Teflon coated piston skirts

[spetz]

I seen that CTR pistons have teflon coating on the skirts.

And, also I can get it done for $50 per piston (my engine is apart now)

And, I am just wondering, what improvements are there?

Worthwhile?

[Slow96GSR]

Look at my car page. I run cooler, the oil get back to the pan to cool and with the motor running cooler there's HP to be gained. Hell yes it's worth it. You can get more stuff coated to. Ceramic coatings for the top of the pistons, cylinder domes and intake/exhaust runners. Check out Calico (www.calicocoatings.com) once their site comes back!! I have been happy and $50 a piston is the going rate. Should include any shipping to.

[tinkerbell]

i think the OEM coatign is a molybdenum coating, not teflon, but does the same job of reducing friction...

and is what helps the ITR engine to rev so high with such a poor rod/stroke ratio... (not an issue on B16A)

[spetz]

But if the engine oil never reaches optimum working temperature, isn't that bad for wear and tear?

But, it seems like I may do that then!

[ProECU]

i think the OEM coatign is a molybdenum coating, not teflon, but does the same job of reducing friction...

and is what helps the ITR engine to rev so high with such a poor rod/stroke ratio... (not an issue on B16A)

According to Mr Widmer, it's the bearing quality, design & material that facilitates it.

[aaronng]

Don't think that molybdenum coated skirts are the end-all of high revvability. Even the Jazz VTi has moly coated piston skirts. As ProECU says, it is the bearings, materials, design and also perfect balancing and lightening.

[tinkerbell]

try to keep it on topic fella's... the subject is quite clearly "if coating pistons provides improvements"... (not "is it the be all and end all of high revability", which it clearly isn't)

and spetz - any coating will not reduce friction so far that the oil doesnt heat up... the coating only provides friction reduction between the piston and cylinder wall, no where else...

[aaronng]

And I was answering to his worthwhile part. He did ask if it was worthwhile.

[Weq]

http://captanis.members.veritel.com.au/turbo/new_setup2/pistons1.JPG

I have since had the domes cermic coated and modified to reduce heat absorbtion. unles ur running a hi-po motor, i wouldnt recommend cermic coating the head side of the combustion chambers though. heat has to go somewhere and the heat is the perfect place with plenty of cooling!

yes its worthwhile. $50 is a small price IMO.

less friction which means less expansion of the skirts. which means ur clearences are kept and can run them tighter.

[spetz]

Will they make more power, or is it a safety and longetivity thing?

[Weq]

more safety then anything

[spetz]

Well, I have a V6, so is it worth the $300 considering stock it didn't have that?

[tinkerbell]

maybe get a quote on blue-printing the crank or similar - what is your aim? to increase reliability? why is the engine appart? what else is being done?

what are your engine parameters? maximum RPM, bore, stoke, rod lenght etc?

[ProECU]

Will they make more power, or is it a safety and longetivity thing?


more safety then anything

Ceramic coatings don't propogate as much heat, its used a type of insulator, hence, the cylinders will run cooler and the combustion event will be cooler.
How much cooler, no idea, but this is where HP is gained.

Stating its a "safety" measure is vague.... Safety against what exactly?

Other thing is, there will likely be less heat transfer from piston skirt to the cylinder walls, promoting cylinder longevity.

[bennjamin]

Ceramic coatings don't propogate as much heat, its used a type of insulator, hence, the cylinders will run cooler and the combustion event will be cooler.
How much cooler, no idea, but this is where HP is gained.

Stating its a "safety" measure is vague.... Safety against what exactly?

Other thing is, there will likely be less heat transfer from piston skirt to the cylinder walls, promoting cylinder longevity.

if there is less heat transfer to the cylinder walls ~ where will this heat dissipate to then ? More so into the cylinder dome and perhaps promote detonation?

[tinkerbell]

the heat would hopefully be transfered (reflected) more into kinetic energy rather than being conducted into the pistons metal... thus creating a better burn and less detonation...

