The 'E' Type Forum

I was looking for a solution to the flaking exhaust manifolds problem which has plagued the E-Type since its launch. In the US people swear by Jethot but it does not seem to be available over here. I found this company though that does provide a high tech ceramic coating and specialise in performance/race cars. They also do classic cars - a pair of E-Type manifolds will cost about ?350 to coat though. Available in a range of funky colours or "liquid black" for the E-Type.



http://www.zircotec.com/page/classic_cars/14

I will also add a link in the Knowledge Base for future reference.

David,

my friend spoke to these guys when we were at race retro regarding his race car , it seems pricey but the main use is for the reduction in under bonnet/cabin heat and not looks,they also said it has a life span before it needs re-doing,

Steve

Known about them for a long time. Used to pass their place but as it's not the same finish as original I figured the cost-benefit over matt black from other sources wasn't that great. Apples and pears, I realise, but once you deviate from shiny gloss enamel, everything else is moor.

On that topic, I am haivng better success than I thought from my latest set of enamelled manifolds... I bought a set of seconds from Barratts at Stoneleigh a while back but they quickly deteriorated. Nothing duanted they swapped them and reinforced the 'conditioning' advice they give (I hadn't received the leaflet with my loose 'seconds').

Anyway, while my wife was out of the house on various occasions I heated them in the oven several times for progressively longer each time. Being brand new they didn't smell at all, but it just seemed wiser to do it whilst SWMBO was absent.

Subsequently I put them on the car and did a few short starting/cooling cycles, followed by progressively longer drives. I'm currently on about 300 miles and not hint of a crack but I've been keeping the revs down. This weekend will see a longer faster run and the weekend after is Spa and a brief foray into Germany afterwards, so that should be a good test. I will report back if they stand up to prolonged highish rev temperatures. So far it looks promising and certainly far far better than my first attempt...

Pete

The killer seems to be water rather than heat. Rain falls on the bonnet which, in itself, is no problem - until you brake, at which point water from the screen, scuttle and rear bonnet is thrown forward down the louvres and onto the hot manifold. Cold water/hot manifolds is a bad mix and causes crazing on the ceramic. Each time you brake the problem get worse.

I like your idea of using the oven though. Our AGA has warming, simmering, baking and roasting ovens each at a different fixed temperature so a staged 'proving' of the manifolds is easy. But even the hottest part of the oven is only 240C whereas in use they probably get up to 600C? Keep us informed though as you (and SNG) may have discovered the Holy Grail!

Good point. I daresay the next few weeks of driving will have rain David- certainly if Spa's reputation holds good. Having said that, our previous visit it did stay dry...

I'm not sure of the physics but I have slight doubts that a few cm3 of water can materially affect the temperature of a huge mass of iron at many hundreds of degrees. The specific heat capacity is neglible, but I guess it might be possible to induce a local miniscule cooling of the glass-like coating sufficient to cause thermal stress. Maybe they should coat them in black Pyrex...

Pete

Doesn't have to affect the cast iron just local rapid cooling of the ceramic surface which will cause it to contract against the iron similar to a bi-metallic strip. In fact a ceramic covered steel tubular manifold would probably have a better chance of survival in these circumstances. We could ask ClassicFabs as they make one:



FIA approved as well!

Heuer wrote:until you brake, at which point water from the screen, scuttle and rear bonnet is thrown forward down the louvres and onto the hot manifold

Thrown forward? In an E-type? Surely you mean 'leisurely rolls forward'..?

:D

Very pretty... probably run somewhat cooler as well if coated inside.

Agree on the rain thing David but didn't express myself very well. There is simply no prospect whatsoever that the cast iron lump is significantly cooled by a few mL of water splashing onto it, but as you say the coating, even intimately connected to said huge heat reservoir underneath, may briefly contract enough to stress the join or the coating itself and cause cracks.

Thing is, I believe the saloon ceramic manifolds deteriorate is similar fashion and there is clearly no louvre spillage on those. Hence I'm still not convinced it's a significant mechanism but no, I shan't be dripping water on mine in the name of science to find out - at least not while they are still in good nick...

Pete

Oh well, another theory bites the dust...

Yesterday alternated 3000 rpm dual carriageway cruising with slow and very wet driving. Today the manifold ceramic is still on there but there are distinct signs of longitudinal cracking along what looksl ikely to be the highest heat zones.

Ho-hum, so much for 'seasoning' or 'conditioning' the manifolds in the oven and driving gently, albeit not for the 1000 miles at max 3000 rpm recommended by the sellers.

Seems the ceramic may be fine for pootling around but not for high speeds. Which we already knew of course, but I was hopnig I'd found the elixir of youth

Does the rain theory now begin to hold water (sorry had to do it )? Seriously though I think it makes sense as you are beginning to find out. Try getting the manifolds really hot and chucking a glass of cold water over them

Heuer wrote:Try getting the manifolds really hot and chucking a glass of cold water over them

Being a shy retiring type, I would not wish to steal all the glory for solving the riddle David. Consequently, I feel it incumbent upon me to share the honours with you, as we perform the definitive experiment.

To wit, you get yourself a set of very hot manifolds and I'll take the minor role of Water Boy.

Deal?

Pete

Deal! Let's do it:

:-)

With all this talk of expensive new coatings that either fall off or need to be done every so often, I thought it relative to post a photo of my manifolds. Painted with high temp barbeque paint (on the left) about 5000 miles ago and still showing no signs of needing to be re-done.



Angus

Angus,

Now they look the same as my manifold and I have now done 10,000miles and they still look good. Do I have the same barbecue paint.

Tony wrote:Angus,

Now they look the same as my manifold and I have now done 10,000miles and they still look good. Do I have the same barbecue paint.

Tony, you might have, I honestly can't remember if I told Barry to get it (or I got some for him). Good stuff though!

Looks better than my barbecue!

FWIW, last year my xk120 OTS received a new set of correctly finished exhaust manifolds (via XKS.com). The manifolds looked good for about 500 miles, but at 2000miles they look like an antique porcelain vase. This car has only been driven in the rain once, and there are no louvers on the hood.

I think our fellow Jag owners that win at concours type events have a set of show manifolds and a set of everyday manifolds. How else could they keep even the manifold nuts looking perfectly new. Might not be a bad thing as it would prevent the manifold to down tube nuts from seizing.

John

bfeng wrote:I think our fellow Jag owners that win at concours type events have a set of show manifolds and a set of everyday manifolds. How else could they keep even the manifold nuts looking perfectly new.

The answer to that question is too obvious and too sad to warrant mentioning it here - though doubtless some concours people DO run their cars as intended...

FWIW my own manifolds, now subtly laced with hairline cracks on the less-visble side areas, appear to have stabilised. I've just done the fastest and hardest 900 miles in the car's time with me and they look no worse. Dorothy and I did a quick 3-night run to the Spa 6-hours and Germany, taking in a social call in The Netherlands and some 'convoy leading' duties this afternoon with a rather rapid group of British bikers heading back to Calais. The hard top meant we were able to do 85-90 for hours on end without ear plugs and the all-standard exhaust kept the noise reasonable too.

Pete

Angus,
Do you know what were the temperature spec's on the "high temperature barbecue paint" that you used? While my rusty manifolds are off for my engine rebuild, I thought that I would like to try to spiff them up a bit. Here on this side of the Pond, Rustoleum makes a "High Temperature Barbecue Paint" that is rated to 1200 deg. F. for brief periods (whatever that means) and 600 deg. F continuously. Do you think that the Rustoleum would hold up? Any better paint advice?