Dynamic compression ratio vs octane
http://www.wallaceracing.com/eff-cr.php WebJan 16, 2015 · Based solely on our thermal efficiency formula, raising the compression to 12:1 should bump that figure to 397 ft-lbs. In practice that number is usually exceeded and the bigger the cam, the bigger the gain. To understand how much more can be had, let’s look at the effect the cam has on the situation. Fig. 12.5.
Dynamic compression ratio vs octane
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WebDec 15, 2011 · Use a good gasoline ( Shell or Chevron ) , keep the compression below 11.0 , and the engine temp as low as possible . I have 10.7 static 7.9 dynamic compression ratios, Cast iron heads 91 octane, motor likes 39 degrees total on 100 octane and can only handle 31 degrees on 91. Engine runs at 170 water temp.
WebJan 3, 2010 · A 72° ABDC closing would put the DCR at 8.16 which isn't much less than the 8.45 he calculated. The difference is most likely he used the .006" duration numbers while I used the .004" duration numbers. BTW, the .004", .006", and … WebApr 13, 2024 · 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. E-85 has an equivalent octane rating of 105, and with an expected operating temperature of around 180°F, the maximum dynamic CR is slightly above 10.5
WebMay 15, 2012 · This makes the dynamic compression less than the static compression...." For example, a recent quote from Jeff: "A 10.5:1 engine can have over … WebMar 27, 2015 · 5,060 Posts. #5 · Mar 26, 2015. corwindotson said: Ok so I have been trying to do some research about compression ratio. So I found out that there are two types of compression ratios that should be considered when building an engine. One is static compression ratio (scr) and the second is dynamic compression ratio (dcr).
The biggest limiting factor when attempting to increase compression ratio is the threat of detonation. This is defined as uncontrolled combustion that occurs after the spark plug has fired. Think of the combustion process not as an explosion, but rather, more like a brush fire burning across a large field of dry … See more When we talk about compression, this should be more accurately defined as static compression ratio. This is literally the ratio of the volume of the cylinder with the piston at the … See more Of course, too much ignition timing can cause other problems. For modern engines, a three-dimensional timing map based on both load and RPM will go a long way toward … See more Some may be concerned about the iron heads, as there is a concern with enthusiasts that iron heads are more detonation prone than aluminum heads. We actually performed a dyno test several years ago using a … See more This effect can be moderated by other atmospheric conditions. For example, high humidity levels tend to reduce octane sensitivity slightly since the additional water in the air finds its way into the combustion … See more
WebSep 17, 2012 · A higher octane rating allows an engine to use a compression ratio of, say, 12-to-one instead of a more usual ten-to-one. The greater the compression, the higher the temperature within the ... howick test centreWebMay 16, 2006 · The optimum intake-to-exhaust ratio could range from as little as 0.75:1 (for a low CR supercharged engine) to as much as 1:0.6 (for a very high-compression naturally-aspirated engine). howick tennis courtWebDec 22, 2003 · Using dynamic compression ratios is the best way to "guess" at octane needed. Gasoline will only compress so much before it blows up like desiel fuel, octane is this resistance to doing so. Dynamic compression is how much the actual air fuel mixture is getting compressed. '74 Gran Torino Project. 351W, c6 trans, 9". high functioning autism ableistWebAug 27, 2024 · Static compression ratio of 9.25:1. Effective stroke is 3.55 inches. Your dynamic compression ratio is 8.61:1 . Your dynamic cranking pressure is 174.81 PSI. … high functioning autism and collegeWebJun 29, 2010 · The cam has 255* intake duration and the 52* ABDC is the .050 lift figure. I had no problem runnung 10.75 static compression with .040 piston to head and 93 octane. My concern is running the same 10.75 compression with .080 piston to head instead of the .040 clearance. The quench thing concerns me. The reason for this: I'm designing … high functioning aspergers treatmentWebMar 27, 2015 · That's counterproductive. I designed my 383 to fight detonation, using all the techniques described above. It runs on 87 octane to 6,500 rpm with 9.7:1 compression … howick tidesWebHere are the exact compression ratio and octane numbers: The compression ratio of your vehicle is from 9:1 to 10:1, you can use 90. octane; The compression ratio of your … howick tires meadville pa