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Getting this 'advanced cam' yadda right!

Discussion in 'VL Holden Commodore (1986 - 1988)' started by Marco-EFIVL, Aug 2, 2006.

  1. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    I've seen this topic being flug around these forums for a bit, and I know a bit about the mechanics of motors in general. However, being here for a few months, and reasonably active at that, I've learnt alot about the Nissan RB range of engines.

    Now being a VL driver, 3spd Berlina, I'm looking at ways to get a tad more oomph without massive $$$'s. Atm I'm looking at installing twin hyclones, a new ecu, 2.5" exhaust and a new K&N filter. However, I would like to do this advanced cam timing that I've read about here.

    All I would like is for someone that has done the procedure, or understands the technicalities of it to outline exactly what it is about. I've read someone talking about advancing the cam 12 to 15 degrees, and others talking about Nissan setting the cam on the 53rd tooth whilst Holden pegged it back to the 52nd tooth, like, what is the diff between '52nd to 53rd tooth' and the '12 to 15 degrees' stuff. Am I right on that? or no? Could someone please clarify this for me so I know what I'm in for....

    Cheers:
    Marco.
     
    Last edited: Aug 3, 2006
  2. BigDaz

    BigDaz New Member

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    do u mean without massive $$$'s ?? coz IF ur lookin at spendin massive $$$'s id highly recommend a twin turbo Gen3 setup in your VL ...... that would give slightly more 'ooomph' :w00t: :yeah: :thumbsup:

    as for mods all im doin with mine is 5speed manual *already in* K&n Filter *already in* and i want to put a 2.5in exhaust n extractors on *already got the exhaust n headers* and then im just gunna save up and buy an old 308, work it and then put that in :D. No-one i know personally has done the cam timing thing so i cant tell ya what it would do. i have read about it but its hard to beleive sum ppl over the net. they think they know more than they do .. sum of them anyway :)

    i know u can advance the timing on the dizzy cant ya? is that what u meant?
     
  3. bangers

    bangers New Member

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    there's a difference between advancing the cam and the ignition. the ignition is when to fire the spark and the cam is when to let the fuel in and out.

    if you have the dosh then turbo the **** out of it. don't get the hyclones, waste of time. build a strong motor with big turbo, strong box and 9" rear end with 4.11 ratio and she'll be very quick.
     
  4. Dose Pipe

    Dose Pipe New Member

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    go do a basic automotive tafe course you obviously dont know as much as you think :)
     
  5. bangers

    bangers New Member

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    come on little man, lets here your view then. don't post that then leave it. can you back yourself up?
     
  6. greenfoam

    greenfoam New Member

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    Advancing the cam will move the power band down lower in the rev range, retarding it will move the power band up higher, you can get cam gears for most motors that have little offest pins to adjust the cam timing but I don't know what's the setup on the RB30
     
  7. BigDaz

    BigDaz New Member

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    i think he was tryin to say he dont have much dosh, well not much to spend anyway. :)
     
  8. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    Well my knowledge is limited, but if you asked me what a crankshaft or a conrod is, I'd be able to tell you, but I'm in the dark with the more finiky things, such as this camtiming yadda. I didn't say I was a genius, but some clear and well written instructions/advise wouldn't go astray mate!:wax:


    Well I'm not tight, but I don't want to waste money. Chances are my old man is going to help me get an R34 Skyline by year's end so there is no point spending a fortune on my VL, but I do want to do SOME work on it in the time being. However I don't really want to go changing heads, gearboxes and whacking on a turbo in this case....
     
  9. bangers

    bangers New Member

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    well if you want it to have more go and be fun to drive i'd say put a manual in it. not that expensive and easy enough to do.
     
  10. rb26dett

    rb26dett New Member

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    If your getting an R34, I would not spend a cent on the VL.
     
  11. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    Yeah but I even doubt it will happen when he says.... I mean, my old man is a bit of a procrastinator, so I might be stuck wit the VL longer that I would like. I've settled for a spending cap of 2k...
     
  12. BigDaz

    BigDaz New Member

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    go the manual for sure, wakes the old rb30 up pretty good :)
     
  13. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    My uncle, a mechanic of 30+ years, reckons it is a c*nt of a job...
     
  14. bangers

    bangers New Member

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    do the gearbox swap and then you can change your diff ratio cos you have the extra gear so you won't be chewing more fuel on the highway but still have better acceleration.
     
  15. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    Well my old man isn't keen, he wants me to keep it Auto so when I get the R34, the girls can use it as a 'spare' vehicle. Not to be sexist, but the females in my family aren't the most coordinated of people... ;)

    Anyways, I do want to stay on topic, can anyone clearly outline the procedure of advancing the cam and provide me with a description outlineing the difference between advancing the cam 'one tooth' and advancing the timing by a certain number of degrees... This bit is confusing me atm... I would REALLY appreciate some clarification..

    Lastly, what is the diameter of the stock VL throttle body, I've seen an elarged' one that is 58mm, how much bigger is it than the stock one, cause I dunno...
     
  16. mag

    mag Member

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    Advancing the cam will shift the basic RPM range downward. Four degrees of advance (from the original position) will cause the power range to start approximately 200 RPM sooner. Retarding it this same amount will move the power upward approximately 200 RPM. This can be helpful for tuning the power range to match your situation. If the correct cam has been selected for a particular application, installing it in the normal "straight up" position (per the opening and closing events at .050" lifter rise on the spec card) is the best starting point.:thumbsup:
     
  17. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    Is moving the cam by a 'set' number of degrees the same thing as setting it at a certain 'tooth'?
     
  18. mag

    mag Member

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    Not really because it'll be unknown how much or how little the cam is advanced or retarded..
    You need a degree wheel and a dial indicator to measure whats going on...:thumbsup:
    And I've added a pic of an adjustable cam gear, u should have a better idea how it's made adjustable..;)
     

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    Last edited: Aug 4, 2006
  19. mag

    mag Member

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    A cam ground with say 110-degree lobe separation will read an installed centerline angle of 110 if installed “straight-up,” or with no advance. Since the cam is connected to the crank via the timing belt, the cam’s phasing to the crank, can be adjusted forward or back, changing the installed centerline angle. This is called advancing or retarding the cam. The installed centerline is what is checked when a camshaft is degreed in. Most aftermarket cams are ground with some advance built in, typically about 4 degrees. Advancing the cam makes all the valve events happen earlier, and generally favors low rpm operation, helping idle quality, cylinder pressure, vacuum, and lower speed torque. Retarding the cam deteriorates these characteristics, though in some cases high rpm power may be enhanced. The real score here is that advance will almost always help improve performance as listed above, but most of the time retarding the cam will gain little if anything, even up top.:thumbsup:
     
  20. Marco-EFIVL

    Marco-EFIVL Now driving R34 GT-T taxi

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    Cheers bud, I got it now. Camshaft 'degree' is the angle in which the cam itself is set upon installation (well, in working configuration) in the head, whereas the 'tooth' is to do with the configuration of the cam gears, so they are related but different... If that makes sense..


    This should be pinned up top, so that people can all know the clear answer to this question without having to make an arse outta themselves like I have..
     

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