13 To 1 Compression What Octane

5l V6, is not unusual). Call 336 814 2241 for more information. Discussion Starter • #1 • Jul 13, 2009. Jimmy Six I understand dynamic compression ratio and the effect of cam timing and overlap, but I am asking about static compression ratio. As has been noted many times on just about every sportbike forum on the net more octane does not mean more power!. 1 compression. AvGas 100LL has an octane rating of 100/130. 0:1, and all US Market Vespas are Octane rated using the (R+M)/2 method or PON, AKI, rRON designations. for many years now, I build all my bbc with compression ratio's between 10 and 10. In the US we run the RON and a second test called the MON that tests the fuel compression in a warmed motor with pre-heated fuel at 900 rpm and variable ignition timing to simulate. Also the tighter the quench (the distance between piston and head at TDC) THE. Ive built 13. 50 tires, a T19 with a 6. Why Higher Compression Means You Need Higher Octane. Sounds like a healthy mill. direct injection has basically made the old notion that Higher compression engine require higher octane fuel all but moot. It is recommend with modern 4-strokes with 12:5 to 13. Torco Racing Fuels is another company with a good history of making quality racing fuels for drag racers. Whoever said 11 to 1 compression is "low" is a really funny dude. I would go through 2-3 tanks of fuel to get a good average. You would have to use 91 or 93 is you were over 13. In the case of octane, using the formula says I am at 20. Sunoco® Standard™ is a 110 octane leaded race fuel that is used in many forms of motorsports. Older gasoline engines did have high compression ratios like 13:1, but we were also 30 years ago able to buy gasoline with 102 octane readily. I ran that motor on the street with 91 octane for years. I run 100LL. Iron heads, 12:1 compresion, and a short duration cam will make crazy cylinder pressure. And this level of compression creates a more powerful explosion. under 12:1 a bike will go bar to bar or to work just fine on 85 - 87 O fuel. What's everyone. 7:1 first gear / 1:1 fourth and 3. 75:1 (for a low CR supercharged engine) to as much as 1:0. It is very nitrous compatible also. Refer back to our formulas, and note that it is possible to gain 40-50 psi by increasing the compression ratio by 1. You can run a little more compression, such as 9:1 or 9. 02-23-13 01:06 PM - Post# 2319895 In response to Jim. Just talked to her about this on the phone. • Color: Red • Motor. I would be tempted to use the. I have an engine with 11. introduction of high compression engines. minimum octane rating of 89 (R+M/2). the down side is you need to always use freshand good quality pump fuel. Higher the compression leads to more force generated when the air/fuel mix is ignited. I usually run 93 octane in my SS with having a Higher Compression motor. (We used to work on antique/vintage autos). 0:1 on the high compression 325 hp 400 4-barrel), the disparity is a lot less or even. ok so im looking at running a 13. for example, you can have a stock OEM port banshee w. If it pings, go up to the next grade and see if it stops, the VTX's are designed for 87 octane. 1 compression. To the contrary, high octane fuel has a more controlled combustion than low octane. I should clarify that I'm asking about putting 87 or 89 octane gas from Mobil/Shell/BP etc, not gas from a "second rate" station. of torque and 16HP more. 4:1 - 100 octane 8. 5:1,,, it made 14 ft. Most engines will lose ET & MPH if you run too much octane, at least all of mine & friends I've helped out did. John said that anything over 14. Maxima Hi-Test is a concentrated octane booster legal for all types of competition. The optimum intake-to-exhaust ratio could range from as little as 0. all a compression tester is telling you is cranking psi. It’s worth mentioning that diesels use extremely high compression ratios, generally from 14 to 25:1, to initiate combustion, which is why they’re able to achieve greater levels of efficiency compared to gasoline engines. 730, RVP 8 *Custom 116 for 16:1 Motors is available - Motor Octane 114,. 5 in, waist 31 in, suit 40R. Therein, to use 93 octane in a moderate compression engine is like using Dom Perignon in mixing a wine cooler. Below that, 87 octane usually does fine and is the recommended fuel to use. I am going to be running 33/12. That's a very HIGH compression ratio for a gas engine. Older gasoline engines did have high compression ratios like 13:1, but we were also 30 years ago able to buy gasoline with 102 octane readily. 1:1 was high when most cars were below 10:1 at that point. Remove the fuel tank cap and add fuel. It's not too far from my work and not far from the SIR drag track out here. I've never had any issues. Engine building book I have says 5 point of octane per each point of compression increase. Factory gaseous Onan engines have high-compression pistons/heads, but getting anywhere near 12:1 in an Onan is, well good luck, especially if it's a flathead. Any advice on the subject? My goal is to make a street legal race car with 500+hp. Combined CR: 13. 7 to 1 air fuel ratio. 0:1, and all US Market Vespas are Octane rated using the (R+M)/2 method or PON, AKI, rRON designations. It has compression ratio of 11. Diesel engines use compression alone to fire. 2) Fill up with 87 octane and keep track of your mileage. no problems. 