Alunox SS manifolds

[Guest Mutley00]

So what's the feedback chaps on those that have been installed? My mild steel manifold has just been diagnosed as 'knackered' and I'm being pull one way by a very well respected Lotus Approved Specialist who says 'avoid SS manifolds like the plague' and  all the positive vibes on the forum.

 

His chief gripe were that several SS manidfolds were tried a while ago and get so hot he has dealt with several 'melted' chassis members. Leon has got one left on the shelf from the latest order and I'm bu*****d if I know what to do.

[sailorbob]

The thermal conductivity of 304 stainless steel is not much higher than the cast ductile iron manifold (assuming it's spheroidal and not flake graphite) so the issue with the chassis tubes is most likely due to the reduced clearance that the tubular manifolds have. Both materials have considerably less thermal conductivity than mild steel. The stock manifold already burns the galvanising off the chassis tube near the turbo so some kind of heat shielding is definitely in order. Maybe ceramic fibre paper sandwiched between some thin stainless steel sheet?

[60N4.7]

My Alunox manifold has been installed for around 2 months with nary an issue. DEFINITE boost in performance too.

[Dave Freeman]

Totally happy with mine, no issues, reduced turbo lag, smoother delivery.

All in all a great purchase.

Dave

[Scotty2]

Not one on the shelf now. I just bought it !

 

My manifold has cracked for the second time. The original lasted 40 000 miles, the replacement cast one lasted 3000 miles!!!

 

Oh the joy of trying to fit this now...

[Dave Freeman]

so have you fitted it yet and what are the results.

[Scotty2]

I just got it today (working away delay in sending cheque..) Looks a well engineered piece of kit. All gaskets and studs/bolts included. WHen I replaced my last one, I got a set of nuts from Garry Kemp which were aircraft spec and shouldnt have corroded which should make the swap easier.

 

I am thinking of taking it to Alunox to get fitted to ensure there will be quibble on potential warranty issues. As you will read above, it may be delayed until I change the coil packs. - If that is the issue?

[ragingfool35]

I got 390 easy engine break-in miles on my manifold and the turbo support mount broke at the weld.  anybody else had this happen?

 

 

 

[Simon350S]

Funnily I was talking about exactly this with someone the other day. A single support arm doesn't hold the turbo in place at all and will still allow movement that will lead to exactly this.

Yours may well have been an isolated incident but I can't help but think this will become a more common issue.

I am tempted with one of these manifolds if/when I replace all my turbo & inlet system with the charge cooler/injection setup I have sitting in a shelf waiting to be fitted. I like them, well made for sure. I'd be adding a second support though to aid in lateral support as well as just the physical weight support. That's the only bit I don't think has been fully addressed.

[CHANGES]

This should not be an issue but i will have a word with Leon and see if he

can add a web to it which will stop the flex at the point of failure on future

units as a precaution .

 

With regards to Simon's comments , It should be noted that the stabilizing or

support arm does not take the full weight of the turbo and was not designed

to do that.. The Pipe fixing to the charge cooler carries the main force, the 

arm is secondary for that job... Anyone who has removed a manifold with the

turbo left in place will have seen how supporting this is.. 

 

The main job of the arm is to stabilize the the secondary's or collectors to the

engine. This is because they float on the slip joints and need that little extra

support.  It may be, and i am guessing here,  that in this case the bar was fitted

tightly to push up against the turbo thinking it is to take the weight. This would

put it into a state of constant compression which along with the expansion and

contraction could cause such a failure.. Maybe it should of been made clearer

that the arm is adjusted once everything is in position, to that dimension, not put

under any strain..

Simon, In my opinion any extra brackets or bars is over kill , this may also

prevent the manifold from flexing and moving in the slip joints as it is designed to

do. The arm that is fitted has been designed that way to allow for movement.

Without the movement allowance within the design structure of the manifold the life

expectancy would be greatly reduced...

 

I am aware of one other arm that failed, but that was the arm, this was replaced FOC

by Alunox, I am positive that Leon will repair the unit that has failed under the guarantee

if it is returned to him..  

 

It may also be wise for those with this system to now check the tension on their stabilizing

arms. ... It should be neutral...

 

There are many units out there including my abused one, that have clocked up a fair few

thousand miles without issue.  This incident seems to be isolated but has been noted..

 

Thank you all for your input.

 

Dave

  

 

 

 

[Simon350S]

I've not the time for a lengthy response so I'll try and catch up on this post again tomorrow.

