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Technical Will same cam rev higher in smaller engine?

Discussion in 'Traditional Hot Rods' started by Greasyman, Apr 21, 2021.

  1. Greasyman
    Joined: Oct 23, 2010
    Posts: 174

    Greasyman
    Member

    Been shopping for a mild cam for my 283. There is always a hp range included in the specs, such as 1200-5000, but they never give any info on the particular test engine. I assume it's usually something in the 350 range, since those are so popular. Anyway, I was wondering if that same range would apply to a smaller engine like mine, or if mine would breath well at higher rpms than listed.
     
  2. I think the range they give is so you know if a manual trans is going to be a better choice than a Automatic,and if you use a automatic what torque converter to use. Its advice so you can match the rest of the drive line.Just one guys thought.283"s can really rev so it should be fine at the upper range if you have the heads/valves to make it work up there.
     
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  3. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 2,111

    ekimneirbo
    Member
    from Brooks Ky

    A somewhat generic cam that is designed for a particular "size" will act differently in a smaller displacement engine.......or vice versa when put in a larger engine. That being said, how much difference is made will also vary according to each cams particular specifications. Generally if a cam is optimized for a larger capacity engine then it will be over cammed on a smaller engine. What can be a barely tolerable cam in say a 350 cubic inch engine would be a much milder cam in a 400 or 427 engine. I would look for one of the older well known grinds that has a good reputation specifically in a 283. The smaller the engine size the more critical it is to get the right cam. Get the right springs to go with the cam too.
     
  4. partsdawg
    Joined: Feb 12, 2006
    Posts: 3,032

    partsdawg
    ALLIANCE MEMBER
    from Minnesota

    Call where you want to buy the cam from Summit,Jegs etc or directly to the cam company and talk to a tech person. If you give them info on your engine they can direct you to the cam best suited for your build
     
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  5. Mimilan
    Joined: Jun 13, 2019
    Posts: 956

    Mimilan
    Member


    Elgin #CL1069PK 1600-4600 rpm 214/214 @ 50 .443 .443 lift
    This is the highest lift you can go with drop in valve springs

    http://www.northernautoparts.com/part/ek-ec0952
     
  6. iagsxr
    Joined: Aug 26, 2008
    Posts: 158

    iagsxr
    Member

    RPM ranges are usually listed for a hypothetical generic 350. A 283 is 19% smaller than a 350 so move the range up that much.

    I'd be talking to your cam company of choice before I purchased. It would be very easy to over cam a 283.
     
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  7. Elcohaulic
    Joined: Dec 27, 2017
    Posts: 2,474

    Elcohaulic
    Member

    The cam would appear larger in the smaller cubic inch engine.. When choosing cams, always go to the next smaller size..
     
    Deuces likes this.
  8. Run what ya want then rev it till it floats the valves :eek::eek::eek::eek:
     
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  9. southcross2631
    Joined: Jan 20, 2013
    Posts: 4,414

    southcross2631
    Member

    Also consider advancing the cam timing in a smaller motor. I run a .680-.672 lift solid roller in my 333 inch Ford motor SEGA super stock 4 speed car. I had to advance the cam 6 degrees to help my 60 ft. times.
    Check with Howard's cams. Call their tech dept. and get a recommendation.
    Picking an off the shelf cam is a toss up as to whether you will get what works best for you. Consider having a cam ground just for your application.
    Schneider cams have some killer grinds for smaller bowtie motors.
     
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  10. moparboy440
    Joined: Sep 30, 2011
    Posts: 718

    moparboy440
    Member
    from Finland

    Telling us what Cams you have been looking at might be helpful..
     
  11. treb11
    Joined: Jan 21, 2006
    Posts: 3,692

    treb11
    ALLIANCE MEMBER

    Last edited: Apr 22, 2021
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  12. Greasyman
    Joined: Oct 23, 2010
    Posts: 174

    Greasyman
    Member

    Thanks for everyone's help. I've been looking at cams in either the 20X-21X @ .050 or 21X-22X. I want a smooth idle but I also want to be able to rev to 5-5500 rpm if possible.