5:1 on my LS1 engine on 93 octane with no issues but my dynamic compression was around 8. So with a deck height of 9. I just bought a bitchin 77 Daytona, and its got 13. If you work at a Sunoco and get gas for free, or if you don't have to pay any more for higher octane, you could run it on 89 or something like that, but you really don't need to. Our target compression ratio is thus 9. This 2019 Dodge Grand Caravan Minivan/Van SXT is a Certified Used vehicle Octane Red Pearlcoat in Color from Kings Dodge Chrysler Jeep in Cincinnati, OH. Maria’s Coffee Shop: Compression Thinking to Earth. Fuel Tank Always refuel with the engine stopped, and outdoors or in a well ventilated area. Octane rating is just resistant to pre-mature detonation. Ray I know it's not a VW but I have 10. Yochemate, Thanks for the article. what should the compression be of my savage octane v1? I performed the compression test cold and achieved 75 psi dry and with a few drops of oil it achieved 85 psi, should it not be at least 110 psi to 150 psi?. Our target compression ratio is thus 9. my maxda cx-5 with a 13:1 compression ratio runs perfectly on 87octane. VP, Cam 2 or Sunoco leaded race gas race will do the trick @ $8. As a general rule though, you can run another point of compression with aluminum heads over cast heads. You could run 12:1 and use 87 octane, but you would have to pull timing to not detonate. 10:1 is high enough though. If you note an improvement in fuel economy that justifies using higher octane fuel at the higher price, then go for it. As a general rule, the best available pump gas will work with an 8. Harley faces their air fuel ratio largely on the fact that they run a 14. It is very nitrous compatible also. You don't need high octane fuel until you start getting into the 11-12:1 comp ratios. If a gallon of gasoline has an 87 octane rating, that means it has 87 percent octane molecules and 13 percent heptide molecules. I was told that you do not need higher octane fuel until you hit a 10:1 compression ratio. Another thing my 15. THIS is the factor that determines octane requirement. I am talking about modern motorcycle engines. List the engine build, but if it is a drag motor C-16 is a very popular fuel for engines in the 14+ 1 1 compression ratios. 1:1 - 92 octane 6. However, by splitting large molecules into smaller ones (cracking), modern engines are both more efficient and better performing than their older bretheren. They charge $7. Most gas stations offer three grades of octane, with regular rated typically at 87, mid-grade at 89 and premium at 92 or 93 [source: Federal Trade Commission]. The Octane Coffee and Tea House takes its name from a 1920s gasoline station. 02/gallon when ethanol is used. I should clarify that I'm asking about putting 87 or 89 octane gas from Mobil/Shell/BP etc, not gas from a "second rate" station. 5:1 compression - what octane? General Tech. 6mm; Displacement 1179cc; Compression ratio: 10. 51 hauling 4000 lbs. 56mm bore 40. Check the compression ratio stamped between 2 and 3 next to the engine number. Higher octane does not mean more power except in some very specific conditions, such as computer controlled ignition advance with a knock sensor. Still curious on the low end power gains, is going from 13. A few will raise it higher than that, so be sure to buy what you need. Compress it just a little and it ignites spontaneously. BMW M3's and M5's, Porsche 911's (non turbo), Ferrari's, Lamborghini's, etc. 5 to 1 compression or if the engine is equipped with a turbocharger or supercharger. I am going to go look at a built up yfz and it has a CP 13. 00 at the dealer when I did mine. Today's gasoline engines on 87 octane fuel will begin to diesel readily at between 13:1-14:1 ratios. I've never had any issues. Apr 30, 2020 #25 F. Your results may have had more to do with driving conditions than octane of the fuel. Fuels with high octane numbers can withstand compression without detonating more than fuels with lower octane numbers. To quickly refresh, E85 is 85 percent ethanol (grain alcohol) and 15 percent gasoline. Endurance training experts specializing in triathlon, swimming, road cycling & mountain biking, and road & trail running. In Australia you use what is called the RON testing system that runs the room temp fuel through a cold motor at 600 rpm to determine fuel compression (octane). It's impossible to guess how much power losing a point of compression will lose because we don't know the rest of the combination. If you use an MSD box and want to cruise around with 87, just pull some timing. a cold air induction can help to build the horses and keep combustion chamber temperatures down. 6L engine a couple years ago that called for 87 octane but hand calculations over many months proved that it got better fuel economy on 89 or higher octane. Therein, to use 93 octane in a moderate compression engine is like using Dom Perignon in mixing a wine cooler. 548 instead of the correct 1. then again, if you just take a stock 10:1 long block and give it cams and valve springs and collets and manifolds, you could see 200hp or close to it by 7500. Higher octane rated gas BURNS FASTER than lower. Now 89 motor octane in a 9:1 boiled the fuel right out of the carbs. You don't really need to use a higher octane fuel until you go over 10. 2) Fill up with 87 octane and keep track of your mileage. It's called "octane" because there was a baseline measurement done for combustion rate on octane (8-carbon hydrogen-saturated molecule, like propane is a 3 carbon saturated molecule I think, it's been a long time since Orgo). 5 to 1, and 93 can go up to about 11. The compression ratio depends on the size of the dome on the pistons (in cc's) and the combustion chamber size of the heads (cc's) among a few other things. 7 psi and the compression ratio is 11:1, the equation to solve for the psi is (14. Check the compression ratio stamped between 2 and 3 next to the engine number. quote] I'll second that. 3:1 compression and it is recommended to run off 87 octane gas by Toyota. 4:1 -dynamic compression. It spontaneously ignites at a given compression level, and can only be used in engines that do not exceed that compression ratio. A diesel has to have 16:1 compression to run at all. 5:1, then 89 octane may be required, depending on ignition timing. When overheating occurs, hot spots form. I filled up today with 93 octane and have burned maybe half the tank. Thirsty 13: Biggest Gas Guzzlers; Goof of the Month: You Put Gas in My Diesel! Illustrated Guide to Gas Stations; In Canada, octane ratings are calculated using an average, sometimes known in shorthand as the Anti-Knock Index, or AKI. In some cases low octane fuel can really zap the power and mileage and this I think is more manufacturer driven than anything. The higher the octane number, the slower the burn. Does higher compression have anything to do with longevity as long as the correct octane fuel is used along with correct timing? If you have aluminum heads and 93 octane availability is there any reason not to run 10:1 instead of 9:1 or 9. 