important for me is prep the guide for easy entrance and alignment ,I prep it on the lathe with a real small step so you can get that sucker going straight fiirst .. and heat the head up some ...
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[rockurob]

performed a google search on HBN Lubricate, first thing that popped up
was an ad: Discover K-Y™ Lubricants - Spark Up a Tantalizing Conversation‎

but then found below info: Hexagonal boron nitride (HBN) is a ceramic that has all of the advantages of graphite as a lubricant with none of the disadvantages. HBN is able to withstand temperatures up to 3,300-degrees F under normal atmospheric conditions before sublimation. It will not conduct electricity, become magnetic, or hold any sand or metallic particles. It would be really nice if we could fabricate rifle barrels out of this material with its extreme hardness under compression, but unfortunately it has a weak tensile strength. Any monolithic barrel fabricated from ceramic will shatter like glass from internal or tensile pressure. However, when applied as a coating to the bore of conventional steel barrels, we can obtain all of the benefits of ceramics without the disadvantages.

The above was from a muzzle loader site..... had to do the search to
further gather info on HBN

now back to the topic: VW Head related.....

Guides, I usually freeze the guides in the ol refrigerator, and warm the
heads in the sun (summer) winter, just vat them in clean hot water from
the tap in 5 gal bucket and install with synthetic Sil-Glyde from NAPPA,
about 7-8 bucks a tube....also works good on shifter tube bushing, does
not attack/disintegrate the bushing as normal petroleum grease does
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[mark tucker]

I make sure the fit is right at around 72 degrees... and I do like some wd or other light lube so it dosent gauld, but you need to be sure there is no edge of any kind on the seats, I like to put them in my lathe anduse some 800 to polish the leading edge and they must have a large raidi!!! some seats come with no or very little raidi or a 45 chamfer that has sharp jagged edges weather you see them or not. I do not like locktight in most cases or any thing that can keep the seat from seating( remember the oil clearance on a crank....that oil has thickness!!! and do not wack them so hard the last time that the seat bounces off the seat and isant bottomed out. Im also not fond of heating the head as that can cause the seat to creep out as it cools. I do chill them.Ive chilled guides and miced them with about 1-2 tenths at the most change in size so...other than it being cold and reducing the possiabilty of gaulding I dont see chilling them doing any more good than that. Ive used anticeez befor, sealers, locktight and even epoxie on marine applications or where the hole was somewhat gaulded but over sizing wasent in the agenda for whatever reason. hell Ive pulled the springythingy helicoil type bronze spiral and epoxied up the spiral and incerted a .030" guide liner witch worked oh somuch better than those spirail pos witch can not be sized accurtly by anyone.....but the Kline .030's can be. the only issue is...when you epoxie up the threads...you dont have but half the heat transfer....but I didnt have any issues with them( that was in my personal v8 race motor that the castings already had the spirails in them)
I have a few snakes around hear but they dont squeek so i dont use snake oil. I do however use some oil mixes when Im building including some chain saw bar lube due to the stickeness&sliperyness of it mixed with the semisynthetic&camshield addtive. Ive seen toomany oils of today that just run off,I like stickey till it's all toghter and running,pumping oil,spining it over by hand degreeing setting valves whatever does not have oil pressure, so i like stickey situations. I do not like greessee in engines. Ive seen it burn up parts.

[raygreenwood]

Great topic!

The use of boron nitride (cubic to start with).....is used in many places especially some semiconductor and solar work......as a band gap metal similar to molybdenum for its electron transference properties and polarity.

The reason it has lubrication properties is because when hou get it into the hexagonal molecular lattice.....hex.......it becomes very similar in properties to graphite....similar heat range ...but with smaller particles, and it bonds better and can be made into a thinner film than graphite.

For all the reasons you mentioned .....oils flashing off at high temps......installing valve seats should be done dry or with a dry lubricant.

The problem with installing valve seats is.....galling and material gouging......both different but related issues......as the seat goes in.
I'm
1. Galling is the extrusion of a softer or alike material hardness....in this case the aluminum....into the surface poors of the harder material.......locking up kf ghat material in the pores.....and shearing off of that material. It creates huge friction and deposits debris in the bore. It can prevent total bottoming out of the seat and creates stress risers at points because of where the galled material builds up.