One question though if I may Dave. Are you on commission for these?

[CHANGES]

One question though if I may Dave. Are you on commission for these?

 

The Answer is NO and never have been. All the work and input along with the write

ups that I have done in regards to the design and development on this exhaust

manifold has been at personal cost to myself.... ( considerable)

Although this is part of my Trade as a designer and classic car restorer I have

no connection with Alunox.  I was asked by Alunox if i would get involved to help

​prove the system, I was happy to do so as it was in line with the developments

being done on my SE.

 All the  consultations on this were done free of charge as i was keen to see it

succeed as a quality replacement  for the Esprit.

I even paid for my own system, 

Hope that answers you question...

 

If your next question is ''why''...  Read the 412 thread again and that should answer that.. 

  

[dodge1979]

As mentioned above and on another thread it was my support bar that broke. But I was doing a 1000 miles non stop except for 5 min fuel top up back from Monaco in the heat and at a very respectable 3figure speed. As dave has pointed out. .its not a support bar its a stabilisation bar. The hoses clamped up correctly to the chargecooler will easily carry the turbo. Therr is a lot of over exageration on the weight of turbo when manifold hot etc etc..simply put it stays put without issue...

[Simon350S]

I only ask Dave because you are always so defensive and opinionated about the subject, any questioning in any way by anyone is always shot down, to be honest I was choosing my words very carefully so as to ensure I was constructive in my post and not confrontational as I know how sensitive you are about it, but you instantly shot straight back with a huge defensive and thanking people for their feedback yet not accepting potential constructive criticism from a potential customer for the said manifold.

I've no interest whatsoever in reading through your lengthy post, done it already, posted enthusiastic response where I felt credit was due but have at all times had concerns about the support for the turbo.

To think the turbo is sufficiently supported by a flexible pipe, mounted to a unit that is connected to the engine by flexible supports, is fairly optimistic at best.

Many many manifolds have been made over the years, none to the quality of the Alunox one, but all have failed mainly due to the inadequate support of the turbo.

To ignore this potential issue is fairly daft, if you feel different then whatever.

As you have now clearly stated, you have no ongoing interest in this project, any questions relating to it should therefore be forwarded to those who do.

Edited August 9, 2014 by Simon350S

[MarkKassim]

Hi Chris, I’ve spoken with Leon about your brace failure. He is having my car this week to recheck the angles and loading on the brace to see if the design is at fault. If this results in a design change for the brace, let’s say the pivot points for the rod end bearings need moving, then Alunox will reissue new brackets.

However I can see from your picture your lower rod end bearing is on the wrong side of the bracket, which could result in the brace being at the wrong angle. Leon will compare this to mine and see if that could have caused the problem. Chris I know Leon has been in contact with and will resolve your problem either way under warrantee.

As Dave mentions when fitting the brace should not be taking up the weight of the turbo, it should be a neutral or slack fit to allow movement.  Also the rods ends themselves should be checked periodically for grit etc from the road to ensure they are free to move. Just spray with WD40 at service intervals to keep them clean.

I think you will agree from my track day video I have put this product through its paces, I didn’t exactly nurse it and it’s held up.

Remember guys Alunox are the experts at this and take a lot of pride their designs and workmanship and I’m sure they will get to the bottom of it.

 

I’ll keep you updated

Mark

[dodge1979]

imon. I think your concerns are viable and genuine in line with others thoughts too..in my experience, I believe that the design of a manifold that can flex at each ports exit route greatly helps with the entire way the unit moves and interacts with the weight of the turbo..i also do believe that it is not that much of a problem with the correct manifold and its material make up. As mentioned, I experienced issued with my manifold..but..I have no doubt it worjs well..and at the end of tge day most esprits are used part time. So we wont ra k up the 100k miles in 5 yrs that warrant extreme testing. I have experienced issues with my manifold setup but then again ive done far more intensive miles on mine than anyone else..

[CHANGES]

Simon..  I am confused. I have read back what you said and what i replied and i can

not for the life of me understand how you could take what wrote as defensive and 

opinionated... As for shooting you down with my comments I can not see where...

 

What i wrote i felt was a constructive account of facts based on experience with this

type of engineering..and there is nothing sensitive about that.. You made some points

and i replied to them. sorry if the reply was not what you wanted to hear...

 

To think the turbo is sufficiently supported by a flexible pipe, mounted to a unit that is

connected to the engine by flexible supports, is fairly optimistic at best.

