BAM S3 full rebuild for Hybrid or BT

well as expected my bores are oval`d:(
so that means re bore and some shinny new pistons are needed:)
whats people recommendations on new pistons and new bore sizes?
I know that 82.5mm is the max safe limit for a road car





Cylinder one average: 81.111mm with ovality of 0.127mm
Cylinder two average: 81.274mm with ovality of 0.224mm
Cylinder three average: 81.308mm with ovality of 0.246mm
Cylinder four average: 81.260mm with ovality of 0.233mm

Cylinder three looked like it was running hotter than every one else as thats the worst one

But this is with a very good factory cross hatch still shown but its done 115K so some things gotta ware.
 
Cylinder 1

Cylinder 2

Cylinder 3

Cylinder 4


the Oil pump chain tensioner didn't look too bad either, but will be replacing it any way


Shame i gotta replace the pistons as theres not a mark on them

 
83mm is the biggest most people take them as its safe. 83.5mm is the limit, but some people do it.
If youre going to rebore may aswell go for the biggest displacement you can, 83mm.
 
well i`d like to air the side of caution plus 82.5mm i can still use the oem head gasket.
If i go to 83mm then the block is scrap if any thing goes wrong, where as with 82.5mm ive still got a bit of meat left just in case:)
 
audi upgrades
Did You measured the ovalness with bare block? As the measuring should be done with the head on and torqued.
 
Was measured by bare block. Didn't know about the head being torqued on.
Didn't think it would make any difference.
Not like they machine the bores in the factory with the head torqued on
 
There will always be a degree of ovality with any used engine due to the way the piston pivots on the rod. Pretty pointless measuring if you ask me. Piston to wall clearences is what you need to be concerned about and if they are within spec all the way round.
Which is something your machine shop will need to know when boring for the larger pistons.
 
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I dont think an ali head is going to alter the shape of a steel block torqued or not, it just wouldnt happen....

Karl, Ive just examined my old block, and still scratching my head in why it failed (#2 piston well down on comp....)
no visable signs of damage, i thought a ring had snapped, but all is fine, i have noticed play front to back in the bore so im guessing it has gone oval, i will measure when i get time, maybe bore wash ??
 
dave there is always the tiniest bit of front to back movement, but yeh if its excessive then bore wash could account for that. I think tuffty had worn rings due to bore wash at one point.
But havent you always been running tuned and afrs ok etc.

Check the head, and the valves/seats.
 
I put oil down the bore when it was still altogether and the comp came straight back up,,,
Andrew As got my head so im sure if anything is a miss he will spot it, the head as only done 5k since rebuilt by Drakes
 
It was me that damaged rings due to bore wash

Dave. Picked up your head today and port three is oily, I'm sure your right about your bore or it could be a bad set of rings or they didn't bed in that well?
 
RS tuning built it last time, and it never made good power on hybrids, so maybe the problem was there all along?

Anyway sorry for the slight derail....carry on :whistle2:
 
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s3dave said:
I dont think an ali head is going to alter the shape of a steel block torqued or not, it just wouldnt happen....

Karl, Ive just examined my old block, and still scratching my head in why it failed (#2 piston well down on comp....)
no visable signs of damage, i thought a ring had snapped, but all is fine, i have noticed play front to back in the bore so im guessing it has gone oval, i will measure when i get time, maybe bore wash ??
Click to expand...

Its not just the ali plate/head that does it... its the force induced from the bolts that can pull the block out of square...

