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with je pistons they've all been between 1 and 1.1m when i've checked them i think.
I wonder what the deck height becomes if you get JE's thermal barrier coating on the piston top? They must have information on that. I couldn't find it on their web site.

To me, what is valuable about these coatings is that they increase the thermal efficiency of the engine. This becomes even more important when the static CR is raised a lot by installing higher compression pistons. Obviously, when the static CR is raised, so is the waste heat. Unless the cooling capacity is increased, reduced engine life will result. So, installing JE 11:1 pistons in the 900 SS motor, from the oem 9.2:1 should make the engine run significantly hotter. With an air cooled motor, there are limited options for increasing the cooling capacity. You can't weld on bigger fins, for example. You can add a bigger oil cooler but the basic motor is not upgradeable in this way. Enter ceramic coatings. I believe they are a good choice for people wanting more power and long life from their engines.

Swain Tech has an independent test reported on their website:

"After coating, all parts were measured again and the motor was reassembled placing all parts in their original positions to eliminate the possibility of performance differences due to new or different parts. Reassembly confirmed that the coating thickness was thin enough that clearance provisions did not need to be made. After reassembly, the motor bolted to the same dyno in the same shop the initial pulls were recorded on. The results were exactly what you would expect based on years of Swain Tech’s independent dyno test on every type of motor from a basic 5 horse Briggs & Stratton Motor to motors that are found at the top levels of circle track, drag and road racing. With over 30 years of testing, we can confidently state you should realistically expect a 2-5% horsepower and torque gain on a motor with coated pistons and heads.

With no modifications other than the coatings, the dyno pulls clearly showed the torque and horsepower curves were much better. Both curves were fatter in the lower rpm ranges where it will improve the drive off corners, and both curves were flatter as well. Peak horsepower was up 2% from 318 to 324 horsepower and peak torque was up 5% from 320 lb/ft to 335 lb/ft. In the heart of the curves, these numbers were even more impressive. At 4,500 rpm, torque was up 7% from 298 lb/ft to 319 lb/ft. At 5,500 rpm, horsepower was up 6% from 302 to 320 horsepower. Most engine builders will take full advantage of the coating by making jetting (or computer), timing, and lighter weight oil for maximum power gains. However for this test, we wanted to document and publish the gains that are achieved if the only modification was coating the engine. If the proper tuning adjustments were made to take full advantage of the coatings, these results would have been even more impressive."
http://www.swaintech.com/store.asp?pid=10321

It's up to anyone to determine if this is worth their time and effort. On a stock Ducati 900 ie motor that makes 80 hp, we can expect maybe 2 hp more from coating the engine parts if nothing else is done.

Also, from Swain Tech:
"Internal engine and exhaust coatings are so widely depended on now that the questions
“Do coatings work?” or “Will it flake off?” are obsolete. Now people just want to know, “What should I realistically expect from coating my parts?” Swain Tech Coatings has always been the leader in engine and exhaust coatings. By developing specific coatings to improve internal engine and parts and professionally applying the coatings in a controlled environment, Swain Tech has earned a reputation for quality coatings with durability that is unmatched. Through the years, we have seen small coating shops start up with inferior materials and inflated claims. Some of the inferior materials are so basic they are sold as “do it yourself” coatings. The inferior materials tend to fail in service and the inflated claims cannot be delivered on. Both leave the customer feeling like they have been bitten by the old snake oil. Swain Tech’s professionally developed and applied coatings have been on the track and in the field-tested for over 30 years. The following is an independent, unbiased test that was conducted in cooperation with Circle Track magazine. The purpose of the test was to give engine builders and performance enthusiast a realistic presentation of power gains that should be expected with quality coatings on a high performance motor. "

So, buyer beware.

full article here: http://www.aera.org/ep/downloads/ep9/EPQ110_34-40.pdf
 

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Dirk, i said it some time ago, and i'll say that again, not to personal offend you,
but to get this place a little more serious.

see Dirk, your Problem is the balance between personal first hand technical experience
and the amount of "Knowlegde" that is at hand through the interweb these days.

Given the oportunity to read, what an obviously very experienced technician
like Higgy has to tell you after so many years of actual first hand track and
workshop experience, you still come up with more and more technical info.

