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snapped cam-belt, help needed with head, block and turbo!
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Josh931  



Joined: 03 Oct 2014
Posts: 29
Location: South Africa

PostPosted: Fri May 22, 2015 3:31 am    Post subject: snapped cam-belt, help needed with head, block and turbo! Reply with quote

Hi, I'm unfortunately going from posting about how far my 924 turbo s2 had come, with intercooler and meth injection to now posting asking for help!

I've done lots of reading and asking around, but there are just too many things for one person to consider alone, so I rate its time to ask for help!

Firstly what happened is my 10 000km old cam belt, recently enough replaced, said cheers the other day. This of course left me with all 8 valves bent and slightly indented pistons. Things would be a bit less rushed and more relaxed if this wasn't my daily car, but it is.

Engines out along with most of the car, I couldn't source the valves, so I've had to get them machined from scratch out of stainless steel, very pricey option! But less pricey then ordering from Europe, I'm in South Africa. Guides ect have been sourced along with, I think the're called, shims. So thats the head done. Unfortunately the head has been skimmed before, it looked fine when i removed it, but the machinist said as i dropped the head off, that because its a workshop, he can't guarantee that it won't require a skim when its done as it may get bumped ect. So now compression is an issue as it already had a thicker gasket installed.

I removed the worst of the four pistons, and took it to a number of different mechanics, asking if its reusable, 4/6 have said that I must go for it without a doubt and just reuse it, no problem, two said maybe not. locally the only real piston option would be the vw flat tops, not a fan, but might not have an option.

With the turbo off, which i thought was perfect before, I decided for peace of mind to get it serviced. R8500 later, ~800$. The hot side manifold is cracked in three places, small but still there, something has gone through the turbo as the hot side wheel has small chips on it so needs to be replaced.

So here is the problems I'm a student with very little money, haha! The cost of the turbo seams outrageous. So I am wondering whether or not to go with a new turbo, such as a golf 5 gti turbo, or t3 or 4 or anything really, around R6000. My wastegate bladder needs replacing as well, so will probably go with an aftermarket unit instead, as its very corroded, which means modifying the j-pipe anyway. The originality of the car has been lost with the installation of the intercooler and golf expansion bottle, so thats not an issue. Would anyone recommend rather keeping the k26 and paying a decent amount of money to keep it going or go with a cheaper newer option that may need a bit of altering of the manifold but might work better. The local parts guy here says all the hot side manifolds he has are cracked as well, so mine is staying cracked.

And then also any tips on how to maintain stock compression as well as measuring it ect please!

Any input would be great!!
Josh
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morghen  



Joined: 21 Jan 2005
Posts: 7674
Location: Romania

PostPosted: Fri May 22, 2015 5:46 am    Post subject: Reply with quote

If the turbo cracks are not all the way trough and there is no blow trough then you can use it..most hot sides are cracked by now. Replace the wheel ofcourse.

Using a modern turbo means blocking the old wastegate, you could do that with an added part inside it to block the valve from moving.
It also means an adaptor from the 931 manifold to the new turbo interface.
New turbo sounds fun as it will spool up faster.

You surely can use the old pistons, but check for small cracks just in case.
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Josh931  



Joined: 03 Oct 2014
Posts: 29
Location: South Africa

PostPosted: Fri May 22, 2015 6:15 am    Post subject: Reply with quote

I was considering using an aftermarket wastegate, and finding a turbo without the combined wastegate. Worried a combined unit would be too big to fit in the available space, and if I use the other route I can keep the stock manifold and j-pipe, just maybe make up some adapters.

Faster spool and possibly cheaper to maintain as the parts are cheaper and easier to access for servicing!
Parts for these cars are becoming extremely hard to come by on this side.

Any thoughts on the compression issues??

Thanks Morghen!
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morghen  



Joined: 21 Jan 2005
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PostPosted: Fri May 22, 2015 7:00 am    Post subject: Reply with quote

i would leave the engine as it is and use the turbo off a 1.8L VW its small and it should fit easly.
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Josh931  



Joined: 03 Oct 2014
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PostPosted: Fri May 22, 2015 7:06 am    Post subject: Reply with quote

I think the vw and audi turbos are twin scroll turbos, so the intake is rather larger, but I will look into this!

