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General => General discussion => Topic started by: Dizzie on 22 June 2004, 00:00

Title: twin cam vw engines
Post by: Dizzie on 22 June 2004, 00:00

someone explain to fielder why our 16v and 20v engines only have 1 cam pulley on the end. ;D

Title: Re:twin cam vw engines
Post by: golfvr6 on 22 June 2004, 00:11

The exhaust cam is driven by the sprocket via the cam belt, the inlet cam is driven via a chain that links to the back of the exhaust cam.
later vw polo 16v engines actually have 2 cam sprockets.

Title: Re:twin cam vw engines
Post by: golfvr6 on 22 June 2004, 00:24

Here is an example
An Audi 20v engine,
The chain is at the sprocket end, on the 4 cylinder it will be on the other end on the cams.
The principle is still the same, one sprocket drives the exhaust cam, then a chain links both exhaust and inlet cams.

(http://img45.photobucket.com/albums/v137/samsmith2000/GTI%20stuff/audi1.jpg)

Hope that helps  ;)

Title: Re:twin cam vw engines
Post by: Fielder5757 on 22 June 2004, 00:40

LOL ok diz you win.........For now ;)

Title: Re:twin cam vw engines
Post by: Dizzie on 22 June 2004, 10:44

too much time looking at Jap engines did that to you fielder ;)

Title: Re:twin cam vw engines
Post by: kniterider on 22 June 2004, 20:44

heres a pic of my 20v four cylinder head, as you can also see the cambelt drives the exhaust cam, which is linked at the other end by a chain and sprocket to the inlet camshaft hence the 'sohc' lookwhen you see the belt just driving one pulley on the 'open side'

(http://homepage.ntlworld.com/c.hunter101/20v12.JPG)

enjoy!!

lol

Gaz 8)

oh yeah turn pic around 180 degrees and it would look like it did on the car!! lol

Title: Re:twin cam vw engines
Post by: Dizzie on 22 June 2004, 23:41

and it would be impossible to work 20 valves with only 1 cam

Title: Re:twin cam vw engines
Post by: Gambit on 24 June 2004, 14:06

Quote from: Dizzie on 22 June 2004, 23:41

and it would be impossible to work 20 valves with only 1 cam

i read somewhere that some engine manufacturer  where able to work 16v's with one cam

or somehting bizarre, ill try and dig it out

Title: Re:twin cam vw engines
Post by: Gambit on 24 June 2004, 14:10

honda crx esi & mazda mx3 are both 16v SOHC engines


and ford have a 2.0 8v twin cam!

Title: Re:twin cam vw engines
Post by: mk1 on 24 June 2004, 18:58

And the Triumph dolomite sprint had a 16v engine and used one cam to operate the valves, and used the same cam lobe to open the inlet and exhaust valves :o.
Steve.

Title: Re:twin cam vw engines
Post by: Dizzie on 24 June 2004, 23:52

not much scope for adjusting the overlap there then