The normal lubricant TYPE used to prevent galling would be an anti-seize......a solution of soft, high temp sacrificial metals of the same metallic polarity so they will not corrode either metal.......but virtually all anti-sieze compounds have far too much body, viscosity and oil in them. Besides the issue of turning to smoke.....anti-seizes are mostly simply too thick for something that needs an interference fit of say..... .006".....with perfect wall contact all the way around.

But the idea of a soft sacrificial metal as an anti-galling lube.....is the correct train of thought.

2. Gouging of material......straight up an issue of hard metal against soft.....and primarily caused by the fact that its virtually impossible to get any bore and any seat.....exactly perfectly round. The risk is that material gouged away from the bore wall piles up at the bottom......and its too much material....it may overwhelm the chamfer at the bottom.....causing the seat to not be straight......and.......where the material was gouged away from the wall you no longer have perfect contact with the seat......so heat transfer van be worse....causing expansion stress risers.

I have a family member who is not only a mechanical engineer.....but who has been building high performance heads for about 35 years......top fuel, some naascar and grand national and everything in between.

I have watched him install every manner of valve seat ranging from copper, beryllium copper, stainless, nickle alloy etc. One thing he noted long ago....was that one of the most critical attributes of the valve seat before installation.......is surface finish.

Just like the surface finish of a freshly ground crankshaft...... .wherein you dont use what the inexperienced mind would tell you to use when grinding bearing journals......you dont use the finest stone in the world. You do not want an absolute smooth and flat at the micron level.......surface profile at the microscopic level for the metal. Not only does it greatly increase the surface area of the journal area at the bearing.......it leaves no room in the surface tooth structure for lubricating oil.
This is why crank grinding wheels/stones for polishing are commonly in the 360-400 grit range to produce a finish of about 10 micro inches or a little less.

In the same way.....if the surface profile of the valve seat is too rough.....it leaves too much pore structure for the aluminum of the head to extrude itself into.....galling.

If its far too smooth....like mirror polish glass smooth......it has so much surface area ....meaning no microscopic little peaks that get bent over to give a little as you press the valve seat in......that the friction between the seat and bore wall can be huge....requiring heat heat or pressure to drive in.

Just like for machining coolant, tapping fluid etc.....there will be different lubricants required for the best surface finish of different metals.

Most of the seats I have seen installed regardless of metal type.....were polished a little.....usually with something like a fine abrasive cloth.....then installed dry.....but with head heated and seat chilled. I will have to ask what lube would be used when one is needed. Ray

[mark tucker]

I pretty much agree but not on the not mirror smooth seat. a rough seat finish will sheer,gauld,grab the aluminum. in no world will the aluminum bend over the rough spots of the seat. just like a ball broach it does not remove any material as it gos through. the seat should not remove any material either when done right. the counter bore also needs a good raidi in the corrner so it dosent crack. the chamfer isant there to collect debris.... heating heads is a stickey situation too. also staking seats is a major mistake,ive seen somany heads effed up by staking. and more droped seats from staked holes than not. Ive used some realy trick seats on offshore race stuff made by aero space company, there so sweet, mirror polished and never had any issue with them. I do have little exp with berrillium seats,long ago. I have them for my 2332 and my 2393.Im still thinken on that befor I do them they dont last all that long(long to me is 100000+) but....since most are in race stuff...I think they will be fine in my street car, some oe apps now have them but then again....highend stuff that usualy dosent last long so thats not a factor at all for the manufacture's. I like skiney seats they keep the seat&valve clean & seal better, but have reduced contact so they dont transfer heat as good but the seat&valve being cleaner helps in that respect. I would never use anti seeze as I recall it has some propertys that would not be good for heat transfer.

[raygreenwood]

[scotth17]

The best I would guess would be Mastinox, but don't get it on you or lick it or breathe it or even look at it funny, it's fairly nasty stuff, but I don't think anything would work better...

[modok]

HA! I knew Ray would have some idea what I was talking about!
Made my day,
And yes, absolutely, I agree with....the general direction of all that. Very good. What it lacks in practical experience I can fill in.

