"Told you so" - melted the stainless header

[Dave Freeman]

well the sun was out today, so time to polish the car, and it looked fantastic, better go for a spirited drive then, went like the clappers, 2nd, 3rd, near 7,000 rpm, blindingly quick. back home all is well, future son in law comes round, "no I have never been in the Lotus, come for a ride I said, same drive again, warm her up, then onto the bypass, 2nd gear full throtttle, 3rd full throttle, throttle back running out of road.

"does go fast he says, quicker then I expected"

back to the house, pull onto drive, sounds lovely on tickover. Had a cup of tea, 1 hour later, must put the car back in the garage, started her up ................then a bang, very loud exhaust, thought that the silencer had fallen off.

Under the back I go, what the F..K, a hole the size of 5 pence and where is the rest of the bracket.

 

The rest of the header seems fine, the 6mm diameter bar used as a support has gone, where it was attached is a large hole. Ok, wheres the 6mm rod, inside the manifold or melted. The header failed on the drive, presumably as it cooled I then re heated it, and bang it broke, looked on the drive for the piece, no sign, so where is it..........in the header........sh.t.

 

So tomorrow the turbo comes off (noticed a lot of oil on the underside of the turbo) and will go fishing in the header for the missing part.

 

let u know how I get on, see tomorrows episode on this forum....

[ramjet]

Not good. Hope it turns out ok.

[Dave Freeman]

I found a contact up in Norfolk, the guy professed to know what he was talking about, he was a bit of a rip off merchant, no point in going back to him, I'll have to swallow this one.

I need either to repair or replace, I have asked Dave I isle , ref anolux, to see if I can purchase a new header. It's a real bummer, apart from the bracket failing, the rest is ok.

However reading the thread re Anolux headers group buy, there is more to header than just joining pipes. Certainly more than the guy who made mine.

[Fast Road]

Dave,   Whereabouts are you located ?   We are in Ashford Kent if that is any help to you.  We will be more than happy to sort it out by way of repair or by fabricating you a new one.

 

Andy

[Fast Road]

Over the years we have developed many Manifolds,and naturally some of these have been Turbo Manifolds. We have fabricated these in both Stainless Steel and Mild Steel and have found that the Mild Steel Manifolds have out lasted the Stainless Steel ones due to the Stainless cracking under stress etc.  Another point is the cost involved.  It is far more customer friendly to use Mild steel.

 

It has been a concern for many that the Mild Steel will rust.  This is not so due to the extreme heat that passes through the Manifold.

 

The Mild Steel we use has a wall thickness of 3mm, the Stainless has a wall thickness of 1.5 mm.

 

If we were to fabricate a Manifold from Stainless we would use 316 Stainless Steel, but this will dramatically increase the cost.

 

Another point to note is whether it is in Stainless or Mild Steel everything we fabricate comes with a lifetime guarantee.

 

Sorry if this a bit brief, but i didn't want to bore anyone with too many details etc. If anyone has any questions feel to send me a PM or telephone me.

 

Andy

 

www.fastroadconversions.com

[Dave Freeman]

1.00 well I removed the boot and under tray and found the bit that was missing chard and looks to be a brittle failure around the weld.

The turbo is now all but off, I thought the turbo should spin very freely but whilst free it will not hold a spin. Blades look ok although one has a tiny mark on it. Everything else on the turbo looks ok.

The manifold, it looks like the second weld could also fail due to the load now only acting on one support, the nuts are coming off ok as they have not been on the car for very long.

Heat shields are off, nuts are difficult to get to so I am off out to buy a 1/4 drive knuckle and extension bar.

Looking at another 2 or 3 hours before the manifold comes off.

I have noticed that the mounting flanges may be mild steel, they look to have corroded, we will when the manifold is off.

Update later today"...........

[Bibs]

The turbo will spin at 120,000 rpm when on full boost, that sounds like it may need a visit to Turbo Technics mate. Perhaps a bit of the weld from the support ended up going through it?

[andydclements]

Don't expect the turbo shaft to spin like a child's spinning top, there's resistance from the bearing surfaces and as it turns it is doing work by moving air at both ends of the shaft.

[Dave Freeman]

Possible bibs, down to last 2 nuts on the manifold, so easy when the most of the stuff u need to remove is new, only taken about 3 hours, turbos off and about 30mins for the nuts. Then I will be able to what's up with the manifold.

Post some more when I am done.

May need a refurb on the turbo, T 35, 360 bearings and suitable for an S4s as this one is the original, for an SE not an S 4

Talk later.......

Good point Andy, will bare that in mind

Edited April 13, 2013 by Dave Freeman

[Trevsked]

Bibs,

Don't think it's that high, more like 10x the rpm so circa 75krpm on a regular road going car. Unless anyone knows different?

Trevor.

