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Jimidan
| Posted on Friday, April 04, 2003 - 09:56 am: |
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I can see how they stick to the piston, as I have had mine coated with the thermal barrier on the crown and the black stuff (technical term) on the skirts. I am curious how you get anything to stick to the bore of the cylinder with the rings scraping it? Also, nic-sil attacts and holds oil (whatever that term was), so how does it stick to that. If you coat nic-sil, it would seem to block this capacity. |
Rempss
| Posted on Friday, April 04, 2003 - 10:33 am: |
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I have used these products, Techline, on several motors (automobile) I built over the past few years. Different types of coatings are used internal and external depending on what outcome you require. The latest were supercharged and I am able to run an additional 6-8 psi than without the coatings before the knock sensors retard timing. It allows more combustion heat to escape through the exhaust. No scientific data, only recorded information from sensors throughout the system. I record heat in several locations on the block & heads, EGT and intake air temp before and after the supercharger. I may be able to pull up some before and after temps, I just use it now to see if anything unexpected comes up. After tear-down there is no appreciable wear on the piston tops or combustion chambers. The lubricants do wear while in use, but have not worn through to the original surface. The stuff stays where put, as long as it is put on properly, which is quite easy. I have used it on the internal components of my X1 just because I had it apart. I will always use at least the dry film on the piston skirts. Works well on firearms parts also. Jeff |
Blake
| Posted on Friday, April 04, 2003 - 12:05 pm: |
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Steve, They don't crack either because they have compatible coefficients of thermal expansion and/or they are able to withstand severe elongation and compression strains without failure. No different than the Jet Hot type ceramic coating used to coat headers right? Jimidan, I'm pretty sure that, as Jeff describes, the coating on the piston skirts is just dry film lubricant. Stock piston skirts are coated with dry film lubricant. There is no coating being applied to the cylinder bore other than the nicasil plating. I'm pretty sure the only coating being used within the combustion chamber is the ceramic type heat barrier coatings. Someone correct me if I'm wrong. |
Steveshakeshaft
| Posted on Friday, April 04, 2003 - 01:44 pm: |
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Hmmmm, when I think of Ceramics, "withstand severe elongation and compression strains without failure" isn't a property that comes immediately to mind. Yes, the Jet Hot coatings. Gotta point there, but it doesn't matter too much if a bit falls off OUTSIDE the motor! I've carried out so much development work on machines with such mixed results over the years, sometimes I'm just too darn sceptical eh? One thing I will pass on to anyone considering hi tech coatings. It's 90% down to preperation, preperation, preperation and then some more. I've had coatings fail where there was most likely a finger print left on a prepped surface. Anyone got any independantly verified dyno data on this stuff applied to heads and pistons? Steve. steve_s@ukbeg.com www.ukbeg.com |
Rempss
| Posted on Friday, April 04, 2003 - 02:23 pm: |
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Techline does offer a powder formula that buffs onto the metal. Applications say to use it on the cylinder bores for improved ring seal. I have not used it for that, but instead for piston pins and other very close fit situations. I agree, preparation is key to good coating performance. Application of coatings is well within the grasp of "regular" people with a desire to do things right. When I first started researching this I was also skeptical about some coming off while in use. I first tried it on some steel & aluminum plate I had around. I found the same results below when the material was cold, room temperature and hot (500+- degrees F). The ceramic is very hard to remove by mechanical means. To remove it all I had to use a grinding wheel to make "breaks" in the surface to get an edge to pull more off. The dry film was a bit easier a steel wire wheel took off the thickness, but left some behind that I could not remove without destroying the aluminum underneath. I cannot show you what the coatings themselves added; by themselves maybe very little, but with just water injection before I could only go to 16 PSI boost before knock set in timing was retarded. With both coatings and water I get to 21 PSI without hesitation. Jeff |
Pammy
| Posted on Friday, April 04, 2003 - 02:45 pm: |
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Blake...we do coat the inside of the nikasil bore with the anti frictional coating as well. Some coatings are for friction(or prevention thereof) and some are to prevent heat build up. I have never seen any of these coatings "flake" off. As I said before, we are still testing(abusing) these and other tricks...so far all are promising. |
Pammy
| Posted on Friday, April 04, 2003 - 03:01 pm: |