<tuffty/>
 
Well today i got my brother who`s a machinist and got him to measure the block, crank, pistons, piston ring grooves and gudgen pins the old fashion way with mic`s and was very happy with the results:)
He didn't believe that on of the cylinders was coming back at 81.308mm which should of been slapping like a ******* and smoking oil.
He also doesn`t like the Faro arms as his work just got rid of theirs as it kept giving false readings.
Here`s what we found





 
Last edited:
Took ages converting back to Metric as the Mic`s were imperial.
But very impressed with the results after the engines done 115K but had FASH and was completely standard when i got my hands on it:)
 
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What's every ones perspective on balancing an engine when you've just replaced the rods?
id agree and do it if I'd re bored the block with new pistons but don't see the point if the new rods are gram for gram?
cheers guys
 
Get the oem pistons checked and balanced. Mine werent within a gram like the rods were.
Also get the crank done, and if going single mass, get that done with it too.
 
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Well not much of an update but parts are starting to roll in.
Shells for the main and big end
Forge coolant hose kit
Will be seeing my Rods and stud kit tomorrow:)



Now i know its not every ones brand of vodka but couldn't just leave the block all rusty and scabby after all the hard work of re building her so painted that and its needing a few more coats but liking what im seeing:)
 
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Well the blocks finally cured after 3 coats:)


A gathering of parts have now turned up so starts the assembly process.




Weighted the new rods and was amazed how they all weighted the same.

The heads off to a specialist i know up here so i`ll have that back in a week, providing its not needing too much.
Some odds n ends blasted and then heat painted

Thinking of making a old crank from the scrapyards and make a pretty cool lamp lol


Crank lower main shells in and lubed up with assembly lube

ARP main stud kit in place

Sump needs a little tickle with a file for the stud clearance on the clutch side
Plastigauge in place for reading the oil clearances


And all within spec:)
Freshly de glazed bores


And slowly starting to look like a engine again

Sumps only there to catch assembly lube drips in case any one says i forgot to fit the crank oil seal flange lol
 
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Forgot to ask but there no mention on the IE Tuscan rods which direction their to be fitted?
Thought there was a arrow which has to be pointed towards the timing belt?
Cheers
 
audi upgrades
Yea that's true. I miss driving the S3 and the smell of the leather seats. Might just sit in her tomorrow and have a nice big sniff lol
Been driving the octy4x4 that has a stage 1 map for the winter car and miss the tight handling of the S3. The octy's like a boat in the corners and shouldn't be running 200 brake with the standard shocks lol
 
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Lol
well that's the engine booked in for balancing. £120+vat. Think that's a bit steep but their the only place up here so gonna have to bite the bullet
 
More bits from TPS



timing belt kit, aux belt, vag sealant, after run pump, thermostat, slave cylinder, crank case breather housing gasket, complete piston ring set and crank cam belt pulley bolt. Just waiting on new crank thrush washers
 
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hoffmanvp3 said:
More bits from TPS



vag sealant
Click to expand...

Vagisil.jpg
 
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A ********...that's prob cheaper lol
always amusing when u wonder in and ask for vag specific sealant :hubbahubba:
 
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Well thats the crank and rod/piston assy balanced now, picking them up today:)
cos i was only getting the crank done got it for £90 all in, normally more if flywheel was geting the same treatment.
They did ask for it but i argued that when its clutch changing time then the balance will pointless.
Plus im getting the LOBA stage 2 SMF kit which is lightened and balanced so happy days then.

Well some intresting parts came through, the Thrust washers for the crank which looked no where near like the old ones and tps were saying these are the part numbers for my BAM, which clearly isnt right
top ones are the originals and the bottoms are what tps gave me

so the correct ones are coming today:) 026 105 635 A
the wrong ones were 06A105637A which look like its for the older 1.8t blocks which have 4 thrust washers where as the BAM only has 2.

New clutch bleeder which is metal instead of the plastic oem so wont flex so im hoping this will make my LOBA clutch on/off feel more precious
 
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Well this morning I've removed and fitted the new clutch slave cylinder and checked the gearbox input shaft oil seal and its not leaking:)
fitted the new clutch bleeder




also picked up the newly balanced crankshaft and con rod assy from Agra machine shop, just a baw hair out they said lol




 
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How have I been watching this on Facebook but not noticed it on here. Keep up the good work and all the best fella.
Callum.
 
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