Fixing My molten Roadster

[spit]

ISTR that the T3 flange is symmetrical, so that, at least, isn't an issue  s;) s;)

Yes it is - at least the gasket fits either way up/round.  s:wink: :wink: s:wink:  

As for repairing, surely to all thats holy we must have a class welder somewhere in our membership?

[spit]

Bump

How's it going Mark?

[kanujunkie]

you may have to shout louder Ste, i lent Mark my dremel thing a couple of days ago to dig around in the crack, guess he's hard at it

[markiii]

still here, if I ever fiish these bloody wardrobes I'll do some more digging
  s:wink: :wink: s:wink:

[Tem]

dig around in the crack, guess he's hard at it

  s:shock: :shock: s:shock:

[philster_d]

Man that dremel  has an attachment for EVERYTHING   s:lol: :lol: s:lol:

[markiii]

Time for an update

firstly how did it happen?

Having batted around a few thoughts with Hass owners on both sides of teh pond I have a working theory.

As standard Jay ships teh kit without a turbo support which in turn puts all of teh strain on teh manifold studs.

Under power the engine tries to rotate downwards and the exhaust fights this. End resut is that teh manifold tried to pivot upwards on teh studs.

Typically this has resulted in stripped studs in a number of instances.


Following Seans having this issue we both had turbo braces made to teh same design to keep the turbo against the block and prevent stripped studs.

however;

We had the brace on teh left hand side of teh turbo. The Hass exhaust exits on the right hand side of teh turbo.

Follow teh same scenario again, engine rotates down (or tries too) but the brace prevents the manifold moving relative to teh block. However it exerts force on teh left hand side of teh turbo. The exhaust tries to fight the downward motion by pulling backwards on teh right hand side of teh turbo.

Effectively a torsional load is placed on teh turbo as it attempts to twist clockwise relative to teh manifold. Obviously it cant, but all of teh torsional stress is now located on the manifold/turbo joint.

On inspection the only stud between turbo and manifold intact on mine was the one around which this pivoting motion would occur. 2 others sheared clean off and the 4th was bent like a banana.

lending credence to teh theory.

Seans issues above occur at what I would consider the next weakest point the mainfold weld. So assuming that his studs coped better than mine (for whatever reason) the next point of failure is exactly where his weld is failing.

Additionally teh only other person to have braced a Hass yet is WTS in the US, and he braced his on teh right hand side of teh turbo. This should prevent teh issue as teh opposig pull forces are now directly opposed and no torsional stress is applied.


Lesson learned Brace Both sides of teh Turbo.   s:cry: :cry: s:cry:  

Fortunately Dan had this done before he sold his car and I've since bought that brace off him.  s:D s:D  


We also discovered o dissasembly that my flexi joint had ripped apart. The Hass Flexi is on teh exhaust to teh right of teh turbo. And as such is subject to the same opposing forces when teh engine attempts to rotate.

Jay has since advised everyone to fit harder engine mounts to prevent this, but I dare say running 10psi and booting it into first on teh hairpin made this one my own fault   s:oops: :oops: s:oops:  


Curious as to how this issue affect other Turbo kits I did some digging

PE, Top Secret, and the TTE ALL have there kits designed so that they mate back up with teh stock CAT. I've always wondered why teh stock CAT takes teh odd route down and under teh grey cross member but am now convinced it is so that the flexi joints get compressed as teh engine trys to rotate, thus preventing them from tearing.

Nice design feature guys.

Looking at teh C2 I beleive it could be sligtly more problematic than teh TTE,PE, Top secret, but is way better than the Hass design in this respect. (Stu don't panic it will be fine)

So what next?

Having wired brushed down my manifold welds they looked OK to me. However rather than take the risk and spend more money coating a potentially suspect manifold it was time to call in teh experts.

in teh form of H&S.

Thanks to Lee for droppig it in for me.

The guys at H&S couldn't see an issue with teh welds short of getting it xrayed but were slightly concerned that teh manifold flange had only been welded around teh outside edge and nothing at all on teh inside edge.

However for £20 they fixed it for me and did a blinding job too.

see below.



so thanks to Lee and H&S

next job was to remove teh sheared studs and boy was that a pain. The studs themselves were so soft that easy outs just ripped back out again, leaving no alternative but to very carefully drill out teh studs. I reckon I got lucky on this one and with some very careful use of a Tap was able to clear out the thread just fine.

Worth noting is that while an American kit these holes are standard Metric M8 with a 1.25mm thread.

So finally I finished Monday with a manifold now ready to be recoated.

see below



Thanks to Lee, Ste, and Tom  for suggesting Camcoat as they are going to recoat  it with their black satin triplecoat for £100, bargain  :-) :-) :-)

Manifold is now all wrapped and being sent off this week. Estimated turnaround is 2 weeks.

Next job is to change the molten release cable for teh engine deck.

Stay tuned
  s:arrow: :arrow: s:arrow:

[aaronjb]

Top job Mark  s:) s:)  

While on the subject of the PE's exhaust design - notice that it also has a divorced wastegate, thanks to mating to the stock CAT pipe.  Nice feature  s:) s:)

As always, if you need an extra pair of hands, just give me a call  s:) s:)

[kanujunkie]

good to hear the progress Mark, as Aaron said if you need a hand then give us a buzz, think i may owe you severely before long anyway

oh and i can vouch for camcoats black satin quality, the gear sat in my spare room speaks a thousand words  s:wink: :wink: s:wink:

[spit]

Thanks for the update Mark. Having seen how substantial the Hass pipework is in comparison to the C2, I've been getting worried about this.

Its amazing though that bracing the turbo off-centre would lead to this kind of catastrophic failure. Is there only a limited amount of flex in the flexi and exhaust hanger arrangement?