Lemme tell you a true story.
Years ago, I asked Randy Bowen about installing guides, and he told me:
To use anti-sieze as lube, shoot for .001-.002 press. If the guide doesn't want to go.... drive it back out, polish it down a little, and try again.
If it goes in too easy, drive back out and use one .001 bigger. Room temp. chamfer the edges.

And at the time I thought to myself "that's probably a ok method but rather crude"
Well actually no, actually it's perfect. Me being a natural smart-ass, I tried all kinds of different things and ended up proving that his system is perfect, but I did learn why, which is actually rather complex.

A freshly "polished" surface, which was done with 220-400 grit silicon carbide sandpaper, does seem to give the least friction.
One time, I had a guide halfway in, and it seemed to be too tight, so I drove it back out and was going to polish it down.......but I though......my measurements say it will go, so i just ran the sandpaper over it a few strokes (removing virtually no measurable amount), and re-lubed it, and drove it in, and it went EASY. You would not believe it until you do this yourself. What does that mean? It could mean I have created a surface finish that makes the lube work better, it could mean I removed the oxidation from the surface and that makes it go easier. I'm not sure why, but it's a true story. It works for me and it can work for you.

[raygreenwood]

[modok]

Another lube I came across but didn't mention, is soot.
Application; aluminum extrusion dies. Sometimes they use acetylene torch to cover the die with soot, which acts as graphite lube. it could work for seats, but I have not tried it yet.

The reason a lubricant is desirable for installing seats, is when using heat to ease a press fit, you do not have the option of aborting. You cannot get the seat halfway in and decide to take it back out. You have at most ONE SECOND to drive the seat home before it begins heating and expanding. I agree no lubricant is required if everything is perfect but it could save the job from ruin if things are not quite perfect.

[mark tucker]

so ray have you even seen all the various seats and thier finishes???? or a crank that has the right serface finish or hard chromed and has the right serface finish? No not the shit most people think is smooth and just fine and dandy. yes I know serface profile and microns and they mean shit yes I said that. unless every piece is tested and certified as such. the "general" oh it has a finish of bizillion microns with a ra of and a lmnop of ..... mean squat without a real certification. not many people are willing to take the time to do it right when they can do what is expected...or almost what is expected,(that would be a great job well done!!! with all the crap being done these days a almost is a good job it seems. and no that cast aluminum aint gonna bend over the peeks of the trick seats. the ell cheepo seats... possiably but I think it's gonna fill in the cracks like a cheep toilet paper first some seats are machine finish and some are ground. some are just powdered and not machined at all. Im not trying to get into a pissing match hear. just real life parts,peices and the work that gets done and passed off as "right". and the people that axecept it. that have no clue.

[modok]

[raygreenwood]

[mark tucker]

real world ray!! real world!! oh I been doing it like this for ever so it must be right......yup thats got to be right. Ive seen seats from major manufactures that were so rough they could take the skin off a weezzell when you throw it away. and some that are smooth with a lip at the bottom edge, witch is what happend on the one modock is talking about mare than likely. fix it like everything and it works right. or do like has been done for hundrad years and dont give a shit as it will work that way too. just like boring a block and no hone or a dingle berry hone job.. and bering races withe sharp edge that sheers off the material as it go,s in...nice way to loose the press fit. but it does make it eazer to change them the 2nd tyme around

[modok]

The real world is a myth, we live in a cloud of our own imagination.
In fact, I consider one of my goals to create procedures so refined and ritual-like, that one can obtain a zen like state during the labor of life, and possibly see glimpses of the real world.

But back to work
There are a lot of procedures, like Ray way saying, that have been developed, by humans. It's hard to say one is right and one is wrong, and they work when done right, but don't work if you MIX THEM UP.

Example: .012" press fit has been used for motorcycle and aircooled heads.
Berg advocated that much press. How? well, that's the question. Today I know, that is too much and it won't work. The answer is that they were using seats made of slices of 4130 DOM 1/8 wall tubing. The seat would collapse down to .008 press, but they were soft enough to do that. I do think there is any seats like this you could buy today, and if there was, don't buy them

[raygreenwood]

OK…for the second time in a week…I must apologize for getting bitchy and popping off. Especially to Mark Tucker.

