slownrusty Posted October 30, 2006 Share Posted October 30, 2006 Gang - Spent the best part of 3+ hours this afternoon port matching my intake to my Port and Polished head. You gotta love getting showered with aluminum from the die grinder. The stock port on the L28ET intake is around 32mm. And I was able to open them up to 41mm to match the huge ports on my head. Should flow quite well! Head should be bolted up this week and piecing the car together slowly. Making progress, all be it slow!! The head: The intake: Regards - Yasin Quote Link to comment Share on other sites More sharing options...
Cruez Posted October 30, 2006 Share Posted October 30, 2006 HAHA... I remember having aluminum flakes all over the place.. Looking good. A assume you are going to smooth up the bores, right? I don't know how far your tool can reach, but is there a way you can taper the intake bore a little more ?? Quote Link to comment Share on other sites More sharing options...
greenmonster80 Posted October 30, 2006 Share Posted October 30, 2006 Small world. I was doing the same thing today. I went to the hobby shop on base to do mine. This way I don't have a bunch of crap to clean up in my garage. Your porting on the intake side is pretty smooth looking. Nice job.. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted October 30, 2006 Share Posted October 30, 2006 Yasin, What tools did you use to port the head? I just bought a P90 and while its off the car I might do some porting and add a wild cam on it.. thanks! Ryan good to see the project is moving along quickly! Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 30, 2006 Author Share Posted October 30, 2006 Thanks guys! Cruez - Yes I am going to smoothen out the port work and make it nice and frictionless as possible. My tools can reach about 3"-4" inside the bore and they are nice tapered as I kept checking as I did the work. The transitions are very smooth. Greenmonster - LOL...yup small world indeed. Yes it was showering aluminum all over my driveway yesterday...I ended up call it quits about 6:30pm and I am sure my neighbors think I am one crazy MoFo! Ryan - I used a Die Grinder connected to my air compressor and bought a set of Rotary Rasp bits that come in different shapes like so, I bought many pieces as the aluminum off the intake bunches up in the rasps and makes them ineffective after about 15-20minutes. Project is coming along! Yasin Quote Link to comment Share on other sites More sharing options...
Mack Posted October 30, 2006 Share Posted October 30, 2006 hate to break it to you, but its not going to flow THAT much better than stock if you are using a stock EFI intake. sure, you can clean up the runners and intake tracts on the head to make the air flow smoother, but all in all, its still getting sucked through a 32mm intake runner. MAJOR bottleneck. the work looks good tho! just get yourself a lonewolf intake and you will be set! Quote Link to comment Share on other sites More sharing options...
tfreer85 Posted October 30, 2006 Share Posted October 30, 2006 Out of curiosity, wouldn't a small Venturi effect help out the flow? As in the case of this "bottleneck"? I mean I don't have a lot of engine building experience, I've just have read a slight bottle neck or taper can increase flow. Tyson Quote Link to comment Share on other sites More sharing options...
karl Posted October 30, 2006 Share Posted October 30, 2006 Do not smooth out your intake runners, they need to be slightly roughend up to keep the air-gas atomization working to its potentail before entering the combustion chamber. The only part you want smooth like glass is the exhaust ports and combustion chamber. Your small intake to large bulb section then back to a small intake runner is going to hurt your flow IMO. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted October 30, 2006 Author Share Posted October 30, 2006 Mack - Here is my intake...a little "modified" from stock....and I will be running a 70mm TB...wink! Yasin Quote Link to comment Share on other sites More sharing options...
naviathan Posted October 30, 2006 Share Posted October 30, 2006 In order to create a venturi effect you would have to start wide and go small which would compress the air. In this case he's starting small and going wide which wouldn't do much of anything. The sudden expansion of the air right before the head could cause he air fuel to atomize a little better, but otherwise it's not going to do much. Wonder if you could take a honing attachment that can reach into the intake and try honing it wider up by the plenum? Quote Link to comment Share on other sites More sharing options...
Mack Posted October 30, 2006 Share Posted October 30, 2006 That looks good! a step in the right direction! still doesnt solve the problems of the stupid small runners tho. Quote Link to comment Share on other sites More sharing options...
proxlamus© Posted November 2, 2006 Share Posted November 2, 2006 Yasin where did ya pick up those rasps?? I have a set from Harbour Freight but .. ehh Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 2, 2006 Share Posted November 2, 2006 I would have to agree, port matching like that 1 or even 2" into the manifold is probably counter-productive. Opening the port as large as possible at the plenum end, tapering to the head end would be productive, and the resultant step at the head would act like an anti-reversionary device helping with that issue at lower flowrates. Quote Link to comment Share on other sites More sharing options...
