24OZ Posted December 30, 2008 Share Posted December 30, 2008 Guys, I'm thinking of having my compressor side and exhaust side coated as I want to reduce the ambient air temps under the hood. Are there any disadvantages to coating the turbo? Will it reduce their life for instance? My turbo is only oil cooled, will it put greater stress on the oil to cool the turbo since it won't be radiating as much heat out after coating. Thanks, Quote Link to comment Share on other sites More sharing options...
Brad-ManQ45 Posted January 1, 2009 Share Posted January 1, 2009 I wouldn't bother with the compressor side. I know a few w/only oil-cooled turbos that have cermaic coated turbine housings with no problems - but make sure you idle down long enough... Quote Link to comment Share on other sites More sharing options...
24OZ Posted January 2, 2009 Author Share Posted January 2, 2009 Thanks for the reply. Do people also have the centre section ceramic coated also? Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 3, 2009 Share Posted January 3, 2009 Thanks for the reply. Do people also have the centre section ceramic coated also? I have done the center sections before, but it's kind of a pain with the newer ball bearing centers. On the turbine housing (or compressor housing for that matter), be sure to only do the exterior of the housing - you'll have clearance problems if you do the inside of the housings. Quote Link to comment Share on other sites More sharing options...
24OZ Posted January 4, 2009 Author Share Posted January 4, 2009 I have done the center sections before, but it's kind of a pain with the newer ball bearing centers. On the turbine housing (or compressor housing for that matter), be sure to only do the exterior of the housing - you'll have clearance problems if you do the inside of the housings. Great info. Thank you. My reasons for coating the turbo, manifold and downpipe is because I wish to run the N42 intake without the heatshield and also I do not want to cut bonnet vents into my 240Z bonnet. As well as keeping the ambient air temps low. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 5, 2009 Share Posted January 5, 2009 Great info. Thank you. My reasons for coating the turbo, manifold and downpipe is because I wish to run the N42 intake without the heatshield and also I do not want to cut bonnet vents into my 240Z bonnet. As well as keeping the ambient air temps low. BTW - I'd recommend not using the shiny coatings, unless you can find one rated for more than 1500 degF. For the exhaust manifold and turbine housings you are better off using the 2000 degree coatings. And especially if you want to ditch the heatshield, then stay with the lighter color coatings, like silver or white - they should radiate a bit less heat than the flat black coatings. Personally I wouldn't - I'd use both and coat the heatshield with the shiny stuff in addition. Quote Link to comment Share on other sites More sharing options...
24OZ Posted January 5, 2009 Author Share Posted January 5, 2009 Tim, I'm having the manifold and downpipes coated inside and out. The coating they recommend is a flat black satin finish, possibly as the coloured ones they can supply don't have the same heat retention qualities. The black satin finish is rated at 1000degC or 1832deg F I won't be getting the turbos coated now as they cant do them in situ as they need to cure them to 400degC. The turbo specialist I spoke to told me not to disasemble them as they were in good condition and taking them apart may dislodge the back plate, I believe he said, which could mean a rebuild may be necessary. Looks like a turbo beanie is what i'll go for. Thanks for all the input. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 8, 2009 Share Posted January 8, 2009 Tim, I'm having the manifold and downpipes coated inside and out. The coating they recommend is a flat black satin finish, possibly as the coloured ones they can supply don't have the same heat retention qualities. The black satin finish is rated at 1000degC or 1832deg F I won't be getting the turbos coated now as they cant do them in situ as they need to cure them to 400degC. The turbo specialist I spoke to told me not to disasemble them as they were in good condition and taking them apart may dislodge the back plate, I believe he said, which could mean a rebuild may be necessary. Looks like a turbo beanie is what i'll go for. Thanks for all the input. The turbo beanie should be very effective, but I guess I don't see why you couldn't remove the turbine housing for coating (outside only). Also, I still think that black is the wrong direction if you are trying to keep heat out of the engine bay. Quote Link to comment Share on other sites More sharing options...
