ABV VR6 techical information (rebore size advice)

[Rpmayne 0]

Does anyone know where to get technical information (must be an internet site somewhere) sepcifically for the 2.9 ABV engine and not the 2.8 AAA engine. Seems the AAA is the more common engine, I have found a few useful pdf's about them (and Andi's spec on this forum) but not the ABV, and in particular the piston size, piston to bore clearance etc..

 

Thanks.

[Chris VR6nos 0]

Interesting, what you planning?

I'm having the same problem, i need to know the std clearence volume to calculate the C/R with a long stroke crank and std pistons, for now anyway.

 

 

Chris

[Rpmayne 0]

I'm in the process of rebuilding the motor with the help of 16vg60. The link below was the start of the process, thought originally and quite obtimistically that it would only be the valve stem seals.. how wrong I was. :shock: :(

 

Was going to get oversize pistons (82.5mm) and get the block rebored but have had no end of grief trying to get hold of any. Ended up getting oversize pistons from VW (the only ones they do are 81.925mm so don't think they are actually oversize) and getting the bores re-honed to suit.

 

I would be interested what size the standard pistons actually are to check against the new ones..

[Kevin Bacon 5]

I thought the standard process was to use stock 2.9 pistons and bore out a AAA block?

[PhatVR6 0]

Just buy some JE pistons and take it out to 3.1.

 

AFAIK, the crank, rods and head and CR are the same, so other than than the overbore and pistons, I don't think the physical block is any different.

[Chris VR6nos 0]

The head is flat & the bowl is in the piston which is smaller(AFAIK) to give the same compression with the smaller 2.8 displacement.

There are oversised pistons available but not from VW, Stealth had 10sets made in two steps for re-boring but he only ha 1 or 2 sets left IIRC, they are cast like the origional ones not forged, this is reflected in the price though for the same £180 re-bore price you may aswell get the JE ones but be sure to specify which of the two C?R you require, either 9:1 or 11:1 for forced induction or N/A. Are-map is essential to get is to run right afterwards.

 

 

Chris

[Bruno 4]

you may aswell get the JE ones but be sure to specify which of the two C?R you require, either 9:1 or 11:1 for forced induction or N/A. Are-map is essential to get is to run right afterwards.....Chris

 

My experience too - I had to go to 3.1 and got my bits from the US, then took the best part of 6 months to do it right. Everybody in the US thats done something serious has said the same thing: (i) get the temps down, (ii) the quality of piston and bore quality up to max available (iii) take your time on the rebuild. The higher compression config has much higher temps and does tend to be less reliable. So I went for a cooler block and decided I'd recoup the power difference with a supercharger one day. Still saving for it. Yet strangely it out-accelerates a standard VR6 C in its present (3.1 L) form. I didnt expect that. 8)

 

Remapping is vital. In the end I had a specialist do it. I understand that both AMD and Stealth are good at this.

 

If in doubt search the US sites. Many vortex forum users have taken the Passat 2.9 engine (which is an ABV), stroked and bolted on a charger of some kind. Thats where I got all of my info, and in fact, my parts.

[PhatVR6 0]

What size pistons did you get what CR? what jead gasket? need to know, I'm planning a 3.1 too.

[Rpmayne 0]

I'm not sure whether to go for the 82.5mm pistons (first overbore for the abv) or larger. Is there any real benefit in going for a larger bore and pistons with everything else stock? Can't afford anything other than that now, also don't want reliablilty and running problems.

[Chris VR6nos 0]

You only need to get different rods if you use a different stroke crank so if you are going to spend money on a re-bore you may aswell go for the biggest as the re-bore and pistons are the same price regardless of size.

Cubes make power.

 

 

Chris

[niels 0]

The AAA 2,8l engine has 81.5mm bore and the 2,9l ABV engine 82,5mm bore. They are mahle pistons The compression is the same 10.1:1.

 

I can supply rebored blaocks with new pistons for about £1200. Thats not yet confirmed though.

 

Niko

[Sadinn 0]

Found this link a while ago - I have not contacted them, but thought as you seem to be having problems, BBR cl;aim to supply teh whole kit - anyone have any experience with them?

 

http://www.bbrgti.com/gti_MK3Eng.php

 

Cheers

[Chris VR6nos 0]

BBR have done lots of things and for the longest time, when i was young (I'm 36) they were the guys doing mad power with the cosworths etc and were notorious for thier endevours.

 

 

Chris

[rixy 0]

im also thinking iof doing an overbore on mine, does anyone know the approximate cost of doing this? wouldnt mind doing it all properly, and i know how to rebuild the block, so just need the work doing to the block, and new pistons and rings etc?

 

any rough prices, and where to go?

[Stan 24v 0]

Pistons

 

I think these are the cheapest ones about, and the postage costs are around $100 to the UK.

[Chris VR6nos 0]

It seems lots of people have the same thoughts about thier engines, i wonder how many actually end up doing what they thought with them?

 

 

Chris

[Rpmayne 0]

I did end up going down the 82.5mm rebore and mahle (standard type) pistons, and 20k down the road its going well. Just read through this thread and forgot about the remapping, was leaving it until it had run in abit. Do you recon its worth it for such a small increase? Don't think it quite makes 3.0L, and everything other than 3 angle guides, k&n panel and exhaust is standard.

 

Had a go in a mates standard VR6 Golf and it seems to pull alot harder than mine. Until then I thought mine was quick, feels bogged down.

[Chris VR6nos 0]

THe thing is, even with a free flow filter and a performance zorst, you could benefit from a remap as the breathing is better.

"3 angle guides"?

Surely you mean 3 angled valve seats?

 

 

Chris

[niels 0]

I did end up going down the 82.5mm rebore and mahle (standard type) pistons, and 20k down the road its going well. Just read through this thread and forgot about the remapping, was leaving it until it had run in abit. Do you recon its worth it for such a small increase? Don't think it quite makes 3.0L, and everything other than 3 angle guides, k&n panel and exhaust is standard.

 

Had a go in a mates standard VR6 Golf and it seems to pull a lot harder than mine. Until then I thought mine was quick, feels bogged down.

 

I find it rather odd that you went through the trouble of boring out the block with oversized pistons, but don't find it necessary to get the ignition remapped accordingly? Its a bit like making a cake and forgetting the icing on top.

 

I've fitted 83.5mm JE pistons to mine, and done about everything else possible for a NA vr6. The result is 220bhp

http://www.locomail.com/niko/mycorradow ... /aug05.pdf

 

for oh.. quite a few hundred squid...I got the same power increase when fitting my 2.2l turbo audi with a no name chip for next to nothing.

So whether all this is "worth it"...no..but it certainly wakes up the engine.

[Rpmayne 0]

I didn't get the ignition remapped straight away because I thought I should run it in abit first before sticking it on a rolling road, and whether it would actually make any improvements. £500 for a EPROM worth a few quid and a few hours labour seems alot.

 

A rebore was never the intention, it apparently needed it and so the situation just snowballed. I wanted it as standard as possible while still improving it to make it seem worth while. After months of other unrelated problems I was just grateful at the end that it worked.

 

Sorry, do mean the valve seats btw. :oops:

[Mike Edwards 0]

Juat out of curiosity, what's to stop you putting an ABV head on a BFH block?

[Kevin Bacon 5]

BFH? Bus Fare Home?

 

Is that a 24V block? The head bolt spacings and fluid galleries are different I believe.

[Mike Edwards 0]

3.2l...