1.8T BT rebuild, Wossner pistons, crank washers, engine rebore West Mids?

desertstorm

desertstorm

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A few questions for those in the know with experience. I am rebuilding my TT engine. Initially I was going to keep the original pistons, they looked good and the bore appeared good. The engine had pretty good compression and no issues .
@Prawn convinced me that I would be better off replacing them as I am not likely to get the best out of the engine and somewhere down the line I am more likely to have issues.
So ordered a set of Wossner 82.5mm 9.5:1 pistons which then throws up a few more issues.

Does anybody know of an engine reconditioners that they can recommend in the West Midlands , Stafford area. To rebore the engine.?
Any tips of bore size and the hone, or just go with what Wossner say.

I now have to remove the crank pulley timing bolt and replace it. This gives me the opportunity to do something with that. I don't really want to spend £200 plus on a billet steel pulley.
I understand that with much higher RPM , uprated valve springs and potentially more aggressive cam profiles the loading on this interface is likely to be a lot greater than on an OE engine.
I am running OE cams with Rosten springs and plan on a fairly conservative RPM limit.
The ARP bolt for £50 seems a bit expensive if it only increases the load by 10% . I have seen that the 2.0 engines on newer cars seem to have a diamond coated washer to assist with this issue and this appears to increase the grip between the pulley face and crank end by upto 300% .
This is an OE VAG item at a reasonable price has anybody used one of these?.
https://www.akstuning.co.uk/engine-components/616-genuine-tfsi-crank-diamond-washer.html
Pinning the crank pulley seems an option but even that doesn't always work, and brings about the possibility of cracks in the pulley as the hole could possibly act as a stress raiser.

https://www.audi-sport.net/xf/threads/my-minor-modding-thread.76389/page-69#post-2225744

I bought myself a copy of the VW tool used to hold the sprocket, £25 delivered off fleabay and it seems to be just the right length too.
DSC 4434
 
I can recommend some in the East Midlands (using a new one this month for a 1.4 tsi rebuild so hopefully that goes okay). What sort of power are you aiming for? Is it a bam engine you have?
 
It is a BAM engine although that doesn't really make much difference as there are lots of bits replaced.
Will have IE rods, 1000cc injectors, Ignitron ECU, dw65v pump, G25-660 turbo, Nortech manifold and down pipe, Wossner 82.5mm 9.5:1 pistons, Supertech Inconel exhaust valves, Rosten Uprated springs, small port head, Sachs 4 puck clutch, Motec oil cooler, welly cooler etc etc .
No water methanol , It's a track car so want it reliable and driveable. Be happy if it makes 460bhp . Not overly interested in the actual number as long as it is fast on the track :) .
Who is good in the East Mids then. Don't mind a drive.
http://www.audi-sport.net/xf/threads/mk1-tt-225-track-day-car.319422/
 
G25, that will be interesting, they look like they have some real potential going by Bill’s thread. Just curious as to why Prawn said you wouldn’t get the best out the engine with stock pistons as they’re capable at your power figure. Unless you wanted to raise compression anyway?
 
I suspect Nick was talking about old pistons in worn bores. If you can afford the small amount extra for some new pistons it's worth doing not only to be able to tweak CR, but also so you're fitting them to fresh metal rather than potentially scored, worn, saggy holes.
 
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I know they would run that much power but not entirely sure how reliable it would be. The car could be running 2 bar of boost and regularly seeing 7500 rpm with periods of sustained high RPM running. The engine has done 90K miles so the bore has wear and is not exactly factory fresh being 16 years old.
 
OE Pistons are Ok but wouldn't want to run them over 400hp too much let alone on a track related engine

<tuffty/>
 
That's crazy with your stroker build desertstorm.

This I don't agree with...

...and plan on a fairly conservative RPM limit...
Click to expand...

why would you state this 'conservative limit' right now with all your other upgrades? How do you know what you'll decide when it comes to it?
Re-read the hp and torque entry on s4wiki about moving the torque to higher rev range, wont you find your turbo will happily keep you going at 7500rpm? And the standard arp bolts are apparently good for 8500rpm?

