Camshaft decision between two cams

Discussion in 'Engine Topic' started by kpb, Feb 27, 2020.

  1. Bradley's Building Junk

    Bradley's Building Junk New Member

    Messages:
    5
    Likes Received:
    1
    Joined:
    Feb 12, 2020
    Location:
    Arkansas
    The lift will be determined by what CFM the heads are producing at different lift intervals on a flow bench. Example = they flow test and open valves .100, .200, .300, .400, etc. If your heads are producing gains of over 10 CFM all the way through to .500 lift opening at the valve then you can safely go up to or below .500 lift on a camshaft before over saturating your head ports. Because you are going to be running a stroked engine crank this allows more piston travel distance from head to crank which means you can have a slightly longer duration that the camshaft will allow the valves to be opening for. The LSA (lobe separation angle) will allow for more or less overlap between your intake and exhaust valves to be opening. More separation angle equals a smoother idle, and less angle equals a rougher idle. Maybe this will help get you closer to a decision. Or maybe its just entirely wrong and useless information....lol. Good luck.
     
  2. 1980RS

    1980RS Veteran Member

    Messages:
    4,598
    Likes Received:
    1,303
    Joined:
    Jun 17, 2006
    Location:
    MN
    Pick the cam with the widest LCA for best streetability. As far as lift goes the best cam is one that has good ramp numbers as the peaks are just that peaks and you are only there one time in the valve cycle and twice opening and closing at all other lift points. As for breaking in cams. One thing I do is run the weakest outer spring I can find for break in and then change them out after 30 minutes of run time. The only cams I have ever lost were due to some bad lifters back in the 80's made by Muskegan and when I had then rockwell tested they were all soft. I don't use fancy oil, just put a good moly paste on the cam and lifters. Also make sure it ready to fire up IE fuel in the carb and the ign is spot on to fire. Now watch, ater talking about it I will loose a cam. lol.
     
  3. Plant Engineer

    Plant Engineer Veteran Member

    Messages:
    404
    Likes Received:
    108
    Joined:
    May 17, 2017
    Location:
    Fort Mill SC
    Ive lost a new cam in the last two years and to me its not worth it. Lots of carnage and then a roller is going in its place when its all over anyway.
     
  4. allend43

    allend43 New Member

    Messages:
    5
    Likes Received:
    0
    Joined:
    Feb 17, 2007
    Location:
    santa barbara,ca
    Both camshafts will have a pretty much stock idle, as far as sound, and will run similarly. Make sure the springs on your heads don’t go over about 300lbs open pressure. Seat pressure isn’t what flattens camshafts. I spray all my flat tappers with moly “paint” which dries and then put on the moly paste, before installing. Good luck finding any good factory vortec heads, every set that I’ve had brought in, have been cracked. I use the Chinese aluminum “assault” head castings. They are cheaper than aftermarket vortec heads and flow even better. I do use all American made valves, springs, spring seats, keepers etc though. If possible find the original type Chevrolet lifters. They are two piece with a hardened bottom. You can tell them by the little band about 3/16 from the bottom. Best hydraulic lifters made, if you can find them. I bought a bunch of sets from an old machine shop going out of business.
     
  5. Penix

    Penix Veteran Member

    Messages:
    1,831
    Likes Received:
    0
    Joined:
    May 28, 2001
    Location:
    Concord, CA, United States
    Why waste your time with a FT cam unless you absolutely have to? You mention Brodix heads so I know you can afford a retro roller setup. It's like doing an LS swap but sticking with a TH350. Makes no damn sense.
     
  6. rocket dawg

    rocket dawg Veteran Member

    Messages:
    383
    Likes Received:
    46
    Joined:
    May 5, 2015
    Location:
    Grand Rapids Mi
    I wish I would have went roller. But I dont have any problems with my cam choice. Performer RPM Edelbrock. Oil is the key. Brad Penn oil I have used. Seems to turn black quickly. I'm using Vavoline 10w40 for the older engines right now, cant remember the exact name on it.
     
  7. jwetsch

    jwetsch New Member

    Messages:
    9
    Likes Received:
    0
    Joined:
    Apr 26, 2007
    Location:
    ND
    In 1999 I had a comp cams go flat on me on a fresh build after 2500 miles. Comp wouldn't do anything about it because it had been in the engine over a year, where I live stuff gets parked over the winter or it would have failed during the warranty period, ended up doing a custom ground Ultradyne with Rhoads lifters. Should have listened to my engine builder when he told me not to use Comp in the first place. Doing it now I'd probably go roller.
     
  8. Robert stuart Bell

    Robert stuart Bell Rsb78LT

    Messages:
    65
    Likes Received:
    13
    Joined:
    Jan 21, 2017
    Go with a cam that makes low end torque, don't bother with brodix heads if it's just a show car. You can get cheaper aluminum heads if you just want the look if not go with vortec heads. Long term you'll have more issues with aluminum heads then a nice set of vortec heads. Always use break in lube on the cam and pour a bottle of break in oil over the cam before putting the intake on and try using amsoil Z rod. I find it takes longer to turn black than penzoil and lucas
     
    biker likes this.
  9. lodgers

    lodgers New Member

    Messages:
    3
    Likes Received:
    0
    Joined:
    May 1, 2011
    Location:
    Chandler, AZ
    I'd go with the Lunati, more low end torque and don't worry about rollers, you're not racing just doing burnouts. Flat tappets are easier on the valve train. I'd recommend using Amsoil 10w-40 oil. It has high Zinc content for your flat tappet and you will get about 4% more power. I'm still a dealer if you're interested.
     
  10. Richard Schultz

    Richard Schultz Veteran Member

    Messages:
    310
    Likes Received:
    30
    Joined:
    Oct 8, 2018
    Location:
    Green River Wy
    Id use the edelbrock 2103 or a 272 duration intake and exhaust,.45 lift.
     

Share This Page