Comp Cams 280 Magnum Cam In 383

Discussion in 'Engine Topic' started by ChaseDale3and8, May 29, 2009.

  1. ChaseDale3and8

    ChaseDale3and8 Veteran Member

    Messages:
    118
    Likes Received:
    0
    Joined:
    May 2, 2009
    Location:
    Battlefield Mo.
    I'm currenly building my 383 stroker. I'm planning on going with a 280 Magnum cam. 230 degrees duration @.050 lift and .480 lift at the valve. I have Pro Comp stroker clearanced rods in it and was wondering if I might run into any problems with this cam profile as far as clearance issues.

    How big of a lift can you get away with on one of these without running into problems? I've heard of guys running huge roller cams in these with lifts in the .600 range but I'm sure that they had some clearance issues to deal with. I ran this grind in a 355 that I built quite a few years back and it pulled like a freight train, and should do even better in this one with the Dart heads that I have for it.

    What I'm wondering is what grinds of flat tappet hydraulics will work without having any clearance issues. I've talked to a few people and some say I'll be fine with such a mild cam, and others say I'll have problems. I want to hear from the guys that "have been there, done that". Planning to install the heads and valvetrain this weekend if all goes well. ...Joe
     
  2. -=79z28=-

    -=79z28=- Veteran Member Lifetime Gold Member

    Messages:
    1,342
    Likes Received:
    0
    Joined:
    Jan 22, 2008
    Location:
    Charlotte, NC
    i just talked to my machinist about this today, and he claims over .525 lift is where clearance issues start.

    im curious to know what others experiences are.
     
  3. justincmorris

    justincmorris Veteran Member

    Messages:
    300
    Likes Received:
    0
    Joined:
    Mar 24, 2005
    Location:
    Arlington, TX, Tarrant
    .480 lift you should have plenty of room to spare just assemble the motor and turn it over by hand to see if it hits(which it shouldn't)
     
  4. TonyZ

    TonyZ Veteran Member

    Messages:
    169
    Likes Received:
    0
    Joined:
    Jan 1, 2007
    Location:
    LaMoille, Illinois
    im running a 355 with flat top pistons,64 cc heads with 2.05 valves and it runs great no issues! I know its not a 383 but i love the 280 magnum cam its a real streetable cam!!
     
  5. ProStreet383

    ProStreet383 Veteran Member

    Messages:
    2,106
    Likes Received:
    9
    Joined:
    May 23, 2007
    Location:
    MD
    Dont skimp yourself with a baby cam like that. That cam is a very old grind on yesteryears technology. Get yourself a lunati voodoo cam. You will thank me later! I suggest the 60104LK

    As far as how big you can go before you run into issues I really cant say. It all depends on what rods and bolts you have. Worst case scenario you have to grind the rods a bit for clearance. In which case you would then have to have the rotating assembly balanced. But to go through the trouble to build a 383 then skimp on the cam so you dont have to grind the rods seems like a waste to me.


    P.S. I am not a comp cams fan. Every engine I have ever had dealings with went faster with a lunati cam.
     
    Last edited: May 29, 2009
  6. hhott71

    hhott71 R.I.P 11/19/18 Lifetime Gold Member

    Messages:
    14,377
    Likes Received:
    7
    Joined:
    Mar 30, 2001
    Location:
    Joplin Mo. 64801
    The bigger the lift, the smaller the base circle of the cam.
    The 292 should be a good cam with shift points near 6,000 RPM
     
  7. 74Lt1

    74Lt1 Veteran Member

    Messages:
    327
    Likes Received:
    0
    Joined:
    Aug 30, 2008
    Location:
    Virginia

    Im building a 383 also and i had the EXACT same cam in it but with factory rods. the #5 and #6 rods both hit the cam... But with the stroker rods you should be ok... Just my .02 but i have been there and done that with factory rods and they hit... hope this helps...
     
  8. ChaseDale3and8

    ChaseDale3and8 Veteran Member

    Messages:
    118
    Likes Received:
    0
    Joined:
    May 2, 2009
    Location:
    Battlefield Mo.

    I already have the cam. Have had it over a year. Bought the cam kit new off eBay for $75. This engine was originally intended to go into my 1986 K10 shortbed 4x4. I had used this grind in a 355 that I had in a 1982 K20 4x4 with a 4 inch lift, 4.10 gears, and 33s. That engine had ported and polished 186 heads, and it pulled like a freight train in that truck, yesterdays technology or not. I was very impressed with it as it pulled harder from the bottom end, and on further up the R.P.M. range than any other cam that I had ever owned up to that point. I snagged this one for cheap, so I intend to use it in something.