[Dave Freeman]

Ok so manifold is off, hole is about 25 mm x 15 mm, had to take off the engine mount but otherwise a reasonable job in terms of time..

To be honest it looks like its been on there for about 25 years.

Photo to follow

[Bibs]

Trevor, some RPM's on old Dermots site...

 

http://users.ox.ac.uk/~ohare/engine.htm#h8

[fjmuurling]

The standard bearing on the turbo is a plain bearing, it should turn freely but it won't hold spin like a ball bearing. Under working conditions hydrodynamic forces force the oil (if engine is running and supplying oil) between the bearing surfaces keeping them apart preventing abrasion of the bearing surfaces. The oil also cools the bearing surfaces and reduces friction. A similar proces takes place in the big end bearings and the mainbearings.

[dodge1979]

Just my two peneth worth...but I wouldnt entertain a manifold made from mild steel...youd get longer out of using chocolate before it melted....stainless is preferred as it has a much higher stability at the temperatures we see in our manifolds. The quality of the stainless used and its designed/developed/tested/proven flow dynamics will determine the credibility of the manifold. Anyone can make a manifold, but it takes proper development and proven data to make a product worth buying.

[Bibs]

10000 Esprits disagree...

[dodge1979]

With which part?...

[pete]

Seems to me that s/s is overrated.A lot of original manifolds have lasted over 20 years and some s/s ones far  less than than that

[Vulcan Grey]

Most stainless steels rapidly loose strength with temperature.  The original cast iron manifold maintained most of its strength at operating temp, and was better for holding the weight of the turbo...

[Dave Freeman]

Good points here, for me this will be my third manifold, the cast item whilst fully tested and approved by Lotus is not gauranteed. So once you have paid your money you are on your own.

The stainless steel header made by Alunox is made in several parts and if you have a problem is possible to replace just the part with the problem, yes cost is relatively high but I am coming around to accepting that.

[dodge1979]

Yes the particular lotus manifold was good for strength, the copies sold by certain suppliers are not of the same material make up. Thats why theyre crap. But a tubular mild steel manifold is what im referring to( im not aware there are 10,000 Esprits using and mild steel tubular manifold on their turbos) as not lasting and worth it. My whole point is that the particular chemical molecular make up of the materials used will detetmin its reliability. Cheaper common materials equals failure.design and testing with give results...this has been covered so many times in other threads in great technical detail..

[Dave Freeman]

Totally Agree Darren. At the end of the day you pay your money and make your choice. There are as far as I am aware very few SS manifolds in use, few still being hard driven in all weathers, snow, ice water, hot climates etc, 10 years time we might have some data, til then it's the owner choice. If you look at high performance cars, race cars etc most have stainless headers, there must be a reason.

Dave

[CHANGES]

The discussion on even considering a mild steel tubular manifold

on a turbo seems silly too me... If they had any longevity we would all be 

using them end of story... The fact is they were tried years ago and

failed  very quickly..The designers tried options s/s being one. The lesser

quality s/s were better but still eventually failed, 321 s/s seems the optimum 

for cost and reliability,   The cost is why they are not popular along with

some early design feature's which created some issues with stress fracture's.

The Alunox system confronts all these points and addresses them. Their 

design incorporates the expansion joints which minimise possibility of stress

fractures, the Turbo has an external support to take the weight and also allow

the natural flex needed with extreme heat.  It is also made from 321 s/s by a

company that does this as a specialist.

 We are in a situation where the cast ones are failing and cast replacements do

​not meet the old standards... We also expect more from our Esprits so look for

upgrades where applicable. Any exhaust manifold has to take into account that

​it provides a function, and must do it effectively.. It seems the Alunox system ticks

all the box's and has been tested to extremes by me. The results are documented

with video proof... No other manufacturer offers this data.. As for reliability, time is

the key. I doubt any road car will give the system more abuse than mine which will

act as a bench mark. As a designer myself I have confidence in this product and believe

it is the best it can be without going silly money...

Should anyone wish to fit and test others to the same standards we will all be interested

in the results... but always remember the 3 P's   penny pinching = problems. 

[pete]

Dave does this apply to all esprits including Giugarios

[CHANGES]

Hi pete,  

Its not so much the car or model, but the application, Turbo manifold regardless get

a lot hotter than N/A , This is the primary reason they fail with inadequate materials

for the job. Design and flow dynamics also come into it. A poor design with quality

materials can fail just as quick..  so the answer is 'yes' on the turbo model's... 

[Dave Freeman]

Ok I is ready to re assemble, it should be straight forward, however I did want to refurbish the turbo but those guys at turbo techniques are far too busy to answer emails or telephone calls, bless them. So the old one goes back on until I can find another supplier who is interested in my money.

The manifold comes with all the gaskets, studs and lock nuts, first question will be does the engine mount have to be removed.

Will keep u up to date