5:1 compression ratio would run the risk of auto-ignition, and it could shoot out a rod or spin a bearing. Renegade Racing Lubricants are specifically designed to lubricate competition engines which run alcohol or higher octane fuels. The 5:1 effective compression ratio is the result of IVC at 63 degrees BTDC (Figure 6). 3mm, giving a displacement of 612 cm3. The car is a high compression engine. 5 in, waist 31 in, suit 40R. If you were to analyze it using the typical R+M/2 method (by which pump gas is scored), then it would likely come it at about 106 R+M/2 octane, give or take. 6 (for a very high-compression naturally-aspirated engine). Discussion Starter • #1 • Sep 25, 2017 I just bought a 88 250r it had a paul turner national cylinder bored. This means about 97 octane or about a 50/50 mix of race gas and regular. We are an integrated company which specialises in the wholesale of petroleum products. I was told that I could run 91 octane pump gas with that high of compression ratio with some type of blow off valve or cam shaft. Higher octane means the gasoline actually has less energy and is harder to combust. MidCitiesMildMan , Oct 16, 2019. Use either leaded or unleaded. RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane. What compression ratio is Sunoco Standard 110 designed for? Compression ratios up to 13:1 4. VP, Cam 2 or Sunoco leaded race gas race will do the trick @ $8. Manufacturers compression ratio will be tested and the octane necessary will be in an owners manual. I found when I was building a faithful Pontiac 400 V8 that if you push the carburetor tuning into its realistic territory (I was using 13. And thus high octane numbers are favoured for the internal combustion engine, but fuels with lower octane numbers, that can withstand compression, are used for diesel engines. Typically I am using 93 octane since that is what is around here. intake, solid roller cam with shaft mount roller rockers. Eighty-seven-octane gasoline is gasoline that contains 87-percent octane and 13-percent heptane (or some other combination of fuels that has the same performance of the 87/13 combination of octane/heptane). direct injection has basically made the old notion that Higher compression engine require higher octane fuel all but moot. As a general rule 10:1 with flat top pistons will work fine with 93 octane. Jump to Latest Follow 1 - 14 of 14 Posts I ran a 12. It sounds like 11:1 is the max for pump gas. Lucas Octane Booster - A Real Octane Booster! Tested and proven to deliver three times more boost than most other brands. The octane rating is a measure of the resistance of gasoline and other fuels to detonation (engine knocking) in spark-ignition internal combustion engines. Cost of octane fuel is more, as to make it bear compression and not to ignite just bcoz of compression. VP, Cam 2 or Sunoco leaded race gas race will do the trick @ $8. now days highrevving, hot running, highly tuned engines require the highest possible octane rating to ensure the fuel stays stable and. They also have C12, which they advertise as one of the winningest fuels in racing history. It can indirectly give an ABILITY to achieve more gas mileage with more aggresive timing/fuel maps but the octane in and of itself does not affect gas mileage. Please contact or visit our dealership location for more information about this Used vehicle using stock number: KR694427 or VIN: 2C4RDGCGXKR694427. 2 to one may knock at higher tempuratures with 87 octane and be fine at lower tempuratures with 85 octane. Elevation also affects your octane need. They will likely be equipped with a knock sensor, which will allow the engine to run on lower octane fuel, but it will make less power, will get less mileage, and will shorten the lifespan of the sensor. you are correct, the higher the octane rating the more resistant the fuel is to burning, that's why vintage cars cannot be run on these modern fuels, they run compressions of 3:1 maximum and have weak sparks. Rufskin LASC Under Armour 2EROS Cell Block 13 Vaux Jack Adams Diesel Model is 6 ft 1. 5 compression then 98 octane is recommended. 4:1 -dynamic compression. 8:1 compression. Hyundai was very conservative picking a 9. The Octane number you see on the pump is a measurement on an artificial scale where the Octane of pure heptane is 0, and is 100 for pure octane. 080" plated overbore again with the stock pipe is an even better choice assuming it's legal for the class you are running in. Simple, higher octane rating= higher energy rating= higher gas burning rate. 5:1 or higher But they wanted that 87 octane use. What's everyone. Pro Circuit claims that their high compression piston is designed to run on pump gas. MY question is, if I do go 11:1, or 12:1, am I shooting myself in the foot if I ever want to get a blower? My dad who was one of the head mechanics for the fastest streetcars from world renowned Niki Chevrolet back in the 60's. 87 octane should be left to 8:1 - 8. One way to increase the HP of an engine of a given displacement is to increase its compression ratio. If you have a high compression motor (over 9. 