News

High(er) performance 308 cams

Discussion in 'Technical Q&A' started by chrismorse, Mar 14, 2004.

  1. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
    2,149
    way north california
    Full Name:
    chris morse
    I understand P-6 cams are a NLA factory racing/high performance cam. I did not realize there were different versions. I also realize that time and the understanding of the high performance/racing cam evolves.
    Regarding the P6,I have read on this forum that the loss to the bottom end is small, the gains in the mid range and high end significant.
    As long as I am changing the exhaust, air filter, possibly venturi and definitely jets why not consider changing to a higher output cam?
    It am hopeing, (or is it hopping), there is a fairly clear division between High performance cams that can be installed in a standard 8.8 c/r stock engine and a fully modified 10.5 c/r+ race engine.
    Put another way, does anyone know of a hypo cam that yields a significant power increase with the stock pistons. Obviously, when I win the lottery, (which I have yet to buy a ticket for??), I will go forged high compression pistons, stronger cam, dry sump, (or kermits magic windage tray??, bigger carbs, no wateium valves, unobtanium retainers and chain driven carburetion, etc. I digress- sorry.
    Does anyone make a significant High performance cam for the stock engine.
    To clarify, we are not constrained by smog, or theoretically budget. I am aiming for a serious high performance carbed streetable 308.
    Clutch, Brakes, Wheels, Tires and Driver attitude to be considered later.
    Slightly disturbed, I remain,
    chris
     
  2. To remove this ad click here.

  3. tbakowsky

    tbakowsky F1 World Champ
    Professional Ferrari Technician Consultant

    Sep 18, 2002
    15,118
    The Cold North
    Full Name:
    Tom
    LOL.... Chain driven Carburetors...tee hee
     
  4. snj5

    snj5 F1 World Champ

    Feb 22, 2003
    10,213
    San Antonio
    Full Name:
    Russ Turner
  5. Matt Morgan, "Kermit"

    Matt Morgan, "Kermit" Formula Junior

    Nov 12, 2003
    405
    Ferndale, WA
    If it were me, I would not advise adding Raceing cams to a stock, or very slightly warmed over motor.
    Everything works best when it is in "harmony" with the other modifications.
    I would rather suggest that you redial in the stock carb cams at this point in the effort, tightening the overlap up a bit to improve top end power, without hurting low end driveability. Without the benefit of higher compression, porting, etc., the P-6 cams will not see their full potential, and the trade off will leave you unhappy with the overall results by going that route. You can always add them later, along with the modifications that will improve the whole package.
    JMO
    Kermit
     
  6. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
    Little Rock
    Full Name:
    David Jones
    I tend to agree with Kermit, that it is best to choose components that work in harmony together... Now lets all join hands and sing, Oh Ferrari, Oh Oh...

    With regard to the "P-6" cam profile, yes it changed over time.
    I have seen readings from three different sets of intake cams,
    and all three sets were different.
    And you are right on the money, cam technology has evolved...
    There are much better grinds for the street, or racing than the P-6.
    Some of the guys that have had Comp Daytona knock offs built from stock Daytona's have used more modern grinds which help these big nasty motors smoke an original Comp Daytona.
    Look at some of the numbers on the racing cams these guys are putting in their Comp motors... The 308 engine is essentially a baby Daytona engine,
    and responds much in the same way.
     
  7. To remove this ad click here.

  8. Mitch Alsup

    Mitch Alsup F1 Veteran

    Nov 4, 2003
    7,021
    When high compression pistons are installed. The piston compression ameliorates the loss at the bottom end from the agressive cam.

    After all, its only money!

    Compression (that is more of it) allows you to degrade the torque of the bottom end and gain power at the top end by using more agressive cams. With standard compression you should not add more than 10/20 degrees to your cams, with higher compression you can add 20/40. Unless you are making a track only car, stick below 35/75 cam timing (F355 is 16/56).

    I would be looking for a cam in the 25/65 range for stock compression or maybe 30/70 for agressive street performance. As you add overlap, you will become more and more subject to carbuetor spit back when the throttle is opened at the anti-resonant point of the headers. This creates drivability issues and makes carb tuning very tricky.

    Do not increase the engine performance without increasing the braking performance, and consider putting more rubber on the wheels and a stiffer set of springs in the suspension
     

Share This Page