Roller Cam Vs Flat Tappet
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Roller Cam Vs Flat Tappet

  1. #1
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    Default Roller Cam Vs Flat Tappet

    Hi all,

    Need some input. Having an engine built and money has become an issue (when is it not, I guess-- Sucks not winning the lotto again this week!). My Engine builder (obnoxious) wants me to pick between roller and Flat Tappet cams. The Flat T cam will save significant coin... No cam grind yet, as he hasn't put the heads together. He's trying to offer me ways to save money, which I REALLY REALLY appreciate! I'm coming here for input, because I feel bad for Barry. I'm burying him in questions and I don't want to piss him too far off.. Think I'm starting to annoy him. (Sorry Barry!)

    I know roller has has steeper ramps and "more area under the curve" than Flat, but I'm wondering how critical it is w/ my motor, because I don't want to turn crazy rpm. Might I get similar power w/ flat Tappet?? Motor is good stuff. 565 NA motor. Single 1050 Dominiator. Dart Tall deck, Dart pro 1 heads etc., and it'll be pushing a Sanger 21 cruiser w/ 37's (currently) and a T-400 tranny. My goal 700 ish HP and want to turn max 6K rpm (when geared properly-- if not currently).

    Also-- can someone shed light as when is the correct time to replace roller lifters? I guess, more correctly, how do I tell when the roller lifters need replacement. Do you hear it? Or does power go away? Or do you do it every x hundred hours to avoid catastrofic failure?

    Prior to build, my heart was set on Roller Cam. Now I'm not so sure because of money and maintenance.

    Thanks for your input!
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  3. #2
    Resident Ford Nut Sleeper CP's Avatar
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    I feel your pain on the budget issue If you can swing it I would invest in the solid roller. They give you so much more "pop" out of the engine it's amazing. A stout flat tappet is okay, but you can't go wrong with the roller as far a hp. Even at 6,000 rpm you will benifit from the roller. imo

    If you don't go crazy on spring pressure the lifters can last you several seasons, but that depends on how many hrs you put on it of course.

    Last year I replaced the Crower lifter's in our 565 with the new type from Crower that have an exra oil slot on them to feed the bearings. They a supposed to last much longer and work well in applications where you do a lot of idling and low rpm cruising.

    I hope that's helpful.

    Sleeper CP

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    Quote Originally Posted by Sleeper CP View Post
    I feel your pain on the budget issue If you can swing it I would invest in the solid roller. They give you so much more "pop" out of the engine it's amazing. A stout flat tappet is okay, but you can't go wrong with the roller as far a hp. Even at 6,000 rpm you will benifit from the roller. imo

    If you don't go crazy on spring pressure the lifters can last you several seasons, but that depends on how many hrs you put on it of course.

    Last year I replaced the Crower lifter's in our 565 with the new type from Crower that have an exra oil slot on them to feed the bearings. They a supposed to last much longer and work well in applications where you do a lot of idling and low rpm cruising.

    I hope that's helpful.

    Sleeper CP
    Yeah, we'd talked about the Hippo lifters as well. Do appreciate your time. Take care.
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    Some guy obnoxious001's Avatar
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    Solid lifter cam(flat or roller) has never been an option, he doesn't want to have to learn to adjust valves.

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    That kind of CID will require the "area of a roller lobe" to make power. You've spent some serious coin and the cam is the brain of the engine. . .you don't want to skimp on brain power.
    Chris Straub
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    E-7 Sheepdog (ret) SmokinLowriderSS's Avatar
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    Quote Originally Posted by Sleeper CP View Post
    Last year I replaced the Crower lifter's in our 565 with the new type from Crower that have an exra oil slot on them to feed the bearings. They a supposed to last much longer and work well in applications where you do a lot of idling and low rpm cruising.

    I hope that's helpful.

    Sleeper CP
    Those are the roller lifters to get, Iskendarian makes a set too. Buy them once, or buy replacements every couple years, which one is cheaper THEN.

  9. #7
    cfm
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    Quote Originally Posted by obnoxious001 View Post
    Solid lifter cam(flat or roller) has never been an option, he doesn't want to have to learn to adjust valves.
    So....hydraulic flat or hydraulic roller ???? Definately understandable wanting hydraulic.