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Pete...did anyone ever tell you what a trouble maker you are? Jim...we coat the inside of the bore,combustion chamber, valve guide, exhaust port, etc... |
Blake
| Posted on Friday, April 04, 2003 - 05:29 pm: |
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Pammy, How would the rings seat with dry film lubricant coating new cylinder walls? |
Rempss
| Posted on Friday, April 04, 2003 - 11:13 pm: |
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Blake, The Techline anti-friction lubricant for cylinder wall use is a powder (looks and feels like molybdenum) that buffs to an advertised thickness of 20 millionths of an inch. It is not a dry film bake on that adds thickness like that used on valve stems, bearings etc. Jeff |
Blake
| Posted on Friday, April 04, 2003 - 11:34 pm: |
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Interesting. What are it's advertised claims? 20 millionths = 0.000020" |
Captpete
| Posted on Saturday, April 05, 2003 - 02:30 am: |
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Guaranteed not to rust, bust, chip, crack or peel, run down your leg, or smell bad in the summertime. |
Steveshakeshaft
| Posted on Saturday, April 05, 2003 - 03:11 am: |
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Well, if it looks like a duck, quacks like a duck and swims like a duck. You can be pretty sure it is a duck. If it looks like Molybdenum Disulphide, feels like it and works like it....... Steve steve_s@ukbeg.com www.ukbeg.com |
Steveshakeshaft
| Posted on Saturday, April 05, 2003 - 03:15 am: |
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Interesting that on the Techline website, you can buy the piston coating for home application at effectively dirt cheap prices. I've got a slightly damaged Thunderstorm piston in the garage that would be interesting to coat to see how it works. In the UK (on their agents website), there is no mention of buying the stuff for home application. Coating one piston top IIRC, is about 50 dollars. Expensive IMO. Steve steve_s@ukbeg.com www.ukbeg.com |
Rempss
| Posted on Saturday, April 05, 2003 - 11:05 am: |
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Like I said I have never used it on the cylinder bores, just close fitting parts like piston pins, some bearing surfaces etc. I don't know how buffing it on quickly can have a long term benefit based on my experience. I have used moly coatings quite a bit for bullet coating when reloading ammunition. It's exact composition I don't know, but it offers more velocity with the same powder charge due to reduced friction of the barrel. It does take many coated rounds shot through the barrel for enough moly to build up to produce consistent results. Very high pressures and continued heat before the coating is applied, but it is almost impossible to remove after embedded into the metal. So by hand/wheel buffing I just don't know if it can be applied in a fashion the promote reduced friction over time on something as large as a 3-1/2" bore without a lot of time and material. I put it on bullets and small parts in a vibratory tumbler using steel shot to help embed it into the surface. If my cylinders would fit, maybe. Jeff |
99x1
| Posted on Saturday, April 05, 2003 - 12:35 pm: |
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"I put it on bullets and small parts in a vibratory tumbler using steel shot" I have this mental image of the 3 Stooges, plugging the tumbler in, then dancing around dodging bullets.... Nyuk, nyuk, nyuk.... John |
Jimidan
| Posted on Saturday, April 05, 2003 - 09:48 pm: |
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"I have this mental image of the 3 Stooges, plugging the tumbler in, then dancing around dodging bullets.... " I kinda get this picture of the 3 Stooges running around the room with kevlar vests, then dancing around dodging these "cop killer" bullets... Nyuk, nyuk, nyuk |
Rempss
| Posted on Sunday, April 06, 2003 - 02:38 pm: |
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Not loaded ammunition guys, just the bullets. Though it would be quite hard (read almost impossible) to impact a primer hard enough cause a panic. Jeff |
99x1
| Posted on Sunday, April 06, 2003 - 07:37 pm: |
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If a header pipe is ceramic coated, (and the pipe runs cooler on the outside), does the head run hotter? (Exhaust is hotter inside the pipe?) Is the heat one feels on their right leg due to exhaust heat or engine heat? (Is it cooler to ride with a coated exhaust?) Does the coating have to be done while the pipe is new? (esp inside coating?). TIA; (searched the archives) John |
Blake
| Posted on Sunday, April 06, 2003 - 11:07 pm: |
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If a header pipe is ceramic coated, (and the pipe runs cooler on the outside), does the head run hotter? Don't know. Probably not. Is the heat one feels on their right leg due to exhaust heat or engine heat? (Is it cooler to ride with a coated exhaust?) Both. A little. Biggest benefit is from header wrap. I've heard a bunch of BS about how some ceramic or other coatings insulate against heat. I have my headers jet hot coated. The header wrap is by far WAY more effective. Does the coating have to be done while the pipe is new? (esp inside coating?). No, they will prep the pipe appropriately. |
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