<VV> Ceramic Coatings Questions (Kevin Nash)

[kevin nash]

> From: virtualvairs-request at corvair.org> Message: 3> Date: Sat, 25 Oct 2008 13:58:38 EDT> From: RoboMan91324 at aol.com> Subject: <VV> Ceramic Coatings Questions> To: virtualvairs at corvair.org> Message-ID: <d4c.333801f1.3634b84e at aol.com>> Content-Type: text/plain; charset="UTF-8"> > Gang,> > I have been thinking of using ceramic coatings in a rebuild I am doing and I > have a few questions. These are as follow.> > 1. Since the head will be thermally insulated from the heat of the > combustion chamber, how will this effect the warm up period of the engine?> > 2. Since the pistons will be insulated from the heat, they will expand less > and/or slower in the cylinder. I believe that the expansion of the piston > is assumed to be a certain amount when the diameters of the piston and > cylinder are set. Is this an area of concern?> > 3. The engine I am rebuilding is a 180 turbo. Am I correct to assume that > I need to also coat components in the exhaust side of the turbo to protect > them from the increased exhaust heat? If so, which components? Also, will the > thickness of the coating cause an interference problem between components > and/or balance problem on the rotating member?> > 4. I assume that the exhaust pipe components must be thoroughly cleaned > before the inner surface is to be coated. Is it practical to coat the inside of > the muffler considering that the inside can't be thoroughly cleaned?> > 5. If I do not coat the interior of the muffler, how much hotter will it > get with this setup and will the increased temperature cause a problem with > surrounding components and paint? Also, what reduced life span can I expect for > the muffler if it is unprotected?> > I guess that is enough for now.> > Thanks in advance,> > Doc> 1960 Corvette; 1961 Rampside; 1962 Rampside; 1964 Spyder coupe; 1965 > Greenbrier; 1966 Corsa turbo coupe; 1967 Nova SS; 1968 Camaro ragtop> **************Play online games for FREE at Games.com! All of your favorites, > no registration required and great graphics ? check it out! > (http://pr.atwola.com/promoclk/100000075x1211202682x1200689022/aol?redir=> http://www.games.com?ncid=emlcntusgame00000001)> > Doc- I have been following the recent threads on thermal barrier
coatings ("ceramic coatings") with some interest, as I had had this done on my early turbo a few years ago
and had some problems with it- I had been meaning to reply to earlier
posts about this, but time constraints havent allowed me to do so
untill now. In my case, I had the combustion chamber, valve faces and
exhaust ports coated only, and had the true static compression set
at 8.2:1. The company that did this (Swain Technologies) recommended
that the timing be retarded 6 degrees, to compensate for the .6 of a point rise in effective compression ratio rise. The effective compression
ratio rise is due to the fact that the cylinder head traps more heat (because of the thermal barriers) and more heat on the compression
stroke will cause it to ping easier. In my case, my effective compression
ratio was 8.8:1 !! When I got my car back together, I really wished that
I had done something different than i did, as it was very prone to 
pinging when not under boost. Under boost, it was screaming fast,
not under boost it would ping if i suddenly accelerated. No matter
how much I retarded the timing, it would ping, as it made the head
temperatures rise, and no matter how rich the carburator was, (i remember at one point getting only 13mpg just cruising along) that
mother would ping when i nailed it too hard. A friend of mine had
a late model turbo with thermal barriers in the combustion chamber
and had the same sort of problems ( and had tried unsuccesfully to
fix it the same way I had). If you want good success with your 
thermal barriers, you will DROP your compression ratio from stock
1 point!! if you try to keep the stock compression ratio and add the
thermal barriers, you will have weird pinging problems that you wont
be able to tune out!
I will answer your specific questions in a later post, as my fingers are 
getting a little tired.
Kevin Nash
63 efi spyder
 
     > ------------------------------> 
_________________________________________________________________
Store, manage and share up to 5GB with Windows Live SkyDrive.
http://skydrive.live.com/welcome.aspx?provision=1?ocid=TXT_TAGLM_WL_skydrive_102008