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Camshaft timing

Posted By 1946international Last Month
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1946international
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I'm building a '57 292 for a project and am installing a Comp cams camshaft in it. Spec are, gross lift both I&E .471      Duration @.015 tappet lift 261 Intake & 267 Exhaust      LSA 108* . My problem is this, when degreeing the cam I have to "retard" the cam 6*, my multi keyway timing gear set can be adjusted to 8* advance to 8* retarded so I,m not maxed out but 6* sounds a little far. What do you all think? I have checked and rechecked my process 3 times and it comes up the same. The cam card says I need a 108* intake center line. 
I did a on-line chat with Comp cams tech guy and he said it "sounds odd but strange things can happen with custom ground cams" & "just put it in and see how it runs" Someone on another site suggested checking the exhaust side to see if the cam was ground right and I guess I could figure out how to do that working off of the cam card but would I have to check each intake and exhaust lobe? Am I just over thinking? 

Cliff
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You might want to install it at 2 deg advance from what the cam card tells you.

Joe-JDC
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We(Ted and I) found the Comp Camshafts for the Y block were ground on the wrong lifter angle and when you advanced or retarded the camshaft, it was off on every lobe from the cam card.  Straight up was the only way it matched the cam card.  Had 3 Jones camshafts the same problem.  Howards, Jones, Comp all use the wrong lifter angle when grinding their camshafts.  ISKY uses the correct angle, and you can advance or retard the ISKY with confidence.   Just my experience, but I called Mike Jones, and he now has the right angles, and he reground me three camshafts for free.  They checked out when degreeing after the modification to correct valve angle.  Joe-JDC

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55blacktie
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Joe-JDC, I had some knowledge of lifter angle, but I did not know about Howard's using the wrong angle. If that's true, I'm glad I didn't buy a Howard's cam. I hope Schneider got it right.

Thanks for the info.
1946international
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Cliff (3/5/2021)
You might want to install it at 2 deg advance from what the cam card tells you.


how does the cam card say that? am I not seeing something?
1946international
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Joe-JDC (3/5/2021)
We(Ted and I) found the Comp Camshafts for the Y block were ground on the wrong lifter angle and when you advanced or retarded the camshaft, it was off on every lobe from the cam card.  Straight up was the only way it matched the cam card.  Had 3 Jones camshafts the same problem.  Howards, Jones, Comp all use the wrong lifter angle when grinding their camshafts.  ISKY uses the correct angle, and you can advance or retard the ISKY with confidence.   Just my experience, but I called Mike Jones, and he now has the right angles, and he reground me three camshafts for free.  They checked out when degreeing after the modification to correct valve angle.  Joe-JDC

So, if I check the valve timing for opening timing and find they are not matching what the cam card says I should try setting it up "straight up" and recheck opening time to see if it then matches the cam card? 
Ted
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As a general rule, always check both an intake and exhaust lobe on a given cylinder.  The two values added together and divided by two is expected to equal the ‘as ground’ lobe centerline.  In your case, 108°.  Only when the camshaft is installed where both the intake and exhaust lobe centerlines are equal is the camshaft installed straight up.  When the intake lobe centerline angle is less than the ‘as ground’ lobe centerline the camshaft is advanced.  Likewise when the intake lobe centerline angle is more than the ‘as ground’ centerline angle the camshaft is retarded.
 
I’ll suggest also checking the cam timing on the #6 cylinder.  This will confirm both your checking methodology and if the camshaft is at least the same on those two cylinders.  If you find a 2° or more discrepancy, then you may need to check all the cylinders and determine if this is a problem where the left bank does not agree with the right bank.  If that’s the case, the camshaft was ground on the incorrect lifter bank angle.  By checking the camshaft timing on different cylinders and especially opposite banks you will get a good feel for how good the cam grinder is doing their work.
 
But back to basics.  Being six degrees off on the cam timing is not unheard of.  And when I say off, I mean from where the manufacturer or cam grinder recommends where the camshaft is to be initially installed.  Most cam grinders specify four degrees of advance and that is typically built into the camshaft so that when the gear marks are properly aligned, the camshaft is close to where it needs to be.  In your case and assuming it’s a new timing chain set, then consider installing that camshaft at 104°-106° intake lobe centerline so that as the timing chain loosens up, the camshaft will not be residing in a retarded position.  I have found camshafts off as much as 18° off either as retarded or advanced and that’s with the timing gear marks simply aligned as they should be.  In those cases, the timing chain is reinstalled with a one tooth offset on the gear marks versus being aligned as was originally designed.  In rare instances I have had to broach a new key way slot in the crankshaft gear in which to compensate.
 
Here are links to the camshaft degreeing articles that were published in The Y-Block Magazine several years ago.
 
https://www.eatonbalancing.com/2015/09/24/degreeing-in-the-camshaft-part-i-finding-tdc/
 
https://www.eatonbalancing.com/2015/09/24/degreeing-in-the-camshaft-part-ii-phasing-the-camshaft/
 
https://www.eatonbalancing.com/2015/09/24/degreeing-in-the-camshaft-part-iii-its-twelve-pins-between-the-marks-for-the-ford-y/


Lorena, Texas (South of Waco)


BamaBob
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Thanks Ted, for the very informative articles. I do have a question, though. In using the piston stop, does it matter whether the piston is as close to the top as it can be, or can it be just close to the top, as in a half inch or so? I have never used a degree wheel, but am intending to in the near future and need to know all I can learn about its use.
Joe-JDC
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The closer to the top you have the piston stop, the smaller the numbers you will work with and less room for error in finding the true TDC.  In reality if you do it correctly, the distance doesn't matter.  I prefer to work with being close to TDC since it makes reading the degree wheel easier.  Joe-JDC

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1946international
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Thanks all for the replies. Ted asked if the timing set was new and yes it is. I read those articles earlier today. 
So I will check the center line of the exhaust on both #1 & #6 to see where I stand. 


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