    I used to be a Crane Cams man until I wiped 4 of them out in a row back in the late 80's early 90's timeline. That was when I switched to Comp. A buddy of mine sold me on them. He too had tried Crane, and experienced the same problems that I had. Then he switched to Lunati. Didn't get what he was looking for there, so switched to Comp. When I was building that 355 for my K20, he suggested a Comp Cam. I made the switch and was immediately sold on them. I didn't have any more flat cam issues either.

    I bought a Comp Mutha Thumpr cam for my 327 large journal block that I intend to build some day down the road, and have even considered using it instead of the 280 Magnum. I figured if I would have any problems fitting the 280 Magnum that the Mutha Thumpr would be worse yet. Then again, it might not be that much different as far as fitment. I might just stick it in there and see. It specs out at 235 degrees duration @.050 lift intake, and 249 degrees duration at .050 lift exhaust, .490 lift intake, and .475 exhaust respectively. It's very similar to the Lunati that you are suggesting.

    A guy that I work with actually had that Lunati grind in his 83 2wd shortbed truck. He recently pulled it out because he didn't like it at all. He told me that it had no low end whatsoever, and quite frankly was a total dog until it hit above 3,000 R.P.M.. That alone kept me from even considering a VooDoo cam. The Mutha Thumpr may be the same way, I don't know.

    The Mutha Thumpr is still a relatively new grind. Might sound cool but be a dog on performance. I don't know of anyone that has bought and used the Mutha Thumpr profile yet, but think that it would be interesting to find out just how well it performs. I thought that for the intent purpose of installing it into my 327 someday, it really wouldn't matter that much since it's a much smaller engine anyway, and will be built more for show than go. If anyone here has tried it yet I'd like to know, and what your opinion of it is.

    I have Desktop Dyno 2000 on my PC and I tested all 3 cams, the VooDoo, the Mutha Thumpr, and the 280 Magnum. I was shocked when the software showed the 280 Magnum to be the best one of all 3 cams. Torque was higher with the 280 Magnum. The Lunati beat the 280 Magnum by 15 H.P. on the top end, all else being equal. Lunati 433 @6,000, 280 Magnum 418 @5,500.

    The 280 Magnum netted 13 ft. lbs more peak torque at 500 less R.P.M. than the Lunati with the torque on the 280 Magnum starting at 347 ft. lbs. @2,000 r.p.m. vs. 305 for the Lunati. The 280 Magnum peak torque is 433 ft.lbs. at 4,500 r.p.m. while the Lunati shows to be 420 at 5,000 r.p.m.. The old give up one end for the other here if you ask me.

    I guess it really all depends on what the intended use is, and personal preferences are, but I think I'll stick with Comp Cams no matter what grind I end up sticking in my 383 unless I am convinced otherwise with some hard evidence (such as actual dyno results) that proves cam A to be better than cam B. Software is software, and may or may not be 100% accurate, but I'm just going on what my Dyno 2000 software is saying here.

    The rods that I have are Pro Comp 4130 forged steel bronze bushed rods. They have capscrews instead of rod bolts like the factory units. Ebay seller Skip White still sells these rods, and they use them in their 383 buildups all the time, so they say. I guess I'll mock mine up and see where I'm at and let everyone know. Thanks for the reply. Didn't mean for this to be so long! ...Joe
     
  9. 1980RS

    1980RS Veteran Member

    Messages:
    2,520
    Likes Received:
    237
    Joined:
    Jun 17, 2006
    Location:
    MN
    The camaro currently has a 292H CC I have had for a while and is worked pretty good. I know if you retard CC cams 4 degrees they makes a great Nitrous cams. 10.66 with a 355 and no valve adjust needed. 280s make good street cams.
     
  10. -=79z28=-

    -=79z28=- Veteran Member Lifetime Gold Member

    Messages:
    1,342
    Likes Received:
    0
    Joined:
    Jan 22, 2008
    Location:
    Charlotte, NC
    heres what a Reed BS282DP looks like on DD... every bigger cam i tried lost HP and TQ?!

    [​IMG]
     

Share This Page



  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.