89 octane for 8. Anti-Knock Index (AKI) or (R+M)/2 In most countries in Europe (also in Australia and New Zealand) the "headline" octane rating shown on the pump is the RON, but in Canada, the United States, Brazil, and some other countries, the headline number is the average of the RON and the MON, called the Anti-Knock Index (AKI), and often written on pumps as (R+M)/2. Search for a New 2020 Dodge Durango Sport Utility SXT PLUS RWD Octane Red Pearlcoat-VIN: 1C4RDHAG2LC393752 for sale at Lithia Chrysler Dodge Jeep Ram FIAT of Bryan College Station in Bryan, TX. 1:1 on 89, I'm sure you can run 13. It's called "octane" because there was a baseline measurement done for combustion rate on octane (8-carbon hydrogen-saturated molecule, like propane is a 3 carbon saturated molecule I think, it's been a long time since Orgo). Octane handles compression very well -- you can compress it a lot and nothing happens. For road trips, my objective is efficiency and range: I will fill with the higher octane and will put this regardless of cost in this. 13" Modified Yamaha V4 - 101. it will work better with higher octane though. If you're only raising the compression half a point (12:1 to 12. engines (compression ratio 8. you can run CR 250R head and base gaskets to bump up the compression a little bit and still get away with 94 octane. I have a whole fleet of saws with compression ratios ranging from 6. High-performance engines typically have higher compression ratios and are therefore more prone to detonation, so they require higher octane fuel. It was a 455, that has been destroked and bored over. 13:1 Compression on a Pump Gas Engine. Fuel octane contributes to stability under compression, with a higher octane rating indicating greater resistance to abnormalities like detonation and engine knock. The blower I'm going to use will up the CR to 9. Looking at the various Rotax 912S durability threads, one thing that rarely comes up is what fuel people run their engines on. I had a Chrysler 3. no problems. When fitted with L. RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane. Discussion Starter • #1 • Feb 13, ive only heard of engines pinging because of a high compression ratio like 10:1 or 10. Using static compression ratio as a guide to what fuel will work is useless you must consider the profile of the camshaft. BOOSTane works great! increases the octane of the fuel. 5 to 1, 91 octane is good up to about 10. What Racing Fuel does NASCAR use? Sunoco 260 GTX 98 Unlead 7. 5:1 piston require? roughly im looking at using the kemco additive inplace of race gas. id be using eagle rods and total seal gapless rings. 5:1 compression piston in it. But, there are so many exceptions to that rule. Don't be a cheap skate. Probably 15 hp going from 10 to 9. 5-1 rated piston were actually only 13-1 in the real world, because my old heads had a huge chamber from all the porting. I had a Chrysler 3. (BMEP goes up octane need to go up) 8:1 bike will pre ignite on 105 O fuel at 100 deg F at full throttle,little above sea level. 5/1 cr in my truck and run 91 octane most of the time. higher compression is going to help with power, but its not a HUGE difference. FWIW, my cast headed combo ran 11. As has been noted many times on just about every sportbike forum on the net more octane does not mean more power!. 74 gallons of unleaded 87 octane fuel to the 93 that was left in the 2,5-gallon tan. With this formula, you can develop a better guide for a specific engine. 4 to 1 are not recommended for use with "premium pump gasoline. 93:1 compression and require better than C16 to do it. Aluminum and Hemi heads let you get away with a bit more and also the available fuel (which can range from 91 to 93 octane depending on where you are at). We do not recommend it for boost or nitrous applications, or for applications with compression ratios over 12. The 5:1 effective compression ratio is the result of IVC at 63 degrees BTDC (Figure 6). But, that 11:1 is an assumption, unless the seller can show you actual measurements (in cc's). 00 at the dealer when I did mine. ive been searching google, ect and the shops arent very convenient for me. RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane. 0∶1 designed for 86 or 87 octane fuel. Compression ratios also factor into cylinder pressures. ill be using crower severe race cams, mad springs,1mm valves with stock sized intake porta on the head(n/a application). An optimum flex fuel point is right about there to be efficient with both gas and E85. On a stock NA model MX-5 the "timing point" is set at 10 degrees before top dead centre (BTDC) when at idle and there is no load. Octane Supreme 130 - Octane Supreme is a Tetraethyl Lead TEL gasoline treatment / octane booster tom, is this the stuff?? i am currently going through the same thing11. 0:1 dynamic compression ratio. 0∶1 designed for 86 or 87 octane fuel. Perfect for extra-long unsupported runs, daily commutes or short fast-packing trips, it's designed to carry tons of gear and keep athletes prepared!. I had a Chrysler 3. Australia mostly uses 91 or 95 octane. I am talking about modern motorcycle engines. 25-1 compression 200lb'si was thinking 50/50 mix av gas to 92i heard all of the shelf octane boosters don't worka good friend of mine said the only additive that works is tetraethylsupposed to be what was in the. 5:1 compression!! The guy I bought it from recommended I use 25% Race Fuel, the rest 91octane. What is the upper limit for a compression ratio to use with 87 octane? Here's what I'm getting at. We do not recommend it for boost or nitrous applications, or for applications with compression ratios over 12. Still curious on the low end power gains, is going from 13. They don't need much timing advance to make full power. No it's not a Mustang, it's a Mitsubishi EVO, but the point is the same. In a nutshell, high-compression engines designed for performance need high-octane petrol. I am looking at buying a CHP dynotec longlock 347 with 11:1 compression that makes 500 flywheel horsepower and 460 lb of torque. 5 more dynamic compression if you have aluminum heads. 3-4 percent additional hp per point of compression. 5:1 static compression and Dart aluminum heads. Ethanol and methanol can take significantly higher compression ratios than gasoline. They also have VP-110™, a 110 octane blend for engines making up to 13:1 compression. The highest true octane rating gas can have is 100. 98-RON E30 fuel at equal performance levels in engines having compression ratio raised from 10:1 to 13:1. Premium 93 octane also has the better detergents in them and burn cleaner. The newer stuff is beyond 13:1 (fuel injection and better combustion chamber shape). Therefore, the answer is 161. 