BUT let us not confuse the two types of coatings being discussed (despite the fact the original poster only asked about friction reducign ones).

FRICTION REDUCING coatings (teflon/moly)

and

HEAT RESISTANT coatings (ceramic)

two entirely different types and roles...

[spetz]

What I am trying to achieve...
Well, I want a quick NA car, the engine is a 6A12 MIVEC (from an FTO) and it is being rebuilt because I had an engine conversion done and the current engine seems to have problems. So another one is being built to be dropped in.

All the mods to it now are simple. Basically everything on the outside of the engine is done and, internals are stock, heads are match ported, intake, everything was balanced, might get the heads skimmed as well. Running a piggyback computer


I don't have enough $$$ for internals and such, so, I just want to do as much as possible without too much money while the engine is apart.

Bore is 78.4 mm and stroke is 69mm

[Slow96GSR]

The heat goes right out the exhaust! Duh! LOL! I mean come on guys, yes some heat will soak in to the cylinder walls and domes but not enough to hurt. The tops of the pistons aren't being done with the ceramic so the heat will also go thru the tops of the pistons. He will not see any HP gains from coating just the skirts. If he did coatings on everything they do he would see a much cooler motor and gain HP there. If he is worried about the domes and valves he can ceramic coat those too and then be safer. The coatings don't add like 20 HP it's more like 5-6 at most and that’s due to the motor running cooler. Get the skirts coated and leave it at that… unless you decide to run nitrous or F.I. then you need the full setup. But you better decide now or you will be tearing in to the motor again. Full coatings of the head and block, pistons, crank, rods, valves, etc. will be about $1,500 USD.

"Skirt Coating - Is a dry film lubricant that retains oil while reducing friction and heat. This coating will allow for the use of reduced clearances without scuffing. The results are less blow-by, and increased horsepower, and less wear on the cylinder walls and piston rings. CT-3 Provides invaluable secondary lubrication that greatly extends piston life and provides superior corrosion resistance. CT-3 Provides invaluable secondary lubrication that greatly extends piston life and provides superior corrosion resistance.
• Reduce Friction and Heat
• Increases Horsepower and Efficiency
• Extend Piston Life
• Available Thickness: .0005-.001
• Applications: Pistons Skirts"

From here! (http://www.calicocoatings.com/index.phtml?coatings)

[tinkerbell]

What I am trying to achieve...
Well, I want a quick NA car, the engine is a 6A12 MIVEC (from an FTO) and it is being rebuilt because I had an engine conversion done and the current engine seems to have problems. So another one is being built to be dropped in.

All the mods to it now are simple. Basically everything on the outside of the engine is done and, internals are stock, heads are match ported, intake, everything was balanced, might get the heads skimmed as well. Running a piggyback computer


I don't have enough $$$ for internals and such, so, I just want to do as much as possible without too much money while the engine is apart.

Bore is 78.4 mm and stroke is 69mm

i would recommend you save the money and put it towards a better EMS/ECU...

[Weq]

Stating its a "safety" measure is vague.... Safety against what exactly?

Other thing is, there will likely be less heat transfer from piston skirt to the cylinder walls, promoting cylinder longevity.

Safety was in reply to him reading my post, #9.


[
less friction which means less expansion of the skirts. which means ur clearences are kept and can run them tighter.


As stated. The coating is more of a friction reducer then anything. This means less heat created due to kenetic engery, hence cooler skirts and less expansion. The coating also promotes proper oiling/cooling (due to ripple effect it gives pistons) of skirts/cylinder walls. All these are consequences of less friction and less expansion.

These are the benifits that the coating offers. They seem to be used alot in bob-cat motors?? Another thing i have heard is that the coating does last very long. when i say 'the coating' i dont know who coated it which could possibly mean that it was not done properly, but i have heard a few people state this.

[bigteethygrin]

i wonder how tough the teflon coating is... i mean will it come off as easily as a teflon coated fry pan?? it is afterall rubbing against metal.

[tinkerbell]

www.google.com

have a search on this subject...

you will learn a lot about this subject ;)