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Post by flipflopoo1oo on Dec 19, 2014 9:25:12 GMT -6
While most need for tune is after the fact of build, we can only go with what we try or listen to in our engines! Revving one up to 5 grand and setting the timing by hand can sometimes get it closer than you think but not if running a power valve and not back at idle with a locked dist.! Cranking is not my main goal in a racing engine's tune, although it does help! Timing should vary as should fuel! Not just to keep up with the pace but to give a better tune-able torque to and when needed! Gas provides a wide range of tune as octanes and compressions battle to keep up with stroke verses bore and piston speed fluctuations! Alcohol has been said to be more forgiving! Does this mean it gets around to doing the job intended regardless of compression or heat factors! It can burn fast or slow depending on the pressure applied by compression, heat expansion or resistance forces! A 30 horse boost if not doing it correctly with gas on most any performance engine! It does get cold more easily and it's expansion rate with heat is greater but the heat from compression to ignite the fuel can be its downfall in longevity of burn at higher rpms! Thus the need for timing and fuel ratio changes! We tend to follow the big guys with our locked dist. and adjusting fuel carbs but if still on gas you are not forgiven the cushion of Alcohol in your tune process!!!
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Post by flipflopoo1oo on Dec 19, 2014 10:56:14 GMT -6
Some Alcohol engines seem to be hard to start and may require use of gas to get it fired! Gasoline seems to work a bit like Ether to a gas engine! If lacking or flooded it makes it fire on the fumes! I have found that too large of spray nozzles does not atomize to have fumes unless pumped quickly! If spinning the motor a few times before the spray of fuel is given, the heat generated by the compression and a slow count to ten to allow fumes to present them-selves will normally result in it starting! How-ever the cooling effect of Alcohol evaporating causes refrigeration and the atomization of it to air temps is directly related to the amount needed! 2-3 long, fast, squirts depending on cc's of spray! A count to ten and give it a try! The spin before the fuel and not during the spin, but ten seconds after the spray should you have fumes enough to start! Give it a go and bust right off! This tip can save your battery, starter and oil your engine before cranking as well as keeping oil milk free! In some cases you only get one shot at this so get it right the first time! The more you spray, the colder the air gets and less heat means less fumes! And you thought the burn was hard to control!!! Timing is still everything!
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Post by flipflopoo1oo on Dec 20, 2014 18:27:48 GMT -6
I am a big fan of pulling vacuum and the use of 108 intake center line to do so! The lobe separation and exhaust location is one thing but the numbers have to change to protect the innocent! Geometry and lash has to do its part to come up with timing at the valves also! Extreme down sizing a big cam to give roller cam specs with a solid or hydraulic cam with the correct lifters, push rods, rockers, and valve numbers off the chart of convention can be had! I am not talking about bleed off lifters but I can see their use and have ran most all of them! Oils seem to be their deciding factors but still you have no constant control over numbers once pumped! They are just back to cam specs of hydraulic or solid cams! You can make a small cam bigger but its the low-end torque that gets lost as a small cam is still not back to roller specs! Even the effects of valve spring pressures can get in the way of their tune! Low numbers at .020 or .050 that grow as RPMS increase to become monstrous can provide the upper range torque while still centered at 108! High tech variable cams of today change cam timing to stay in tune! I see valve spring quickness as floated in most limits of direct flow! The intake can give more but the exhaust has to function to control the flow! The wider lobe separation by valve numbers gives a bit more time to control such issues! The first tune improvement on any engine is timing the ign. to the exhaust burn and valve closing number! If you can move both within the range of RPMs desired, I would consider it a torque advantage, at least it has proven to be so winning at 6,400 with less!!!
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