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| ebs_4l |
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cjh wrote: When would fuel get a chance to sit there.???? on a polished surface
take an engine idling 800rpm, so the cam is doing 400rpm, which means the inlet valves are opening & closing at 6.66 times per second, so when is fuel going to get a chance to "Puddle".???? Fuel can be mommentarily suspended in motion by negative pulsation from the inlet valves closing, so the more violent the cam, the more lopy the idle gets from this happening.. i think we have pretty much covered the smooth vs rough port topic, i have to comment on flow reversion though, as a lot of people seem to think that all airflow into an engine happens in one direction.. it does not, and if anyone gets to see an individual throttle trumpet inlet engine running on full throttle on a dyno, you will be amased at the amount of fuel spray that makes its way back out of the end of the inlet trumpets.. it becomes a haze of fuel spray, which displays the amount of flow direction happening within the inlet tract, even at 7500rpm. im not saying anyone hasnt on this thread doesnt know about this, but im saying it as general info for everyone else... hence the amount of airbox fires in V8 supercars
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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| Slick |
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^We forget that flow bench only measure's one direction{vacuum} it does not what so ever simulate real world situation. So in reality, if it flows well in one direction then it must flow well back out during the 4 stroke cycle.
_________________ Mind f**k!!! it works on feeble minded ignorant sheeples... there's plenty of em on this site... some are very intelligent but by god they are so thick!!! Pakrat wrote: You can buy them seppertly
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| Delta |
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ebs_4l wrote: cjh wrote: When would fuel get a chance to sit there.???? on a polished surface take an engine idling 800rpm, so the cam is doing 400rpm, which means the inlet valves are opening & closing at 6.66 times per second, so when is fuel going to get a chance to "Puddle".???? Fuel can be mommentarily suspended in motion by negative pulsation from the inlet valves closing, so the more violent the cam, the more lopy the idle gets from this happening.. i think we have pretty much covered the smooth vs rough port topic, i have to comment on flow reversion though, as a lot of people seem to think that all airflow into an engine happens in one direction.. it does not, and if anyone gets to see an individual throttle trumpet inlet engine running on full throttle on a dyno, you will be amased at the amount of fuel spray that makes its way back out of the end of the inlet trumpets.. it becomes a haze of fuel spray, which displays the amount of flow direction happening within the inlet tract, even at 7500rpm. im not saying anyone hasnt on this thread doesnt know about this, but im saying it as general info for everyone else... hence the amount of airbox fires in V8 supercars The fact that an engine depends alot on the way that waves move up and down the pipes leading into an out of the engine is the VERY point I make quite often, especially when someone brings up the whole backpressure thing. Acoustics have an incredible amount to do with making power, exhausts and intakes are basically bandpass filters that work well in a certain band, and roll off from a tuned frequency (or more than one depending on design complexity). Its very interesting to watch the pulses in a simulation moving up and down the intake and exhaust pipes and see how they interfere constructively and destructively. I've seen cars even with relatively long inlet tracts fill up the pipes to the airbox and then backfire on the dyno.....the result isn't pretty, one car had the turbo blades "straightened" followed by the wheel belting the compressor housing, stuffing housings wheels bearings etc, and blowing the airbox piping on the front of the turbo basically to bits, it had shortish piping tho (no intercooler). |
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| blackxr6 |
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i always thought that was because the had timiming issues ,over fueling ,running to much boost ,or the later no F**k intercooler , there are reasons but i dont think its quite that scientific, you can also say that alot of reverse airflow in the inlet chamber is caused by valve event due to camshaft ,lobe separation and lift and duration ,airbox fires are normaly started because the driver forgets to turn fuel system off and run car out off fuel v8 super cars are renown for this as is kinsler mechanical injection . As for the ports rough or smooth the owners choice they both pool very small amounts of fuel ,ask me how i know a friend used to work for pro action cylinder heads in nz and they used to do v8 super cars ,indy ,nascar. AS for the top thats just my opinion and you guys are that clued up you should be working for n.a.s.a ( compliment to you both)
_________________ ONCE YOU GO BLACK YOU WILL NEVER GO BACK,what a shame im white .......... |
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| cjh |
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I went to the Ford Discovery Centre in Geelong, 2 X'mas's ago, and in there was an engine, a Cosworth 4 cyl, DOHC with injection,(electronic) and the injectors were facing out at the butterfly. That engine was on loan from England, ( I think ), so I don't know if its still there.