I had a scan through this ie site yesterday, I'm sure you've read it already.


https://www.performancebyie.com/blog/guide-building-1-8t-1997-2005-engine-block-right-first-time/

You are near the end of the article :D

Nice looking girdle :)
 
Thanks for chiming in Paul, I think it all goes down to build it right and build it once. I am trying to do that which is why I skipped the usual hybrid route a lot of people take before going big turbo. Have you ever seen/ used these friction washers on a 1.8T. Don't think Bill stocks them so does he not rate them? TBH the bank account could do without another £300 withdrawl for a billet pulley and ARP bolt.
 
Sweet... are you getting a tfsi crank as well?
(Or whatever is used for the stroker builds)

I still can't believe Ian G built a whole car then changed it to a v6 a month later.
 
desertstorm said:
No TFSI crank.
Click to expand...
Rev slower with these don’t they?

desertstorm said:
I know they would run that much power but not entirely sure how reliable it would be. The car could be running 2 bar of boost and regularly seeing 7500 rpm with periods of sustained high RPM running. The engine has done 90K miles so the bore has wear and is not exactly factory fresh being 16 years old.
Click to expand...

Yeah that is quite a lot of boost. Are you planning on head studs? What sort of track driving are you planning?
 
No head studs just OE Elring bolts. Done a few track days already at Rockingham and Donnington. Hopefully will be doing 1 a month this year when the engine is all sorted, Donnington again, I like the track, and Oulton, Bedford are on my list. Quite fancy a trip upto Anglesey.
 
Donnington is a nice track, I’ve not been round it myself but I’ve watched some track days there as it’s close to me. I have been round Curborough a few times, doesn’t favour big power being small but it’s good fun. Plus they do an open day in April where you can have a few laps for free. Think it’s called introduction day or something.
 
I wouldn't mind coming along to watch at Bedford one day (I am only 15 minutes up the road) - I'll bring my scarf, rattle and DS bunting. I watched some stuff at the Peterborough motorbike festival thing quite a few years ago - other than that I have only watched F1 at Silverstone a few times camping with in-laws, and my dad took me to a motor bike drag strip thing maybe santa-pod? when I was about 10 on his CB900 Bol'dor .

my mate wanted to take his mx-5 to a track day and everyone wanted to know what roll cage was fitted, so he decided against it :D :D
 
Some tracks are more fussy than others I think when it comes to open top cars. A minimum is a full face helmet, Open face helmets in open roof cars are a no no.
 
I think it was the other people on a red letter track day that put him off it.

my neighbour used to go to track days on his "vertimati" supermoto and overtake everyone on their superbikes going round the corners and then get overtaken back on the straights - hooligan
 
desertstorm said:
A few questions for those in the know with experience. I am rebuilding my TT engine. Initially I was going to keep the original pistons, they looked good and the bore appeared good. The engine had pretty good compression and no issues .
@Prawn convinced me that I would be better off replacing them as I am not likely to get the best out of the engine and somewhere down the line I am more likely to have issues.
So ordered a set of Wossner 82.5mm 9.5:1 pistons which then throws up a few more issues.

Does anybody know of an engine reconditioners that they can recommend in the West Midlands , Stafford area. To rebore the engine.?
Any tips of bore size and the hone, or just go with what Wossner say.

I now have to remove the crank pulley timing bolt and replace it. This gives me the opportunity to do something with that. I don't really want to spend £200 plus on a billet steel pulley.
I understand that with much higher RPM , uprated valve springs and potentially more aggressive cam profiles the loading on this interface is likely to be a lot greater than on an OE engine.
I am running OE cams with Rosten springs and plan on a fairly conservative RPM limit.
The ARP bolt for £50 seems a bit expensive if it only increases the load by 10% . I have seen that the 2.0 engines on newer cars seem to have a diamond coated washer to assist with this issue and this appears to increase the grip between the pulley face and crank end by upto 300% .
This is an OE VAG item at a reasonable price has anybody used one of these?.
https://www.akstuning.co.uk/engine-components/616-genuine-tfsi-crank-diamond-washer.html
Pinning the crank pulley seems an option but even that doesn't always work, and brings about the possibility of cracks in the pulley as the hole could possibly act as a stress raiser.

https://www.audi-sport.net/xf/threads/my-minor-modding-thread.76389/page-69#post-2225744

I bought myself a copy of the VW tool used to hold the sprocket, £25 delivered off fleabay and it seems to be just the right length too.
View attachment 175173
Click to expand...
why choose wossner ?
 
desertstorm said:
A few questions for those in the know with experience. I am rebuilding my TT engine. Initially I was going to keep the original pistons, they looked good and the bore appeared good. The engine had pretty good compression and no issues .
@Prawn convinced me that I would be better off replacing them as I am not likely to get the best out of the engine and somewhere down the line I am more likely to have issues.
So ordered a set of Wossner 82.5mm 9.5:1 pistons which then throws up a few more issues.

