Looking for some advice for a change

Discussion in 'High Performance Modifications' started by jvle95, Feb 1, 2018.

  1. jvle95

    jvle95 Veteran Member

    157
    2
    May 14, 2007
    SF Bay Area, CA
    So here is the deal. I have a nice 72 RS/SS that has a nice running little 355 that works well as an around town fun weekend car. The TH350 is due for an overhaul so I am thinking of making a little cam change.
    Motor:
    9.7:1 compression
    4 Bolt main block
    AFR 195 heads (older heads not the newer eliminators)
    RPM Air Gap
    Quickfuel 750 vac sec
    Comp Cam XE268
    Mid length Header 1 5/8" headers
    You get the idea.

    I am thinking that when I pull the tranny I will pull the engine to fix a stubborn rear seal leak. I am thinking I may swap out the cam for the Comp Cam Magnum HR280 to make better use of my heads. How much of a benefit do you all feel switching to this cam or one similar would be?

    I have had this car for over 30 yrs (drove it in high school) and every 5 yrs or so I get an itch.
     
  2. slayer021175666

    slayer021175666 Veteran Member

    1,212
    57
    Feb 29, 2016
    Idaho
    Best thing to do is call the cam companies and give them all your specs. They will have an off the shelf recommendation but, if you got the scratch, a custom grind is AWESOME! Fatkid would know because he knows how to do the math but, I haven't heard of him around here for quite a while.
     
    Cardinal likes this.
  3. larrylarry

    larrylarry Veteran Member

    1,495
    62
    Dec 22, 2011
    San Antonio Tx
    Maybe I shouldn't throw in my 2 cents but I had a XE268 in my 350 an didn't like it,wouldn't start making HP until almost 4 grand / 90 mph / WFO. I think your getting to the point of to much cam with a 280. Might require a higher stall torque convertor, single plane intake & might be a dog to drive until you hammer the go peddle. Id consider a 280 to be a medium 1/4 mi. cam. I don't know, everybody different.
     
    Last edited: Feb 2, 2018
  4. 1980RS

    1980RS Veteran Member

    1,841
    65
    Jun 17, 2006
    MN
    I stopped using CC years ago after a few flat lobes with their cams. I have used some of the Elgin cams and very pleased with the results. I had one cam that was an Hyd. .488I and .510E 234° and 244° duration @ .050 on a 106°LCA and that cam pulls better than any of the Comp Cams I have used. The Elgin was .2 tenths quicker that the 292h CC.
     
  5. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    9,461
    250
    Nov 4, 2004
    Ringgold, GA
    You can easily get out of balance with a new camshaft. A higher performing camshaft will require matching components like intake & exhaust system, heads, torque converter, etc. What series AFR heads do you have? They're known for performance so you may have some room to expand with another cam. I'm not big on Comp Cams either but they must be doing something right, they've been in business a while.

    One thing on a cam, don't even think about going with a high performance grind with flat tappets, too many horror stories right here on NastyZ about wiped cam lobes.

    I've had very good service with Howard Cams, tech guys always seem to be knowledgeable and friendly. Whichever way you go, make sure the cam manufacture knows about your torque converter, power brakes, intended use, etc. Most companies will have an online questionnaire you can practice with. Good luck with your project.
     
  6. jvle95

    jvle95 Veteran Member

    157
    2
    May 14, 2007
    SF Bay Area, CA
    I guess maybe I should have included a little more info but I hear what you are all saying. By no means do I expect this motor to become something it is not but I am curious to how a cam better matched to my heads would act. The cam I listed is a Hydraulic Roller 224 duration at I believe .525 lift. I have run the old 280/480 Comp Cam hydraulic flat tappet cam with good results back in the day as well as a custom ground Elgin. The Elgin surprised many people, lol. Very tame numbers based on the low flowing heads I was using then but it packed some duration. Anyway, I am not dead set on Comp but rather threw that cam out there as a reference based on its numbers. I think I just want to try the roller route and see how it acts. Currently running a 2400 stall convertor that works ok with the XE268. I don't dislike the XE268, just thought I would try something new and see how it goes.

    Forgot to add that I don't have the AFR heads model numbers on the top of my head but I will look into and get back to you on that.
     
  7. larrylarry

    larrylarry Veteran Member

    1,495
    62
    Dec 22, 2011
    San Antonio Tx
    When I pulled out the 268xe I filled out a form online for Howards Cams. After filling in all the blanks I told them Im going to a roller cam & wanted to build HP & torque starting at lower rpms . One nice thing is I don't have to hunt for the proper oil anymore for an oil change.
     
  8. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    9,461
    250
    Nov 4, 2004
    Ringgold, GA
    Sounds to me like you're at a good median with you engine setup. Really need to question if a cam swap will be a bang for the buck deal.

    Have you looked into replacing the TH350 with one of the 4 speed automatics?
     
  9. larrylarry

    larrylarry Veteran Member

    1,495
    62
    Dec 22, 2011
    San Antonio Tx
    A66CEFA5-B6A0-4566-9C8B-43DEFC08D79F.jpeg Or buy a 3.75 crank and make a 383. I just bought a new Engle crank from Jegs, cast steel, 3.48 delivered to my front door for 189.99 total cost. Jegs has the same crank for a 383 for the same price. Didn’t want to use my old crank shaft that’s cast iron & made in 1978, nothing wrong with it but how much longer will it last???
    Cranks do twist when you apply heavy go pedal pressure, cast steel can handle twisting better than cast iron. FYI
     
    Last edited: Feb 3, 2018

Share This Page