5lb of boost would blow the head off the damn thing. He said they use to blow cars even at 13:1. Everything else was the same. 3:1 compression and it is recommended to run off 87 octane gas by Toyota. This single-cylinder wonder has a four bowl carburetor and a movable cylinder head that can vary the compression ratio between 4:1 to 18:1 while the engine is running. minimum octane rating of 89 (R+M/2). Gasoline is rated by octane. Discussion Starter • #1 • Feb 13, ive only heard of engines pinging because of a high compression ratio like 10:1 or 10. 4 to 1 compression. Today's gasoline engines on 87 octane fuel will begin to diesel readily at between 13:1-14:1 ratios. This increase, while undoubtedly real, was not further investigated. In high altitude areas, engine draws less air due to the reduced density of the atmosphere. As a general rule though, you can run another point of compression with aluminum heads over cast heads. Cost of octane fuel is more, as to make it bear compression and not to ignite just bcoz of compression. (BMEP goes up octane need to go up) 8:1 bike will pre ignite on 105 O fuel at 100 deg F at full throttle,little above sea level. A higher compression ratio (higher cylinder pressure) is directly related to power and thermodynamic efficiency of an internal combustion engine, allowing it to extract more energy from a given amount of fuel. result: Static compression ratio of 9. There are far too many variables to say with accuracy. Alexia wrote:I have a 10:1 static compression ratio in my stroker and I can run AKI 91 octane. Diesel engines usually start at around 20:1 and up (have seen 22:1). I had a Chrysler 3. When researching on what octane fuel I should be using I am getting mixed answers. I was surprised to see the manual say 87 octane with a compression ratio of 10. Several years ago only high powered sports and muscle cars ran ratios like that. at 9,000 RPM Custom 105 for 11:1 Motors is available - Motor Octane 103, Specific Gravity. All fuels have about 100,000 btu's per gallon regardless of the octane rating. Maria’s Coffee Shop: Compression Thinking to Earth. Now if you properly built and forged the motor it could handle it but you would have to run race fuel. 87 octane should be left to 8:1 - 8. generally, what octane does a 13-13. So, they're concerned about the octane being too low, not too high. 4:1, so I figure the compression ratio with the new GT40p heads puts it at about 9. Please contact or visit our dealership location for more information about this Used vehicle using stock number: KR694427 or VIN: 2C4RDGCGXKR694427. And that's a mid-eighties design. at 9,000 RPM Custom 105 for 11:1 Motors is available - Motor Octane 103, Specific Gravity. Engine building book I have says 5 point of octane per each point of compression increase. Tumble dry low. the time from when the. But, has a compression ration of 12. The owner runs C12 in it now. Arbitrarily, pure iso-octane (2,2,4-trimethylpentane) is accorded a research octane number of 100, while the straight-chain paraffin n-heptane is given an octane number of zero. So, if the gas you're bying is 87 Octane, then it burns as easily as a mixture of 13% heptane and 87% octane. 00 it will stil be down the hole by 0. The higher octane rating will allow it to be used in higher compression engines which tend to produce more power per unit of displacement than their gasoline counterparts. 8 etc? Pro's Versus Con's Thanks, Dave. RON is determined by running the fuel in a test engine with a variable compression ratio under controlled conditions, and comparing the results with those for mixtures of iso-octane and n-heptane. This other motor I want to rebuild my goal is to have something street but also build a big block buster with (or at least give them a run for their money). The fuel performance. PDF Author: mbaker Created Date: 9/9/2003 3:30:16 PM. I went to school for mech eng and had a professor named Dean Hill that was a famous hot rodder in the 60s, anyway, he had a basically stock engine that was running 16:1 compression on 87 gas. Understanding Octane Grades. Like the others said, use 93 octane, don't crowd the timing, and watch for ping. 112º LSA and decent duration makes dynamic compression much less. 5-1 rated piston were actually only 13-1 in the real world, because my old heads had a huge chamber from all the porting. However a Honda Rebel with a compression ratio of 9. 5 more dynamic compression if you have aluminum heads. So what gives. Whoever said 11 to 1 compression is "low" is a really funny dude. It was astoundingly low: 1935-1950 engines ran said 6-ish CR and Octane was 70-80. The higher compression ratio needs the high octane so the engine won't "knock" igninate the fuel before the spark plug fires. You don't need high octane fuel until you start getting into the 11-12:1 comp ratios. it kinda depends on if you want to run high octane fuel. 25:1 78cc chamber. you need to know what the trapped volume is of the engine, and then based off of the UCCR and CCR, you then can correctly determine the octane needed. 4:1 - 100 octane 8. Your static compression is 12:1 but what is your dynamic compression? Your cam plays a big part in the equation. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The CR on a engine can be 10-1 on one and run 87 octane just fine but that don't mean that all with 10-1 CR can because the camshaft determines the DCR. Jeff Smith: This is an interesting question that came out of last month's discussion about E85. Compression ratios also factor into cylinder pressures. 5 to 1 - if the motor is properly dialed in. To release all the potential power of 91 octane gasoline, it is necessary for an engine to have a compression ratio higher than 9. my 414 ci 396 had 11. 5 compression, maybe more, 282 degrees duration, 34mm VM mikuni, dual 12mm plugs, 30 BTDC. 04-02-2012 , 03:09 PM #3. 