Block rebore

[Jamo]

Bit of a daft question but I need to know the answer.

When reboring does the block have to be completely stripped of crank, oil squirters, shells etc?

[s2dude]

Bit of a daft question but I need to know the answer.

When reboring does the block have to be completely stripped of crank, oil squirters, shells etc?

ideally ..yes
and of course it needs a suitable torque plate used to simulate the cylinder head being attached

[Jamo]

Yeh i'm aware as I've spoken to a few people about it, although I don't want to rebore if possible.

Aelred has a spacer and torque plate

[aelred]

Yes the block has to be totaly stripped and mains caps bolted down. It has to be well cleaned afterwards.

[Jamo]

Cheers Aelred, i'm hoping I can get custom pistons to the size I need, else I'll be intouch about hiring your torque plate.

[HPmuirt]

From what I have read and understood in the past, you are supposed to install the torque plate a minimum of 10-12 hours before boring/honing, to ensure that everything has settled, otherwise you can get a slightly oval bore and loose ring seal.

You are also supposed to use all the new bolts and head gasket when installing the engne plate and torque plate, all torqued to the normal specced amounts.

Since the old wisdom was always that a 'seasoned' block was always better than a new (saves having to heat cycle it and resonate/shake it), I quite like the idea of having my block striped, cleaned, cryo frozen, rebored and honed

My questions are...

1. Who is the recommended engine rebuild guru who will do the above?
2. How much will it cost?

Cheers n

Si

[S2central.net]

I would only entrust engine work of this nature to the people that someone like Aelred or Basset Down Balancing would sub it out to.

Another block related question though - there was a thread in the dark distant past about an oil pressure valve in the block that appears on the family album for 'modified' engines only. I think it was Doug who tried to find the difference... but I can't find it.

Can't remember if the alternate valve is intended to provide more or less oil to the head, the small ends or the mains or what. Can anyone else unearth some knowledge on this one ?

Paul

[S2central.net]

The family album for RS2 shows it on 103-20 as item #25. One of which is for 'modified vehicles'. The modified part number is 046 103 175A and I see that is called up with the complete short engine along with part number 034 103 179 as an adapter #26 which seems to mate with this modified valve.

It looks like the RS2 uses the modifed valve and adapter on the same block (034 100 105S) as they are not listed for 3B, ABY or AAN applications. Weird... Just wish I could see where the darn thing connects to - looks like its in the area of the two oil pressure sensors.

[mcandmar]

I've seen a pic of the "modified valve" on here and it looked very different, so much so i dont think it will fit an early block. Think it was in one of MarkH's engine build threads.

[mcandmar]

Found it http://www.s2forum.com/forum/showthr...?t=3685&page=2

[S2central.net]

Good find Mark...

PS - I'll be in Dublin next month - would be good to catch up for a beer or two and talk Audis if you like

Paul

[mcandmar]

Absolutely you have my number

Mark.

Good find Mark...

PS - I'll be in Dublin next month - would be good to catch up for a beer or two and talk Audis if you like

Paul

[Jamo]

Good news for me is that CP Pistons have said they can make my pistons to fit my custom bore.

No rebore needed! phew

[pixsaudisex2]

just wondering i thought the 5 cylinder was just a four cylinder v.w engine with another pot on the end as i remember with these that boring out was more a less a no no as there was so little to bore out with to increase the capacity ( it is possible as i had it done on my golf ) but it was such a little amount that it was more or less pointless in having it done i only had it done really to get rid of lips on the bores but even then the bloke was saying you have to be carefull as the water jackets etc on these engines run so close to the bores anyway you would just be making the engine really un relablie ( and im sure you have had enough of this..) anyway im sure im missing the point of you having this done and im sure you will enlighten me on your next post but surely the cost of all this would be better of spent getting another engine.. anyway mister jamo enlighten me...

[Jamo]

You can rebore the 20v Turbo block from any size up from the standard 81mm to anything up to 83mm.

Anything up to 82mm you can retain the stock OEM headgasket. Above this it's copper gaskets

You can get a true 2.6L if reboring a stroker to 83mm.

I'm under 82mm so have plenty left to play with.

Most rebores are done due to high wear on the cylinders and it's just a case or reboring to prolong engine life.