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The Super Mechanic
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645 Posts
Discussion Starter · #1 · (Edited)
Pic #1
Pic#2
Pic#3
Pic#4
Pic#5

Here is a quick explaination of how the VVL valvetrain works. If you notice in pic#5 (The shaft in the center). This shaft runs through the head from one end to the other. This shaft does not spin and is staked by a small bolt at the cam gear side of the head. There is a Channel that runs the length of the shaft. The end of the shaft is blocked off. There are four feed holes, which are located at each rocker arm location. The rocker arms are located on a pair of valves. The other end of the rocker arm pivots on the shaft. Notice The "whole" or the channel the shaft runs through (Pic#1). As the solenoid(top of pic#5) is activated, there is a passage in the head that opens and allows the oil to pass through the shaft. At this point the oil passes through the feed wholes (Notice pic#2) into the rocker arms. This pushes the pin foward in the rocker arm. (notice pic#3) This locks the center part of the rocker arm which enables the center cam lobe. Notice pic #4. This engine works completely different than a DE. There are no "lifters" pushing the rocker arms up. The shaft is machined at the proper height for the rocker to swivel or rotate on. The lash adjustment is adjusted by the shims on top of the valves. This is a completely mechanical operating system. The only hydraulic part of this set up is the pin which enables the center part of the rocker arm to activate.

I hope this is a good explaination for those of you who do not understand how this works. I will post a pic of the head complete.
 

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seen the light
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374 Posts
Re: How the vvl works

This is why the VE will rev quite high then?No HLA's to get in the way of high revs...How often will the shims require attention/replacement?
Good pictures, supercowboy, cheers. :D
 

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VE junkie
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907 Posts
Re: How the vvl works

yea does that mean we will need to get the valves adjusted every 60k like a honda motor? :( and who knows how to do it, and the proper specs...since there no hydraulic lifter.
 

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aka Mr Ryte on G20.net
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1,478 Posts
Re: How the vvl works

Interesting.... :eek:
Well, that certainly clarifies a lot of things. :D
 

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The Super Mechanic
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645 Posts
Discussion Starter · #6 · (Edited)
Re: How the vvl works

92nx2k said:
yea does that mean we will need to get the valves adjusted every 60k like a honda motor? :( and who knows how to do it, and the proper specs...since there no hydraulic lifter.
There should not be any adjustment. You can check lash to make sure it is in spec. I havent heard of people adjusting the lash from wear. You would have to adjust lash when the machine shop does a valve job.
 

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The Super Mechanic
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645 Posts
Discussion Starter · #10 ·
Re: How the vvl works

PennyFan said:
hi, is there anyone know if a adjustable cam pulley is needed with a SR20VE 20V cam swap?
You can use a adjustable pully on anything. To make it right you really have to degree it to put it in the right spot. Then you can adjust it on the dyno.
 

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"Keep firing, Assholes!"
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796 Posts
Re: How the vvl works

excellent pictures and explaination. i was always kinda wondering how it worked. i'd need to see it in person to really get it though.
 

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www.FAIRTAX.org
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8,920 Posts
Re: How the vvl works

Very enlightening, thanks for posting that.
 

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yup
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1,208 Posts
Re: How the vvl works

agreed... this is very very sticky material... as in this post should be made a sticky
 

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Off-Topic lurker..
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3,122 Posts
Re: How the vvl works

Wow, that's great! I just learned something.
 
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