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| Timing gear dilemma https://slantsix.org/forum/viewtopic.php?t=63750 |
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| Author: | tattoosteve99 [ Sat Jun 22, 2019 12:03 pm ] |
| Post subject: | Timing gear dilemma |
So after my 78 slant 6 decided it wanted to misfire like crazy I parked it to put a new timing chain and gears on it. The book says to align the marks but no matter where I put the marks, camshaft in either position and crank as well, whenever the crank is at TDC the valves are not right? What is going on and what am I not doing right? Please help! I need this truck as it’s my only form of transportation. And yes I have looked in the search and nothing is broke.  .
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| Author: | Reed [ Sat Jun 22, 2019 12:53 pm ] |
| Post subject: | Re: Timing gear dilemma |
Is the camshaft locating dowel still in the end of the camshaft? That little dowel can break off or come out of its hole and let the cam timing gear spin independent of the cam. What do you mean by the "valves are not right"? If I remember correctly, when the timing marks are ined up the engine should be at TDC on the firing strike of cylinder #6. The valves on #6 should be loose. The valves on #1 should be under tension. |
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| Author: | tattoosteve99 [ Sat Jun 22, 2019 1:03 pm ] |
| Post subject: | Re: Timing gear dilemma |
Quote: Is the camshaft locating dowel still in the end of the camshaft? That little dowel can break off or come out of its hole and let the cam timing gear spin independent of the cam.
Pin in not broken and in the right place. I see now what you mean about the valve springs. Will have to check that after this storm passes by. I thought the number one piston should be up and both valves closed in order to be correct?
What do you mean by the "valves are not right"? If I remember correctly, when the timing marks are ined up the engine should be at TDC on the firing strike of cylinder #6. The valves on #6 should be loose. The valves on #1 should be under tension. |
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| Author: | Charrlie_S [ Sat Jun 22, 2019 1:43 pm ] |
| Post subject: | Re: Timing gear dilemma |
Quote: Is the camshaft locating dowel still in the end of the camshaft? That little dowel can break off or come out of its hole and let the cam timing gear spin independent of the cam.
What do you mean by the "valves are not right"? If I remember correctly, when the timing marks are ined up the engine should be at TDC on the firing strike of cylinder #6. The valves on #6 should be loose. The valves on #1 should be under tension. Correct. When the dots are lined up, #1 and #6 pistons are at the top. But it is #6 that is at the power stroke. The valves should be loose on #6, and the distributor rotor pointing at #6 terminal on the cap. |
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| Author: | tattoosteve99 [ Sat Jun 22, 2019 2:36 pm ] |
| Post subject: | Re: Timing gear dilemma |
Quote: Quote: Is the camshaft locating dowel still in the end of the camshaft? That little dowel can break off or come out of its hole and let the cam timing gear spin independent of the cam.
What do you mean by the "valves are not right"? If I remember correctly, when the timing marks are ined up the engine should be at TDC on the firing strike of cylinder #6. The valves on #6 should be loose. The valves on #1 should be under tension. Correct. When the dots are lined up, #1 and #6 pistons are at the top. But it is #6 that is at the power stroke. The valves should be loose on #6, and the distributor rotor pointing at #6 terminal on the cap. |
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| Author: | hyper_pak [ Sat Jun 22, 2019 4:49 pm ] |
| Post subject: | Re: Timing gear dilemma |
Dang, learn something everyday! What am I missing, why would they do 6 and not 1? |
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| Author: | Doctor Dodge [ Sat Jun 22, 2019 6:19 pm ] |
| Post subject: | Re: Timing gear dilemma |
#1 and #6 are both at TDC with #1 being at the "beginning" of the 4 stroke cycle... starting the intake stroke. #6 is in the middle of the cycle, at the start of the power stroke. Cam / intake / exhaust valve "overlap" is the reason why the both valves are under tension on #1, at the end / beginning of the 4 stroke cycle. At #1 TDC is where you want to be checking for correct cam to crank "phasing", when "degreeing" a cam. (seeing if the overlap event is somewhat "centered" over TDC... or a little advanced) As we know... It is pretty "risky" to just "line-up the dots" when installing new time gears and chain. You should at least verify that the overlap event is happening "over" TDC. DD |
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| Author: | tattoosteve99 [ Mon Jun 24, 2019 4:18 pm ] |
| Post subject: | Re: Timing gear dilemma |
Quote: #1 and #6 are both at TDC with #1 being at the "beginning" of the 4 stroke cycle... starting the intake stroke.
I surely didn’t know that either! I’ll be checking that. I might have more problems than just this as well #6 is in the middle of the cycle, at the start of the power stroke. Cam / intake / exhaust valve "overlap" is the reason why the both valves are under tension on #1, at the end / beginning of the 4 stroke cycle. At #1 TDC is where you want to be checking for correct cam to crank "phasing", when "degreeing" a cam. (seeing if the overlap event is somewhat "centered" over TDC... or a little advanced) As we know... It is pretty "risky" to just "line-up the dots" when installing new time gears and chain. You should at least verify that the overlap event is happening "over" TDC. DD . Seems I can hear the compression either coming through a valve or back down in the oil pan . Not sure how to explain this correctly. There was little resistance when turning the crank with a ratchet and the spark plugs are still in (all but #1)
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| Author: | hyper_pak [ Mon Jun 24, 2019 6:14 pm ] |
| Post subject: | Re: Timing gear dilemma |
Check your valve clearance and make sure your rockers are letting the valves close. But you could have a burnt valve. |
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| Author: | tattoosteve99 [ Sun Jul 07, 2019 10:38 am ] |
| Post subject: | Re: Timing gear dilemma |
Can’t find the torque spec for the harmonic balancer. Anyone know? It’s almost back together yay! |
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| Author: | SpaceFrank [ Sun Jul 07, 2019 10:49 am ] |
| Post subject: | Re: Timing gear dilemma |
Are you driving the balancer in with a bolt? I don't think there is a torque spec, as Chrysler didn't usually leave a bolt installed there for slant sixes. I just install the water pump pulley and tighten the balancer bolt until the belt grooves line up. If you're using a mechanical fan, make sure it clears the bolt head before you fire it up! |
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| Author: | tattoosteve99 [ Sun Jul 07, 2019 10:52 am ] |
| Post subject: | Re: Timing gear dilemma |
Quote: Are you driving the balancer in with a bolt? I don't think there is a torque spec, as Chrysler didn't usually leave a bolt installed there for slant sixes.
The bolt was there when I removed it. The book doesn’t describe it only saying some had it and some didn’t. It wasn’t really very tight to remove but I surely don’t want it flying out while driving down the road. I started the balancer with light taps and a wooden block then used the bolt to finish the job.
I just install the water pump pulley and tighten the balancer bolt until the belt grooves line up. If you're using a mechanical fan, make sure it clears the bolt head before you fire it up! |
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| Author: | tattoosteve99 [ Sun Jul 07, 2019 12:29 pm ] |
| Post subject: | Re: Timing gear dilemma |
Well it didn’t stay running  I’m not sure what’s going on so it’s back to the drawing board
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| Author: | tattoosteve99 [ Sun Jul 07, 2019 3:01 pm ] |
| Post subject: | Re: Timing gear dilemma |
I’m wondering if this problem may be related to the ECU and not timing. I did use a old I had laying around when the original one died awhile back. I have all the parts to do the HEI swap so I guess now is as good a time as any. |
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| Author: | DadTruck [ Sun Jul 07, 2019 6:28 pm ] |
| Post subject: | Re: Timing gear dilemma |
Quote: do the HEI swap
Wise Words
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