56mm bore 40. Crown Honda of Greensboro Home; Shop New New Inventory. But the pre-ignition is a serious issue and is worse in high compression engines such as most modern day vehicles. I am building a driver that has to run in cold weather so I want to keep compression around 13:1 to allow for a slightly higher gas content for easier starting below freezing. You can check the brushes and the bushings, but the starters are an excellent part. The Toyota vehicles of today are well-equipped to bring you high amounts of performance and adrenaline, from the time that you turn on the ignition to when you press the gas and let loose on the road. Engine temperature is also a factor. more so than just the compression value. Discussion Starter • #1 • Jul 13, 2009. AND yes it stays plenty cool. The Research Method tests for knock at 600 RPM with the ignition timing fixed at 13 degrees Before Top Dead Center (BTDC). I was going to go with an AFR 185 61cc head but can I go with the 58cc head and still run pump. In Europe, 95 and 98 octane are the two most common grades; in Japan it’s 91 and 96/98 octane. Then,as usual,the results and opinions on these subjects may vary widely. Using static compression ratio as a guide to what fuel will work is useless you must consider the profile of the camshaft. Bad spark plugs, inferior gas with low octane and defective fuel injectors can all trigger hot spots on the pistons and eventually lead to holes. Higher octane does not mean more power except in some very specific conditions, such as computer controlled ignition advance with a knock sensor. my maxda cx-5 with a 13:1 compression ratio runs perfectly on 87octane. 1:1 on 89, I'm sure you can run 13. The octane number relates to the percentage of these molecules in a gallon of gasoline. Higher octane rated gas BURNS FASTER than lower. I bought a complete running Chev 355 that was built for drag racing and raced for 1 year. All of the 2 liter racers use C16 for their 13:1 cars, so you mgiht be able to interpolate a calculation from those numbers. I set my new motor up for E85 and makes more power and torque yet runs cooler. Combined CR: 13. The magic number is AROUND 9. Low compression high boost makes more power per cubic inch than high compression low boost. | Honda TRX 450R. You can run up to 14:1 cr on E85. The motor is getting fixed right now. These engines run well on pump fuel above 92 Octane, and this is actually recommended by the manufacturers. 10:1 is high enough though. If you're only raising the compression half a point (12:1 to 12. Pinging unresolved will damage the piston surface and effectually cause the piston to fail!. timing was locked out at 36 degree. I'm running a 350 with 12. Octane Supreme 130 - Octane Supreme is a Tetraethyl Lead TEL gasoline treatment / octane booster tom, is this the stuff?? i am currently going through the same thing11. 5 drag thanks for any help. The motor is 13. my 414 ci 396 had 11. I am going to go look at a built up yfz and it has a CP 13. The higher octane fuels are for high performance, high compression engines. 1:1 was high when most cars were below 10:1 at that point. What compression ratio is Sunoco Supreme 112 designed for? Compression ratios up to 15:1 5. Now if you properly built and forged the motor it could handle it but you would have to run race fuel. To release all the potential power of 91 octane gasoline, it is necessary for an engine to have a compression ratio higher than 9. (RON) method = 91 octane Running higher octane levels above recommendations increases carbon build up which can cause you severe problems. should net around 13. Today's gasoline engines on 87 octane fuel will begin to diesel readily at between 13:1-14:1 ratios. The longer the jug sits, the lower the octane level becomes, and at some point the fuel is simply too low of octane to be safe for use. 5:1 compression piston in it. Above that, OR turbo or supercharging, usually demands 92 octane. at 13:1 you should be fine with a 50/50 mix of primium and 101 race fuel. Elevation also affects your octane need. 13:1 compression, questions on octane. all a compression tester is telling you is cranking psi. The thick gaskets give the ideal compression ratio for crappy 87 octane. 012 A felpro gasket with compressed height of 0. Most engines will lose ET & MPH if you run too much octane, at least all of mine & friends I've helped out did. FORGET “mid-grade”. For example, if the atmospheric pressure is 14. The blower I'm going to use will up the CR to 9. :thumbsup:. The high compression ratio offers more power given that the air and fuel are compressed tighter than average. Mar 21 2016 You can widen the intake but by very little. If you run a richer air fuel ratio around. You might be able to get buy with 93 octane gas if the compression ratio was no higher than 10. With 94octane, I'd say you could push just pass the 8. Above that, OR turbo or supercharging, usually demands 92 octane. A diesel has to have 16:1 compression to run at all. Case in point, I know that in 2006 Engine Masters competion, the were limited to 91 octane, yet every entry had over 11:1 compression, but they don't give enough info to figure DCR. Your 1999 Honda XR80R engine has a 9. OS1st Compression; Brooks Ghost 13; Saucony Arrivals; CamelBak Octane Dart 50 oz Hydration Pack - 1141601000. But, there are so many exceptions to that rule. i understand i will need higher octane. 110 octane race gas is much tougher to light than low grade 87 octane. I also run 13:1 in my small block but run 110 or 112 in it only. On the pricier 98 octane, they’d consume 1228 litres – just seven litres less – at a total annual cost of $2651, or $84 more. 4:1 are not recommended for use with "92 octane pump gas". 0:1 compression. 