Does anybody know of an engine reconditioners that they can recommend in the West Midlands , Stafford area. To rebore the engine.?
Any tips of bore size and the hone, or just go with what Wossner say.

I now have to remove the crank pulley timing bolt and replace it. This gives me the opportunity to do something with that. I don't really want to spend £200 plus on a billet steel pulley.
I understand that with much higher RPM , uprated valve springs and potentially more aggressive cam profiles the loading on this interface is likely to be a lot greater than on an OE engine.
I am running OE cams with Rosten springs and plan on a fairly conservative RPM limit.
The ARP bolt for £50 seems a bit expensive if it only increases the load by 10% . I have seen that the 2.0 engines on newer cars seem to have a diamond coated washer to assist with this issue and this appears to increase the grip between the pulley face and crank end by upto 300% .
This is an OE VAG item at a reasonable price has anybody used one of these?.
https://www.akstuning.co.uk/engine-components/616-genuine-tfsi-crank-diamond-washer.html
Pinning the crank pulley seems an option but even that doesn't always work, and brings about the possibility of cracks in the pulley as the hole could possibly act as a stress raiser.

https://www.audi-sport.net/xf/threads/my-minor-modding-thread.76389/page-69#post-2225744

I bought myself a copy of the VW tool used to hold the sprocket, £25 delivered off fleabay and it seems to be just the right length too.
View attachment 175173
Click to expand...

ARP crank bolt only clamping 10% more? lmao
when you've done ARP up vs OE, its way way way more tightening torque required to do the 90 degrees on ARP. I dont believe the 10% figure..
 
desertstorm said:
Thanks for chiming in Paul, I think it all goes down to build it right and build it once. I am trying to do that which is why I skipped the usual hybrid route a lot of people take before going big turbo. Have you ever seen/ used these friction washers on a 1.8T. Don't think Bill stocks them so does he not rate them? TBH the bank account could do without another £300 withdrawl for a billet pulley and ARP bolt.
Click to expand...
we do stock them. just not listed on the shop (yet). Our own builds always have ARP crank bolt & billet steel bottom gear.
 
JonnyDerv said:
Rev slower with these don’t they?



Yeah that is quite a lot of boost. Are you planning on head studs? What sort of track driving are you planning?
Click to expand...
rev slower?
erm, nope. We take them to 8200-8500rpm is powers still there . They still spin up nicely
 
Hi Bill thanks for replying. Went for Wossner as seen a few builds successfully using them, @Prawn has them in his car and if they manage to survive the abuse there then they have to be reasonable.I looked into JE and Supertech, which I noticed you stock. Both more expensive than Wossner and I wasn't seeing anything that jumped out at me other than the Supertech pistons come with tool steel pins, which is a good upgrade but do I really need that in this build?.
Assuming the ARP bolt is one of the lower spec ARP fastners then it looks like yield will be around 200,000 PSI , The OE bolt on my car is a 10.9 so yield at 900Mpa which converts to 130,000 PSI. So roughly speaking I would expect something like a 50% greater clamping load with an ARP bolt. But the ARP bolt is reuseable, so I am assuming it's not coming near the yield stress so maybe only a 20-30% increase.
And from a video I have seen of you doing up an ARP bolt on an engine it definitely looks like more than 10% to me, But that's what ARP say ? . It's all finger in the air maths though.
If the Diamond coated washer increases the friction between the interface by 200% which looks to be a realistic conservative figure then it would seem to me that an OE bolt and a diamond coated washer would be better than an ARP bolt by a good margin . The washer acts like hundreds of small dowel pins connecting the faces of the contacting surfaces.
 
