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| INDUCT |
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all hand done?fair effort.....no offence but i think i would prefer cnc porting...i hav seen th damage that a lean cyl can do.lol.
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| ebs_4l |
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CJH, pity you went to all that work but left the swirl ridge in the chamber????? thats not a good thing
_________________ 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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| Steady ED |
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INDUCT wrote: all hand done?fair effort.....no offence but i think i would prefer cnc porting...i hav seen th damage that a lean cyl can do.lol.
They gotta map the CNC program off something. A CNC ported head is only as good as the one hand-ported cylinder that was used to create it.
_________________ ED XR8 Sprint - S-Trim, V500, 249rwkw |
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| aaron_hogan |
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Steady ED wrote: They gotta map the CNC program off something.
A CNC ported head is only as good as the one hand-ported cylinder that was used to create it. bingo 
Thats my point about consistency though. The CNC is repeatable. From a shop perspective they should aim to do all base porting by CNC and then finish by hand. Its just a time saver. One of my close mates is running his own Rotary workshop and believe me nearly every engine he builds gets ported in some way. He's doing porting for a couple of other workshops too (he's seriously THAT good at it). Mind you he hates doing it for hours on end. If he had a CNC machine he could knock out a fair bit of the time involved then just finish them by hand. With rotors though i think its much more straight forward in some respects until you start looking at his angle cut race bridge ports which are a work of art. In reference to the swirl chamber in CJH's pic, i guess it depends on the intended use of the engine. N/A and high comp i would leave it in. Turbo i would pull it out and kidney shape that bit around the side of the valve. /aaron
_________________ EA SVO Fairmont Ghia - Recaros, Bilsteins, Sunroof, SVO rims and body kit, Genie headers, DBA rotors. T5 steeda triax short shifter. 3.27 lsd. (EL 4.0 ported/polished, rebuilt and balanced, Dev5 cam. J3 chipped EL ecu, AU injectors). |
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| cjh |
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aaron_hogan wrote: Steady ED wrote: They gotta map the CNC program off something. A CNC ported head is only as good as the one hand-ported cylinder that was used to create it. bingo Thats my point about consistency though. The CNC is repeatable. From a shop perspective they should aim to do all base porting by CNC and then finish by hand. Its just a time saver. One of my close mates is running his own Rotary workshop and believe me nearly every engine he builds gets ported in some way. He's doing porting for a couple of other workshops too (he's seriously THAT good at it). Mind you he hates doing it for hours on end. If he had a CNC machine he could knock out a fair bit of the time involved then just finish them by hand. With rotors though i think its much more straight forward in some respects until you start looking at his angle cut race bridge ports which are a work of art. In reference to the swirl chamber in CJH's pic, i guess it depends on the intended use of the engine. N/A and high comp i would leave it in. Turbo i would pull it out and kidney shape that bit around the side of the valve. /aaron You know what a CNC machine is worth?????? A couple of 100G's for a decent one. I just do it by hand just like they did before CNC machines were around. Here's a Pic of my head, EX port verses an EF one. Mines on top.
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| fritzz |
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imo the swirl ridge should be removed in any performance engine. alot of head porters aim at getting the valves un-shrouded as possible to allow less flow interruption when entering the cylinder. wouldn't really help with detonation ether.
_________________ # 1997 EL Falcon GLI - 600+rwkw |
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| cjh |
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Has anybody noticed that all the edges have been "Deburred".
I do this with every cyl head I have modified, whether it be for car or bike. This helps with keeping detonation to a minimum.
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| ebs_4l |
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its my opinion also that for no matter what the use, remove the swirl ridge, its like having a curtain covering a 1/4 of your open valve area... you should de-shroud the valves as much as is possible..
i prefered mine to look more like this. 
_________________ 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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| cjh |
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I'm trying this head first, if it doesn't work out, i'll do the EF head.
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| blackxr6 |
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just reading through your post and had a look at the shop your talking about theres alot of( potential,resonable ) words in there and i notice that the engines are not much more than 1 hp per cubic inch most good race come street engines are around 1.85 to 2.0 hp per cube and wicked outa control race cars or drag are well over that for the price your better off learning and building one your self .cjh i to would be interested in seeing one of these claimed (500 hp) heads. take into account 2v clevend cylinder heads will flow max 490 jack roush couldnt do any better than that so these guys are the best porters on the planet or are you getting a bigger slab of alloy with slightly enlarged ports or the real deal , hope you can fill us in.
_________________ ONCE YOU GO BLACK YOU WILL NEVER GO BACK,what a shame im white .......... |
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| cjh |
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Out of all the engines I have built, only 3 have been dyno'd, by the owners, and usually about 6mths later. The first one was a 245 Hemi in a VG sedan and had 2.92 gears and 3sp manual. It made 120 RWHP at only 2300rpm, which was 100kmh and thats as fast as the guys wanted to do it, coz they were after A/F ratio to tune it better. It was running a little lean.
