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By napaunderground - 2 Years Ago
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I am about to install my timing cover during my build... but this quote from Ted stopped me dead in my tracks...
..., then it would be time well spent to make sure it is degreed in and not just installed with 12 pins between the marks.
For our build, we've got a 292 bored .040 over, and had the cam reground to a T-Bird 4bbl profile (was originally a truck 2bbl we're putting a 4bbl on it).
I've installed the cam with stock placement of 12 pins between marks.
Re-iterating this is just a "fun" build and going to be used for going to the yard for bark/rocks/etc and just cruising around town.
Should I do something other than stock for the cam timing?
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By Ted - 2 Years Ago
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napaunderground (11/16/2022)
I am about to install my timing cover during my build... but this quote from Ted stopped me dead in my tracks...
..., then it would be time well spent to make sure it is degreed in and not just installed with 12 pins between the marks.
Should I do something other than stock for the cam timing?
There are a multitude of engines out there with the camshafts simply installed with the link count and/or marks being aligned. They all start up and run. In fact, most will start and run if inadvertently being installed one tooth off. Degreeing in the camshaft ensures that cam is installed in the correct position for the best economy and performance. If the engine is troublesome or not performing as expected once fired up and the camshaft was not degreed in, then that becomes something else to question during the troubleshooting process. If the camshaft was degreed in, then you get to take that off the list and look elsewhere.
Simply installing the Ford Y camshaft without actually checking it only tells you it is installed as per whatever the link count is. On other engines where the cam and sprocket marks are aligned with each other, the same scenario exists. Marks are aligned but you have no way of knowing where the camshaft is actually installed without doing a degree wheel check.
With manufacturing variances being thrown into the fray, I have seen camshafts off as much as 18° in both the advanced and retarded positions. One of those was a 340 Mopar and the other was a Ford 390 FE. With dowel pins, keys, locating holes and slots on the cam, crank, and sprockets allowing for the cam timing to be ‘off’, stack ups come into play and that’s assuming there’s nothing funny going on with the camshaft lobes themselves. Stack ups are where all the locations for potential variance are all positive or all are negative. When there is a combination of both positive and negative variances, those will tend to cancel each other out thus making the camshaft being more in the ball park to where it needs to be.
If you want to take cam degreeing to the next level, you will want to check at least a pair of lobes on both banks. For the Ford Y, checking the #6 cylinder along with the #1 cylinder is relatively simple as the degree wheel does not have to be moved or readjusted as #1 and #6 share the same TDC on the wheel; the dial indicator is just relocated from one bank to the other.
Here are links giving more detail on degreeing in the camshafts.
Degreeing in the camshaft – Part I – Finding TDC – Eaton Balancing
Degreeing in the camshaft – Part II – Phasing the camshaft – Eaton Balancing
Degreeing In the camshaft – Part III – It’s twelve pins between the marks for the Ford Y – Eaton Balancing
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By napaunderground - 2 Years Ago
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Ok, thanks Ted! Off to purchase the required tools...
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