I'm trying to relate what happened to you to the early C2 design. Not good at physics but I may be unwittingly OK!

My brace is not physically connected to the turbo housing   s:oops: :oops: s:oops:  That might be a good thing....... I'd already ceramic coated when the brace arrived and I discovered that when everything was offered up the brace nestled nicely (and tightly) dead centre under the base of the casting.

More luck than judgement, but this supports the weight of the turbo and allows any twisting forces to be absorbed by the bits that are designed to absorb them ie the flexi joint and rubber exhaust hangers.

.....but I'll keep an eye on it  s:roll: :roll: s:roll:  ....particularly cos I'm still on stock engine mounts  s:shock: :shock: s:shock:

[markiii]

Ste,

From memory the C2 exhaust design allows a little more give.

The HASS flexi while I reckon able to absorb a compression movement isn't vwery stretchy at all.

My intention is to replace with an 8-10" section of higher quality flexi, perhaps with a small kink to alleviate this.

thinking about it Martin's old Turbo (Now with BenF) was PE based and he replaced teh whole exhaust with a custom jobby which changed teh design of teh flexi.

As a result he cracked it at least 5 times. His exasperated exhaust shop eventually put around 2 feet of flexi in and it hasn't gone since.

ref teh engine mounts for $40 they really are a no brainer

[Anonymous]

Fortunately Dan had this done before he sold his car and I've since bought that brace off him.

I'm just too generous. Had the brace on there for about two days, then ripped it off and sold the car!  s:lol: :lol: s:lol:  Damn nice brace it is, too.


BTW, have you dug your wallet out Mark?  s:wink: :wink: s:wink:   s:wink: :wink: s:wink:   s:wink: :wink: s:wink:

[markiii]

hmmm mental note to self not to remind people you owe them money LOL

I'll send it over in teh next couple of days

[philster_d]

I'm just too generous. Had the brace on there for about two days, then ripped it off

Yeah Marks said it was a rip off     s:lol: :lol: s:lol:     s:lol: :lol: s:lol:     s:lol: :lol: s:lol:

[Anonymous]

hmmm mental note to self not to remind people you owe them money LOL

I'll send it over in the next couple of days

No rush mate, whenever is good for you.


@Phil:  s:P s:P  He wasn't wrong though: Great brace, but not worth the £200-odd I paid for it.

[markiii]

er no, you were right royally bent over on that one

[Anonymous]

Nice writeup!
My problem all involved cylinder head studs and happened within 2000 miles of the turbo installation. These all occured before bracing and before kirkosaurus motor mount inserts were added.

The bottom centre stud fell out like a dead tooth and that makes sense if the engine twists back and down under acceleration. The bottom edge of the exhaust flange would act as a jerking lever against it.

The 2nd exhaust manifold stud to go was on the far right (your drivers).
It simply sheared in two. Possibly from thermal expansion. I just put another one in its place thats been OK ever since.

3rd stud to strip was the upper middle left . Head threads came out with it.
Its brother to the right immediatly suffered the same fate as I gave it a viscious crank with a biggish spanner. Just twisted it right out of the block.
Drove it to my buddies shop with all 3 center studs missing and there was no exhaust leak.

Am redoing everything this summer and will look at new bracing options as well.
Any pics of your £200 brace?
Mines just a $1.50 worth of mild steel.

[markiii]

I'll takle some and posta  template as well, but seriously Dan got screwed on teh price, I suspect it's not different to yours

[Slacey]

I'll takle some and posta  template as well..

That would be handy. My new manifold is now on and I don't want this one going bad if I can help it.

[spit]

Looking through the TTE install manual it just shows how much more sensible the layout is. Not only is the Turbo braced dead-centre underneath, but making the DP into a full U-bend to retain the stock Cat position makes for a very clever alignment. The stock Cat flexi pair must be pretty decent to cope with the extra vigour of stretching under boost though. I'm sure this has been engineered to be FFP.

Because us non-TTET guys all have more off-centre forces in play, I think capacity for both compression and stretch needs to be looked at on our kits. I'm getting worried again cos my exhaust isn't as free-hanging as I'd like it to be (remember those awful twin-tip alignment issues I had?) and the DP flexi isn't as mobile as the twin stockers.

Worth keeping an eye on........  s:roll: :roll: s:roll:

[philster_d]

Do I need to worry ? oh mighty turbo guru's ?

[spit]

Its something we're just going to have to keep an eye on for now, Phil.

Just been in the garage replacing a T-DP allen bolt that had gone AWOL (

hate those things).

I figured the twisting etc might have caused it, but on closer inspection it turns out the hole in the DP flange is "dished" (in a saddle-type stylee)   s:shock: :shock: s:shock:  The head of the old bolt was only mating with the flange at two points, so no wonder it rode loose. Turns out I've lost 2 of the 5, but all replaced now and I'm carrying stock  s:lol: :lol: s:lol:  

Also loose was one of the Mani-Turbo fastenings. Tweaked up and nutlocked..... but I'm gonna have to review these fixings soon I reckon. You're on a stud Phil, aren't you?  s:P s:P  [/list]

Anyhoo, back to the twisting - I tried to gauge the twisting from a reverse angle......by lifting the o/s exhaust tip. This causes the engine to move  s:? :? s:?  The flexi absorbs some of it but I'm concluding that it probably isn't enough.

So I'd also value the guru thoughts and any preventative maintenance ideas.

[philster_d]

Im all spotted up       s:?: :?: s:?:    s:idea: :idea: s:idea:

[markiii]

seriously get the enginemounts

[philster_d]

Good point, Stu I have your mounts in my living room, when you next pop over or vice a versa Ill hand em back to you.

Thanks,
Philster.