Would this help or hurt?
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Joined: Aug 2005
Posts: 862
From: Columbus, IN
Would this help or hurt?
Suppose you have an engine block that, after being sonic tested, showed that the cylinder walls were thick enough to safely bore 0.060 over. Then you took a set of .030 cylinder sleeves and had the outside diameters of each one thermal barrier ceramic coated. (We'll say we used "Jet-Hot 2000.") After installation, you would then have a 0.030 over block that had a thermal barrier sandwiched within the cylinder walls where it would never be subjected to friction from the pistons.
I've seen several examples of ceramic coatings being used on cylinder walls for the purpose of reducing friction and retaining oil, but unless I'm just not looking in the right areas, I haven't seen any mention of these ceramic coatings acting as thermal barriers as well. Is this something that should just be taken as a given, or is there a reason why it would be a bad idea to discourage heat from passing through a cylinder wall?
I've seen several examples of ceramic coatings being used on cylinder walls for the purpose of reducing friction and retaining oil, but unless I'm just not looking in the right areas, I haven't seen any mention of these ceramic coatings acting as thermal barriers as well. Is this something that should just be taken as a given, or is there a reason why it would be a bad idea to discourage heat from passing through a cylinder wall?
West South Central Moderator
Joined: Oct 2000
Posts: 3,371
From: Kilgore TX 75662
.030" sleeves are too thin. From what it looks like you are saying, you are wanting a .015" wall thickness sleeve. The thickness of a dollar bill is .004" so hold 4 of those together to get a better idea. Check out Darton's website to learn more about resleeving engines. http://www.darton-international.com
West South Central Moderator
Joined: Oct 2000
Posts: 3,371
From: Kilgore TX 75662
after some more reading on Darton's site, I found out about the newest sleeve material that they are using. It is 45% stronger than the current ones.
Maybe the steel sleeves that they mention might let you do it?
In addition this new material from Darton Sleeves will make it possible for a whole range of engine builders to take advantage of the superior strength of DDI-2007 to increase bore sizes and reduce sleeve wall thickness in dry sleeve applications to as little as .040. This will allow engine builders to consider DDI-2007 at an economical price, where they might have used a steel sleeve before.
Thread Starter
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Joined: Aug 2005
Posts: 862
From: Columbus, IN
I appreciate the insight on sleeve tolerance(s). That was really informative reading. What are your thoughts on the thermal barrier surrounding a cylinder idea?
The angel on my right shoulder says that if they're currently doing it to every other part in the flame path, surely it must be good for cylinders too. But the devil on my left tells me that when it comes to engines, things are rarely ever that simple...
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Joined: Feb 2004
Posts: 4,800
My concern would be the sleeve itself getting too hot and being a source of detonation. I do think having less heat lost thru the cylinder would be a good thing just think this is not the way to accomplish it.
Then again those are two very good quotes in your sig, the first one especially applies here so let us know how it works.
Then again those are two very good quotes in your sig, the first one especially applies here so let us know how it works.
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