 

Never the less the fact still remains that it carries the weight without flexing and as a part

of the structure plays a major role in supporting the turbo in this design application..

 

Many many manifolds have been made over the years, none to the quality of the Alunox

one, but all have failed mainly due to the inadequate support of the turbo.

 

I am yet to see any solid proof that the weight of a turbo has been the influencing factor for the

failure of a manifold.. Most manifolds fail by cracking due to the material used or/and the design.

An exhaust manifold is a complex piece of engineering little understood by most.. As a result so

many that are made fail as a result.. Blaming the influencing factor as turbo weight is loose at 

best. Nearly all turbo weight is carried by the the compressor pipes along with the turbine exhaust

outlet.  What the manifold experiences as weight is quite small if any, so as i have said the stabilizing

arm is to steady the secondary/collector section not hold up the turbo.

 

   To ignore this potential issue is fairly daft, if you feel different then whatever. 

 

This potential issue has not been ignored, I stated at the end of my reply it has been noted.. 

  

As a result of it being noted, I have since spoken to Alunox, He was surprised by the failure but

agrees that it is more than likely down to an installation issue as described...

The Conclusion is the whole bracket section is in redesign and will be implemented on the new

manifolds.  The bracket will now be a bolt on section... (Details will follow from Mark K)   With regard to

all the existing manifolds already supplied , the new design bracket will be made available to all

free of charge to retro fit if you so desire... The new bracket will be more substantial with a change

to the angle, but still has exactly the same function as the other... Not to carry the turbo weight. 

 

As you have now clearly stated, you have no ongoing interest in this project, any questions relating

to it should therefore be forwarded to those who do. 

 

As an Esprit owner and someone who invested a lot of time and money to see this succeed , I do have

an on going interest in this project... as do we all.... What was asked and replied to was,   i have no 

​financial incentive or reason to outwardly support Alunox on this forum... When issues arise i generally

consult with Alunox and forward technical info as needed, along with Mark K. to the forum, so that we

can all remain up to date on things... 

 

I am so sorry if you don't like the replies i give, but i can only tell it as it is... nothing in what i say is pointed

​at, or implied personally to anyone... just open forum discussion and information sharing..

[dodge1979]

As he says

............. ♡

[ragingfool35]

Leon did respond immediately indicating he was thinking along he same lines as I was:  a bracket not welded but mounted using the turbo-to-manifold bolts.  He indicated he was going to send out kits FOC to owners.  I cant remember if that is the orientation that the unit arrived, but I did move it to the other side and made a temporary repair bracket as noted above.  There was no preload on the support, the eyes lined up perfectly and the arm could be rotated by hand once installed.  I would suspect vibration as the culprit before anything else.  Sometimes during my 400 mile break-in, the engine ran so smooth I thought it was electric;  other times, the interior would buzz madly thru 2500 to 3000 rpm.  im checking on that.

The manifold is high quality, but uses very thin tubing and I am using a heavier GT3071 turbo.  Thin wall, esp with a stainless alloy, is key to preventing stress from thermal expansion.  I believe the Alunox manifold would last a very long time if it wasn't also holding up a heavy turbo cantilevered.  I was also thinking of a second support attaching horizontally the same way the existing support does.  This would allow fore and aft movement for expansion, but not up and down.  The cast manifold is very thick and rigid, even hot, and could support the stock turbo sufficiently.   I'll run these ideas by Leon. 

thanks for all the replies.  i'll you updated.  it's a mad world out there...stay sane and friendly in here!  all we have is each other

[Simon350S]

I was also thinking of a second support attaching horizontally the same way the existing support does. This would allow fore and aft movement for expansion, but not up and down.

Pretty much exactly my suggestion.

Be prepared to be shot down in flames and told how wrong you are.

Glad they are looking into this. Product development and customer feedback is key to making a very good product even better.

[CHANGES]

 

No seriously lads , i don't want you to think i am being critical here i am trying to help

an advise.. This sort development work is part of my day job which is why Alunox contacted

me in the first place..   The support on the turbo is fine. I personally run one of the biggest

turbo's being used at present on an Esprit which is  attached to this manifold without issue...

When the design of this manifold was being undertaken and tested , it was with an insight of

why others before had failed.. The main criteria on the LCB design is rigidity. Too much of

it and it will crack... not enough and it will leak.. Finding a balance is not that straight forward..

The material used is the primary importance , then understanding its expansion characteristics

follows.. This design allows for these forces to breath so not putting the manifold under undue tension

when expanded. All this helps the molecular structure with in the material to remain stable which

goes along way to preventing cracking... The support of the turbo was looked at in detail, and as

i have said before not an issue... you will just have to trust me on this..