To me, that is an usual way of doing it, but then again, the guys that came up with it, more than likely spend countless hours on an engine dyno.
_________________ http://youtu.be/jJTh9F3Vgg0 |
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| blackxr6 |
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i used to do a bit of work on a cosworth back in nz and they are preety cool engines that can take alot of boost when built properly i imagine that the set you are talking would be very high vacuum engine and i like the weird and wonderful stuff that people come up with as far as engines go
_________________ ONCE YOU GO BLACK YOU WILL NEVER GO BACK,what a shame im white .......... |
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| INDUCT |
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now that we r all over our smooth vs rough an our golf balls ill let u no i hav found some1 willing to give it a crack...its funny that no1 wants 2 attemp anyhtin till u inform them that u r willing 2 spend money....most places r assuming that u r just another person tryin 2 go fast an spend less so they try an sell u an "off the shelf item"....that all changes when u mentoin $2000 an supply a few heads 2 practice on!!!i started gettin results when i spoke with Gilbert's Cylinder Head Service, located on the gold coast...they r th ppl responsible for designing an building th "au 4l" head in the auto speed thread...this head only produced 412 potential HP by memory but when i started talkin coin the numbers started 2 grow!!!
strange how that happens.......
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| cjh |
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INDUCT wrote: now that we r all over our smooth vs rough an our golf balls ill let u no i hav found some1 willing to give it a crack...its funny that no1 wants 2 attemp anyhtin till u inform them that u r willing 2 spend money....most places r assuming that u r just another person tryin 2 go fast an spend less so they try an sell u an "off the shelf item"....that all changes when u mentoin $2000 an supply a few heads 2 practice on!!!i started gettin results when i spoke with Gilbert's Cylinder Head Service, located on the gold coast...they r th ppl responsible for designing an building th "au 4l" head in the auto speed thread...this head only produced 412 potential HP by memory but when i started talkin coin the numbers started 2 grow!!!
strange how that happens....... Let us know how you go.
_________________ http://youtu.be/jJTh9F3Vgg0 |
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| Delta |
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My head is back from KEC, and on the car, but the return line from the turbo is split, so it dumped oil all over my driveway
 huge cam has gone in (just over 300 deg and 0.545" lift) doesn't idle for s**t hahah, but its not tuned yet and running awfully awfully rich. Will have it on the dyno tomorrow hopefully. Post some results when I've got them.
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| blackxr6 |
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induct anyone will give you good numbers if you offer them enough money but am friend of mine who worked for pro cylinder heads they do all high end gear including v8 super cars indys and so on he said that the cylinder heads dont physically hold enough material to be able to flow that much 470 is around the maximum you will get from them. this is a personal friend of 12 years and has been doing heads for 20 . i am not out to burst anyones bubble just try to give you some idea of wat you will get even for top dollar good luck
_________________ ONCE YOU GO BLACK YOU WILL NEVER GO BACK,what a shame im white .......... |
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| ebs_4l |
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blackxr6 wrote: 470 is around the maximum you will get from them. this is a personal friend of 12 years and has been doing heads for 20
ABSOLUTELY PERFECT.......!!!!!!!!!!!!! this is exactly what we have been looking for... now, just need to convert those words into something physical. what the aim of the project is, is to make the absolute biggest animal of a N/A 4l that anyone has built... WHY? because we think some good HP is still yet to be seen from the old girl, and i beleive one of the big keys to this will be the 6 throttle inlet... hell, a 265hemi can pull 260rwkw, why not the 4l OHC???
_________________ EB 4L, 8.4:1, R154, GT4202r, 4in exhaust, Greenslade Engineering exhaust manifold, plenum chamber, 90mm throttle, Garrett W2A cooler, Surecam custom, autronic SM4, Bosch 120lb, Crane HI-6, LX-92, LM-1, Turbosmart Reg, 2x bosch 044, turbosmart 48 gate. 470kw+ @ 18PSI |
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| blackxr6 |
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ebs4l i agree it will be a feakin animal if you get that and thats wat my friend said . he also said he did one years ago back in nz and it was pretty wild but that was in a cortina lots of fun let us know how this goes for you all
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