The second one was a red 308 taken out to 367, all red internals (except crank & pistons), fully balanced, red heads with L34 valves, etc..etc..Blew up the TH400 three times, buggered 1 histall, and would smoke a set of 275/60R15's (on 15 X 10 rims), and it made 320 RWHP, don't know what the torque was, but it would spin up a bit on the rollers, and it had 3.36 LSD gears. The amazing thing with it was it would get 500k's on 65lts of fuel, and 1/2 ton of plumbing gear in the back of it. It was an HJ Sandman Ute, with factory A/C & P/S, TH400 auto, 3.36 LSD . The next one was an XD sedan, 351C (10:1 comp ratio), fully balanced, C10F auto, 9" LSD 3.25 gears, 4 wheel disc brakes, This car is a daily driver, has P/S and the A/C is yet to be mounted., etc ..etc, was being tuned on dyno, after some other idiot mucked around with it, this is in Sunshine Coast, and it manged 270 RWHP, and running lean as hell. I have since sorted it, but hasn't been back to a dyno. All of these engines have had the heads ported by me. All of these engines are daily drivers, and are reliable, coz thats what they wanted. I'm no "Guru", but have a fair idea of what to do.
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| INDUCT |
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not meanin 2 kill ur thunder but from my understandin an research on ford 4l heads urs is far from a good port job....#1, th swirl ridge,like already said on this forum,piss it off....#2,th standard shape of the compression chamber...#3,the size of ur port,size isnt everythin,air flow an air velocity an minimal turbulance is the key....#4,the pollished port,a shiny port is more restrictive then a rough port,a polished port makes air slide over metal causing warmth(static,resistance),where as a rough port(not real rough,im meanin like clean up th burrs an make it neat like eb_4l's job)cause a thin layer of air sits on th rough an allows th passing air through with less resistance.(same as a honing job on a cyl bore...)
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| cjh |
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Have you ever seen the port jobs done on speedway bikes???
They are like mirrors, ever seen port jobs done on the V8 Supercars??, like mirrors, ever seen port jobs done on F1 cars, like mirrors. All that "its gotta be rough", to me is old school. As for velocity of the air going in, thats where my port jobs do well. Same as port jobs on the exhaust. Like a funnel, the air speed gets faster, and denser. That ridge in the head, as far as I can understand, is for direction of the swirl, for better combustion.
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| ebs_4l |
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CJH, no i have not seen a port job done on an F1 car, and im WILLING to bet that you havent either.... hell, ure lucky to get a look at the're exhaust headers.
i HAVE seen the heads off a V8 supercar, during the half a day i spent in the engine dyno room at 888, and i did not see any polished ports, although, i did see some polished insides of the blocks. speedway bikes?? well, i cant claim anything there. however, old school to you or not, polished ports do basically nothing for performance, the thing that is the most old school to me is the term "port and polish" one problem is fuel sticks to polished sufaces, so you loose fuel atomisation from having a smooth surface i take it you are cutting your own valve seats and valves?? since the valve seat is basically THE most important area when looking to increase a ports flow, to be more precise, the area 1/4in before and 1/4in after the valve, hence the need for good de-shrouding. time is better spent on port shape than polishing, and with your exhaust port, that thing is huge... that would be lacking some velocity as for the swirl ridge, it was put there for nothing other than decreasing emissions. it was fords first go at making a 4l head remember.... thats why you never saw the ridge in anything other than a 3.9l head, cos it was a waste of time something for all to consider, Why do golfballs have dimples in them and not just a polished smooth surface???????
_________________ 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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| cjh |
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The dimples are for stability in flight.
When would fuel get a chance to sit there.???? on a polished surface.??? Some of the people I have built engines for have been disappointed about not having a lopy idle, when the specs/info sheet said it would, but I think it was my port & polished jobs as well as other selecting of other things to be done at same time, and in the end, they were very happy with it. I have seen the heads from speed way bikes, got mates that used to race them, about 5yrs ago now, and for the F1 stuff, I was lucky to see a film on how they do stuff, was about 15yrs ago. One shot showed a guy using fog/smoke to see how it was flowing into a ramstack (had a vacuum at the small end), and he was polishing the inside of the ramstack. They did the same for the cylinder heads. The weird part was the guys were wearing lab coats with goggles, and the whole joint was spotless. Those ramstacks they use on the V8 supercars are carbon fibre and they are super smooth. Anyway, when the donk is finnished in my car, I'll be going to the dyno and see what it does. The proof is in the pudding, so they say.
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