2003 trailblazer vvt setup timing

jigfeett

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#1
Make
chevrolet
Model
trailblazer
Year
2003
Miles
275000
Engine
4.2
Helping a friend, with timing setup with variable valve timing.
She has a 2003 trailblazer 4.2 engine and has it out of the vehicle, all new parts and head is rebuilt.
Question is how exactly to set the vvt, at full advance?

Alldata states when installing the cam sprockets and chain to set the exhaust side to full advance. I am not finding much information on exactly how to do this. Does she need to rotate the camshaft clock wise or counterclockwise to achieve this or turn the end of the vvt unit??
I thought I could just look it up but not so. does anyone have good experience with this type of setup?
Thanks and I hope to help her get this setup soon.
 

grcauto

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#2
Advance goes against the travel of the chain and retarded goes with it.
 

jigfeett

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#3
Thank you, when she gets the chain and gears and tensioner on she just needs to rotate the cam counterclockwise with the flats on the cam.?
 
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#4
Ha, this youtube video is funny if not happening to you.


Just like any other overhead cam engine, have timing marks on the sprockets and colored links on the chain or some other kind of markings. Variable valve timing should be at neutral.

If you have questions with alldata, can ask them, kind of prefer having the full shop manual for this kind of work, really hate to repeat it. And can wreck the valves and pistons if not done correctly.
 

jigfeett

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#5
Thank you, yes I've seen this vid.
My friend did break 8 bolts, 4 on the head side and 4 on the mains. I went over and center punched each one and drilled with a left hand 5/32 and they all came out no problem. In chassis probably not so easy.
I think she did it right by removing the engine and giving herself advantage of room to work. I had a buddy make 2 drill guides but didn't need them.
Your statement, ""Variable valve timing should be at neutral."" Are you stating that Alldata is incorrect in the full advance statement?

I still have not found any actual video or pictures of the task of setting the cam, to either full advance or neutral.
Thanks