engine coatings
 

Does anyone use coatings, thermal barriers or anti friction coatings in their engines. I'm thinking about raising the compression ratio in my engines to 10.2 to 1 and I would use the coatings on valve faces, combustion chambers, piston tops to help control detonation. I trailer and fill up at gas stations so premium gas is not much of a problem. Does this stuff work? Will it increase hp by itself?

Re: engine coatings
 

I use Polydyne, piston top and side coatings, the motor torched a piston after 170 hours due to a vacuum plug on the carb base plate coming off. The other pistons were in very good shape.

Most seem to favor coatings, however I remember Raylar had something to say about them in my thread back then.

Re: engine coatings
 

i send all my coating work to calico coatings (bearings,pistons,heads inc. valves and pipes ) never a flaw

Re: engine coatings
 

i also coat my cust. harley eng . big reduction of radiant heat

Re: engine coatings
 

How do you send your heads to them? Is there any clean and prep work you have to do first? Pistons will be new so that's not a problem.

Here is some interesting reading that I came across while researching this project. http://www.popularhotrodding.com/tec...ion_ratio_tech

Re: engine coatings
 

This part of the article had somethingpossibly about your engine. Was your block 0 decked?

Chamber cavities between the piston and the cylinder head between about .060-inch - .0120-inch appear most likely to be the site of detonation. Speeding up combustion mixture motion/agitation is vital. This means maximizing the quench action. On a small-block Chevy with a stock block height, a stock compression height piston is typically .025-inch down the bore. With a .040-inch gasket this makes the static quench clearance .065-inch, which is way too wide. By cutting the quench clearance the burn rate and quality improve to the point where the motor gains compression and is less likely to detonate even at the higher ratio involved.

So how closely can the pistons approach the head face? Although it comes under the heading of "don't do this at home" I have run the static piston/head clearance down to as little as .024-inch in a 350 with stock rods and close-fitting hypereutectic pistons. The pistons just kissed the head at about 7,000 rpm. As far as power is concerned, an associate of mine ran some tests in a nominally 450-horse 350 and found that each 10 thousandths of quench reduction was worth approximately 7hp.

Re: engine coatings
 

i mostly send them new heads or fresh heads they told me i could send them heads just cleaned up and apart i use calico from there reputation nothing but top notch there is a guy in your area that has a machine shop that has done a couple of blower eng. for a close freind of mine ron foster in waterford his name is scott carter 248-240-4265 used to work for wilson eng.

Re: engine coatings
 

Ian,when I upgraded my 540 2 years ago I sent my new afr heads and pistons to swain tech and had the valves,chambers,poston crowns and skirts coated. My old pistons had burn't oil on the bottom fro running slightly lean. I stuck with fairly tight clearences even though I'm running 10 psi of boost,I haven't torn motor down yet but I never stuck any pistons yet. I will give you a call when I tear the motor down and see how everything looks,Smitty

Re: engine coatings
 

more

Re: engine coatings
 

Smitty ..... Everything I have ever seen of yours is spotless .... :drink:

Re: engine coatings
 

Smitty is the man!!! He unfortunately has had an expensive education, but his info is dead nuts on and he knows what he's talking about.

He should charge for the info he gives out here!!!

Thanks for all your info lately Smitty, even though I decided to go another route. You were the only one making me feel comfortable about what i was planning.

Kirk

Re: engine coatings
 

I agree....ol' Smitts has given out some very valuble info all based on personal experience. He's a great test bed for much of the stuff we all use. He's an asset to this forum.

Re: engine coatings
 

Thanks guys,I try to take pics of everything I do then put them in my boat pic files for later uses like when posting. I sure don't know everything but have learned alot,some things the hard way :evilb: (I got the broken parts to prove it too :eek: ),Smitty
p.s-if someone is rebuilding a motor and their old pistons are a little looser than they'd like swain tech can apply the skirt coating extra thick to "save" from buying new pistons (as thick as .002 vs the std .0005 coating they use),Smitty

Re: engine coatings
 

You just have them cleaned SPOTLESS,leave the springs off and finish the valve job befire sending them in (they coat the exhaust valves,ports and seats so you wouldn't want to have to cut the coating off when doing your valve job),Smitty

Re: engine coatings
 

Ray and PatriYacht are correct.

First, you have to be very carefull about anything that increases the combustion temps. Yes, you may see a slight power increase if you're always running plenty of octane, but knock characteristics will probably be worse. If you coat the entire chamber, you'll also notice cooler running temps (especially in an air cooled engine)

Getting quench right is a much better thing to do for increasing compression.

As far as friction reduction is concerned, there shouldn't be metal to metal contact anyway!!! That's what oil is for. I've never seen a single study showing any benefits here.

Coatings tend to be usefull in highly restricted race classes where the builders are looking for every last hp. I don't know Nascar rules anymore, but I remember in the past they made good use of coatings, but I also remember them going nuts over an extra 3hp.