But I meant what I said and here is a finer point to it. My pet peeve is when people ignore, disregard or deny the technology in what they use simply because they don’t see it, provide it themselves or measure it. It’s like saying oxygen is not important…because I don’t make it, buy it or measure it.

A better example set of what I was getting bitchy about if you please to take the time.

You say…that measurement of surface profile, texture, ….microns, micro-inches etc….don’t mean anything cause none of you measure them….and all your stuff works anyway. Just assemble it and run….right?

Well…yes…you are measuring it….or you are being governed by these critical measurements….you just are not thinking about.

In the first more trivial usage..…if you have a micrometer in your tool bag that measures to .0001”…and you think that is useful and important….. .0001”= 2.54 microns. So yeah….it’s critical….and you do measure to microns.

In the more important case, you guys aren’t stupid right?
You don’t purposely by the crappiest parts right?
You KNOW through experience that the best quality parts..…like crank bearings, cam bearings, valves and roller bearings for your wheels are different from the crappy parts….right?
....and that the better quality parts generally work better with less or no modification…right?

Well trust me….the people that make those parts…and any parts that are labeled as “micro-finished”….are measured to the micro-inch or even the angstroms…every day…all day….just so that they are consistent so YOU don’t have to measure them.


Do you think Timken, SKF, FAG etc….. do not measure and control the micro-finish of their bearing rollers and races?

Do you think Valve manufacturers like Manley, SI, InterValve etc…..don’t measure and control the micro-finish of their valve stems?

Do you think valve seat manufactures like SBI, MS, Federal Mogul, SSV and many others who cast, machine and form both solid alloy and powder metal seats….don’t measure and control surface profile and micro-finish to establish machine-ability and press fit standards?

Do you think oil fed crank, cam and rod bearing manufacturers like KS, Mahle and Silverline do not measure, control and verify coating uniformity and micro-finish with measurements like this?

All of these precision companies and many more….measure to the micro-inch at minimum or high in the angstroms at best….and use specialized measurement tools and techniques for Rockwell and Brinnell hardness…and measuring ranging from surface profiling as I mentioned to simple Dyne fluid tests for in shop surface profile testing of lubricant wettability to goniometer testing (look that one up) of oil droplets on machined and textured bearing surfaces to determine if the surface profile is ideal for oil flow and wettability.

So yes….your engine work…no matter how little you measure…is linked at the hip to these measurements….because your parts manufacturer does them for you to keep parts uniform so you can install them without owning a zillion dollars’ worth of equipment….but to say it does not matter because you don’t do them is ludicrous.

The measurements of these parameters are usually the difference between a crappy Chinese part no one wants…and a quality part.

An example or two such parts:

I measured the surface profile of the stems of four new Intervalve brand valves ( have to see how these hold up) for my current type 4 build with my Starrett SR-100 profile gauge……just to see what they looked like for consistency sake.
This is all in Micro-inches…bearing mind that ONE micro-inch= 0.0254 microns and 1 micron is 1/25,000th of 1”.

This tool is a field usage tool. Most manufacturing facilities have bench mounted versions…at 20X the cost.

Valve #1: Ra: 0.40 mi/ Rz: 2.9mi/ Rv: 1.4mi/ Rp: 1.5mi/ Rt: 3.8mi
Valve #2: Ra: 0.41 mi/ Rz: 3.1mi/ Rv: 1.3mi/ Rp: 1.8mi/ Rt: 3.4mi
Valve #3: Ra: 0.43 mi/ Rz: 3.0mi/ Rv: 1.2mi/ Rp: 1.5mi/ Rt: 3.7mi
Valve #4: Ra: 0.39 mi/ Rz: 2.6mi/ Rv: 1.5mi/ Rp: 1.7mi/ Rt: 3.6mi

So….you will notice…..that the difference is VERY, VERY small between each valve. This is a CONTROLLED, MEASURED MICRO FINISH. These measurements and these tool MATTER…to you…every day. You just don’t need to do them yourself.

Just for giggles and grins…I also measured three Timken differential bearing races….yet another product that I KNOW FOR FACT…has controlled micro finish.

While the peak, valley and modulation are very different than the micro finish of the valve stem (different surface finish)...…they are highly controlled nonetheless. Tight averages.

