Fraid probably so
But before you pull things all apart again, carefully check the ignition timing. When you replace a worn timing chain and sprockets with a new one, your ignition timing can move a lot.
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| do i have to degree the cam when changing the timing set? https://www.slantsix.org/forum/viewtopic.php?t=46717 |
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| Author: | Brothercactus [ Wed Oct 19, 2011 12:49 pm ] |
| Post subject: | do i have to degree the cam when changing the timing set? |
I just changed to the timing chain and gears on my 65valiant. At the time i assumed that lining the marks on the gears up was all that was necessary. Now everything is back together and the car is running badly. Searching the forum makes me think i should degree the cam to insure proper timing. Sound right? |
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| Author: | SlantSixDan [ Wed Oct 19, 2011 12:50 pm ] |
| Post subject: | |
Fraid probably so But before you pull things all apart again, carefully check the ignition timing. When you replace a worn timing chain and sprockets with a new one, your ignition timing can move a lot. |
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| Author: | Sam Powell [ Wed Oct 19, 2011 2:26 pm ] |
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Did you align the marks with a straight edge, or just eye ball it? Sam |
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| Author: | 805moparkid [ Wed Oct 19, 2011 5:15 pm ] |
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Quote: Did you align the marks with a straight edge, or just eye ball it?
thats not degreeing a cam lol...
Sam |
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| Author: | Sam Powell [ Thu Oct 20, 2011 10:13 am ] |
| Post subject: | |
Quote: Quote: Did you align the marks with a straight edge, or just eye ball it?
thats not degreeing a cam lol...Sam We cannot help him out if we don't know if he did the proper FSM process. It is very possible to get things off one tooth if you do not use a straight edge. Sam |
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| Author: | WagonsRcool [ Thu Oct 20, 2011 10:42 am ] |
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I'd check engine compression in a couple cylinders. If cam timing is off, then it's gonna affect compression pressure. |
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| Author: | Brothercactus [ Thu Oct 20, 2011 11:13 am ] |
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The car is a project i'm working on repairing so the timing was trash to begin with. Once i got it back together i spent a bunch of time making timing and carb adjustments. It seemed like nothing i did would smooth out the way the car was running. I'm pretty sure the dots line up. I thought that was all i needed to do so i was sincere about it and used a straight edge. It's easily possible that i made a mistake though. How would the car run if the timing set was installed wrong? rough and impossible to time? I'm working on getting a FSM, for now i have the digital pirate version of the 66' that i found on here. It's hard as hell to use with a netbook screen though! Much Thanks! |
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| Author: | Doc [ Thu Oct 20, 2011 11:23 am ] |
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Sounds like the car has never really run well, since you have owned it. Have you checked the valve lash settings? DD |
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| Author: | Brothercactus [ Thu Oct 20, 2011 1:03 pm ] |
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Ya. I bought the car rough so i could learn my maintenance chops. I checked the valve lash before and after i replaced the timing set and believe it to be good. I'll check again though while the covers off. compression test is noted. i've never done that and would be curious to know anyway. |
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| Author: | wjajr [ Thu Oct 20, 2011 1:31 pm ] |
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Quote: I checked the valve lash before and after i replaced the timing set and believe it to be good.
Lifters run off of camshaft so lash will be the same before and after changing timing chain. What may change when messing with timing chain & gears is the timing, that is, when the valves open & close in relation to piston position.Quote: compression test is noted. i've never done that and would be curious to know anyway.
Compression assessment can show if valves are sealing correctly, and if piston rings are doing their job, and how well that these two items are functioning. In other words, one can determine how worn the engine is, and if it needs repair.
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| Author: | Reed [ Thu Oct 20, 2011 1:36 pm ] |
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Quote: Compression assessment can show if valves are sealing correctly, and if piston rings are doing their job, and how well that these two items are functioning. In other words, one can determine how worn the engine is, and if it needs repair.
Also, if cam to piston timing is way off, compression may be low due to grossly incorrect valve timing, i.e. a valve is hanging open on the compression stroke.
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| Author: | Sam Powell [ Thu Oct 20, 2011 1:52 pm ] |
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Quote: The car is a project i'm working on repairing so the timing was trash to begin with. Once i got it back together i spent a bunch of time making timing and carb adjustments. It seemed like nothing i did would smooth out the way the car was running.
If you used a straight edge, it is probably safe to assume the dots lined up. This leads us to look elsewhere, as others are suggesting. But if you did not use a straight edge, then the set up is suspect from the git-go.I'm pretty sure the dots line up. I thought that was all i needed to do so i was sincere about it and used a straight edge. It's easily possible that i made a mistake though. How would the car run if the timing set was installed wrong? rough and impossible to time? I'm working on getting a FSM, for now i have the digital pirate version of the 66' that i found on here. It's hard as hell to use with a netbook screen though! Much Thanks! Sam |
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| Author: | Reed [ Thu Oct 20, 2011 2:23 pm ] |
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Sam is dead on. Sadly, manufacturing tolerances are not what they used to be, and very often the timing marks on new timing sets are not stamped in the correct place. So, when using new timing sets, it is not uncommon for the cam timing to be anywhere up to ten (or more) degrees off from the "correct" timing position. Finding and correcting this error requires the somewhat tedious task of "degreeing" the cam and then using offset bushing to put the cam where it should be. |
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| Author: | Doc [ Thu Oct 20, 2011 4:20 pm ] |
| Post subject: | |
Quote: ...How would the car run if the timing set was installed wrong? rough and impossible to time? ...
The engine should still run smooth even if the cam timing is off +/- 20 degrees or so... the engine will be low on power production but will run and idle OK.If the idle is rough & "choppy" then there may-be some other problems to deal with first. A compression check is a good next step. DD |
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| Author: | 805moparkid [ Thu Oct 20, 2011 6:24 pm ] |
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Quote: Quote: Quote: Did you align the marks with a straight edge, or just eye ball it?
thats not degreeing a cam lol...Sam We cannot help him out if we don't know if he did the proper FSM process. It is very possible to get things off one tooth if you do not use a straight edge. Sam but as known just because the dots line up dosn't mean squat... i understand what you ment by using the straight edge but with the way things are made now days there is no reason not to have it degreed. "Sadly, manufacturing tolerances are not what they used to be, and very often the timing marks on new timing sets are not stamped in the correct place. So, when using new timing sets, it is not uncommon for the cam timing to be anywhere up to ten (or more) degrees off from the "correct" timing position. Finding and correcting this error requires the somewhat tedious task of "degreeing" the cam and then using offset bushing to put the cam where it should be."- Reed |
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