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| Timing question https://www.slantsix.org/forum/viewtopic.php?t=62666 |
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| Author: | drauhut [ Thu Aug 02, 2018 6:27 pm ] |
| Post subject: | Timing question |
1966 slant 6 rebuilt by previous owner who grew bored with it.225, new rings, 230dur @ 050, 495 lift cam, head shaved , oversized valves, ported, Holley 390 4160, 2-1/2" single exhaust, hedman 6-1 ceramic headers, HEI setup. Initial timing,( with vac disconnected and plugged, lowest idle I can get is 800 -850, ) is around 32°, can't get it lower, I've read that the HEI can somehow affect timing, but cant see how..ive set timing by ear, and it's fairly smooth, ( taking cam into account), AF ratio is at 12.2, ... Does this sound like weights or springs in distributor possibly stuck..the distributor is out of my stock 73 slant, and it had sat in a barn for close to 10 years without running. I'm not an auto mechanic( industrial millwright/electrician) and this is my first crack at trying to build myself a nice, punchy classic mopar. Any tips or suggestions helping me understand this would be appreciated. Thx |
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| Author: | SpaceFrank [ Fri Aug 03, 2018 2:50 am ] |
| Post subject: | Re: Timing question |
What do you mean when you say you can't get the timing any lower? If you physically can't turn the distributor any more in the proper direction, you might be a tooth off. If it was closer than 32 degrees, you might instead need to adjust the hold down plate; it's held into the back of the distributor with a second bolt. If the engine just won't run with less than 32 degrees initial timing, then first I'd make sure the TDC mark on your harmonic balancer is still accurate using a piston stop tool or similar method. If the balancer is old, the outer ring can slip. If it won't run with any less initial timing AND the mark is accurate, then I'm not sure what the problem is. I'd be curious how the previous owner degreed the cam. Has the engine ever been running since the rebuild? |
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| Author: | drauhut [ Fri Aug 03, 2018 3:34 am ] |
| Post subject: | Re: Timing question |
Thx for responding. Engine is running now, I'm driving it. I've tried shifting dist both directions and it doesnt fire. I set timing notch on balancer to timing tab on chain cover at zero, and using a straw in spark plug hole it seems to be TDC. When I fire it up, balancer notch is about 2-1/2" away ( ccw) from timing chain tab. But the engine runs smoothly. I keep assuming I have done something wrong, but dont have a clue what. |
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| Author: | Charrlie_S [ Fri Aug 03, 2018 4:36 am ] |
| Post subject: | Re: Timing question |
It is possible the timing tab, on the cover, and the damper are mismatched (different years). The timing marks changed over the years. The 66 engine (if original) had a timing tab, that bolted to the timing cover, at the lower driver side. PS: The timing marks/covers, and dampers can be interchanged between years, as long as both are from the same year series/style/type. |
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| Author: | drauhut [ Fri Aug 03, 2018 5:33 am ] |
| Post subject: | Re: Timing question |
I did not know that, so I will have to identify precise TDC, If different from tab/notch lining up , I will need to basically create my own marking on the balancer. On a side note, when I replaced the timing chain, I lined up Mark's on crank and cam sprockets, and reassembled the same way..but it was mentioned about timing the cam shaft, is that something i need to consider? |
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| Author: | Charrlie_S [ Fri Aug 03, 2018 6:08 am ] |
| Post subject: | Re: Timing question |
Quote: I did not know that, so I will have to identify precise TDC, If different from tab/notch lining up , I will need to basically create my own marking on the balancer. Correct Quote: On a side note, when I replaced the timing chain, I lined up Mark's on crank and cam sprockets, and reassembled the same way..but it was mentioned about timing the cam shaft, is that something i need to consider?
Actually, you should degree the cam (not just line up the dots) when replacing the chain and sprockets. Location of the "dots" for timing purposes, is inconsistant, in todays world. However that would not cause the problem you are having.
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| Author: | drauhut [ Fri Aug 03, 2018 9:09 am ] |
| Post subject: | Re: Timing question |
Thanks for your info and advice..I appreciate your time |
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| Author: | drauhut [ Fri Aug 03, 2018 6:46 pm ] |
| Post subject: | Re: Timing question |
So I just figured out my problem. The adjusting bracket that allows about a 1" adjustment of timing, is bolted to the underside of the distributor with a 1/4"-20 bolt that also is adjustable. I moved it to the opposite end and voila...now I have 12°btdc at 650 rpm with vac disconnected and plugged. Had no idea of this adjustment till I pulled dist. and looked underneath it. What a difference. |
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