30, the block was then decked to gain the compression back. Since my Frontier seems to be drinking gas at a more alarming rate than I first thought, I will try 89 octane on this next fill-up and see what happens. Research Octane Number (RON) The most common type of octane rating worldwide is the Research Octane Number (RON). I have actually ran it on 87 octane and it was fine, but it was only to move it around while the truck was being worked on. A engine that is pre-igniting can produce displaced energy. From what I read online, anything under 10:1 will run fine with 87 octane regular gas. 5:1 compression (ran on regular with a low gearing and a very light foot, but ideally needed 91 octane), and 15. org ok so im looking at running a 13. In that case, I would recommend buying the highest octane rating available (generally 93). It's impossible to guess how much power losing a point of compression will lose because we don't know the rest of the combination. 02/gallon when ethanol is used. 5mm, the stroke is 114. under 12:1 a bike will go bar to bar or to work just fine on 85 - 87 O fuel. The higher compression ratio needs the high octane so the engine won't "knock" igninate the fuel before the spark plug fires. My DeSoto 291 has a Stock CR of 7. Some websites say 93, some say 105+ The car is tuned and is running on 93. Ideally it it better to use a custom piston instead of using a thicker gasket, but we like the fact that these pistons are in stock and are cheap (around $450 with rings). Also, when using supercharging or turbocharging you can get more power with a lower compression ratio since this allow for a higher boost pressure without knocking. The Vespa GTS 250 has a Compression Ratio of 10. Just for giggles I modeled a 406 in Engine Analyzer using E-techs, a hydraulic roller cam similar to the duration you list, gave it plenty of carb, exhaust, pump 93 octane and 9. The 100 is the Motor octane rating, and so therefore AvGas 100LL is 100 Motor octane. 8:1 compression engine will run OK on low octane fuel. Well said, I would add : If the car has higher compression ratio then use higher octane fuel. Probably 15 hp going from 10 to 9. all of the drawbacks of higher lead with no benefits from the higher octane. Because too much octane can make a stock engine run hotter and RC motors don't have high-compression ratios that warrant using a higher octane fuel. Higher octane fuels allow for higher compression ratios. Sunoco Standard is designed for compression ratios up to about 13:1 in conventional V8 engines with iron cylinder heads. 75:1 (for a low CR supercharged engine) to as much as 1:0. Running richer with better fuel distribution effectively adds 2-3 octane numbers and provides even more on-track protection against detonation than its standard ASTM motor octane rating would indicate. The compression numbers are good. Seriously considering getting a KLE500 just for this trip. 2:1 compression ratio in a small bore with a 4-valve optimized combustion chamber shape vs an large bore with a domed piston & a 2-valve combustion chamber will need significantly different octane ratings, even though the compression ratio is identical. 7 (86 Octane) 5 299. FYI: *the later Vortec's (sb + bb) can typically run more compression with the same octane because of their unique combustion chambers. Please also post a reply with current hours on the engine, or any problems you have had. Today's gasoline engines on 87 octane fuel will begin to diesel readily at between 13:1-14:1 ratios. Final Compression Ratio (FCR) = [(Boost/ 14. If you put low octane in (87) your engine will retard ignition timing, and lower boost to a non-knocking level. 051, in the ball park but not the ideal 0. One would be well advised to get the numbers together prior to a piston replacement and/or bore increase to determine a precise compression ratio. In the end, all that octane predicts is AKI-Anti Knock Index as measured on a knock engine. 9 -1 and use 89 all day long with zero issuesof course this is just my :2cents:. People often think of high octane fuel as being more flammable, and easier to explode, whereas that is actually the opposite of the truth. I was going to go with an AFR 185 61cc head but can I go with the 58cc head and still run pump. 5:1,,, it made 14 ft. Compression ratios also factor into cylinder pressures. 75:1 (for a low CR supercharged engine) to as much as 1:0. 56mm bore 40. then again, if you just take a stock 10:1 long block and give it cams and valve springs and collets and manifolds, you could see 200hp or close to it by 7500. 35 use 98 octane. 8:1 really even that much?. Using static compression ratio as a guide to what fuel will work is useless you must consider the profile of the camshaft. This other motor I want to rebuild my goal is to have something street but also build a big block buster with (or at least give them a run for their money). Note that in our Dyno Test #21, a 740 HP GEN 3 Hemi used pump gas and 13:1 c. 5mm stroke, redline 14,000 rpm. ok so im looking at running a 13. All fuels have about 100,000 btu's per gallon regardless of the octane rating. Maria Morgan did not found it to make money – a sign of Compression Thinking. 5 to 1 compression. A high ratio in a gas engine would be 13:1, whereas that of a diesel engine is around 14:1 to 23:1 based on the type of engine. Higher compression = higher pressure = higher temperature in the combustion chamber. 5:1 piston and proper deck height will meet your goals. 5:1 isn't exactly "high" compression; however, it seems to be the highest you can generally go while on 87 octane. Ultimate hp levels on high octane fuel are mainly determined by the physical strength of the engine. 91 octane 14 PSI 93 octane 16 PSI 94 octane 17 PSI 100 octane 20 PSI. Not to mention you would have to run around 110 octane or better. Running richer with better fuel distribution effectively adds 2-3 octane numbers and provides even more on-track protection against detonation than its standard ASTM motor octane rating would indicate. They also have C12, which they advertise as one of the winningest fuels in racing history. it will work better with higher octane though. It was a 455, that has been destroked and bored over. Desired pressure is 160-170 psi, so we need to increase pressure by 40-50 psi. Engine cell data of Table 5-1 at a compression ratio of 8:1 show that the 1969 heads with the higher squish area gave a two number higher octane requirement with primary and full boiling range fuels. more so than just the compression value. It's easy to find what octane rating a gas has. Combined CR: 13. 