Has anybody tried ceramic thermal coatings?

[Number21]

I think I'm going to be building a new stroker. Not too wild, I want to focus on efficiency more than anything else.

I'm wondering if anybody has used any of the new ceramic thermal coatings for piston tops, combustion chambers, intake/exhaust chambers, and valves? They are known to make a difference on old school V8s, but I've never heard of anyone doing it with a Jeep.

Leaning more and more towards the Eddelbrock aluminum head, which I think might benefit even more from this due to the extra heat conduction from the aluminum.

Also curious if anybody has tried oil shedding coatings for things like the crank and inside the oil pump or lubricity coatings for things like piston skirts?

The price for this stuff doesn't seem that bad, especially with only 6 holes!

[Bertismyname]

I haven't personally used them on a jeep engine. But, most of tricks used on pushrod v8 work on jeep engines.
If I had the extra cash I would probably have the intake and head extrude honed instead. This process removes restrictions that Traditional porting cant.

[Number21]

If I had the extra cash I would probably have the intake and head extrude honed instead. This process removes restrictions that Traditional porting cant.

Oooooo....I hadn't thought of that! I do plan on using the 99+ Chrysler manifold, sounds like a good idea there.

Is this something that would benefit the Eddelbrock head? I have no idea how well machined they are. I know they sell a full ported version but I'm not looking to win any races.

[Bertismyname]

It will help as long as compression and cam will support the flow.

[Number21]

Ugh. Just got a quote back for $600 on the intake and $700 on the head. Add more if I want it matched to the gasket. I don't think it would be worth that much...thermal coatings should only be a few hundred for the pistons and combustion chambers.

[Bertismyname]

Yeah. I wasn't too sure about pricing. An allout effort would probably be worth it.

[Number21]

Does anybody have any thoughts on aluminum heads, compression ratios, and 87 octane?

I will only run 87. I would like the highest possible compression ratio with the Edelbrock head.

Would it be better for the aluminum head/combustion chamber/piston to have a thermal coating to help prevent detonation? Or would it be better to conduct away more heat for less detonation?

[GoatBoy4570]

Would it be better for the aluminum head/combustion chamber/piston to have a thermal coating to help prevent detonation? Or would it be better to conduct away more heat for less detonation?

Your assuming that detonation is caused by heat ... while that's a component, mixture distribution, pressure and available space during the ignition phase weigh in pretty heavily as well.
I think a coating on the head is going to negate the advantage aluminum has over cast iron in terms of instantaneous thermal conductivity.

I think the general rule of thumb is that aluminum allows 1 point of compression over cast iron so the max you can run with 87 octane is about 9.75 to 1
not addressing any other factors such as tuning, quench, air temp, timing etc ...

[Bertismyname]

Cam timing is one of the largest contributing factors in determining static compression ratio. Early intake valve closing favors lower static compression ratio. While a later intake closing is desirable for higher compression. Aluminum will help with detonation control but, is not the end all be all in detonation control. The more efficient chamber shape of the edelbrock head has a greater effect on controlling detonation than the material.

[Number21]

I think a coating on the head is going to negate the advantage aluminum has over cast iron in terms of instantaneous thermal conductivity.

Well then, I guess that brings up the question, which is more efficient? An aluminum head with no coatings and higher timing, or a coated head with lower timing? Or just a ported iron head because I'm not concerned about weight?

Conventional wisdom says keeping more heat in the cylinder, especially with a square/undersquare bore = better efficiency.
Modern wisdom says aluminum heads, aluminum heads, aluminum heads and higher compression.

They kind of contradict each other...

[GoatBoy4570]

It could be that a aluminum head is better able to deal with combustion chamber hot spots allowing better heat distribution and a higher tolerance to uneven (and unstable) heat pockets in the burn mixture.

Yeah it is confusing because on one hand we are saying, convert as much heat energy into work as possible, keep heat energy out of the cooling and exhaust systems AND somehow control the burn (with available fuel) while trying to achieve all of it.

You might want to look at intake air temp, having a heat shield or header wrap between the header and the underside of the intake ?
Ceramic coat the inside of the header, ceramic coat the outside too ? Engine compartment temp ....