VR6 engine layout?

[maff 10]

Just having a bit of a read of an old post about the vr meaning and that the vr6 engine is effectively a v engine but has one cylinder head like an in line engine but does that mean that the pistons have a plumb vertical (0 degree) crank throw as in the pistons on a traditional v6 travel up and down at 45 degrees so I therefore thought that the pistons in a vr6 would moving up and down at a 7.5 degree angle from the centre of the crankshaft? Or is the crank widened so the pistons are thrown up 0 degrees?

I suppose they would have to be cause the cylinder head is one piece and flat right?!

 

Is this really obvious or am I just being stupid?! I've never took apart a vr6 engine either so just trying to understand the 15 degree and one cylinder head bit

[Kevin Bacon 5]

No you're not stupid and it's the first time this has been asked on here! The crank is offset to reduce side loadings, but I can't remember by how much. It's in one of the VW white papers (self study) circulating the internet, but I can never remember where. The R32 and R36 self studies are worth a read too.

[maff 10]

Right so the cylinder head/valves will cast to marry up with the angle of the bores then?

[Jim Bowen 1]

Found a lovely diagram :lol:

 

[maff 10]

Cheers jim, it's all clear now... lol!

 

But is that a bird, bloke or photoshop!

[maff 10]

edit... I know it's a bird ;-) but what's she got tattooed on the front:-D

[Dox 22]

http://www.scribd.com/doc/8762040/23-V5-AGZ-info-doc

 

The link is for a 10V V5 (AGZ engine code), the engine block is similar to the VR6 set up with just one cylinder less.

[Kevin Bacon 5]

And the 24V engines - http://sandbox.enjoybeing.net/veedub/vw_vr6_self_study.pdf

[timthetinyhorse 0]

I think it's study 127 you want, I have it in German so no use for anything, I'm trying to get an English version

 

---------- Post added at 4:25 PM ---------- Previous post was at 4:19 PM ----------

 

http://www.volkspage.net/technik/ssp/ssp/SSP_127.PDF

[maff 10]

Good reading but I still cant understand if the crown of the piston is level with the top of the block at TDC? if you know I mean? or are the pistons cast to be level as they meet the top of the block or TDC?

 

Still don't get that bit??

[timthetinyhorse 0]

Scroll through the German document and you will see that only part of the piston is flush with the top of the block so part of the piston is cast with an angled section on it :-)

[maff 10]

I thought that's how they got round it;-)

[Kevin Bacon 5]

Only the 24Vs have flush piston crowns because the head has combustion chambers. The 12V has a flat head with pocketed pistons instead, which aren't flush, so the squish area is triangular.

 

12V piston -

 

24V piston -

12V block -

 

24V Block -

 

[VR6Pete 0]

interesting read!

[maff 10]

Great pics:-) they've obviously designed the crank pistons/combustion chamber to reduce the load on the outside of the bores then as the piston isn't travelling straight down, interesting! I am now more knowledgeable!

[Kevin Bacon 5]

It's certainly an intriguing and clever engine!

 

I prefer the 24V though as it's a master peice of engineering and smoother, and torquier.

Edited March 28, 2013 by Kevin Bacon