Octane additives?

Mopar Racers Forum

  1. j par

    j par Well-hung Member

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    Since I've had this motor it's ran on nothing but 100ll. It's got 596 heads with 202 valves and from everything I read there about 68 to 72 ccs? And I know I'm about five hundred thousand out of the hole with the flat top icon Pistons. I used a 1008 Fel-Pro gasket. On paper this calculates I believe out to be around 11.2 - 11.3 to 1 compression? I have a 10 gallon fuel cell and plan to drive it on the street much more often this year. I already went down and filled a gas can with 92 non-ethanol. That's the best we can buy here out of the pump. $4.69 per gallon. I was thinking one of the first things I would do would be knocking a couple degrees out of the timing. And now I'm considering instead of buying some expensive race gas to mix in there may be trying a can of something I can buy almost anywhere, octane booster. For all I know it could possibly work just fine on the 92. The cam is very dragstrip oriented and has a lot of overlap that may bleed quite a bit of compression to compensate?
    Dur@50-- 259 in. 267ex.
    Dur@20-- 294 in. 304ex.
    Lob see 107
    Lob center 104 in. 110ex.
    Lift 364 in. 377ex.
    @rocker 582 in. 603ex.
    Opinions wanted welcome and appreciated, thank you...
     
  2. cannucky

    cannucky The Guy With No Birthday

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    I got caught in the middle of nowhere northern ontario in the middle of the night and had to fill my empty tank with 87 +15% ethanol so I added enough octane booster to get it up to the 91 the 10.5-1 needs . Man it didn't sure didn't run like 91 I ended up dumping the rest in going to about 97 and dropping timing to get it to run until the next open station with real 91 .
     
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    • fishmens67

      fishmens67 Well-Known Member

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      I don't think you gain much more than a point with booster you can buy almost anywhere.
      There are some specialty brands available online that claim a few more points. but the cost may be the same as if you just added a little race fuel to your blend.
       
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      • cannucky

        cannucky The Guy With No Birthday

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        yeah I dumped several bottles and each one was supposed to be for a much bigger tank than our little ABody tanks still not the same as actual octane fuel .
         
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        • j par

          j par Well-hung Member

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          Thank you men. I was just reading some of the articles online that were supposed to be independent studies blah blah blah.
           
        • cannucky

          cannucky The Guy With No Birthday

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          yeah other than an emergency I would never bother with that crap again , another miracle in a bottle gimick
           
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          • j par

            j par Well-hung Member

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            I was thinking of maybe going with some kind of ratio? Like maybe buying a five gallon can of the 108 for $67 at Baxters auto parts and adding a gallon for every four or five 4 or 5 gallons?
             
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            • Lelo Dart

              Lelo Dart *

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              Your best bet is mixing in a few gallons of race gas from the track or drag strip with your 92 gas. I've tried quite a few brands of octane booster and the only ones that really work turn my spark plugs (piston tops, combustion chamber) a thick coating of orange. I don't know but it doesn't seem good.
               
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              • clifftt

                clifftt Well-Known Member

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                In the ‘80’s, I ran a SCCA MGB with supposedly 12:1 compression. With my beer budget, I ran Moroso octane boost. It pinged a little but served the purpose.
                I got a chance to buy Union76 race gas at Laguna Seca, and OMG! What a difference!! Never opened the Moroso can again. Sucked it up and bought race fuel after that. My two cents.
                 
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                • jimjimjimmy

                  jimjimjimmy lobsterman FABO Gold Member

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                  I run 50\50 mix of 100ll and 91 pump works real nice in my setup . love the smell also .
                   
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                  • j par

                    j par Well-hung Member

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                    Agreed on the smell! I had that gallon and a half left from last year and I fired it up on that and it smelled great!
                     
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                    • jimjimjimmy

                      jimjimjimmy lobsterman FABO Gold Member

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                      100ll is easy to get addicted to and my chain saw loves it as much as I do .
                       
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                      • j par

                        j par Well-hung Member

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                        The 45-minute trip to the airport each way with 5 gallon cans is all over with. I need a much more convenient way to refill my 10 gallon fuel cell. I was thinking I can always leave full and carry a 2-gallon can strapped down in the back to add to some super I can find on the road?
                         
                      • yellow rose

                        yellow rose Doctor of Thinkology.

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                        If you are going to do it there are only two that I know work. There is one that may work, but I haven't tested that one. That one is called Race Gas.

                        The one I have tested is Torco Acclerator. I know it works. You can buy it either in leaded or unleaded.

                        There is also a product called BOOStane. It is a copy of Torco Accelerator. I don't think you can get that in leaded. I called them and they were going to send me some info, but as of yet I have nothing on it.


                        Most of the stuff you can get at backstabbers isn't worth messing with.
                         
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                        • j par

                          j par Well-hung Member

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                          I agree it is a beautiful thing it works great in the lawn mower dirt bikes everything. It's nice to mow the lawn and not get choked out by the fumes of the lawnmower.
                           
                        • yellow rose

                          yellow rose Doctor of Thinkology.

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                          BTW if you use the Torco you can use it with straight pump gas. Doesn't matter if it has alcohol in it or not.
                           
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                          • j par

                            j par Well-hung Member

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                            I think I'll start with buying a 5-gallon can of the 108 at backstabbers and mixed 1 gallon per 4 gallons of 92 non ethanol? Then I can carry a couple little one gallon cans of 108 for mixing with four gallons on the road?
                             
                          • j par

                            j par Well-hung Member

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                            Again convenience to get the product and cost per gallon? And of course performance is always nice.
                            The 92 non-ethanol is 4.69 a gallon and the backstabbers 108 equals out to about $13.40 a gallon. Which equals out to about $6.43 per gallon at a 4 to 1 mixture. And that's about what the hundred LL goes for. The difference in convenience between the two feels is Worlds Apart. The backstabbers is 15 blocks one way and non-ethanol is 25 blocks the other way 100ll is gas cans only all the way out to the airport.
                             
                          • j par

                            j par Well-hung Member

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                            No cracked machinist thoughts on the overlap bleeding enough compression to run a little less octane? Or do I completely not know what I'm talking about which is highly likely?
                             
                          • skrews

                            skrews Well-Known Member

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                            I've been running 50/50 100LL 92 unleaded non eth in my 11.75 comp 360. 596 heads 252 @ .050 Been good to me so far.
                             
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                            • 318willrun

                              318willrun Stomper 4x4... we kept energizer in business

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                              Back off total timing a tab, put 1053 Fel pro head gaskets (about .025 thicker than 1008), run 93 octane..... there you'd be getting closer to a street car :)
                               
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                              • j par

                                j par Well-hung Member

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                                Thank you for that! The seems like a very close comparison? I would venture that I have I bit less compression and if my math serves me correctly your concoction makes about 96 octane? And the 4 to 1 concoction that I proposed is about 95.2 ?
                                And as 318willwin proposes Maybe a degree or two less timing which I was already thinking about?
                                 
                              • j par

                                j par Well-hung Member

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                                Crap I got to keep in mind that I'm not King s*** and everybody doesn't know what I have! It's a 410 Stroker. Sorry..
                                 
                              • 318willrun

                                318willrun Stomper 4x4... we kept energizer in business

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                                If you are going to mix the fuel....... but straight off of pump gas you may need to pull 5* out of timing. That would be trial and error....
                                 
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                                • j par

                                  j par Well-hung Member

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                                  I'll likely always add something to it.
                                   
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