Rollmaster timing set

Discussion in 'Street/strip 400/430/455' started by Dwayne B, Sep 26, 2020.

  1. Dwayne B

    Dwayne B Well-Known Member

    I installed A TA c113 cam in my 430 and I'm trying to degree it. I'm using A TA rollmaster gold timing set.Im using the centerline method finding total lift on intake and going 50 each way adding them numbers and dividing by 2.Im getting 111.5 and card says 113.That is using o on crank gear .
    My main concern is when I have it on true TDC the dots don't line up. I'm using A old spark plug that I threaded A bolt throw,so I know I'm at true TDC.
    I stuck my old crank gear on and it seems to be closer. 20200926_075348.jpg 20200926_075355.jpg 20200926_075509.jpg
     
  2. 436'd Skylark

    436'd Skylark Sweet Fancy Moses!!!!!

    The dots won't line up at tdc. That got me too. Even at zero advance the dots are off.
     
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  3. Mark Demko

    Mark Demko Well-Known Member

    Don’t confuse yourself, trust the degreeing instructions and the Rollmaster timing set, make sure you run thru the degreeing process a couple times to make sure you get repeatability.
     
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  4. Dwayne B

    Dwayne B Well-Known Member

    Hey thanks guys ,that makes me feel better. This is the first cam I have degreed .
     
  5. No Lift

    No Lift Platinum Level Contributor

    This is why the Rollmaster must be degreed in. If you used a stock setup it would probably be closer. The way the RM is set up the lower gear is machined 4 to 5* retarded the way I look at it. Some will say that it is machined correctly and the factory is 4* advanced. Using the RM most times when installing cams you will end up at the +4* mark or better even if the cam is ground at 4* advanced which is the usual except for TA's depending on when it was made. Does your card say install at 109* ICL for 4* advance or does it say it is ground +4* already? If you move the RM lower gear around to the +4* position and then slide the factory gear on you will notice it is very close to aligning the teeth. Something like <1* off and will be close to aligning the dots at TDC. However aligning the dots doesn't mean much if the cam still needs adjustment. That's why you are degreeing it in. If you are getting 111.5 ICL then you are still 2.5* retarded from the usual preferred position of 109*. Use the +4 position of the lower gear and retry. In just about any street going setup advanced is preferred compared to a retarded cam.
     
  6. Dwayne B

    Dwayne B Well-Known Member

    I intend up retarding the gear 2° and now I'm right at 113 on the intake centerline. 20200926_215105.jpg
     
  7. No Lift

    No Lift Platinum Level Contributor

    Nobody that I know of for a street car installs their cam "straight-up" as yours is now, 113* LSA/113* ICL. Notice it says "degree to 113* for 0 advance". For some reason TA likes to do that on some of their cams. I'd advance it 4* and then it will be installed at 109* ICL which would be typical. Even where you had it the first time you at least were about +2*. You have to remember that no matter how good the timing chain set is when push comes to shove and all the forces of a running engine are applied to the cam it starts to retard a little and as the miles rack up it starts to retard more as the chain stretches. On a very finely tuned race engine and the cam is ground for exactly what it is intended the builder may go for straight up because it will probably be pulled apart on a regular basis. As I said, advanced is always better than retarded and yours will go from being straight up to slightly retarding the minute it starts up and will continue to do so as running time goes by.

    Advancing the cam generally helps out the low end torque. If you have big gears, high stall converter, higher compression(noticably over 10:1) and you wanted to shift at slightly higher rpm I'd say go with the current positioning because you don't need the extra low end power and you want to stretch out the rpm a bit.

    I wish they had more info but in this example the cam must be pretty big because the engine has more HP than TORQUE and I believe that is why the difference in torque was greater. IMO you probably have to get up above 250* duration at .050" before a Buick 455 starts to make less peak torque than peak HP. That may even change depending on compression ratio.

    https://www.hotrod.com/articles/mopp-1211-degreeing-a-camshaft/

    https://help.summitracing.com/app/answers/detail/a_id/4706

    The current cam, which is in my '69 400, is an old school KB C113 which the TA cam pretty much copies with minor changes over the years. If you run it through a cam calculator you will find it is ground at +4*, ICL@109*.

    KB MK C113.jpg
     
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  8. BQUICK

    BQUICK Gold Level Contributor

    I agree with Mike....if you start at 2deg retarded after some chain stretch you will be at 4 to 5deg retarded.....not so good for a street car although I have seen some set up that way to kill bottom end and run well up top as in stock classes running on skinny bias tires.
     
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  9. Dwayne B

    Dwayne B Well-Known Member

    Hey thanks for the information, I have installed cams but never degreed them.I thought I would try it on this one.I understand what you are saying about advancing it.The motor that I installed this cam in is A 430 which should have A pretty good compression number .I'm installing the motor in my 72 Skylark with 3.73 gears and 4 speed manual transmission.
     
  10. Bens99gtp

    Bens99gtp Well-Known Member

    I've had RM take +6 to get a reading to match the card......then I wsnted to go 4 more advance and it got real confusion because I had to skip a tooth on the cam the retardthe crank to bring it back.......lord help anyone who looks into thst one.....lol

    I dont know if its the factory gear or the RM that is off, I dont seem to run into this issue with RM on other brands???

    It for sure gets confusing when some are degreed to x for 0, and other say degree to x for +4......
     
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  11. BQUICK

    BQUICK Gold Level Contributor

    I bought a motor from a guy that put a 455 Buick into a 68 Camaro. The cam timing was so far off that at high rpm the valves were kissing the pistons.
    He was actually a Chevy guy trying to be different. He ran 10.80s even so....sad because if it was right he would have been a believer. And yes...it was a Rollmaster...whoever built it got it WAY off. Not sure how it even ran.....
     
  12. 87GN_70GS

    87GN_70GS Well-Known Member

    All sorts of inconsistencies in the first cam card. Advertised duration says 285 for the intake yet 25+71+180 = 276. Exh duration says 292 yet 80.5 +34.5+180 = 295. Timing numbers form the exh at 0.050" are off by 0.5 deg but....
     

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