5:1 piston require? roughly im looking at using the kemco additive inplace of race gas. It's not just CR that matters, but ignition timing as well, and how clean your combustion chamber is and even the shape of it, plus there is load factor. 5:1 on my LS1 engine on 93 octane with no issues but my dynamic compression was around 8. On the economics of high octane fuels, one study found that the refinery cost of increasing octane to 98 RON from 93 RON is only $0. 5lb of boost would blow the head off the damn thing. 50 tires, a T19 with a 6. Looking at the various Rotax 912S durability threads, one thing that rarely comes up is what fuel people run their engines on. This is for engines with compression ratios below 15:1. 039 So a calculated quench of 0. my 414 ci 396 had 11. 6mm; Displacement 1179cc; Compression ratio: 10. I know there is no steadfast formula for compression to HP, but that is close. Engine building book I have says 5 point of octane per each point of compression increase. Since my Frontier seems to be drinking gas at a more alarming rate than I first thought, I will try 89 octane on this next fill-up and see what happens. 0:1) Premium fuels of minimum 93-octane Research up to 97-octane are required, with preference to 93/97. compression work which is also a loss. cleavitte bearings all around and the whoel 9. If the octane rating of the mid-grade gasoline in your area is lower, use premium unleaded fuel. Hello All, A question about Octane vs Compression ratio: With the prices of gasoline going sky-high, and the possibility of running lower-octane, what is the relationship between the two? If you are going to rebuild an engine, should the compression ratio be high or low if you run 89 octane? Steve [This message has been edited by SteveFlier (edited 05-09-2001). The compression ratio depends on the size of the dome on the pistons (in cc's) and the combustion chamber size of the heads (cc's) among a few other things. This is why some engines require 100+ octane with an 11:1 compression ratio while others are perfectly fine on 91 octane with a 13:1 compression ratio. Aluminum and Hemi heads let you get away with a bit more and also the available fuel (which can range from 91 to 93 octane depending on where you are at). 5 to 1, even the V-Strom 1000 is 11. Only above 14:1 do we recommend that race fuel is required. Like I said in the other thread, in general you can run 1 point of compression higher for aluminum heads. Designed in Los Angeles. Can I use 91-93 octane or no? Could I do a 50/50 mix of 110 with 91-93? Or would I be best off swapping the piston to a lower compression, if that is the case I prolly won't. I had a Chrysler 3. For carbureted engines with compression ratios of 9:1 or less and boost levels in the 8-14 psi range, pump gasoline works very well. 7) +1] x CR. Pinging unresolved will damage the piston surface and effectually cause the piston to fail!. 75 stroke 6. You can get another point due to the reverse flow cooling and another can be added with a tune so 13. " Typically, your fuel doesn't ignite until it's lit by the spark plugs. 7:1 first gear / 1:1 fourth and 3. So - in 1947 Pump Gas was NOT the 89/92 R+M/2 of today. The highest true octane rating gas can have is 100. The Toyota vehicles of today are well-equipped to bring you high amounts of performance and adrenaline, from the time that you turn on the ignition to when you press the gas and let loose on the road. What is the upper limit for a compression ratio to use with 87 octane? Here's what I'm getting at. (BMEP goes up octane need to go up) 8:1 bike will pre ignite on 105 O fuel at 100 deg F at full throttle,little above sea level. If you have 94 octane close by, ok, 11:1 is doable, if you take out alot of timing, (hp), and do not run it at high RPM's for long periods of time, maybe. 5l V6, is not unusual). Likewise, if the dynamic compression were 8:1 @ one atmosphere, under the improved VE it would rise to 9. In a regular car that is REALLY pushing it on 92 octane pump gas, but with EFI systems and knock sensors that adjust timing before detonation happens, they can get away with it. Products and services for all your petroleum needs. Quite simply, octane ratings are a measurement of a gas's ability to resist detonation. 7 (86 Octane) 5 299. Good luck running 85 octane, though. There are two common ways to determine octane ratings and the manual (Vulcan 900) gives specifics for both ways. There are far too many variables to say with accuracy. 50 tires, a T19 with a 6. I went to school for mech eng and had a professor named Dean Hill that was a famous hot rodder in the 60s, anyway, he had a basically stock engine that was running 16:1 compression on 87 gas. Renegade Racing Lubricants are specifically designed to lubricate competition engines which run alcohol or higher octane fuels. Vp mr12 or mrx02 any thing else. 49 a gallon. 74 gallons of unleaded 87 octane fuel to the 93 that was left in the 2,5-gallon tan. I don't know how the D-series head compares with B-series, but Jeff at IB had some B-series motors running 12. My dad had a bay boat a few years ago and it would top out 500 RPM better with 93 vs 87 octane. 60 over std crank length mid range port single layer gasket and it has 204psi when I compression tested it. Page 1 of 3 - Compression and octane needs - posted in REV Chassis - Performance and Trail Models: Bought an 07 500ss with 3400 miles. I would be tempted to use the. 5 to 2 points. However, being a) not confident of hearing pinging over all that er, music, b) having seen more than a few pistons burnt completely through and c) it's my baby, - I run my 308 on higher octane fuel which here is only a little more expensive. D2As changed at some point from 8. 4:1 (it's Australia: my ride, a 3.
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