Fuel Requirements |
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skitique179
Senior Member Joined: December-06-2011 Status: Offline Points: 176 |
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Posted: March-15-2012 at 11:50pm |
Hey Guys,
So I was thumbing through the PCM Owner's Manual the other night and came across the section on fuel requirements. I was surprised to see the section that said 93 Octane Leaded Fuel is recommended and not to use unleaded fuel... Is this really required? I thought that you couldn't even buy leaded fuel anymore other than av gas? Should I be putting an additive into the fuel for my 302 and is 93 Octane really required? Thanks |
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SNobsessed
Grand Poobah Joined: October-21-2007 Location: IA Status: Offline Points: 7102 |
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No additives! Waste of money. I use '87 octane non ethanol ( we still have that in Iowa, where gasahol was born, go figure).
If it doesn't knock, you are good to go skiing. |
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“Beer is proof that God loves us and wants us to be happy.”
Ben Franklin |
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Keeganino
Grand Poobah Joined: October-27-2009 Location: North Carolina Status: Offline Points: 2063 |
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I always use 93 in my 1973 Skier (Waukesha 302)which also calls for "High Octane Leaded Gasoline" Have never tried using lower octane and probably will not ever, but my engine is stock and has never been rebuilt. Modern gasoline already has components in it that take the place of the lead so there is no need to waste money on the additives as stated above.
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"working on these old boats may not be cost effective but as it shows its what it brings into your life that matters" -Roger
1973 Skier |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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As mentioned, no additive needed. I've been running 87 in my 302 since I got it without any problems.
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Jllogan
Platinum Member Joined: May-18-2011 Location: canton, OH Status: Offline Points: 1728 |
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I switched over to 89 but the PO always ran straight 87 in it and it ran fine.
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TRBenj
Grand Poobah Joined: June-29-2005 Location: NWCT Status: Offline Points: 21120 |
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Here is the excerpt from the '89 PCM manual. If you are pulling the "93 octane" reference from an older manual, read the fine print. It denotes the method used to define the octane (there are more than one). The verbage called out in the '89 manual is consistent with the current octane posting requirements, as far as I can tell.
Do NOT worry about leaded fuel (you cant find any), nor about lead substitutes (theyre a waste of money). Take the savings and put them towards a head job or new heads... it will be a while before you need it. Personally, I run 89 octane, but I would think that with the ultra-conservative compression ratios that these engines run (~8.3:1), 87 should be fine as well. So long as you dont get any pinging (pre-detonation), youre fine. |
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skutsch
Grand Poobah Joined: June-19-2008 Location: Racine, WI Status: Offline Points: 2874 |
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I run 93 Octane but only because it is the only way I can run non-ethanol gas, and then I have to look very hard to find it.
When I am in Iowa, I do revert back to 87 or 89, again because it is readily available with no-ethanol. No knocking experienced with any of the fuels above. Oh BTW, the Interceptor 312 (Ford)in the 63 Ski Nautique has also been running unleaded since the early 80's, usually 87 octane in that too. I know its not relavant to a PCM discussion... |
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4945 |
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Ski dim has some verbeage about identifying heads and how no raised ribs indicates non hardened seats. It says to run lead substitute or Valvtech. Unfortunately the entire 3 paragraphs blinks
I understand that Valvtech is supposed to help for stabilizing fuel, but how would it help the valve seats? Anyway, I feel that adding Startron, Valvtech or Marine Stabil, for the ethanol is good, but I agree not to worry about the lead substitute. |
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