JE 13:1.......... Thermal coated or not??

[shamisc]

I'm in the market for a piston. Does the thermal coating make any difference on HP? Also, does JE make a Hi-comp piston that you can run 93 octance with, like a 12.5:1 or 12:1?

[tucson450r]

There are many opinions on this topic. I have a JE 13:1 thermal coated that I am puttting in this weekend. I will let you know.

[Pappy]

the thermal coating will not take away any power and offers benefits over a non coated piston. (better heat dispertion, less wear on the skirt, better resistance to detonation, etc)

if you have a choice go with the coated unit.

[Martin Blair]

has thier been any problems with the coating cipping or flaking off?

[Pappy]

im sure with ceramic coating there has been a case or two, but none that i could confirm. most piston companies have the process down perfectly

[450 Racer R]

piston companies? I thought you coated them for c&d pappy?

[Pappy]

nooo....

colby uses a local company that does excellent work. and alot of pistons come pre coated or as an ption at the time you order them.

i use some of these same coatings to help prevent corrosion on pivot bolts and sleeves, and to help cut wear on sprockets. they have way more then 1 use:p

[Martin Blair]

pappy what do you do for a living besides pcing?

[Pappy]

for the past 15 years ive managed a company that deals with batteries.

[honda350r]

Originally posted by Pappy
for the past 15 years ive managed a company that deals with batteries.

What kind of batteries?

[Pappy]

all kinds of batteries:p

id state the name, but prefer to keep it off the boards until i retire:blah:

[ThumPIN_450R]

I would stay away from JE pistons I have seen 4 JE piston failures in person in the last year 3 of them cracked across the top and one broke where the wrist pin goes through breaking a hole in the front of a YFZ cylinder. I have also seen many other cases of JE failures on message boards such as this one.

[cals400ex]

some engine builders recommend the coatings, others don't. we have heard of some benefits. just to change things around, i will tell you a few things some engine builders don't like. first, they said with the coatings on the top, the piston will definatly run cooler. they said it then won't expand as much as it should when it is heated up for proper clearance issues. also, some have said the coatings on the skirt tend to come off over time and while they are on the sides, it makes no difference in friction reduction. or not enough to know better. with that said, i still run the coatings. i have had good luck with them so i will stick to using them. i get my header and piston coated by www.swaintech.com

i have had C&D's coating company do one of my pistons before too.

[DirtDevilBT]

Originally posted by ThumPIN_450R
I would stay away from JE pistons I have seen 4 JE piston failures in person in the last year 3 of them cracked across the top and one broke where the wrist pin goes through breaking a hole in the front of a YFZ cylinder. I have also seen many other cases of JE failures on message boards such as this one.

I wouldn't go saying that around the board too much, some ppl like myself might get very offended at the remark. FYI: look into how many wristpin failures have happened on stock YFZ's. Also, look at how many ppl use and are happy with JE products. Last, I wouldn't use anything other than JE or CP, and I have both.

[shamisc]

On other boards, people are saying that the coating keeps the piston from expanding. Will this cause it to burn oil b/c the cylinder is going to expand? I want the coated piston, but the regular JE has NEVER let me down! I'm stuck!!:confused:

[Pappy]

id geuss that some of the builders are running tolerances so tight with pistons configured to expand more then a standard piston and issues could arise.

just a geuss...fill us in all knowing ones:devil:

[shamisc]

NE1 ELSE??

[cals400ex]

i have been told you can run tighter clearances with the thermal coated pistons. i believe they are a benefit if you match the thermal coated piston to the cylinder. i have no idea how you would know to do that though.

[Pappy]

cals, ive been told to break the engin ein, tear it down and coat the piston and reassemble.

this comes from not only quad builders, but from some well respected drag car engine builders.

im no expert on the subject, just passing on what ive been informed.

[cals400ex]

you could be right. i have done this with my 426 and my 450r and i have had good luck with both of them. when you say coat, i assume you are talking about thermal coatings?

[Pappy]

yep thermal....

all i try and do is molycoating. i have done a few with ceramic on the dome but i dont plan on doing them unless im forced to..lol its too easy to order one already done, of course if you believe some of the builders its a waste of time having it coated prior to break in.

i see a dog chasing his tail...lol

i love learning stuff so i hope someone will come in here and make heads and tails of this stuff.

[shamisc]

ttt:confused:

id like to know about this aswell

[shamisc]

Can any of you motor heads shed a little light on this subject?? I'm ready to buy YESTERDAY!!! THANKS!!!:confused: I'm leaning towards the 13:1 Thermal coated JE.

[TRX250R87]

People have been using non-coated pistons for years with good luck. I had one moly coated and ceramic coated dome for my 250R a couple years ago, and I was not too impressed.
I'm running a 13:1 JE in my 450R without a coating, and I'm having good luck so far.
ERIC

i was talking to Dan from DASA about this subject, and he said that there are really no major gains at this time due to the coatings, but he is working on trying to get gains out of it, so we can wait and see what he comes up with, until then it looks like a normal or coated JE will be close to the same

[shamisc]

C&D racing said with the coated piston, you could still run 93 octane with the 13:1. That was suppose to be the main advantage of the ceramic coating.

[TRX250R87]

Yea, with my 13:1 and HRC cam, I run 92/93 octane fuel with no problems, and my piston isn't coated.
ERIC



Originally posted by shamisc
C&D racing said with the coated piston, you could still run 93 octane with the 13:1. That was suppose to be the main advantage of the ceramic coating.

[shamisc]

Originally posted by TRX250R87
Yea, with my 13:1 and HRC cam, I run 92/93 octane fuel with no problems, and my piston isn't coated.
ERIC

How long have you been running thie piston? Have you always run pump gas?

[iceracer65]

ceramic or thermal coating doesnt really do much to make HP. what it does do is maintain HP that the motor makes at colder temps.

in the combustion chamber, heat = Hp, and this heat isnt going to make HP if it is being absorbed through the top of the piston. with a thermal barrier, the piston has a shield to keep the heat where it needs to be, on top pushing down.

i even did other various parts of the engine/braking system with this theory in mind.:devil:

[TRX250R87]

I have been running the piston since early spring and have ran 92 or 93 octane since day 1. Of course this is with the HRC cam, and as I have been told, something about the overlap or whatever allows this to work OK. With a stock cam this wouldn't be possible, as far as I know?
ERIC



Originally posted by shamisc
How long have you been running thie piston? Have you always run pump gas?

[shamisc]

Originally posted by iceracer65
ceramic or thermal coating doesnt really do much to make HP. what it does do is maintain HP that the motor makes at colder temps.

in the combustion chamber, heat = Hp, and this heat isnt going to make HP if it is being absorbed through the top of the piston. with a thermal barrier, the piston has a shield to keep the heat where it needs to be, on top pushing down.

i even did other various parts of the engine/braking system with this theory in mind.:devil:

So with this being said, the coated piston is the way to go. Right?

[iceracer65]

sure!