With the compression,the fact that the head has been skimmed, its now going to increase, and im not sure if a thick enough gasket is available? So how would I make sure the compression remains the same?
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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Fri May 22, 2015 11:11 am    Post subject: Reply with quote

If you can find a k26 from an audi, or many many other k26es, it will have the correct turbine wheel and shaft in it for your turbo, I have some kkk part number cross reference stuff if you want to scrounge for parts..

http://www.henzolturboparts.com/turbopartcatalog/kc.pdf

Find any of those turbo's in rebuildable condition with the correct TW turbine wheel part number (5326-120-2119 ) and your gold...
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Josh931  



Joined: 03 Oct 2014
Posts: 29
Location: South Africa

PostPosted: Fri May 22, 2015 5:23 pm    Post subject: Reply with quote

Hi Eddie

I saw a post you made about a year ago where you had picked up a audi 5000 turbo. what did you end up mounting from that?

See I can get the correct parts that i require for my s2 turbo. Its just the place doing the work for me, I really didn't want to fiddle with the turbo but now i wish i did, a is a bit expensive.

So you're saying if i can source an audi k26 turbo, I can just interchange the parts and use their TW? See that helps and it doesnt help, as I wont be able to source a decent conditioned unit for less than the place is charging me for a new TW.

I am now quite interested in changing the turbo all together. Our log style manifold isn't overly efficient, so I could try change this for a twin scroll type, and then get rid of the external wastegate as Morghen mentioned. The gaskets from mani to turbo and turbo to exhaust will also be easier to source. Any thoughts on that approach? or pay more and get my bolt straight on turbo back?

Anyone had problems occurring as a result of the heads being skimmed twice?
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Josh931  



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PostPosted: Fri May 22, 2015 5:31 pm    Post subject: Reply with quote

Sorry I was mistaken! The audi unit isnt a twin scroll!
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morghen  



Joined: 21 Jan 2005
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PostPosted: Fri May 22, 2015 6:59 pm    Post subject: Reply with quote

Ofcourse its not twin scroll, thats the expensive stuff..they dont put that stuff into cheapish production cars and the ports are smaller on the 1.8 turbos and even 2.0 turbos.
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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Sat May 23, 2015 3:05 am    Post subject: Reply with quote

Josh931 wrote:
Hi Eddie

I saw a post you made about a year ago where you had picked up a audi 5000 turbo. what did you end up mounting from that?

That Audi turbo has the proper turbine wheel/shaft and compressor wheel for us s1 931 turbochargers, all different housings.. Actually I'm still running the turbo I built in my bedroom from the best pieces from my original s1 turbo and an s2 turbo I picked up also.. The audi turbo pieces are sitting in a CHRA I put together for the next turbo to replace my homebrew one if/when I need a replacement

See I can get the correct parts that i require for my s2 turbo. Its just the place doing the work for me, I really didn't want to fiddle with the turbo but now i wish i did, a is a bit expensive.

So you're saying if i can source an audi k26 turbo, I can just interchange the parts and use their TW? See that helps and it doesnt help, as I wont be able to source a decent conditioned unit for less than the place is charging me for a new TW.

Almost ALL k26 turbo's share the same TW/shaft, 5326-120-5001,
5326 120 5002, and 5326 120 2119, are the same/interchangeable/like part number evolutions for replacement parts, it doesnt have to come from an audi.. When I was looking here in USA a new replacement turbine wheel/shaft is around $300 and not original German and the reputable shops told me that parts from an old original k26 are better/higher quality than the new replacement parts offered.. I strongly advise against buying any turbo parts made in China... I scored that audi turbo for $100 shipped i believe and got a TW, s1 compressor wheel, maybe useable water cooled bearing housing, and an s2 sized compressor housing without the bypass valve incase I ever want to configure with that.. Much better deal than buying a new inferior TW/shaft for $300


I am now quite interested in changing the turbo all together. Our log style manifold isn't overly efficient, so I could try change this for a twin scroll type, and then get rid of the external wastegate as Morghen mentioned. The gaskets from mani to turbo and turbo to exhaust will also be easier to source. Any thoughts on that approach? or pay more and get my bolt straight on turbo back?

