drago86

Acording the racing beat there are slight differences between the 86 and later 13b housings and the earlier ones, they dont recomend 86+ rotors in earlier housings because the trichoid of earlier engines is a few thousands of an inch different, does your machine account for this?

drago86

Also i think you should ****** up as many of thoose aluminum side plates as you can, if they are exact castings all you have to do is take em to your coating shop to spray em, then have any machine shop lap them, surface grind them, and voila we can all take 100 lbs off out engines for a half as much as RB charges

drago86

O, and the coating on the R26b's side plates and housings was hot-sprayed chrome-carbide cermet, id look into that, even if only as an option for your housings, id pay a couple hundred bucks extra for ceramic coatings, id never have to rebuild again, The stuff you found sounds great though, almost exactly like factory spec, and if it does have pores, all the better, except when ive heard them talked about in the mazda engines they were microscopic. Before mazda had the porous chrome, it had horrible problems with chatter marks, which is why the frist engines in the cosmo used carbons seals, they are self lubricating, until they got ahold of the porous chome, which allowed much harder cast iron seals for better wear.

Scalliwag

From my communications with the people the do the spraying (not the Armacor people who make the product I decided to use) they steered me away from ceramic and it was because the pro's and con's to each product not the price. For instance you would never see ceramic used in some of the equipment Armacor is used in. Ceramic would not last no time. About the only pro for ceramic was the thermal efficiency. Ceramic is a "buzzword" and the thermal spray people say that everyone comes in talking about ceramic (including me) and that they have to look at the application the customer has and give the options. They would put down ceramic for $75 more, but they don't think it is the best product for the job.
Fortunately the guy I talk with has a lot of patience because I have drilled him and another guy there with an incredible amount of questions.
The spray shop is in the position of being blamed if something does not hold up. It may be the shop's fault but if they put a ceramic coating in a coal crusher and it lasted 10 minutes it would be due more to the person that decided to use ceramic than the product.
I have to go to work but I have more on the "grain structure" and notes I took at work that I need to refer to.

Scalliwag

I did not know this. The housings I measured and worked with were all 2nd gen (86-91) That is where I final finish to. If someone wanted a few thousandths either way it just have to adjust for it. That is great info for me to keep in mind once I start making these for other people. At least it is easy to tell an '85 and older housing because the o-ring grooves are on them instead of the side plates.

Scalliwag

If that guy ever lets me at a set I will get them. If they work I will get as many as possible.

Scalliwag

Okay, I have the notes from my conversation with Huey Jackson at Armacor. We talked about 45 minutes. Here are the highlights. One of the biggest pieces of information as far as it helping me working with the housings is this; the surface does not "work harden" in the true sense of the word. In effect it does work harden but it is a different process. Yeah, I was confused too! He said that when I am grinding under pressure it is NOT hardening. When the force is decreased like during the finishing process the coating has a "metamorphic transformation". (I'm thinking about the "Incredible Hulk" when I look at that word!) The amorphous metallic structure is actually created during the finishing process.
The reason this is good to know is because you want to avoid light grinding until you are pretty close to where you want to be. This **** is hard enough when you are gring it the first time that if you make if harder early you will be in for a lot of extra work and wear on tooling. Once you do get close to where you want and you start a light pressure finish everything changes.
We went into a lot of details as to how the material is applied through a twin wire arc spray which I have already seen at the spray shop, but he just reitterated the details of which I did not take many notes.... if I ever buy a $25,000 system capable of spraying their product he said I can call him back for more information as to the setup. My work is cut out already without spending 25k and trying to learn how to use the stuff!!!
Then we got into the industrial diesel engines and how well that had went. Then he told me about the 350hp snowmobiles and that they are the closest thing to my application because they are aluminum blocks with steel sleeve inserts and the inserts are bored over and sprayed, machined and honed.
Of course Huey thinks that his product is better than ceramic because he sells his product. And while we are not making coal crushers isn't it good to know that this product should be "overkill"?
My notes have equipment he recommended if I ever did decide to try to spray.
If anyone has any questions about their material they can call them to. At least that way I wn't be the only person bugging the hell out of them! Below is the details from their site on the grain structure and other qualities. If you read it over a few times if you are like me you will actually pick up more from it. Some of the questions I ended up asking were actually covered on this and I had already read through it. Maybe I just think everyone is as slow as me

zyounker

kinda makes me wonder if the apex seal going across it would be enough to change it.. might be a really good way to seat them????


just thinking out my ***

Scalliwag

You know I wondered the same thing. I use regulated air pressure on a hydraulic during the entire process.
The way I did the first one is I cranked the pressure up as high as I could run it without screwing something up and I backed it way off at the final stage. I backed it off just out of knowing that when you want to polish something you need to do it at the lightest pressure possible.
I will try increasing the force and using a finer abrasive. It would be nice to be able to do non-destructive hardness test during each phase of this and then check the hardness again after the motor is pulled apart.