desertstorm said:
Hi Bill thanks for replying. Went for Wossner as seen a few builds successfully using them, @Prawn has them in his car and if they manage to survive the abuse there then they have to be reasonable.I looked into JE and Supertech, which I noticed you stock. Both more expensive than Wossner and I wasn't seeing anything that jumped out at me other than the Supertech pistons come with tool steel pins, which is a good upgrade but do I really need that in this build?.
Assuming the ARP bolt is one of the lower spec ARP fastners then it looks like yield will be around 200,000 PSI , The OE bolt on my car is a 10.9 so yield at 900Mpa which converts to 130,000 PSI. So roughly speaking I would expect something like a 50% greater clamping load with an ARP bolt. But the ARP bolt is reuseable, so I am assuming it's not coming near the yield stress so maybe only a 20-30% increase.
And from a video I have seen of you doing up an ARP bolt on an engine it definitely looks like more than 10% to me, But that's what ARP say ? . It's all finger in the air maths though.
If the Diamond coated washer increases the friction between the interface by 200% which looks to be a realistic conservative figure then it would seem to me that an OE bolt and a diamond coated washer would be better than an ARP bolt by a good margin . The washer acts like hundreds of small dowel pins connecting the faces of the contacting surfaces.
Click to expand...

wossners = cheap shyte = shrink (3 sets now) - gave up with them.. unusable when you get an 82.5mm piston which measures 82.47mm new, and after 2/3 races then measures 82.29mm... to put into perspective 0.07mm is the correct wall clearance and after only 3 events they had shrunk to 0.18mm clearance.. First set shrunk so bad after one use, they would fit into 82mm bores! You've been warned. In practical terms (until they rattle up and down the bores so bad the rings dont seal) the knock sensors will be hearing all manner of sh1t... and tuning a mechanically noisy engine will be a challenge without dulling down the sensitivity to a much lower (deafer for knock) level.



I know how the coated washers work.. and know in REALITY how effing tight the ARP is vs OE.
Incomparable regardless of your paper maths. ARP holds way way tighter..
 
badger5 said:
I know how the coated washers work.. and know in REALITY how effing tight the ARP is vs OE.
Incomparable regardless of your paper maths. ARP holds way way tighter..
Click to expand...

Is there any reason you couldn't use both, Bill? ARP bolt with a coated shim thingy? Assuming the "ultimate" setup (if a little overkill) would be the shim, a couple of 5mm dowels and an ARP bolt holding it all together.
 
Rainbird said:
Is there any reason you couldn't use both, Bill? ARP bolt with a coated shim thingy? Assuming the "ultimate" setup (if a little overkill) would be the shim, a couple of 5mm dowels and an ARP bolt holding it all together.
Click to expand...
no, I'd use ARP and diamond shim together. all the grip + clamping then.
We use steel billet bottom gear from choice however vs drilling the monkey metal std ally bottom gear for a dowel (which we've seen sheared off anyhows with the ones folks sell/fit)
 
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badger5 said:
not 9k like my ibiza used to go to.. its a relative thing i guess.
low 8k's is plenty for some.. who needs vtech 'yo' - haha
Click to expand...

It wasn’t how high they can rev, it was that they revved slower, like more inertia? Are tfsi crank’s heavier? Annoying I can’t remember when I saw it but I thought I saw Paul mention it regarding stroker builds v stock. I’m questioning if I dreamt it now.
 
Hi Bill thanks for posting the video, That is worrying, can't argue that they are cheaper, but they are a well used piston and I can't find many people having issues with them.They are used in a lot of high power builds but maybe not quite as extreme as yours. Piston slap seems to be more of a reported issue with JE pistons made from 2618 instead of 4032. Looking for a decent engine shop who can take the time to measure the pistons in the first place and accurately machine the new bore with the correct honed finish.

With the ARP bolt I was just trying to get my head around why ARP them selves only quote a 10% improvement, even though it's obvious that the 90 degrees is a mission. I have read posts where people have not been able to get the extra 90 degrees, Another reason why I would like to avoid fitting one of these. I suppose after 60 degrees or so with an OE bolt it starts stretching so the amount of torque needed to turn the last 30 degrees doesn't really increase much. The ARP doesn't stretch like an OE bolt so the amount of torque required will keep increasing.
It seems VAG identified the need to improve this weak point on the engine with the 2.0 TFSI and their solution was the washer. AFAIK they still use a sintered pulley and normal high tensile bolt.
 