ktm Posted January 9, 2009 Share Posted January 9, 2009 Tim, as I understand it only the satin black is rated at the high temperatures that turbo's operate. The cerachrome (sp?) is not rated up to 2000 deg F, or at least that is why my ceramic coater stated. My exhaust manifold was coated on the outside as was my turbo turbine housing. The DP was coated on the inside and outside. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 9, 2009 Share Posted January 9, 2009 Tim, as I understand it only the satin black is rated at the high temperatures that turbo's operate. The cerachrome (sp?) is not rated up to 2000 deg F, or at least that is why my ceramic coater stated. My exhaust manifold was coated on the outside as was my turbo turbine housing. The DP was coated on the inside and outside. It might vary from shop to shop, but I know that JetHot has more than one color rated for 2000degF: http://www.jet-hot.com/headercoatings.html My local shop had a white coating available, which is what I used. The 2000 degree coatings generally have a rough finish and are not shiny. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 9, 2009 Share Posted January 9, 2009 JeffP used the JetHot 2000 Blue, and I can personally attest he's had that baby glowing pink (see his website!) without any flaking issues. George, if you are considering coating and not running the heatshield, you may want to Shiny Silver Cermacoating at least the bottom of the intake manifold to prevent heat transfer to it. If you do the whole thing, it likely won't cost considerably more, and will make the outside a nice shiny uniform color. Make sure they use the silicone plugs on the threaded holes so you don't have to chase the threads and risk chipping the coating. Also, if you are considering altering the intake you can use the propane or MAPP gas torch aluminium brazing sticks Lumiweld to do the patching' filling, recontouring and then have it coated and nobody will know the difference once that's done! Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 9, 2009 Share Posted January 9, 2009 JeffP used the JetHot 2000 Blue, and I can personally attest he's had that baby glowing pink (see his website!) without any flaking issues. Agreed - I have used the 2000 Blue on a previous manifold and found it to be very durable. George, if you are considering coating and not running the heatshield, you may want to Shiny Silver Cermacoating at least the bottom of the intake manifold to prevent heat transfer to it. Also agreed. Again - personally I'd do both - the more you can isolate the exhaust heat from the intake, the better. Actually, the stock heatshield looks pretty sharp once it's been CermaChrome coated. Quote Link to comment Share on other sites More sharing options...
24OZ Posted January 9, 2009 Author Share Posted January 9, 2009 Thanks for the replys guys. I have just spoken to a company in the UK called Zircotec, http://www.zircotec.com/page/-_performance_white/41 they do colour options on the ceramic finish. I asked what colour would have a greater advantage in reducing the ambient temperatures in the engine bay and they advised that they are all the same. And it's actually the ceramic coat which insulates the heat out and its nothing to do with the colour chosen. They told me that the colour they add is simply a layer of colour over the original ceramic coat coating, which is whitish in colour. The only conclusion I can come up with is that the coatings you use in the US are more advanced then the ones we have over here. Here is a company that I was thinking of using camcoat http://www.camcoat.com/, they are US agents for Tech-Line Coatings. And they just recommended I use the Black satin. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 9, 2009 Share Posted January 9, 2009 Have you checked out a company called Sermatech Airfoil Management? I believe they have offices in UK. The shop here in Los Angeles takes orders at the will call counter for ceramic coating. They are a jet engine parts coating/machining operation, so their stuff is 'the real deal'---and at least here the guys with Cobras and all the local NHRA/IHRA guys have their headers and brake discs treated there. Tech-Line is out of Temecula (20 minutes from my house!) and they make good coatings as well. I used their abradable coating on blower rotors, etc... Aerospace Jet Engine Coatings is what you want to search out for these components. The thermal barrier stuff on the intake manifold is more open to application as the base metal isn't getting hot. Hell, white paint there could help underneath. Simply painting the pushrod tubes on a Corvair with VHT Ceramic Paint in white where the head cooling airflow goes across them can reduce the sump oil temperature almost 20 degrees! Barriers have come a long way since 1979 when I did those tests to check if Mr. Finch was B.S.'ing me or not! For turbo manifolds, the 2000 degree stuff is what you want, period. Jeff had used some other coatings that flaked from dyno time alone. And he's tuning for EGT's that were considerably less than 1685F that some advocated! Matter of fact, when we were straightening his SFP Header, we had the center section of the piping to yellow-white heat and that only resulted in minimal coating damage that was localized to where the flame was actually hitting the surface. FWIW, that TURBOX looks like stuff I'd consider if you want something other than black. Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 9, 2009 Share Posted January 9, 2009 Here is a company that I was thinking of using camcoat http://www.camcoat.com/, they are US agents for Tech-Line Coatings. And they just recommended I use the Black satin. From their website: Black Satinâ„¢ is an advanced high temperature thin layer thermal insulation coating. Developed for us on competition vehicle exhaust systems it has industrial uses as insulation for steam pipes, curing ovens, boilers and flues.By nature of its colour the coating dissipates heat very quickly once the source has been turned off. I apologize for being a pain in the ass here, but this illustrates why I was saying to go with a lighter color. When they say that it dissipates heat quickly, the way that it's doing this is by more efficiently radiating it's heat away from the manifold, and into the components that are surrounding it (such as your intake manifold). This is kind of counter-intuitive. Generally speaking, darker colors radiate (transmit) heat, lighter colors reflect heat. In your engine bay, I think the better approach is to try to keep the hot exhaust manifold from transmitting its heat to the things that are around it. Quote Link to comment Share on other sites More sharing options...
