The bottom end of the new engine it togther and the heads etc are being finished. It was decided to bump the CR up a fair bit and because if this, ceramic coat the piston tops and combustion chambers and exhust ports on each head. I understand the theory behind this, eg to stop heat transfer etc.
But it was also suggested i ceramic coat the outside of the barrels, what are ppls opinions on this? i assume its a different coating to the inside as you want to be dissapating heat rather than keeping it in? is it a good idea?
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!
BiX wrote:The bottom end of the new engine it togther and the heads etc are being finished. It was decided to bump the CR up a fair bit and because if this, ceramic coat the piston tops and combustion chambers and exhust ports on each head. I understand the theory behind this, eg to stop heat transfer etc.
But it was also suggested i ceramic coat the outside of the barrels, what are ppls opinions on this? i assume its a different coating to the inside as you want to be dissapating heat rather than keeping it in? is it a good idea?
My understanding is that external coatings can block the heat flow.
judson that is incorrect,
research coatings and you will find heat dispersing coatings widely used in many apps ,for our need they are particularly good ,i have used it and and was very happy with the results however i cant give you empirical data as i didnt have another set to swap over too ,ceramic and heat dispersant coatings work well in my experience:beer:beer:beer
Don't argue with an idiot; people watching may not be able to tell the difference.
ANY smooth coating,weather it be ceramic or polished dog sh*t will REDUCE the ability of the cylinders to dissapate heat when used externally.The air flow will lose turbulance if the surface isn't "rough" and the cooling ability is reduced as the air flows over a reduced surface area.Do a search,this has been brought up before. Coating the inside of the head is a different ketle of fish...😀:beer
v8 supercars and almost every othre form of motorsport involved in extracting the last bit of performance will disagree with your sweeping statement,if you need to dissapate heat fast you need these coatings ,they are not ceramic and they dont smooth they ENHANCE the heat shedding properties of a cast piece be it alloy or iron,this stuff on plain ordinary cast iron cyls works and in conjunction with ceramic combustion chambers and ex ports and valve heads really gets things under control ,its not cheap, but it works:beer
Don't argue with an idiot; people watching may not be able to tell the difference.
toplessbug wrote:v8 supercars and almost every othre form of motorsport involved in extracting the last bit of performance will disagree with your sweeping statement,if you need to dissapate heat fast you need these coatings ,they are not ceramic and they dont smooth they ENHANCE the heat shedding properties of a cast piece be it alloy or iron,this stuff on plain ordinary cast iron cyls works and in conjunction with ceramic combustion chambers and ex ports and valve heads really gets things under control ,its not cheap, but it works:beer
Don't get your nappy in a knot.We are talking about CERAMIC coatings,as the title of this thread suggests.My "sweeping statement" as you so politely put it, is actually a fact when referring to ceramic coatings on the outside of an air cooled cylinder. We are also talking about an air cooled motor,not a supercar water cooled donk,who's thermal output would kill a VW engine. I will now practise what your signature suggests.......:kiss
Ok well i have already done a search and read the other thread, but it turned into a thread with no real back up or data. just ppl slanging each other.
Done some more investigation, and the barrels will be coated with a heat dissapating coating, which is different to the ceramic coating of the piston tops and chambers.
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!
68AutoBugBeetle Restorer - Experience over 138\% - YIKES --
BiX wrote:Done some more investigation, and the barrels will be coated with a heat dissapating coating, which is different to the ceramic coating of the piston tops and chambers.
Now that sounds better as ceramic or chrome or anything else would stop the dissiapation of heat from the cylinders.
VW used to use chromed tappet covers in the Artic circle back in the 50s to keep the heat in.....
maybe they could have chromed the cylinders too???
although I believe you could paint the bare cylinders with any paint, as its not going to stop the heat disapation.
the paint would have to be very high tenp stuff too....
Sounds like an expensive exercise....
ceramic coating the heads of the pistons etc....
exhaust ports etc....
probably pick up a few extra horsepower though...
Lee
- Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY---
the compression ratio really requires it (10.5:1). Its a 90% race motor... i won't talk about the cost. But hopefully will have it fully sorted for the hillclimb championships a mt cotton this year.......
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!
