Talk Morgan Forums Morgan Sports Cars Classic Morgans (pre-CX) What Did You Do To Your Morgan Today?

When I were a lad we used rattle cans of VHT, I doubt it gave much insulation but the cosmetic look actually lasted quite well if cured properly

I'll live with the bluing & buy 250 pints at Spoons

Thank you Richard. Good to hear the process is now easy to find in the UK. Sadly, like everything.the price is multiples what it once was. This options didn't exists at all in the 2005 UK.

Aside from the aesthetics:

- Ceramic coating contains heat. where stainless steel radiates it. The difference is very noticeable.
- Hot contained gases move faster than cooler contained gases..so there is a beneficial scavenging effect, which does increase bhp, as do branch manifolds for same
reason by getting rid of the gases quicker
- Ceramic coating inner and outer coating rust proofs the pipes, where other methods used on mild steel will trap moisture. It is best when the pipes are coated both inside and out.
- No one talks about tendency of stainless steel causing sad embrittlement. The ss trade refers to it as 475C embrittlement. The first ss exhaust set I bought from a popular Morgan dealer cracked and sheared in places. Only my original MMC branch manifolds (coated) remained fully intact. The latter are still doing well after almost 40 years. I tossed the rest piece by piece. Be very wary of the grade of stainless you are sold. Both the best and the worst exhausts systems look the same and are priced the same price.

Of course, most of the benefits of ceramic coating are for the manifolds and, if you have them, the downpipes. The rest of the system can be quality stainless steel.

The only minor watchpoint is the ceramic type you choose. The ceramachrome pipes discolor quickly turning a not unattractive even dull bluish gray.
The color choices will not do that as much and the darker colors not at all. Usually, the darker the color chosen, the higher the heat they can withstand and not change shade.

The sad thing is most of the aftermarket offer mild steel any more.

gmg

P.S. Here are ceramic coated cast iron manifolds on an USA Morgan 25 years ago. The effect is noteworthy as well.

I imagine the difference in surface roughness from stainless tube to ceramic coating makes very little difference to the pressure drop of the gases given the obvious turbulent flow in the system.

I can understand the heat retention argument at the headers but my question remains what impact in real terms does that have on bhp. What bang do I get for £500?
I suspect the exhaust gas temp at the tail pipe will be similar if not the same so logically the overall back pressure will be similar. Has anyone measured the difference in actual flowrates, pressure drop & temperature?

I fitted a Librands stainless steel manifold to my T16 engined +4 and the impact was very impressive in mid range torque particularly. It replaced the BL cast iron one so also saved a lot of weight & looked far nicer.


I'm guessing ceramic coating of a mild steel manifold would help reduce the surface roughness & deliver a similar but lower result.

Stainless stress cracks and also corrodes with chlorides like road salt & not all stainless steels are the same. I agree visually you can't tell AISI304 from AISI320L

Seems my memory is not so good John

Apologies but checked and a four branch manifold ceramic coating from £90. Vaguely recall a figure of £170 for both three branch manifolds on V6 now. Still not cheap.

But more affordable.
I can't say I would do it as Belle has enough umph for me. Reducing under bonnet temperature & its impact on cabin temperature would be a plus in summer.

with ceramic coated manifolds where does the heat dissipate to? does it increase the cylinder head temp. or increase the exhaust temp?

David Byrne

I don't know, but a valid point to query David

It raises exhaust gas temperature David. Hot gas molecules move faster hence increased flow. This provides exhaust scavenging which allows cylinders to pump with less resistance hence some power gain. Similar effect to wrapping exhaust down pipes.

And the cat is more efficient !