Tony D Posted January 9, 2009 Share Posted January 9, 2009 I'm with Tim on this last point. What you want is a thermal barrier, not a heat disbursing agent. The thick ceramic coatings hold the heat IN the components and PREVENT transfer to others. And similarly they can act as barriers to other sources of radiant heat. This was why I did the Corvair Experiment, and mentioned it above. The difference between the FLAT WHITE VHT on the tubes and the FLAT BLACK on the tubes led me to believe the color DOES make a difference in heat rejection/absorption. Coating the same tubes, in the same engine, in the same car flat black resulted in a 10 degree INCREASE from the baseline oil temperature, compared to a 15 degree DECREASE when painted flat white in the exact same area. There are a lot of guys who coat the exhaust to keep it looking decent (er...JeffP) but in terms of thermal transmission it probably isn't the thing you want. For that the thick ceramic coatings like JetHot seem to be the ticket. I know you don't burn nearly as bad when you stupidly lay the back of your hand into a Jet-Hot Silver header while the engine is running compared to an uncoated one! Quote Link to comment Share on other sites More sharing options...
24OZ Posted January 11, 2009 Author Share Posted January 11, 2009 Thanks for the information guys. Quote Link to comment Share on other sites More sharing options...
RIP260Z Posted January 12, 2009 Share Posted January 12, 2009 Slightly straying off topic....as this is turbo and the thread has pointed to an external coating only and hence whether what colour is better for radiating heat, but what about if its an N/A exhaust manifold that is coated inside and out? Would the same apply? I presume that the thermal barrier inside would reflect heat back in, and if it was black say, would this radiate the heat back into the manifold (in the same way if external, but to the sorounding components). Does that make sense? Quote Link to comment Share on other sites More sharing options...
TimZ Posted January 12, 2009 Share Posted January 12, 2009 Slightly straying off topic....as this is turbo and the thread has pointed to an external coating only and hence whether what colour is better for radiating heat, but what about if its an N/A exhaust manifold that is coated inside and out? Would the same apply? I presume that the thermal barrier inside would reflect heat back in, and if it was black say, would this radiate the heat back into the manifold (in the same way if external, but to the sorounding components). Does that make sense? Like I said - it's somewhat counter-intuitive. Generally speaking, darker colors transmit heat more readily, in both directions. If the dark colored surface is cooler than its surroundings it will absorb heat from the surroundings more readily. Conversely if it is hotter than its surroundings (as is the case here unless your car is made of magnesium and is on fire ) it will will radiate heat to its surroundings more readily. So in the case of the exhaust manifold/downpipe, etc. In order to keep as little heat from transferring from the exhaust gas into the pipe as possible, it would be best to coat the inside with the lighter color. Then to keep whatever heat does transfer into the pipe from transferring to the surroundings, you still would want the lighter color on the exterior. BTW, this applies to both turbo and n/a manifolds and exhausts - the only thing you don't want to coat the inside of is the turbine housing so that the coating can't screw up the impeller to housing clearance. Quote Link to comment Share on other sites More sharing options...
Wedge Posted January 12, 2009 Share Posted January 12, 2009 It might sound stupid but why does the darker color coating doesnt work as good ? isnt it all the same coating but with a color ? Quote Link to comment Share on other sites More sharing options...
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