2 quick questions (V5 motor & turbos)

[tannguyen]

1. Does anyone know how the 5th cylinder is orientated in Volkwagen's VR6 based V5 engine? We know 5 cylinder engines tend to have vibration issues, but I'm curious about the V5, and no one I talked to seems to know the answer (and they are actually wondering themselves)

2. How does a variable geometry turbo (or a compressor, either-or) work?

thanks

 

[Whittey]

I don't know about #1, but for #2 the answer is yes. They used them on the late 80's mopars for a couple years, but ran into carbon deposits fouling up the movement. The newer electronically adjusting ones are supposed to be much better.


-=Whittey=-

 

[GregLocock]

I seem to remember that the V5 is like a 3 in-ine with 2 cylinders nestled in on one side to form a narrow V.

I don't know how they productionise it, but while I was at uni they were messing about with nozzle angles and throat dimensions on a turbo. I'd guess that a moveable flap would do the job. Cheers

Greg Locock

 

[NickB]

Chrysler used the VNT25 turbo on their 89-90 2.2 turbo IV motors. It used 12 moveable vanes to change the angle that the exhaust gasses approach the turbine inducer. It worked very well, but was prone to coking up. They would make 220 ft-lbs of torque at 1800 rpm from an 8 valve 2.2 liter 4 cyl. VERY quick spoolup.

 

[PJGD]

The VW engine is a narrow angle unit with the angle as small as possible so that it is not so very different from an in-line 5 cylinder. Yes, there are some features to minimize NVH issues, but it is not a wildly radical engine.

Back in the early 1980's. Ricardo designed a V5 diesel engine for Oldsmobile, about 3.5L capacity. It had a conventional angle, probably around 72°, and the rotary injection pump was mounted where the 6th cylinder might have been, had it been a 6. The engine got close to production, but then the shortcomings of the other two Olds-designed engines killed the diesel market.

All turbo manufacturers have to have Variable Geometry Turbos nowadays; modern diesels demand them for performance and emissions reasons. There are several different mechanisms; variable angle guide vanes (Honeywell), moving sidewall (Holset), and others.

PJGD

 

[Chumley]

Tannguyen:

If I understand the VR6 VW engine you are referencing, its a 6 cylinder engine, not 5. The layout uses a single cylinder head and the cylinders are staggered in 2 rows on the same bank. The stagger between the rows is +-15° Kind of like this bad ascii art below. I hope it comes out ok. If not, see the link below for a better drawing.

[o o o ]
[ o o o]

PLAN VIEW OF TOP OF CYLINDER BLOCK

Using IE 5.0 or better, go to this site

http://catalog.exist.ru/

There is no

http://www in

front on the URL. At the opening page, put the dot under the VW mark and select "1995" in the year box, then hit the red "next" button.
From the menu select "Corrado (1989-1995)" Wait until the picture shows up, then hit "next." Select "engine" from the menu and wait until the picture shows up, then hit "next." From the menu select "cylinder block with pistons and oil sump" for the 2.9L engine. There's your picture. If you hit next again you'll get all the OEM factory part numbers for the parts shown in the picture. You can look at the crank, cylinder head, and other engine components as well if you navigate around a little. For Audis and VW's its a VERY useful site that starts off in Russian but it's mostly in English.

Enjoy!


Chumley

 

[tannguyen]

it's a VR6 based V5 motor. As much as it sounds like a typo, it's not. The V5 motor is available certain Golf & Bora markets.

 

[Chumley]

Tannguyen: At the above referenced site, you'll also find a drawing showing a 5 cyl. version of the VR6. Its the same staggered inline configuration as the 6 cyl. just missing one hole on the front right side location.

Look at the same site again for the 2000 model year and select the Bora model. Then select "engine" as before and go to the "cylinder block with pistons oil sump" drawing. There it is! A 2.3L staggered I5 configuration. An interesting unconvertional design to say the least.

Chumley

 

[evelrod]

Chumley---you should become a member of these forums and post a brief profile so we can better 'know' you. Your posts I have read seem to indicate you would be an asset to the automotive engineering forums.

Rod

 

[tannguyen]

can't get the link to work

 

[NickB]

That motor just doesn't look right, lol.

Are the bores parallel, or is it really a V? If it is a V, are the piston tops slanted? Does the headgasket have round or oval holes?

 

[JayMaechtlen]

see

http://www.vw.com

for some nice flash presentations of the v-motors and a nice animation of the W-8 crank/rod/piston assembly!

http://www.vw.com/engine/index.htm?locnav=home#

Balancing must have been interesting...

cheers
Jay

 

[quatro]

Hello, I am new here. This is my first post ever, I am interested to see the site Chumley posted.

http://catalog.exist.ru/

For some reason I cant get it to work. Also I dont know if you can get the V5 in the golf/bora. But i know that here in Canada it comes in the audi S4.