Ceramic coating ?? hey Disco !!

[steptoe]

Adrian, aka Discopotato03, has mentioned ceramic coating of his EA82T piston crowns and valves . Anyone else been doing this ?

Adrian, wanna share with us an indication of cost of this sort of thing and who/where ? It used to be something only race engines got but I get the impression the coating is getting used more in recent years. was sitting behind a van advertising said service but my memory failed me on the name and phone number

[discopotato03]

Ears burning .

Don't know the cost of coating the piston crowns and chamber side faces of the exhaust valves , will ask Jacko when I see him next .

The company who did them is called Competition Coatings - somewhere in Sydney .

Night all , A .

[RSR 555]

I have done a few engines now... not only just coating the pistons and valves but also the combustion chamber, exhaust headers and in some cases the exhaust housing on the turbo. I have found the temp in the exhaust increase by 10% which means the the combustion flame is not getting soaked into the engine.

The company we use over here in the West has the same name as the one in Sydney, so it maybe a Australia Wide setup? but don't quote me on that

It's not a cheap process and it's really only beneficial if your planning on drag racing or running your engine at high revs for long periods of time.

[discopotato03]

As RSR mentioned its not dirt cheap to do but the $ value you place on it would depend on the intended purpose of the engine .

If you want a bit more than most do from a prehistoric technology starved engine like an EA82T you have to find ways of making it operate reliably at the sorts of outputs one would expect from a standardish EJ20 turbo engine .

EJ turbos have better heads pistons management than an EA82T and the safety margin of intercooling . Generally detonation and heat are the toughest issues for turbo engines and factories go to a bit of trouble to make production versions reliable long term .
The sorts of differences you find on a turbo vs NA engine are generally things like piston oil squirters and oil/water heat exchangers and sometimes higher capacity radiators .
Subaru did very little with the EA82 when they turbocharged it , basically lower compression ratio thicker crowned pistons and different camshaft profiles to cope with the lower off boost dynamic compression . They had to alter the ECU settings and added knock sensing to give them a measure of protection against fuel system failures and garbage grade fuel .

For me its not a practical proposition to make piston oil squirters for an
EA82T so thermal barrier coating the piston crowns is the next best solution . It made economic sense in my engines case because the bores and pistons were in such good condition that we reused the std slugs . Someone switched on has rebuilt this engine before I got it and not too far back judging by the internal condition of it . Handily they decked the tops of the cases to get the compression ratio up to 8.6:1 which is about what Subaru would have run had RX L's had intercoolers .
I always intended to raise the compression ratio though someone beat me to it and achieved it with std factory EA82 turbo pistons , we just wanted to keep the piston temps down because its excessive heat that makes cast production pistons collapse their ring lands trapping the rings so they can't seal on the bores any more .
Anyway I figure that if we can protect the weak links in this engine it should be reliable at reasonably high outputs (150-160) and not need another rebuild while I have it .
The other thing we intend to run is an air to air oil cooler and synthetic oil again to keep the overall temperature manageable . Having the oil cooler totally divorced from the engines water cooling system should allow us to get by with a new Koyo std radiator .

Time will tell , cheers A .

[steptoe]

Alrighty, thanks for the replies. I think it was Competition Coatings van I was behind too ! Still would not mind a ball park figure for curiosity sake. My current rebuild of an EA81 is going pretty standard. If I do turbo it in the future it will need to be low boost given normal pistons .040" oversize. s

[marshy]

I had 4 pistons done and it was around the two hundred mark?

[discopotato03]

Steptoe if you did that and ran effective intercooling eg WAIC 9.0:1 compression ratio is not so bad . If you could use the early EA82T's stand alone knock box and distributor it should help prevent detonation .
Porting those heads would make a noticeable difference as well . If you happen to cut up a dead 81 head you would see how much material there is in the flat parts of the chambers decks , you may be able to lay the walls back a little and bring the CR down a smidge .

One thing we noticed was that turbo Vortex chambers have rounded or radiused edges so we duplicated that on the heads we are using . These are the only set of L heads I've seen so far with no cracks at all , they are the first gen EA82T heads too .

Cheers A .

[steptoe]

and throw my preferred motion lotion of LPG in of course

for normal power needs the EA81 head standard flows quite well according to an old head man - it's the std manifold and carb that is restictive

ta, Marshy, curiosity satisfied

[discopotato03]

I was quite surprised when I looked at an EA81 and an EA82 MPFI head side by side , the 82's were far from perfect but less restrictive than the 81's .
If you get the chance have a look .

Cheers A .

[steptoe]

I wonder if EA81 T heads inlet match EA82 T ? Spidered EA81T !

[Gannon]

I wonder if EA81T heads inlet match EA82T

Nope!

EA81T heads use the same intake pattern as normal EA81's.

If you wanted a better flowing intake for an EA81, you would have to build it yourself.

If you are considering putting money into an EA81 to make power, have you considered SUB4 or RAM

These start with the SUB 4 Port heads. These have been modified to give "one port per valve for both inlet and exhaust to allow for tuned length of induction and exhaust. They have two spark plugs per cylinder for true dual ignition. The heads are cast in ASTM 356 aluminium alloy, which is heat treated and CNC machined. The heads come with bronze valve guides, 42 mm inlet valves x 7 mm valve stems. Performance valve springs, match cam and h.p. option

Power output of these engines varies between 115HP NA up to 200HP with just 6psi of boost from a rotax supercharger.

A little pricey though RAM Engines

[steptoe]

I found prices on these some years back - enough to pay for someone to DO an EJ conversion if you include roller rockers with the heads!! My brocken block is mounted up to turbo crossover pipe and gonna fit up to an engine stand and look at getting a oil supply hose for a turbo made up to run off oil pressure switch port for a one day maybe project - NO BLOODY HYDRAULIC LIFTERS TO POSSIBLY PLAY UP ( still to fit my newies in the GLTA)