Mentioned it in context of 2.1 builds using tdi cranks...

I have revved mine to 8.2k but peak power is 7.8k so I keep it there to prevent accelerated wear on valve train

<tuffty/>
 
JonnyDerv said:
It wasn’t how high they can rev, it was that they revved slower, like more inertia? Are tfsi crank’s heavier? Annoying I can’t remember when I saw it but I thought I saw Paul mention it regarding stroker builds v stock. I’m questioning if I dreamt it now.
Click to expand...
I cant say I've ever noticed a difference in how they rev..
The 600bhp club members will confirm this too.. Strokers..
 
desertstorm said:
Hi Bill thanks for posting the video, That is worrying, can't argue that they are cheaper, but they are a well used piston and I can't find many people having issues with them.They are used in a lot of high power builds but maybe not quite as extreme as yours. Piston slap seems to be more of a reported issue with JE pistons made from 2618 instead of 4032. Looking for a decent engine shop who can take the time to measure the pistons in the first place and accurately machine the new bore with the correct honed finish.

With the ARP bolt I was just trying to get my head around why ARP them selves only quote a 10% improvement, even though it's obvious that the 90 degrees is a mission. I have read posts where people have not been able to get the extra 90 degrees, Another reason why I would like to avoid fitting one of these. I suppose after 60 degrees or so with an OE bolt it starts stretching so the amount of torque needed to turn the last 30 degrees doesn't really increase much. The ARP doesn't stretch like an OE bolt so the amount of torque required will keep increasing.
It seems VAG identified the need to improve this weak point on the engine with the 2.0 TFSI and their solution was the washer. AFAIK they still use a sintered pulley and normal high tensile bolt.
Click to expand...
Shrinkage. Pistons which shrink.. think about it. Good idea?
Not a one off.. 3 x sets.. yes 3! all shyte and shrunk.

Slap is a function of clearance. simple as. too much cold start rattle..
We manage to make JE's in 2618 not rattle from cold with suitable bore clearance applied (learned from experience of building many of these engines) - Ignore what the "book" says.. Practical experience trumps whats written as a guide. I've shared my wossner experience... prawny who you cite as example is well aware of what wossners do... he's seen it first hand.

Undo an ARP and undo a stock bolt and tell me which one was tighter ;)
 
At the time we thought Wossners were ok. People rave about how good, this and that is, but you find out later that they do not push their engines anywhere near the limit that some of us do. We had the same with brakes.

I believe Wossner said "you must have overheated the engine".. That was not the case. They just don't want to take responsibility. GREAT. Lets hope they get what they deserve.
 
Well hopefully got a machine shop sorted. Sounds promising the machinist has been building race engines for the last 30 years. Plenty of engine reconditioning places around but from what the guy was saying they take the time to do it right.
I suppose it will all be in vain if the pistons shrink.
https://competitionengineservices.co.uk/
 
Can you not send the pistons back or exchange them for different ones? Would be a shame to crack on with the build knowing that there is a good chance they will shrink.
 
Anxiety overload
 
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They actually arrived this evening . I was originally intending on refitting the OE pistons, On reflection that wasn't a good idea. Are these going to be better than an OE piston thats done 90K , I hope so. This engine is not going to be worked as hard as Bills race car. There seem to be a lot of people using these with not a lot of posts from people complaining about them.
Usually if something is really bad people complain about it. What pistons do you run in your race engine now Bill ?.
For not a lot more I could of got a set of JE's from Stacy at Pro Race and had them rattling when cold because of the excessive clearances required for 2618 alloy pistons. There are Supertech and CP pistons that come in more expensive . £800 for a set of CP pistons with a skirt coating.
Will strip the block and take it over to Competition engines on Monday and see what they have to say. Will ask them to measure the pistons and see what they come out at. My £15 digital vernier caliper isn't something I would entirely rely on.
 
audi upgrades
Just to clarify, our engine knock sensor started to pick up excess noise and it was put down to piston shrinkage.
 
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