    One cam I was looking at seemed pretty close to what I want, but it revs to only 4600. That's what inspired this thread in the first place. I don't remember the grind right now but it was a mild Comps 4x4 cam.
    Here's a video of an XE250H from Comp. That's another cam that seems like what I'd like as far as idle quality, but it also revs only to 4600. That just seems a little to sluggish for me, I like the sound of a high reving engine now and then. COMP Xtreme Energy XE250H 206/212@.050″ 110LSA (12-230-2) 283 - YouTube

    I'm leaning towards the milder cams. What do you guys think of Clay Smith cams? They make a point of mentioning that a lot of their cams work well with stock manifolds, and I'm going to be using stock ram's horns. Do you find that the smaller cam company cams are as good as the biggies like Comp and Luanati and so on?
     
    Last edited: Apr 22, 2021
  13. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,055

    1971BB427
    Member
    from Oregon

    How high the engine revs isn't really dictated by the cam. But the cam will dictate where that engine makes maximum HP. So it may continue to rev higher, but HP with start to nose over at some point.
     
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  14. Greasyman
    Joined: Oct 23, 2010
    Posts: 174

    Greasyman
    Member

    I called the Comp Cams tech line just now. The guy said that a 283 might make power a couple hundred beyond a 350. Said that it didn't make much of a difference at the beginning of the power band.
     
  15. We have used the L79 cam in the short stroke motor, its a 327 cam and is rated at off idle to 5200 with a 6200 red line. Depending on how the motor is built and how the cam is timed that can move a little bit. I run one in a 355 for instance that starts climbing up on the cam at about 2800-3000 and we regularly spin it to 7200 or so.

    Running it straight up in a 283 the useful power band is going to move up slightly from the stock 327. You want to have healthy compression (min 9.5:1 and 11:1 would be better) and it helps to make it breath (raise the roof of the intake ports and blend the bowls at the very least) and advancing the cam timing a couple of degrees helps. But one will run fine in a stock motor. Just not optimal.

    Depending on the cam shaft it is hard to know what they dynoed it in. One would think 350, but a more traditional grind may have been tested in a short stroke motor.
     
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  16. Jmountainjr
    Joined: Dec 29, 2006
    Posts: 1,367

    Jmountainjr
    ALLIANCE MEMBER

    You really need to look at the HP and torque graphs to get a feel for what a cam will do. The operating range that you are seeing on the cam descriptions are more the useful, but that's not the entire range. What you are asking for a stock 283 will do. There are a number of older cam profiles being reproduced that would work and be a step up from stock. You don't need much of a cam to do what you are asking.
     
    Last edited: Apr 22, 2021
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  17. 55blacktie
    Joined: Aug 21, 2020
    Posts: 464

    55blacktie

    jagsxr offered the best advice. Talk to a cam grinder who knows your engine and tell him what you want it to do. If buying off the shelf, buy a smaller cam for a smaller engine, unless you're going drag racing.

    I've made several attempts to contact Howard's, using their online contact form. I never received a reply. Maybe you'll have better luck calling, but what's the purpose of their online contact form if they don't reply?

    I bought a Schneider cam for my Ford Y-block. Jerry Cantrell was very helpful.
     
  18. And shift when the oil light comes on :D
     
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  19. Greasyman
    Joined: Oct 23, 2010
    Posts: 174

    Greasyman
    Member

    Does anyone know what the stock cams specs would be for a bread and butter sbc, like with a two barrel and single exhaust?
     
  20. Truckedup
    Joined: Jul 25, 2006
    Posts: 4,218

    Truckedup
    Member

    I believe the 60's 283 used a cam of about 194-200 degrees duration at .050 lift, around .420 lift. I also think this cam was used in up to 327/300 engines.
     
  21. ekimneirbo
    Joined: Apr 29, 2017
    Posts: 2,111

    ekimneirbo
    Member
    from Brooks Ky

    JmountainJr gave you good advice. What you have to consider is that you have to give up something to get something else. Most people get enamored with the maximum hp a cam produces. Whats really important ......especially with a small displacement engine is driveabilty...........which somewhat translates into "average hp across the rpm range". If you get a cam that doesn't give you a lot of HP down low but suddenly comes to a power curve at the upper rpm range.........you won't like driving it. Its especially critical to get a cam that spreads the average hp across the entire rpm range when you have limited displacement to work with. I learned that lesson many years ago when a friend of mine overcammed a smallblock and it was a complete dog. It was so bad that at first we thought something else was wrong. Then it finally got to its power range and there was a little blip of power, a quick shift......rpms dropped and it was in total dog mode again. The cam was out of a local dragster and way too much for the otherwise stock engine. You are not looking to do anything that radical, but you need to remember that your engine will only spend a moment making maximum rpm and it will spend a lot more time getting to that point. Think of it this way.......how many hp will the cam be making at each 1/10th of a second during its accelleration. The cam that has the biggest total for all the 1/10th increments will be better than the one that just has high hp numbers at upper rpms.;)

    Edit: I just saw your post about having a two barrel carb and single exhausts. Why don't you just put a stock reground cam in it ? A higher performance cam with a limited intake and exhaust is not going to help it. I'd sell the 283 to someone who just wants to be nostalgic and buy a stock 350 to replace it.
     