    I personally don't see a hydraulic flat making it to that hp level. A hydraulic roller will be tough in of itself. It will require a valvetrain package that will let the engine rev (and maintain) to the rpm's needed for that power level. Actually, will also need lobes that are carefully designed to not only make that power but more importantly let it hold those rpms also.

    Sounds like some major thinking/planning/etc will be needed for this one.

    "Poor Barry" is right. LOL.

    Let us know how it all works out.

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    Quote Originally Posted by cfm View Post
    So....hydraulic flat or hydraulic roller ???? Definately understandable wanting hydraulic.

    I personally don't see a hydraulic flat making it to that hp level. A hydraulic roller will be tough in of itself. It will require a valvetrain package that will let the engine rev (and maintain) to the rpm's needed for that power level. Actually, will also need lobes that are carefully designed to not only make that power but more importantly let it hold those rpms also.

    Sounds like some major thinking/planning/etc will be needed for this one.

    "Poor Barry" is right. LOL.

    Let us know how it all works out.
    Decision was made today. Roller cam w/ hippo lifters, and we'll see what we get. And that's why I hired Barry!! I can do mediocre myself.
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    Senior Member H20MOFO's Avatar
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    Hippo lifter? Is that sorta like a roades(sp?) I regret not going solid(roller or flat) with my motor. BTW how often would you need to adj. a solid tappet camshaft? I know you race guys beat em up pretty good but I mean an average joe lake guy. Aren't they good for a season once adjusted? Just read the thread again, I guess hippo's are the crowers that cp was talkin about?
    Another Hot Boat refugee

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    mo balls than $cents$ IMPATIENT 1's Avatar
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    Quote Originally Posted by H20MOFO View Post
    Hippo lifter? Is that sorta like a roades(sp?) I regret not going solid(roller or flat) with my motor. BTW how often would you need to adj. a solid tappet camshaft? I know you race guys beat em up pretty good but I mean an average joe lake guy. Aren't they good for a season once adjusted? Just read the thread again, I guess hippo's are the crowers that cp was talkin about?
    i fit in that category , i check them after the 1st 30 minutes of runnin a new motor, then at the 1st oil change(@3hrs), then every 8-10hrs on the motor from then on till the season ends. end of season, i back off the rockers, give the springs a break

    so per summer, i may adjust twice.


    comp cams has some great option in solid roller cams for guys like me who want a roller motor to last longer and are willing to give up a few hp to make it happen. my current solid roller cam only requires 150lbs of seat pressure(i run 175lbs) and a 450-500lb spring(i run @500lbs). the low spring pressure makes the valvetrain last a verrry long time compared to motors with high pressure spring. call comp cams
    Last edited by IMPATIENT 1; 02-08-2008 at 05:50 PM.

  13. #11
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    I personally don't see a hydraulic flat making it to that hp level. A hydraulic roller will be tough in of itself. It will require a valvetrain package that will let the engine rev (and maintain) to the rpm's needed for that power level. Actually, will also need lobes that are carefully designed to not only make that power but more importantly let it hold those rpms also.
    Huh???
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    Quote Originally Posted by cfm View Post
    I personally don't see a hydraulic flat making it to that hp level. A hydraulic roller will be tough in of itself. It will require a valvetrain package that will let the engine rev (and maintain) to the rpm's needed for that power level. Actually, will also need lobes that are carefully designed to not only make that power but more importantly let it hold those rpms also.



    "Poor Barry" is right. LOL.
    Two years ago I build a pump gas 548 jet boat engine that made 700 HP at 6100 rpm with a flat tappet hydraulic. I did call the cam grinder and thank him for making me look good, I had only given the customer a 600 HP target at 6000 rpm.

  15. #13
    cfm
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    Quote Originally Posted by steelcomp View Post
    Huh???
    Steel, Which part are you saying "huh" too ?

    Side note: Compression was not mentioned on this build and maybe I should have asked that first, since this is, of course, a big factor with what power an engine will make.
    Last edited by cfm; 02-09-2008 at 04:46 PM.

  16. #14
    Senior Member Hallett's Avatar
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    This may help you rightytighty some good info.
    http://www.superchevy.com/technical/...ams/index.html

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