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Octane boosters are snake oil. With that high of a compression ratio, you will need 100% VP-110 octane racing fuel.
E-85 will not work for you. E-85 is equal to 100 octane but only if the fuel delivery system is twice as rich than used with pure petroleum based gasoline. That is because alcohol has a cooling effect and less heat release (energy per volume) in order to reduce detonation but only if it is rich enough. That is why E-85 has a false economic value and is not in general use. The production of E-85 as a fuel is just to make the corn farmers happy by giving them another market for their product. About 80% of corn production is used to make chicken feed for all the chickens used by "The Colonel" and other fast food establishments. |
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You can buy race and street carbs setup for e85. But with 13:1 compression the cam will need to be pretty big as well. If your buying heads as well. why not just get a street car style engine and save the race motor for when you need it or sell it to pay for the street motor. Sounds like you have a complete race engine. To change it all back to stock or close to stock will cost more than a good low mile 350 from the junk yard or internet. Octane boosters sold in the stores are just for when your engine runs fine on normal days but gets a slight knock when its hot out. Octane booster can help in those situations. But with 13:1 you got a long way to go before its going to be right. Yes you can buy the chemicals to raise the octane of gasoline. I will knock explain how it is done since you cant test if its right so its best to buy gas from the pump at the track. I can tell you I know someone that drives a crazy boosted engine on the street with 87 octane and a gallon of "....." that allows the 87 octane to run better than 104 from the race track. But its not safe or smart so I am going to skip the chem names and proceedure. Best to get a cheap street motor that is already setup for the street. If you just take compression out of the engine all the other parts will be out of whack and run poorly. |
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The only place that sells E-85 where I live in a metropolitan area of over 1-million drivers, is one Kroger Food store. There are some turbocharged ricers that use Kroger Food Store's E85. None of the race shops sells the stuff. If you think your fuel system is prepared correctly and can successfully use alcohol based fuel, use VP M1 or M3 Methanol racing fuel that contain lubrication and combustion additives. M3 is easier on the eyes and nose.
Speed shops in my area sell VP M1, M3 and M5 Methanol racing fuels. VP M5 is what the top alcohol race cars use. My cousin, Mark Talliaferro, uses VP M5 Methanol exclusively in his MARKCO Top Alcohol Dragster. |
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Methenol is another animal all together. e85 is ethenol not meth. It packs in more btu's than meth and works a little better with normal engines. Meth is cheaper than eth but its not better for performance or economy. It is what is use in race engine for other reasons. Meth is an oil by product not made from corn. But for sure a meth conversion will sort all the issues. I am changin my honda over to meth since i found out my local oil company sells meth in 55 gallaon drums deleivered to the house! But its not cheap for street use. about 3 bucks a gallon and only half as many mpg. so it can get costly but will take lots of compression and make good power. also has the effect of cooling the engine so hot days are no sweat. |
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Off the top of my head I'd say you'll have to give on compression for the street and maybe even have to calm the cam. A 13:1 the pistons are probably pop-up so figure on their replacement as well. Bogie |
| The Following User Says Thank You to oldbogie For This Useful Post: | ||
janus (02-11-2013) | ||
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13.1 compression Chev 355?
That a good point.... I dont know if the high compression is from the pistone or smaller cc heads. I dont know. I assume from the pistons but I didnt build it. I have a build sheet but not with me now. I think it eagle rods and Wiesco pistons. I think iron 2.02 ported heads. If the rise is from heads cc maybe new edelbrocks will lower it... Where I live E-85 is everywhere. I dont care about to 30% more fuel comsumption. I thought E-85 is 105 octane? Based on what I've read it sounds like it might be the best for me to sell it to a racer. Someone said ger a 350 from a junk yard and?? No. I may build anther but not something cheap....
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If you can't find the build sheet, at least pull a valve cover and get a casting number. Acc holes mean they likely aernt camel's but who knows, 0 decked, flat tops and 49cc chambers gets you real close to 13:1 depending on hg thickness. Which means a set of 64cc (most after market) heads gives you a real easy pump gas 10:3 comp. Be a shame to dump the motor if its full of good parts. Especially if u planned on buying heads anyway.
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Is there a way thru compression testing I can calculate the the actual compression ratio? I dont have a true build sheet. I have a word document typed by the owner outlining the items in the motor. Im sure it makes no reference to the decking of the heads if any. Like I said the plan would be to go to Edelbrock heads anyways. Not if my only option would be 110 gas. I live in a large metro area (Minneaplois) so E85 is everywhere but I dont want to regulate my trips around town based on where I can buy 110. If E85 is not an option, which I hear mixed reviews about, and I would need to change pistons and heads then its not worth doing anything to it. Id sell it and build another. ??????
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That said; if you look at the numbers and the process of determining octane for unleaded pump and leaded race fuel which is taking the fuel and testing it two way one the Research Octane Number (RON) method which always drives a higher number than does the Motor Octane Number method (MON). When one goes to the tables you find that fuel grade ethanol is rated at 109 octane RON but only tests to 90 octane in the MON test. Since to make a comparison to gasoline octane ratings the 109 and 90 need to be added together and divided by 2 which nets out 99.5. Better than pump unleaded but not the same as high octane leaded race gas. Then E85’s ethanol is diluted with 15 percent gasoline. If one assumes that the gasoline is a pure petrol premium 92 octane base and that the octane rating of either ethanol nor the gasoline reduces when mixed (the kind of thing that often happens with fuel mixtures) you get ethanol at 99.5 times .85which nets 84.6 as its contribution and gasoline at 92 octane times .15 which gives 13.8 the sum of which only makes 98.4 total octane. Scientific data of the octane rating of blended fuels that makes any sense to my simple mind is hard to find. Everybody’s trying to sell something and distorts the truth with the most favorable numbers they can find and certainly ethanol’s high RON number is quoted against gasoline’s ROM+MON/2 average a lot and everywhere. Problem where I live is pump gas already has 10% ethanol in it. When I read the blend data from the manufacturers and the scientific communities it looks to me like one of the first things they do with 10% alcohol is use it to raise a lower grade petrol feed stock to the needed octane of sale at the pump. It does appear that this is a situation where more is not better, it looks form the data like 10 to 15 percent alcohol is in an octane sense the biggest bang for the buck. So it’s not a clean exercise to figure out what a pure petrol feedstock that would make 92-93 octane without any alcohol and how it would behave when mixed with 85 percent ethanol would really be like. Then consider that 100% fuel grade ethanol can actually be 95% alcohol and 5% water. And if I know the fuel companies at all; you can be sure that looks more like 93 to 7 maybe even 90 to 10 because when mixed with 15 to 90 percent petrol the stuff will burn even with that much water in it. So the other question is how much octane behavior is due to the unknown amount of water injection that comes along for the ride. My limited experience with E85 roughly tells me that its actual performance in a competition engine when compared to VP’s C12 which is rated 108 RON+MON/2 for example is not equivalent to E85’s oft stated 105, 107, 109 octane depending upon the reference source. Bogie |
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