OK Topless I guess my 30 years work in advanced engine research counts for nothing - so go ahead and coat your barrells and fry your engine. As others have said your signature is pretty spot on!
toplessbug wrote:v8 supercars and almost every othre form of motorsport involved in extracting the last bit of performance will disagree with your sweeping statement,if you need to dissapate heat fast you need these coatings ,they are not ceramic and they dont smooth they ENHANCE the heat shedding properties of a cast piece be it alloy or iron,this stuff on plain ordinary cast iron cyls works and in conjunction with ceramic combustion chambers and ex ports and valve heads really gets things under control ,its not cheap, but it works:beer
Don't get your nappy in a knot.We are talking about CERAMIC coatings,as the title of this thread suggests.My "sweeping statement" as you so politely put it, is actually a fact when referring to ceramic coatings on the outside of an air cooled cylinder. We are also talking about an air cooled motor,not a supercar water cooled donk,who's thermal output would kill a VW engine. I will now practise what your signature suggests.......:kiss
if i may
who said anything about a waterbottle donk ,i mentioned performance of an entity,brake calipers are aircooled and need to dissapate heat like now, along with a host of other components,
add to the fact that in most if not all circumstances the coatings are produced and applied by the same company ,most people refer to specialist coatings as CERAMIC and dont bother to differentiate between heat retaining , heat shedding ,
OH and i stand by what i said ,judsons ,you said and i quote "Any coating will impair heat flow.", this is not correct and i would refer you to here http://www.brookscoatsit.com/heatdisp.html or perhaps here http://www.competitioncoatings.com.au/ or perhaps http://www.techlinecoatings.com/introduction.html#thermaldispersant:beer
Don't argue with an idiot; people watching may not be able to tell the difference.
As a general statement I'll stand by what I said "any coating will impair heat flow" You can believe what you like about snake oil type sales information but the fact of the matter no engine manufacturer of air cooled engines use any form of coating other than paint or anodizing on aluminium barrels. This includes Porsche, Honda, Yamaha and also aircraft engine makers like Pratt and Whitney Lycoming. The risk of any coating that claims to improve heat dissipation is that if is not correctly applied a air gap forms between the cylinder and coating and this further impedes heat flow.
Rather than believing sales information educate yourself by searching the technical papers published by SAE and leading engine research universities like the University of Wisconsin. They have no axe to grind.
I'd save my money and stay away from coating barrels.
The links you posted are interesting as they all look like low budget operations and when you read about their heat dispersant coatings they sound like expensive forms of black stove enamel - which I originally said was the only thing you should coat barrels with.
The post topic is "ceramic coatings" and you are leading the even less informed to believe ceramic coatings of barrels are a good idea.
BiX wrote:the compression ratio really requires it (10.5:1). Its a 90% race motor... i won't talk about the cost. But hopefully will have it fully sorted for the hillclimb championships a mt cotton this year.......
10.5:1 isnt that high.....money would be better spent elsewhere IMO. Whats the specs on the rest of the motor?
Spend your money on buying the last 10% of the race motor:P
BiX wrote:the compression ratio really requires it (10.5:1). Its a 90% race motor... i won't talk about the cost. But hopefully will have it fully sorted for the hillclimb championships a mt cotton this year.......
Cool.................you can see how it goes against a pobjoy 1916:P
craig craig...are you saying that if you win its simply the motor and not any driver skill whatsoever..if thats the case perhaps you should change from a pobjoy and see if u sitll win :p
Anthony
"what kinda creator would make a race of people
and make em act a certain way or else He deems 'em evil?
HOW can You give a living being the freedom to breathe
and then lead em into a sea of decievers who greet em, see!"
Bix, without getting caught in all the other crap, when I did my motor (2L type 4) in addition to ceramic coating the compustion chamber I also did the exhaust. The only other thing I did was to get a molybond type coating to the piston sleeves and valve spring.
:blah
Hi Craig, what sort of times do you run around mt cotton? i normally run road reg rather than imp prod.
There is also another bug (pobjoy powered) that just hit the road up here, and did its first run on the hillclimb a few weeks ago (more of a shake down).
Andy, exhaust ports are being done but not the ex system, i was going to heat rap that.
I have no sympathy for my car, only the wallet that pays for it!
Go hard or go home!!!!
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
