2.8 - 2.9 Differences - blown engine - worn out engine issue

[Storm 0]

With my own situation, I have been looking at this. So thought it may be a good topic for all to share. Especially people with the blown engine/ worn out engine issue.

 

Their are many more 2.8's than 2.9's floating about and the rebuild costs are high. So surfing around I've found the following basic information, my knowledge is limited :roll: :?: .

 

2.8 Bore 81 x 90.3mm Compression Ratio 10:1.

2.9 Bore 82 x 90.3mm Compression Ratio 10:1.

The capacity difference is 69cc, as a % its small.

The only real differences I can find are the throttle body on the 2.9 is miles better and the intake manifold is supposed to be better. Any other differences?

 

Is the AMD throttle body much better than the 2.9 type?

 

So is the only real internal difference the bore? If this holds true then does the following apply loosely with the 2.9 external bits?

190BHP / 2.9 x 2.8 = 183.4BHP I know this may not be right but tell me, waiting to be shot in flames on this one.

[vr6storm 0]

my knowledge :oops: :oops: :oops: of the grubby bits is almost if not worse than yours :oops: ..........but i would imagine 2.9 Pistons are different to 2.8 pistons size-wise(tho admitedlly a small difference).....given that there is a difference in bore size?????

[PhatVR6 0]

2.9 pistons are 1mm bigger.

 

you'd need the 2.9 TB and inlet manifold.

 

cams are also different. and the map is also slightly different to (denoted by an AG suffixed ECU, rather than the 2.8 AB one).

 

Get an old block and bore it out to 3.0 or 3.1 and use JE pistons. That's what I'd do if I was in the same situation.

[Storm 0]

Phat VR, I'm going to be doing this at home so there are two issues.

1. I have never stripped an engine and I think the VR is a little complex to learn on, but I know I'm going to have to do it one day. The first phase on the confidence side is the transplant.

2. The cost of the 3.0/3.1 conversion is high, this car needs much work so if I can get the coilovers on, brakes and paint done then I'm happy. I can do the engine as a spring project next year.

 

I'm going to use the ECU and from the 2.9. I'd be interested in knowing the difference on the cams and what the AMD throttle body is going to give over the std 2.9.

[Kevin Bacon 5]

The VR engine is far from complex. The only tricky thing about it that beginners will stumble on is the cam timing. Even professionals bugger that up from time to time.

 

If I were you, I'd remove it from the car yourself and strip it all down. No special tools required, other than spline keys for the driveshafts, HT lead covers and the head bolts. Then get a 2.8 block from a scrappy and get it bored out to 2.9 specifications. My local engine shop charge £15 per bore, so it can be cost effective if you're prepared to put all the ground work in.

 

The AmD throttle body is gas flowed and enlarged. It's flows approx 17.5% more at wide open throttle than the standard one. In conjunction with a remap, it's a good mod. I've got one on mine with the Schrick manifold and there's more torque everywhere in the range than a standard engine with just the Schrick.

 

K

[PhatVR6 0]

Vr6's are p1ss easy to work on. there is nothing hard about them at all. and you 'll find all the help you'll ever need on this very forum if you speak to the right people. csam timing can be a bit tricky at first, but once you'd done one, it's easy.

 

I suggest you buy one of theose little blue Peter Russecl VR6 engine manuals that come up on ebay all the time (or buy it direct from russek publications for £6.99)

 

Everyone's gotta learn somehow you know, and that means getting stuck in.

 

6 years ago I'd never so much as fitted a sapre wheel, now look at what I'm up to. I'm proud as puch with what I've done with my car, and it's never even been near a garage since I bought it. These forums are fantastic for getting in touch with peopl in the know. I'd have never got mine going right without the help of others.

 

just go for it and surprise youself.

[aposegil 0]

I would agree with Phatvr6 as VW are not that complex.

 

I cant talk about the vr engine itself but i have been working on the 16v and 8v engine and learnt it all via freinds etc and its scare first time but once uve done it its fine and we have saved ourselves a crap load of money

[dr_mat 0]

So is the only real internal difference the bore? If this holds true then does the following apply loosely with the 2.9 external bits?