    Last edited: Apr 22, 2021
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  22. 55blacktie
    Joined: Aug 21, 2020
    Posts: 464

    55blacktie

    Truckedup's specs sound about right. I would add LSA of 112 or higher for a stock 2-bbl, single-exhaust 283. If looking for street performance, keep duration @ .050 under 220.
     
  23. Atwater Mike
    Joined: May 31, 2002
    Posts: 10,707

    Atwater Mike
    ALLIANCE MEMBER

    For personal advice for cam specs (and they have a LARGE stock!) is DELTA Cams, Spokane, Wash.
    GREAT service, they did my new 406 cam from a new blank, same with my flathead cam: Winfield SU-1R, on a N.O.S. flathead blank. VERY reasonable, had the 406 cam in 3 days. Flathead took 5 days.
     
  24. Greasyman
    Joined: Oct 23, 2010
    Posts: 174

    Greasyman
    Member

    Thanks for all the advice, everyone. Just to clarify, my car doesn't have a two barrel and single exhaust, I was just looking for a frame of reference to compare the new cam against. I can find specs for old performance factory cams, but not for the non-performance cams, which is what I believe it currently has.

    The car is a 23 T bucket and has duals with glass packs, a 4160 450 cfm and I'll probably replace its old school second gen Streetmaster with a Performer, just to see if it makes a difference. The car also has a TH350 and an open 2.73 diff. I know some people will want to tell me to replace that diff, but at 1700 lbs the car does not feel like the diff holds it back at all.
     
  25. Budget36
    Joined: Nov 29, 2014
    Posts: 7,272

    Budget36
    Member

    I’m not a cam expert by any means, that’s why I have a few manufacturers on speed dial;). The thing is, cam isn’t going to let you rev higher, but larger displacement vs smaller, the operating range the cam makes its power, or allows the engine to make power will shift.
    As mentioned before, a cam that has an operating range to 4500rpms, doesn’t mean the engine won’t keep going till it comes apart higher up. A cam isn’t a rev limiter. It’s what it’s expected to perform in a given RPM range. That range should move up some with a smaller displacement engine vs larger. Only way to know 100% is to see the dyno pulls of a like kind engine build vs build. Issue then is head flow, etc.

    Bottom line is call and talk to the folks that make them, or even better yet, take advice from those with the same engine you have and what they run:)
     
  26. 55blacktie
    Joined: Aug 21, 2020
    Posts: 464

    55blacktie

     
  27. 55blacktie
    Joined: Aug 21, 2020
    Posts: 464

    55blacktie

    Greasyman, your car probably won't spend much time on the highway; therefore, it doesn't need highway gears. You'll have more fun with 3.50s. I went from stock 3.31s to 2.72s in my 55 T-bird, but it will see highway use, and I somewhat compensated by putting wide-ratio gears/w 2.80 1st into a C4 transmission. Even though we're talking about a 283, I think it must be a rather mild build if it has a 450 cfm carburetor.
     
  28. 55blacktie
    Joined: Aug 21, 2020
    Posts: 464

    55blacktie

    Edit: 2.90 1st, not 2.80.
     
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  29. RodStRace
    Joined: Dec 7, 2007
    Posts: 2,717

    RodStRace
    Member

    Light car, small carb, torque based intake, small displacement, sounds like you have a pretty good setup.
    The rear gears will keep the engine at lower RPM, so having less overlap and no crazy lift or duration is good for idle and driving. When you talk to the cam companies, have all this info ready so they can plug in the specs and determine the best approach.
    I'd guess that once you have talked to a half dozen companies, you will have a window of specs within less than 20 degrees and 0.020 lift. Choose which company has a reasonable price and was the best service pre-sale. Ask about lifters, springs and any other issues that might crop up.
    I will mention being very happy with Schnider also, but this mild spec cam if ground and hardened properly will be well within the abilities of most any decent company.
     
    ekimneirbo likes this.
  30. gary macdonald
    Joined: Jan 18, 2021
    Posts: 142

    gary macdonald
    Member

    390-410 onmost all
     

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