I do like people that think like you. If that was coming from your *** you're an Einstein compared to me!

Scalliwag

If you go back to page 4 of this thread and look at the two bigger pictures of the housings. Notice on the first picture how bold the pores are. The second picture was after it had been ground under less pressure during the finishing process. This appears to be where the amorphous structure took place.
If this is the case the size of the pores concerns me if I put the motor together like that the reason being is that I just do not know what the effect would be for oil to get into the pores during the amorphous process. I am going to see if Huey will give me the phone number to the snowmobile people so I can pick their brains.

Scalliwag

I keep calling this place Armacor, their name is Liquidmetals and Armacor is their product, oh well I am probably the only one here who has not already figured that out. Anyway I called Hewy (I found out that is the way he spells his name) and he gave me the number to the snowmobile people. It turns out that the snowmobile place is actually a spray plating shop and that the owner is a hardcore snowmobile nut that does the snowmobile stuff as a biproduct.
So this guy can spray whatever he wants, whenever he wants as often as he wishes to do it. He was out of the office today but when he gets in Monday I will get to talk to him.
This is great because now I can talk directly to a person with both arc spray knowledge as well as first hand high performance engine application knowledge. Hewy said that he is a helluva nice guy and can talk for hours about this stuff...hmmmm we have ALOT in common.
So hopefully Monday I will get a big scoop and get back with you guys on it.
I won't promise that I won't post over the weekend as I get to thinking out loud.

zyounker

No, you should post your thoughts.. helps to work through them

Scalliwag

Okay, the people in Chicago have a website http://www.accuratemetallizing.com/index2.html
They have been doing this since at least 1985 (probably longer since that is when they opened their own shop)
But you guys can surf their site and get a feel for them.

I will describe what I'm doing to them and get their suggestions and input on Monday.

drago86

Try to get the coeficent of friction of the armacor, all they say is lowest of any metal coating, also what exactly is it made of? hard nickle?

Scalliwag

I didn't think to ask about it but I would think they would have a very detailed data spec sheet. Just looking at the specialized equipment that is used would lead me to believe that the spray shops would want all that information. Maybe they have it in a pdf file. Otherwise I will scan it and post it.
an MSDS sheet will tell the composition. Hewy mentioned that the large pores in the first picture was due to chrome oxide particles popping out during the course grinding. He said that if the spray shop uses nitrogen instead of air during the spray that would not happen. So my theory that the pores were tightening up as it was hardening was not the case.
The pores in the finish now look great so I think I will go with this for the first set unless the people at Accurate Metallizing tell me different.
If this works out I may have to seriously think about getting a used spray system in the future and looking into training on it. I would probably take the training first just to see exactly what I was getting into.
I have Linux class all next week. I will probably not be posting quite as much as the week rolls on. Linux is cool but damn it is a huge learning curve.

drago86

The fact that the stuff has good responces to heat cycling is very assuring, also i wasnt talking about full ceramic, the r26b used cermet, which is ceramics in a metal metrix, the ceramic give the coeficient, and hardness, and the metal adds flexability and holding, the shop can probably mix some carbides into the armacor mix, i think all that stuff comes powdered, and its faily common to mix, dont do that now though, go with the armacor and make it work :-) then when you get some cash from all the housings people are sending you experiment a little to find the best mix you can

Scalliwag

The Armacor for the twin arc is in a wire form so it cannot be changed at least for that process. I am hoping that the little pores retaining oil along with whatever the coeficent of friction that the material already will result in a very effective coating.