With regard to additional supports ... well that's up to you... But remember any alteration to the

initial design will affect any guarantee on the product...

The original bracket should do the job fine, but as with all new products a possible issue has been

brought to the attention of Alunox.. As a result a new improved bracket will now be fitted to all

future manifolds to prevent a re-occurrence, This bracket will be a bolt on unit which can be retro

fitted to all existing manifolds. It will be made available to all FOC as soon as production is complete.

 

Hopefully this will make things a bit clearer..

  

 

 

 

 

     

[ragingfool35]

Dave

to fit my 3071 I had to cut off/shorten the barbs/ribs on the CC inlet and turbo outlet and t bolt clamps would not fit (on the turbo) there is only 7/16" nipple to grab the coupling now.  I'm dubious there is enough clamping force now to suspend the turbo.  did you have to modify your setup at all?  it's moot but I would be interested in any pics you have of your turbo installation.  I am not fluent in turbos, the 3071 with the Cosworth housing is a honk'n lump of casting; I was surprised by it's weight, maybe 20 lbs

also, there was no fillet weld on the bottom of the bracket, just a groove weld on the top.  is yours the same? I could barely get the nut on the bolt with a thin wall socket for the closeness of the bracket so I imagine that was why the fillet weld was omitted.

I suggested a bolt on bracket (formed, not welded) to Leon and he replied that was his plan as well

[CHANGES]

Chris,

I take it back, sounds like you have one huge heavy turbo on there..

My c/cooler was custom built, but the inlet position and bracketry  was

in the same position. no cutting and extra modifying needed.. The only

major noticeable points are the size of the compressor outlet bore and

the fact that it nearly touches the c/cooler inlet.  My C/cooler needs

completely removing to get the hose joint off. When all fitted in place but

without the manifold on, it is actually quite rigid but still flexible enough to

allow for the expansion movements .. much the same as a standard unit.

 

Anyway , back to your situation, Now we know you have an oversize turbo

which may not have sufficient independent support , it may go a little way

to explaining the reason for the bracket failure. As we have said the bar is

to act as a stabilizing unit for the manifold design.  At the same time it also

aids turbo support but this is not a design function for weight. more so 

stability as it is directly mounted to the manifold.

In your case it seems you require a greater percentage of turbo support..

The solution may be a more substantial bar to take the extra weight but in the

same position to allow the design functions to remain.. This along with the

new bolt on bracket should go a long way to insuring reliability.

 

I am curious why you have such an oversize turbo fitted,  was a smaller unit not

available at the time...?  I only ask as the Turbo Technics unit i have fitted will

generate up to 2.5  bar boost and run 1.6 bar all day...It is a direct replacement for

the standard unit with only a mod to the heat shield and oil pipe needed..

 

In your case It may also be beneficial if you can add additional support to the turbo directly,

or via extra support on the exhaust outlet off the chassis.. But remember these should

not be solid. A rubber anti vibration joint must be fitted in these cases..the turbo should

always be allowed to have some movement so the manifold designed expansion features

can work efficiently....

hope this helps

I am sure you will engineer your way around this problem, it will be an example to others

doing the same mods as you, on how to overcome these issues...

 

keep up the good work   

 

 

[60N4.7]

Leon did respond immediately indicating he was thinking along he same lines as I was:  a bracket not welded but mounted using the turbo-to-manifold bolts.  He indicated he was going to send out kits FOC to owners.  I cant remember if that is the orientation that the unit arrived, but I did move it to the other side and made a temporary repair bracket as noted above.  There was no preload on the support, the eyes lined up perfectly and the arm could be rotated by hand once installed.  I would suspect vibration as the culprit before anything else.  Sometimes during my 400 mile break-in, the engine ran so smooth I thought it was electric;  other times, the interior would buzz madly thru 2500 to 3000 rpm.  im checking on that.<SNIP>

 

Any news on the replacement by Alunox? 

 

Bracket on mine broke at the bend in the 90 degree angled piece after around a month, maybe 300 miles. That was many, many months ago and two trips each in excess of 500 miles. No adverse effects as yet but would rather have the bracket on.

 

Since I am in the U.S. whoever is in contact with Leon from here, can you ask him to contact me as well?

 

Thanks!

 

Kenny West

[Simon350S]

We have been assured this isn't a problem? Imagine.

Thanks for your feedback.