190BHP / 2.9 x 2.8 = 183.4BHP

 

I think the 2.8 is quoted at 175bhp. That manifold and throttle and different cams mean it's not quite so "tuned" as the 2.9.

 

The benefit of taking a 2.8 and boring it to a 2.9 is you get a rebored engine for not much cash, and you don't have to buy new pistons etc. Unless you can pick up a low mileage, good 2.8 (or even 2.9) that doesn't need any work, of course. But this is less likely.

[Storm 0]

I've got an engine and gearbox lined up. Its low mileage, hence my reluctance to strip it. With the support of the forum anything is possible. I'm going to get a russek manual and have a read.

[dr_mat 0]

If it's a standard 2.8, you might see good gains from putting your 2.9 TB and manifold onto it, along with the 2.9's ECU.

[H8RRA 0]

I'd agree with all that the VR is surprisingly easy to work on. Once the inlet manifolds off, its a surprisingly small block.... don't be scared at how complicated it looks - theres nothing to it below.

 

Just built up a 3.1 with Chrisvr6Nos and it was P!$$ easy. Got the timing a tooth out cos its hard to gauge - even when you get it right, the cut-outs on the cams don't line up perfectly horizontal - but this doesn't do any harm anyway and always turn it by hand before starting.

 

We have done a couple of heads now and this complete build and every time the VR has started up in a fraction of a second from complete rebuild and purred to life!!!!!! The latest one - the block had stood for 18 months and the head for 8 months but still it fired into life in a fraction of a second.

 

One tip though - when we did a compression check we had no compression in 2 cylinders and finally worked out it was the hydraulic tappets which had stood for a while and were locked open and kept the valves slightly open thus giving a reading of no compression.

 

Definately get a russek book as they are invaluable and offer good advice on the hydraulic tappets.

 

On other points mentioned above

 

re-reboring - the vr is a "V" and cannot be bored by any old shop as a jig is required for the 15DEG "V" of the cylinders. If you know of a shop that does the VR for £15 a bore, I want to know about it. As far as I'm aware, budget for £250. Vince at Stealth will tell you where to go - can't remember off the top of my head.

 

PAY PARTICULAR ATTENTION TO THE CHAIN GUIDES COS THEY'RE ALWAYS WORN/BITS SNAPPED OFF ETC. Oops - sorry for shouting that bit.

 

I have lots of spares available after this build inc a 2.8 block - could even offer a rebuild service if you came to the North East :?

 

And finally - wouldn't get GSF head gasket as i've popped mine already :roll: :roll: :roll: Mind you, it is long stroke with a charger but even so, the buggers split in half and the waters pissing our as fast as it can be poured in!! So if you saw a mobile smoke machine travelling at 120+ on the A19 Sunday, it was me :oops:

 

Pics'll be on the board soon but have another head to do first :(

[Storm 0]

Guys this is all briilaint advice, it seems that those of you who have taken the plunge have quite enjoyed it a learned alot.

 

My block has stood for a long while with the head off. This has been because the eengine blew up due to coolant loss. R those pistons likely to be knackered, they look manky?

 

dr_Mat thats the plan, but the guys seem to be talking me round. :wink:

[Kevin Bacon 5]

re-reboring - the vr is a "V" and cannot be bored by any old shop as a jig is required for the 15DEG "V" of the cylinders. If you know of a shop that does the VR for £15 a bore, I want to know about it. As far as I'm aware, budget for £250. Vince at Stealth will tell you where to go - can't remember off the top of my head.

 

Take it you mean't *isn''t* a V ?

 

I just asked my shop how much boring was and that's the price he came up with. I assumed the price would be the same for a VR as it's just a case of tilting the plinth on the CNC machine to 15 degrees.