If your going to do that you might as well go all out and custom fab an efficient exhaust manifold, exhaust, and all else, lot of work..

Anyone had problems occurring as a result of the heads being skimmed twice?

Heard it can skew cam timing and require an adjustable cam pulley to rectify besides compression change also..
[/b]
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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Sat May 23, 2015 3:09 am    Post subject: Reply with quote

morghen wrote:
Ofcourse its not twin scroll, thats the expensive stuff..they dont put that stuff into cheapish production cars and the ports are smaller on the 1.8 turbos and even 2.0 turbos.


I believe those newer audi turbos (anything since the late 80's) use K03 turbochargers and they arent real parts compatible with the k26..
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Fasteddie313  



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PostPosted: Sat May 23, 2015 3:22 am    Post subject: Reply with quote

any turbos with the TW part number 5326-120-5001, or
5326 120 5002, or 5326 120 2119 would be a good donor for a TW for any 931 turbos all the way to the carreras and k26/8 951 turbo just not k26/6 as its an oddball..

http://www.henzolturboparts.com/turbopartcatalog/kc.pdf

K26 starts on page 97 and goes to pg 129 with 4 per page thats 128 turbos that are possibly TW donors minus very few that have oddball TW's (like the k26/6)..

Like this, look at your local ebay or whatever for any k26, then use ctrl+f "find" to search that pdf for the part number of the turbo you found, then look at the TW part number of that turbo to see if its a transplant candidate...

Whats the prices your getting on new TW's over there? The ones on ebay are china and most likely junk..
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morghen  



Joined: 21 Jan 2005
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Location: Romania

PostPosted: Sat May 23, 2015 4:39 am    Post subject: Reply with quote

Yep, i was saying as a complete replacement with adapters for the manifold and downpipe.

Fasteddie313 wrote:
morghen wrote:
Ofcourse its not twin scroll, thats the expensive stuff..they dont put that stuff into cheapish production cars and the ports are smaller on the 1.8 turbos and even 2.0 turbos.


I believe those newer audi turbos (anything since the late 80's) use K03 turbochargers and they arent real parts compatible with the k26..

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canyonblaster  



Joined: 20 Aug 2012
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PostPosted: Sun May 24, 2015 3:08 pm    Post subject: Reply with quote

I can;t add anything but moral support, I am sorry for that! bummer!
Kinda scary to hear. My car has already been a sink hole but is "almost done" it will kill me $ if that happens, my belt is new 2,000M ago but 10K isn't much older. good luck, fun cars to drive!!
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Josh931  



Joined: 03 Oct 2014
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PostPosted: Mon May 25, 2015 3:34 am    Post subject: Reply with quote

Eddie I've decided against going for a different turbo, the idea seamed great but the more I thought, the more fabrication work I realized its going to take. So I am currently looking at getting my turbo sorted for cheaper, by looking at cheaper parts. The part numbers have helped, so thanks for that!

But in the meantime I am considering changing the J-pipe, and the turbo to manifold connections to V-clamp type fittings, as these don't require the gaskets which are rather difficult to source, and they will make removing the units easier in the future as there are less opposing faced bolts making things tricky to remove.

I've bought a TurboSmart wastegate, so while I am waiting on the head to be finished I'll start mocking up the adapter plates for that. Beautiful unit! sad to hide it where no-one will see it!

Current agenda is sourcing gaskets. Considering taking the block to be honed, so need to source new rings and if possible new main bearings. Any alternative rings that work on my car?? I have been told how to regain my stock compression! stoked! there are two possible methods, the one requires that I get an aluminium spacer made that will go against the head or the second method is I need to source a three layer gasket, and then remove the middle layer and replace it with a thicker shim which would be made from stainless steal. Any thoughts on which would be better suited? Could someone please give me an idea of how to measure up the spacer I'll need? I have no idea how much the head has been skimmed previously, so how would I determine what the stock dimensions were?
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