Technical info, that you can either not understand or are not willing to read
by yourself.

short example:



I wonder what the deck height becomes if you get JE's thermal barrier coating on the piston top? They must have information on that. I couldn't find it on their web site.

in the same text:

Reassembly confirmed that the coating thickness was thin enough that clearance provisions did not need to be made.


so, for me, there was just no reason to post more from the snakeoil tech
company, Higgy has well explained the pros and cons, and the theory of
result/risk while searching for more power in an engine.

well understandable and very rational of course.

you for yourself will not see too many if any benefits from coating your
engine parts, you could rather paint your cylinders and heads black and
have a larger or second oil cooler installed.

but get it back together and running at first, and stop thinking too much
about it in between.

please. :)
 

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3,890 Posts
Dirk, i said it some time ago, and i'll say that again, not to personal offend you,
but to get this place a little more serious.

see Dirk, your Problem is the balance between personal first hand technical experience
and the amount of "Knowlegde" that is at hand through the interweb these days.

Given the oportunity to read, what an obviously very experienced technician
like Higgy has to tell you after so many years of actual first hand track and
workshop experience, you still come up with more and more technical info.

Technical info, that you can either not understand or are not willing to read
by yourself.
First you say you don't want to offend me, and then you call me an idiot. Which is it?

Second of all, the two quotes you provided are for two DIFFERENT coatings. They are by DIFFERENT manufacturers. So who is the idiot now? One is by JE and the other is by Swain Tech.

Even further, who in the hell are you to tell me who to believe? Don't you think that the people who actually have experience with these coatings might have something useful to say about them?

Finally, a wise person does a lot of research before taking action. So of course I'm going to research something before deciding what to do about it. Also, change your avatar to something else. You ARE offending me now. If you had any courage at all you'd put your own mug up there.
 

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Dirk, please stay nice and friendly, i have no intention at all to start any
kind of arguing or debate.
It was not my intention to call you an idiot, the idea behind my post is
to get this supersport area technical discussion a little more serious.

I sure realised, that these two quotes were from different companies,
but it is about the very same matter, isn't it ?

I am Jesus, you better believe me, and not that company that just wants
to sell you their stuff.

Research is okay and needed, i will change the avatar, no problem.
i hope it is okay when i have another attempt with this pic later on.

how about a chinese version now ?

:) ;) :abduct:
 

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3,890 Posts
Dirk, please stay nice and friendly, i have no intention at all to start any
kind of arguing or debate.
It was not my intention to call you an idiot, the idea behind my post is
to get this supersport area technical discussion a little more serious.

I sure realised, that these two quotes were from different companies,
but it is about the very same matter, isn't it ?

I am Jesus, you better believe me, and not that company that just wants
to sell you their stuff.

Research is okay and needed, i will change the avatar, no problem.
i hope it is okay when i have another attempt with this pic later on.

how about a chinese version now ?

:) ;) :abduct:
I am having a technical discussion, as far as I can tell.

Different manufacturers have different coatings. They are similar, but some are thicker than others.

Please do not do anything with my avatar. I don't think it's funny any more.
 

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you could rather paint your cylinders and heads black
I looked at my heat transfer book from college and this is actually a good idea. Bare, rough aluminum does not have very good emissivity, but almost all paints and similar coatings do. So, putting some kind of flat finish coating on bare aluminum would improve radiant heat transfer from the part. I do not know what percentage of the heat transfer from an air cooled engine is radiation though. I imagine most of it is convection.
 

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if i remember the tech talk on our vespa board correctly, the black painted
two stroke head ( with lots of fins ) leads to a reduction of 10° celsius in
engine temperature. ( edit: on a only aircooled two stroke single that is ... )

sure a good idea to think about heat radiaton while the engine is tuned
for more power or upgraded in cc.
the factory does paint the cylinders of the 1100cc monster engines in
black, not just for cosmetic reasons i suppose.

:)


 

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If the paint is thin enough, it won't add much insulation value to the heat conduction path while at the same time increasing the emissivity.

Another option is to anodize. Anodized aluminum has an emissivity of 10 times plain aluminum, pushing it to near the black body ideal of 1.0, but the thermal conductivity is much less. The anodized surface is an insulator, but the net effect in general is to increase heat transfer. I did some reading on this, and in the electronics field, they anodize the transistor and chip heat sinks to increase heat transfer. They found that the chips overheated when they used plain aluminum heat sinks.

Has anyone noticed a brown residue in the exhaust valve area inside the head? When I take the valve covers off, I can see a brown residue with bubbles in it that appears to be from overheating the oil there. I suppose this could be just part of the problem with my bike, since it did once run with glowing exhaust pipes, but I'd thought I'd ask anyway.
 