[Henny 0]

VWs are just like a giant Meccano set... they're really simple to work on in general with very few "gotchas" in there, most of which have been discussed here in great length! ;)

 

As long as you take your time, and make sure that you double check everything you do before you do it, and then again once you've done it, you'll be fine... 8)

 

Pistons don't tend to get damaged unless the engine has run with lots of pinking of MAJOR overheating in which case they can melt/change shape slightly, or if they've made contact with a valve or suchlike... The could have a coating of carbon and antifreeze if the headgasket has gone, but they should clean up nicely pretty easily... 8) Look for chips, nicks, rub marks and scrapes on the pistons... there shouldn't be any... if there are then alarm bells should start to ring... :|

 

Good luck! 8)

[PhatVR6 0]

 

I just asked my shop how much boring was and that's the price he came up with. I assumed the price would be the same for a VR as it's just a case of tilting the plinth on the CNC machine to 15 degrees.

 

7.5 degress :wink:

[H8RRA 0]

15 degs between pistons - of course its a "V" but only a little "V" by comparison to most.

 

All the info and advice i've been given about boring them is as stated. I wouldn't assume - ask the shop - i'd be surprised if they could do it - if they can i want their address!!??

[Kevin Bacon 5]

I'll give em another ring this week sometime. They specialise in Ford Zetec and Duratek engines these days, so I know they have the ability to remachine V engines. They rebuilt a 16V head for me a few years ago and it was top workmanship.

[vr6storm 0]

15 degs between pistons - of course its a "V" but only a little "V" by comparison to most.

 

 

i'm getting confused a bit here,as i was always under the impression the VR is more akin to being a staggered straight 6 rather than a conventional Vee engine :?: :?: :?: or am i way off the mark here :oops: :oops: :oops: :oops: ......just trying to broaden my very limited engine knowledge here btw :oops: :oops:

[Joe M 0]

Its like a straight six in that it uses a single cylinder head and it has the inlet on one side and the exaust on the other. Its also a V due to the angle so its both really, though it probably does have more in common with the inline 6. Vee Reheinmotor apparently means Inline V.

[stormseeker 0]

Yep - that's the literal translation of Vee-Reihenmotor - "in-line Vee"

 

...quoting from the infamous technical guide that's loose onthe internet...

 

 

Volkswagen has developed a new six-cylinder engine called the VR-6.

This 2.8-liter engine is unique in that the V-angle between cylinder

banks is 15° rather than the 60° or 90° found in most conventional

V-6 engine designs.

 

The name, VR-6 come from a combination of Vee and the German word

Reihenmotor. The combination of the two can be roughly translated

as "in-line Vee."

 

Volkswagen has designed the 15° VR-6 to take advantage of

conventional in-line six-cylinder engine features (single cylinder

head, narrow width and excellent balancing) with the advantages

of a V-6 engine design (short overall length and compactness).

 

*** VR-6 ***

 

The VR-6 was specifically designed for transverse installation

in front-wheel-drive vehicles. By using the narrow 15° VR-6 engine,

it was possible to install a six-cylinder engine in existing

Volkswagen models.

 

*** V-6 Conventional Design ***

 

A wider V-6 engine of conventional design would have required

lengthening existing vehicles to provide enough crumple zone

between the front of the vehicle and the engine, and between

the engine and the passenger cell.

 

Using the narrow VR-6 engine will help Volkswagen meet current

and future front-end crash standards.

 

[H8RRA 0]

aauuuuhhhhh pplllleeaaaase!!! - a vees a vee, a straights a straight - see your point but its not straight, its a vee, as its name states!!???

 

Compact ickle vee with ickle angle compared to some but its not straight

[stormseeker 0]

But there's only one cylinder head, if it's a true V then there should be two...

 

:wink:

[Joe M 0]

Its a true V but with the layout of an inline if you ignore the cylinders. :? :lol:

[stormseeker 0]

Some good info on http://autozine.kyul.net/technical_scho ... kaging.htm ...

[Storm 0]

Guys,

 

Please can you tell me what NM range I am going to need on a torque wrench for the VR.

 

A mate has said get a secondhand Norbar, Britool or Teng, what do ya reckon?

 

Cheers.