Scalliwag

Hopefully I can get this out the door at a low enough cost to move enough to pay for a used spray system OR run enough housing through the spray shop that they will reduce the price.
I know that the spray process can be done by hand or with a post mounted gun for automated. A "seamer" is a welder I ran before I became a computer geek. It is like a big wire feed welder that is post mounted. The operator controls the wire speed, amperage, and the travel speed of the part that is traveling. Once you get used to running one you know where every setting should be to get a great weld. Since I welded components for the Texas DOT the welds were x-rayed or sonically tested. That is an area that is indirectly related but very relative in theory in many ways here.
It the spray head was fixed on a post and a motorized table was designed to make the housing travel around the head it could be made to be much more consistant than the hand process. You have control over amperage, air pressure, wire speed, and travel speed.
Making the part travel instead of the head is because of the hoses and cables connected to the head would not do too well spinning around while a table with the part could be implemented with bearings and guides.
This would mean less material waste (excess build and overspray) and less of that freaking grinding time due to high spots.
The first housing from the spray shop was not very consistant and the build up in the center of the housing made for a lot of extra work. The shop said they can avoid that (I think I covered this in an earlier post)
Well I'm tired and rambling on now. I hope the specifics or endless blathering by me is not turning to many people away. I'm sure a lot are just waiting for a "bottom line". I am glad to be getting input from those of you who are posting. Keep the ides coming. I will be asking for a data sheet on Monday thanks to your questons Drago.

cement

this thread would have to be one of the best ive ever read and i look forward to reading the updates as you post them Scalliwag
if you can pull this off its going to be a great effort ,sounds like the snowmobile guy is going to be a handy guy to talk too
well good luck and i for one will be watching with anticipation ,i can only imagine the time and effort your putting in on this project

Darren

007007

you just want another polished bit to add to your engine bay don't ya daz.

By the way i can't really see a way of testing the hardness without leaving an indentation in the surface. There is a gadget called the shore scleroscope which is used as a means of non destructive hardness testing, but i don't know how effective it would be as you only want to measure the hardness of the coating. It is basically a tube with a tiny bullet like probe in it. You pull the probe back to a predetermined height and let it fall. The distance it rebounds is used as the hardness value measured of the markings on the tube. Plus it is more accurate on samples which have a reasonable size/mass.

Scalliwag

As long as it measured hardness one way or another I would be happy. As long as I can get an idea of where it is compared to the stock surface. I could do a destructive test to the housing I just got back and a uncoated housing. Even if the uncoated housing gets dinged pretty good it would be fixed when it got coated.
When I was getting Mazda o-rings duplcated the people had a tested like you described. It told them the density of the rubber and what the compund was likely to be. The o-rings are another story, a good one though. I got them in Viton for a lot less than anywhere else.

Scalliwag

Well last week was very long in Linux class and took up alot of time. It was good though. I finally got to directly speak with the guy at the thermal shop in Chicago.
He said that he does NOT spray the liners as I was told. He does the combustion chamber and valve faces and some other areas. So the info I was given was not accurate. (yep, again)
I told him what I was doing in detail and he thought that the Armacor would work like a champ for it. He had no doubt even though he had not used it on the cylinder walls. Since he has used it in the chamber of a cylinder he knows it will hold up to the temperature cycling and range. Since he knows how it holds up to friction on other applications the seals are not a problem.
So I at least got some consolation in the theory from someone who knows the thermal process and has used the material at least partly in the same environment.
This week I am back to work on the project and happy to be back on it.

Scalliwag

I just got off the phone with Hewy Jackson at Liquidmetals (the place that makes Armacor) He is mailing me all the data on the product. To answer the question on the coefficient of friction, it measures between .11 to .12. Steel measures between .38 to .45. Teflon measures around .12. So the **** is like Teflon?!?!?! I know that when you rub your fingers on it that it feels waxed even though I did not mirror polish it. So now I just wonder about seating. Hopefully that will not be a problem. If it is not then this is going to be pretty bad ***.

nimrodTT

Whew, I just read the whole thread for the first time - that took forever. I'm intriged by your approach, I thought about doing the same thing except with titanium nitriding and running a CNC mill so there wouldn't need to be any guesswork. You might want to look into getting the rotor housings acid dipped to remove all the corrosion that's built up before they are sprayed with the Armacor, but after you prep them - it should give the optimum bond.

nimrodTT

I'm no physicist, but is that static or kinetic? And what is it in relation to? I looked up teflon on teflon and it's said to have a coefficient equal to 0.04