Race #1: Ra: 1.62 mi/ Rz: 5.2mi/ Rv: 4.4mi/ Rp: 0.8mi/ Rt: 7.2mi
Race #2: Ra: 1.58 mi/ Rz: 5.5mi/ Rv: 4.7mi/ Rp: 0.7mi/ Rt: 6.9mi
Race #3: Ra: 1.60 mi/ Rz: 5.4mi/ Rv: 4.5mi/ Rp: 0.7mi/ Rt: 7.0mi

This is what I was getting at in my original post with reference to this thread.
Surface profile and texture has definite impact on what type of lubricant (if any) needs to be used or can be used with any given metal with a specific profile.
The people who make your parts know this. Just understand that when the way a part installs or press fits……changes.... or becomes less than normal….there may be more going on than is visible to the human eye. Ray

[mark tucker]

hey ray some do some dont some do on 1% and some do but print the intended not acctual out come.!!! Ive seen some nice seats and some pure shit from the same company!!! and lips on some skf races but not on timkin or bower. just because you do not see it dosent mean it isant going on.it is. the fancy tech you speak of means squat!!! when it isant addheared to or certified. almost none of this stuff has tractability. so good enough works just fine. the best seats(steel) Ive goten were from martin wells aerosapce.the next best were from tucker.. no not me.and they make custom sizes fast and there what you tell them you want every time. dell west has some awesome seats as well as thier QC. these days if the company has the 9001 or 9002 crap going on you better check the parts well.I personaly think that was set up like the carfox to misslead the ones righting the check.it sounds good but ....dont mean squat in reality when you seem to get stuf that isant what it should be.but it's got the 9002 taged allover the boxes so.....kinda like sticking you head up tommy boys ass to see how good the steaks were he ate last knight......yes ray I know what your saying. and in a perfect world that may be true.(the tech stuff) Ive goten seats from sbi and others that almost look like there threaded .....thats not a good finish, and some that have harmonic wavers in the machining.(chatter or hard&soft spots) so is that axceptable??? yes it is because so many people will install it in a heart beat. and somany shops have wore out chiped one size cutters that wobbel around till there is a hole there what diff does it make...not much. but I dont do work like that, and dont have a 1 size for all seats cutter assortment and hope the seat is the right size or the cutter isant wore out or the drive or the guide. there are oh soamny ways to do it and somany that will work. Im not into the thattel do stuff. thats for the guy down the road that likes working on his stuff all the time.
somethings you want a little rough some things you dont like a mirrior head finish for the head gasket....works on most stuff but not race stuff in most apps unless you have a receiver groove to hold it.some stuff needs traction some dosent.
bying crappy parts cost less well sometymes...and since Im going to totaly rework them any way....why spend2x as much for the ones that are supposed to be better??? some yes ,some no.depends on just what it is. some stuff just cant be fixed. but some stuff can.
dont apoliguize to me I understand where your coming from.I used to do a lot of aerospace machining&manufacturing ...and yes QC So I do understand your point of view and reference totally. but this crap isant aerospace and has zero traceability and 2% of the quality. go figure whoo cares about obsoleate car stuff for a disposable car. there is plent of companys selling crap to make a buck, and some trying to keep it alive with some nice stuff (CB performance,scat,pauter,weddle just to name...most) I wish I had the $$ to buy only american parts&machines and tools&tooling. but I dont. my new lathe is....enco...chiwan as is all the tooling for it, some of the cermets&polycristoline incerts are from somewhere else...where I havent a clue. but there the best I can afford at this point in my useless life...Im looken for a dro now...Ill bet it wont be american made and will not be as good as I want nor as accurate.but...ittel do ( yes Im in the prosess of totaly rebuilding&setting up this lathe before I ever pug it in.

[mark tucker]

see the black round edge on those bearings?? feal to see if there is a lip?or transition that will sheer away the material that it's getting pressed into....sweet. I remove that" burr/lip" many seats also have that"feature" some seats do some dont!!! ALL THE TECH&MACHINES IN THE WORLD DONT MEAN SHIT WHEN YOU LEAVE SOMETHING LIKE THAT ON THE PART!!!thus the point Im trying to make. no I cant tell if that seat has the lip/burr,but many do some dont...mine wont.
neer net forging is awesome but it can leave some issues that need to be addressed.