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Has anyone noticed a brown residue in the exhaust valve area inside the head? When I take the valve covers off, I can see a brown residue with bubbles in it that appears to be from overheating the oil there. I suppose this could be just part of the problem with my bike, since it did once run with glowing exhaust pipes, but I'd thought I'd ask anyway.
it's common.
 

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it's common.
OK, thanks. I guess that area just gets really hot. I wonder if a significant part of the heat in this area is from the exhaust pipe radiating back into the head. The pipe is recessed into the head, so maybe a thermal barrier on the pipe will reduce the heat in this area.
 

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it is not the header that heats up the heads, but the hot exhaust
gas that travels through the exhaust port.
the SS1000DS has got shorter exhaust ports for that reason,
and they are sliced for some ventilation too.

a close to stock road engine does not need any further modifications,
get it back together and running, it is well develloped as is, ready to
enjoy with nothing to worry about.

:)
 

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Discussion Starter #92
This thread certainly went down a different road, but all the information is certainly interesting.

Got it all put back together. I think it was a good thing that I took it apart. The vertical cylinder was caked with oil, maybe from the broken rubber valve seal. When I took the piston out, it looked like the valve had contacted the piston at some point, see pic. Maybe the contact with the piston caused the piston to rock and preceded to blow by oil.

Anyway the bike was running ok except for the loss of about .5 qt every 2k miles.

I inspected the bores for any disturbance, ovality, and taper. Everything seemed to be inspec, so in went the new pistons.

Started up, smoked off the assembly oil, and all is well except for a slightly rich vertical cylinder. No oil is getting through on the vertical anymore thankfully.
 

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it is not the header that heats up the heads, but the hot exhaust
gas that travels through the exhaust port.
the SS1000DS has got shorter exhaust ports for that reason,
and they are sliced for some ventilation too.

a close to stock road engine does not need any further modifications,
get it back together and running, it is well develloped as is, ready to
enjoy with nothing to worry about.

:)
Well, I and others are finding evidence of cooked oil around the area of the exhaust valve. This means that this area probably gets over 300 deg F. To me, that is a design flaw and I intend to do what I can about it. I need to figure out the most likely cause first of course.

Also, if it was true that this engine was fine as it came from the factory, then why did my valves leak so badly that I need to lap them again? There are many things that are "wrong" with this bike. Other people have had problems with things like early valve guide wear.
 

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This thread certainly went down a different road, but all the information is certainly interesting.

Got it all put back together. I think it was a good thing that I took it apart. The vertical cylinder was caked with oil, maybe from the broken rubber valve seal. When I took the piston out, it looked like the valve had contacted the piston at some point, see pic. Maybe the contact with the piston caused the piston to rock and preceded to blow by oil.

Anyway the bike was running ok except for the loss of about .5 qt every 2k miles.

I inspected the bores for any disturbance, ovality, and taper. Everything seemed to be inspec, so in went the new pistons.

Started up, smoked off the assembly oil, and all is well except for a slightly rich vertical cylinder. No oil is getting through on the vertical anymore thankfully.
Wow, it's a good thing you took that engine apart!

How did you determine that the vertical cylinder is running rich?
 

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then why did my valves leak so badly that I need to lap them again?
Wear, corrosion, deposits from burning oil due to leaky rings or valve guides, etc.

It's normal, at least in my 2V Ducatis and Guzzis, as well as air-cooled VWs I've owned in the past.

Tom
 

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Pulled the plug after a short trip just to check things out, black soot, but not wet so I know it's not oil.
Other than an ignition issue on that one cylinder, I really don't have a solution for you, sorry.

Oh, I meant to ask if you checked that valve for trueness. If it hit the piston, then it could very well be bent.

After looking closely at that damaged valve pocket in the piston, I would be very surprised if that valve was not bent!
 

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Wear, corrosion, deposits from burning oil due to leaky rings or valve guides, etc.

It's normal, at least in my 2V Ducatis and Guzzis, as well as air-cooled VWs I've owned in the past.

Tom
None of the above, as far as I know. The bike only has 5,000 miles on it, give or take. The guides, rings, etc are good. No oil burning. After lapping the valves, the intake on the vertical cylinder clearance for the opening rocker was too tight, so I opened it up a little, to 0.1 mm (from 0.05). The ECU does have an issue with running too rich, but I hope to have that fixed soon. I suppose the excessive carbon deposits from running too rich could be a problem for the valves in my case.
 
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