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Rallye and XSi cam specs

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  • Bastek333
    replied
    Originally posted by sandy309 View Post
    Only the Rallye and XSi heads AFAIK.
    So it can not be something really bad as 90hp 306 version. Maybe it's S1 as it has different torque spec to S2 so maybe that's the case.

    So let see what it will do as i'm back to ori soft for safety.

    Have to start to tweek soft again. Do you guys have experience how far with ignition advance i should go with my mods ? (Head skimmed 1mm and head gasket 1mm thick instead of 1.37 ori)

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  • sandy309
    replied
    Only the Rallye and XSi heads AFAIK.

    Leave a comment:


  • Bastek333
    replied
    Originally posted by sandy309 View Post
    You need to measure lift at the valve, rather than off the lobe, to see what it does.
    So question number TWO - do you (or some-one) knows which engines has camshaft with big bearings ? Maybe that will show up what this camshaft is....

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  • Bastek333
    replied
    Originally posted by sandy309 View Post
    You need to measure lift at the valve, rather than off the lobe, to see what it does.
    As the lift on shaft is bit higher and shape nearly the same i think that will be not much difference - only one big change is angle between lobs - J i wide - that new one narrow.

    Who knows what is the angle between rocker arms in and ex?

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  • sandy309
    replied
    You need to measure lift at the valve, rather than off the lobe, to see what it does.

    Leave a comment:


  • Bastek333
    replied
    Originally posted by sandy309 View Post
    I've measured the inlet side of the cams, exhaust to follow. The 1.3 Rallye, 1.6 Rallye and 1.6 XSi all use the same cam, stamped "J" on the flywheel end. The 1.4 XSi uses a different cam, stamped "Z" on the flywheel end.
    Headline specs:
    "J" cam:
    Peak lift 10.6mm
    Duration at 0.1mm lift 270 degrees
    Duration at 1.0mm lift 235 degrees

    "Z" cam:
    Peaklift 10.3mm
    Duration at 0.1mm 270 degrees
    Duration at 1.0mm 234 degrees

    .
    I have found that topic looking for some info about PTS camshaft - i have bought one advertised as PTS but .... i'm not sure about it....

    Did comparison my J shaft to new one and .... please take a look on pictures above and tell me which one is better as i'm confused








    I will appreciate and comments about both cams ... as i'm going to increase CR now when head is on the table

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  • stockhatch 123
    replied
    has anyone compared VTR cam to the Rallye cam is there much difference? (later model VTR)

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  • mcd240
    replied
    Originally posted by sandy309 View Post
    The Newman PH4 actually lifts the valve 11.5mm peak, the specs they publish on the site doesn't seem to correlate in an obvious way with the actual profiles I've received. I don't know why that is and I'm not complaining, because the profiles I've had from them so far have been closer to what I wanted than the actual spec. I've plotted the curve for the PH4, I do it for every cam I use to help me develop the rest, but I don't know that my various cam suppliers would be too chuffed if I published their profiles publicly! If they weren't concerned, I'd imagine the curves would be available already, I wish they were.
    Cams from different manufacturers are quite different and what some of the manufacturers make for the specialist engine builders are quite different in many to what's publicly available. But clever cam design/choice isn't much use without knowing what else is needed anyway.
    What you said about the actual lift of the cam makes sence to me i have a 8v roller rocker head on my 1400 and have a one off cam based on a ph 4 newman cam with that sort of lift but confused me because it did not tie up with valve lift on the spec sheet. DTI gauge is never wrong! Just to be cheeky i added a link to my timing problem am having is anyone cam help many thanks.

    http://www.106rallyeforum.com/forum2...hlight=timming

    Leave a comment:


  • pugmadnath
    replied
    What is the difference in performance gain between a longer duration and higher lift?

    For example, what advantage would a 300 degree duration camshaft have over the standard one, if it produced the same lift as standard?

    Leave a comment:


  • sandy309
    replied
    Yes exactly. I use the same method every time and measure/check every cam I use to ensure consistency etc. Aligning the DTI isn't hard or super critical and obviously check you have full travel over the profile.

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  • simon182
    replied
    Does that not make it really hard to measure?

    i.e. getting the DTI directly in line with the direction of travel of the valve?

    I guess there just different ways of measuring the same thing - so long as I use the same method for measuring when comparing cam profiles all will be ok.

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  • sandy309
    replied
    I always measure at the valve, which takes the full effect of the rocker shape and ratio into account; as long as the gauge is firm and zero'd correctly, it can't be wrong. What can vary, although not greatly, is wear on the cam and/or rocker pad.

    Leave a comment:


  • simon182
    replied
    Right then:

    S1 J cam measured!
    Direct from the cam, Was doing this to compare to my 300 Duration Piper jobbie....
    (which is actually for the quiksilver/early VTR not a rallye! - self inflicted for not checking before I bought it - see the for sale section)




    Does anyone know the cam to rocker ratio?? 1.4 rings a bell...

    OK,
    now im confused,

    Ive measured a max lift of 6.7mm (ignoring base circle) giving a Valve lift of 9.38mm (ratio 1.4:1)

    but Sandy gets a peak valve lift of 10.6mm....

    Pipers lairiest cam gives an advertisd lift of 10.42... (including ratio)

    So whose right... me or sandy?

    :S
    Last edited by simon182; 20-07-2009, 10:09 PM. Reason: Automerged Doublepost

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  • simon182
    replied
    Originally posted by rajjinator View Post
    lol.. wont take long to measure!
    Depends on how many points you measure!

    :P

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  • rajjinator
    replied
    Originally posted by simon182 View Post
    because ive not had chance yet! :P And i wondered if anyone had done it on my Cam before! - it could save me some time!

    Piper are useless at replying to emails too!
    lol.. wont take long to measure!

    Leave a comment:

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