KR> OT: heat rejection capacity from exhaust port walls
On Feb 12, 2015 3:11 PM, "Dan Heath via KRnet" wrote: > > Yes, keep the heat in the pipe. This is good for many reasons. Get your pipes coated inside and out, or do it yourself. I had Jet Hot do mine and I believe that Mark L. does his. > > That's very interesting. Is it enough to keep head temps below 160 c? How durable are the coatings? Thanks!
KR> OT: heat rejection capacity from exhaust port walls
I wrapped my bd4 crossover pipes with ceramic tape from JC Whitney, to minimize heat conduction inside the cowl. I painted the engine white and the cowl interior black to maximize heat radiation to the cowl. The cowl exterior became noticeably hotter to the touch, so ideally you would use a conductive (i.e. no foam) cowl material. My Osprey cowl, made of polyester/fibreglass becomes quite plastic on the ground. Peter It appears keeping the heat in the exhaust flow is the key.
KR> OT: heat rejection capacity from exhaust port walls
I had a company in Denver do their version of ceramic coating on the inside and out side of my exhaust pipes. I have about 100 hours on them now and they have not discolored at all and do seem to help keep the temp down in the cowl. The coating seems very durable. I scrape the pipes pretty hard getting the cowl on and off without scraping the coating off. I'll have to go through my records to come up with the name of the company. Roger Bulla -Original Message- From: Rogelio M. Serrano Jr. via KRnet Sent: Thursday, February 12, 2015 9:01 AM To: danrh at windstream.net ; KRnet Subject: Re: KR> OT: heat rejection capacity from exhaust port walls On Feb 12, 2015 3:11 PM, "Dan Heath via KRnet" wrote: > > Yes, keep the heat in the pipe. ___ Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org please see other KRnet info at http://www.krnet.org/info.html see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options
KR> OT: heat rejection capacity from exhaust port walls
Yes, keep the heat in the pipe. This is good for many reasons. Get your pipes coated inside and out, or do it yourself. I had Jet Hot do mine and I believe that Mark L. does his. It appears keeping the heat in the exhaust flow is the key.
KR> OT: heat rejection capacity from exhaust port walls
I met a guy at Oshkosh who had an RV 6 with a Lyc 360. He had the piston tops, exhaust ports and exhaust pipes ceramic coated. The cooling air inlets are 2 1/8 diameter and he has no problems with cooling issues. It appears keeping the heat in the exhaust flow is the key. Interesting stuff. Roger Baalman rbaalman at cox.net > > > > That means if we don't alter anything else but reduce absorption, can > > we see a significant drop in cylinder head temps? > > > > Maybe an effective thermal barrier coated exhaust port makes a > > difference? Anybody tried that yet? > > > > ___ > > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > > please see other KRnet info at http://www.krnet.org/info.html > > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > > options > > > > > > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options
KR> OT: heat rejection capacity from exhaust port walls
Hi, Slightly OT but i don't know where to ask. Is heat absorption from exhaust port walls more significant than that absorbed from chamber walls? That means if we don't alter anything else but reduce absorption, can we see a significant drop in cylinder head temps? Maybe an effective thermal barrier coated exhaust port makes a difference? Anybody tried that yet?
KR> OT: heat rejection capacity from exhaust port walls
Depends on port and chamber design of a given engine. The exhaust ports are typically the hottest areas on the cylinder head. If we're talking VWs, the exhaust port areas are designed to be fan-cooled. Thermal barriers work, so I would think a reduction in heat absorption would occur. Significant reduction? I think you would have to try it and measure the results to see how effective it would be. I doubt if the results could be predicted. Chris On 2/10/2015 4:39 AM, Rogelio M. Serrano Jr. via KRnet wrote: > Hi, > > Slightly OT but i don't know where to ask. > > Is heat absorption from exhaust port walls more significant than that > absorbed from chamber walls? > > That means if we don't alter anything else but reduce absorption, can > we see a significant drop in cylinder head temps? > > Maybe an effective thermal barrier coated exhaust port makes a > difference? Anybody tried that yet? > > ___ > Search the KRnet Archives at http://tugantek.com/archmailv2-kr/search. > To UNsubscribe from KRnet, send a message to KRnet-leave at list.krnet.org > please see other KRnet info at http://www.krnet.org/info.html > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options > >
