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1963 196 not running right |
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vinny
Supporter of TheAMCForum Joined: Jan/05/2012 Location: Calgary Status: Offline Points: 2837 |
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That goes in the groove first under the ring I think to keep it centered.
I know that antifreeze eats aluminum because I had one eaten away on a Rover 2000 TC because of a leaking head gasket and it had to be replaced. I don't think it did anything to the pistons yet, or at least I wasn't aware of it.
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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A quote from an old Otto Cycle engine book I have:
"High frequency compression vibrations with a fast lighting fuel air mixture (low octane fuel) together with raised temperatures lead to erosion type surface damage of a piston on the crown edge, leading edge and top ring groove because of "knocking" combustion."
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al1630
AMC Apprentice Joined: Oct/05/2017 Location: Boise, Idaho Status: Offline Points: 174 |
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Thanks for the ring info. I wonder how someone let the engine knock for so long that the pistons got this bad though. And what happened to the piston chunks.
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Alex
1963 Rambler American 440H |
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purple72Gremlin
AMC Addicted Charter Member Joined: Jul/01/2007 Location: Illinois Status: Offline Points: 16591 |
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al1630
AMC Apprentice Joined: Oct/05/2017 Location: Boise, Idaho Status: Offline Points: 174 |
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Alright, I've got a good update. I honed the cylinders, replaced all the rings and pistons, and cleaned everything out, and now it's running much better. The car doesn't shake while it idles and smokes a lot less.
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Alex
1963 Rambler American 440H |
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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The 196 from what I read had 7.5:1, 8:1, 8.5:1 and 9.5:1 compression ratios.
If yours is not 9.5:1 CR then it is recommended to run non ethanol fuel. Even though ethanol has a higher octane rating there is problems with it igniting too soon and causing damage like seen in your engine. SN Plus motor oil "IS" supposed to be the fix for this, but yet to be proven. Ethanol under low compression seems to be unstable, Low Speed Pre-Ignition (LSPI). My opinion and research.
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tomj
AMC Addicted Joined: Jan/27/2010 Location: earth Status: Offline Points: 7522 |
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huh, interesting! the combustion chamber of the 195.6 ohv has a lot of surface area, and probably dead spots. i always wondered why they bothered with such a complex shape for what was clearly a short-term, interim design. a flat top would have been much better. all that surface area and complex shape probably doesn't help flame propagation. how many low-compression gasoline engines are on the road today? probably nearly none! the point being, it's probably reasonable for the petro industry to not consider them. there's 14.5 million cars in CA alone, i doubt more than a few thousand of them are pre-1964. i wonder if CA DMV/CARB would provide that info? |
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1960 Rambler Super two-door wagon, OHV auto
1961 Roadster American, 195.6 OHV, T5 http://www.ramblerLore.com |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19612 |
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1958-64 195.6 OHV engines have 8.7:1 compression and it's safe to run E10 gasoline in them. The 2956 OHV (first year) had 7.47:1 compression and the 57 had 8.25:1. I can't say about those, they may have issues with E10 fuel, may not. Trader, I don't see how a change in motor oil would affect combustion in an engine... where did you get this info? The domed piston was used due to the OHV conversion. A flat top piston would have required valve notches and/or the pistons lowered in the bore. I'm not sure the pistons could have been lowered/notched enough to clear the valves and retain 8.7:1 compression... obviously not lowered enough to clear the valves and retain compression. So the offset dome design was used instead. Not ideal, but easy enough to manufacture with fewer changes to other components and a lot less engineering time.
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Frank Swygert
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Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6762 |
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I'll let Pennzoil answer that, what they don't say directly is that ALL low compression engines can experience this (production turbo engines at idle, not getting boost, like any low compression engine):
They still don't even know if this is a fix. But SN Plus has Better HTHS or shear pressure properties, that's a step in the right direction. |
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farna
Supporter of TheAMCForum Moderator Lost Dealership Project Joined: Jul/08/2007 Location: South Carolina Status: Offline Points: 19612 |
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Thanks! Interesting...
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Frank Swygert
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