slownrusty Posted November 2, 2006 Author Share Posted November 2, 2006 an anti-reversionary device helping with that issue at lower flowrates. What is an anti-reversionary device?? Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted November 2, 2006 Share Posted November 2, 2006 I bought many pieces as the aluminum off the intake bunches up in the rasps and makes them ineffective after about 15-20minutes. Project is coming along! Yasin Buy a block of beeswax (not in a honeycomb form but rather melted down and molded into a block) then run your rasp on the block of beeswax prior to using it on the aluminum, this will help to keep the aluminum from clogging the rasp. The beeswax will also make it easy to use a wire brush to clean out the rasp after each use, just remember to apply more beeswax prior to grinding the aluminum. Dragonfly Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 2, 2006 Share Posted November 2, 2006 anti reversionary devices are like "flow check valves" they are present in some headers. Basically it is a device that inhibits flow in one direction, but does not affect it in another. In headers the tubes usually neck down slightly, and project into another larger tube. The increase in velocity through the neck-down makes it hard for gasses to backflow when it hits the larger area of the next tube, and the difference in tube sizes makes for a turbulence at the edges of the flow to prevent it from reversing as well. Basically a small tube dumping into a larger tube is an anti-reversionary device. Leaving a small step at the head/intake manifold juncture (intake manifold being smaller than head opening) causes it to flow in one direction easier than the other direction. I know Gerolamy mentioned that a small step in that area can help with engines that are turbocharged and have exhaust backpressure that is high, and in N/A engines with large overlaps it helps with reversion at lower engine speeds. I second the beeswax suggestion, it helps with loading immeasurably. For my port matching I found cartridge rolls (tapered) from Merit Abrasives in 36 grit to be very fast acting and easier to control than the carbides. Quote Link to comment Share on other sites More sharing options...
Twoeightnine Posted November 2, 2006 Share Posted November 2, 2006 Hey yasin, did you solve the throttle body linkage issue yet. Want to see some pics! (Edit) I just found the pics that you posted. Very nice. Flipped both. Genius. For others. http://forums.hybridz.org/showthread.php?t=114708 Quote Link to comment Share on other sites More sharing options...
Silent Posted November 2, 2006 Share Posted November 2, 2006 i can see the velocity going down the toilet. but never the less, valiant effort! Quote Link to comment Share on other sites More sharing options...
slownrusty Posted November 3, 2006 Author Share Posted November 3, 2006 Tony - I see your point somewhat....but I am not convinced. Its ironic that my daily grind is designing high pressure pipelines (natural gas and water) up to 20" in diameter and 1000psi in Max. Operating Pressure and I have never heard of "anti-reversionary devices" and I deal with an incredible amount of fittings specific to the industry and my life is all about FLOW and PRESSURE and lab testing as well. I went back to my Engineering books last night (Fluid Mechanics) and could find nothing on "anti-reversionary devices" either. From my online research, its seems that your "anti-reversionary devices" are almost like back flow preventers and used heavily in lubrication to prevent some machinery parts from being accidently lubicated...its a fancy one way valve. There were some exhaust references I found but the descriptions were sketchy and I could not find any illustrations or drawings. An engine's intake is the recipient of a certain flow at a certain velocity and volume and basically an internal combustion engine is an Air Pump - this we all know. By increasing the size of the passages (like I've done) increases the overall pump efficiency. Flow due to the combustion chemical reaction is only one way (providing you have a balanced reaction with no back fire), so how can you have backflow anyway? And as well know Turbo engines are all about flow. I am all ears so I am very keen to listen to your reply. Yasin Quote Link to comment Share on other sites More sharing options...
Tony D Posted November 3, 2006 Share Posted November 3, 2006 I defer to Nathan at BCG in Sacramento on this one, they are (were) one of the premier head porters back in the day, and he clearly stated the anti-reversionary benefits of a small step at the manifold / head juncture. Normally it would be smooth, but having a small step there helps with reversion on high overlap cams, and in turbo applications. I will search myself, I just saw some photos of "anti reversion" bulges in headers, I will post the links as I find them. I had heard of them at the head in some production headers for a long time, but recent design practice is to use them along the length of the header primary pipe, whilst stepping up the diameter of the pipe at each juncture. This is latest header design philosophy, and "step headers" are being used more an more in N/A applications. But back to the intake, the step at the head performs the same function as the steps in the headers, no so much 'preventing' reversion, but hindering it without any penalty in flow down the pipe. Natural Gas pipelines are not travelling at supersonic (or near supersonic) speeds, so dynamic flow devices will not have an application there. Take a look in some turbomachinery design texts and you will see the "step" design on turbine discharge piping. Centrifugal compressors are a good place to find a 4" discharge pipe on the machine, but an engineering specification that calls for a 6" check valve and discharge piping into the main header... Some of this is to prevent surge, but it does that by decreasing the speed of the gas in the larger pipe, diffusing to pressure...I digress. This will get way obtuse if we go down that route. I'm going to look for the photos of the reversionary devices in the step headers I saw earlier... wish me luck! Quote Link to comment Share on other sites More sharing options...
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