06-02-2022, 07:50 PM
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#51 (permalink)
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I did a video on Head Porting ( , ) that might give you some ideas. There is also Head Porting for Performance & Economy. Also, many years ago I wrote several articles for Allpar.com. There are a few on Head Porting there.
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06-03-2022, 06:59 PM
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#52 (permalink)
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Since you're asking about cylinder head modifications, here are some pictures of the work done on the X-Prize Sonata. For starters, work was monitored using a Super Flow SF-1020 SB flow bench. The head was flowed stock to establish a baseline. The basic concept I was targeting was to have a 4-valve-per-cylinder head deliver "Swirl", and not just "Tumble". I found 2-valve-per-cylinder heads deliver better low-end torque and fuel economy, and 4-VPC heads flowed more total air for better top-end horsepower; swirl versus tumble. Another quirk with the Hyundai 2.4 engine was extremely low valve lift; 0.17"! The amount of air capable of flowing through the valve-seat gap at that lift was minuscule compared to the port sizes. I decided to reduce port sizes to boost velocity.
Second objective -- along the lines of "Swirl" vs "Tumble" -- was to bias the ports so that one intake port would admit the air-fuel charge at an almost straight-in-at-the-tangent direction, while the other would try to come in perpendicular to the 1st one. Initial testing was done with modeling clay to simulate the effect on the flow bench. I raised the floor on one side and lowered the ceiling on the other. This forced the charge high on the one side and low on the other.
After getting the basic shapes I wanted, the clay was removed, the ports thoroughly cleaned, and 2-part epoxy replaced the modeling clay. I used 5 tubes of epoxy on that head! That is the most I ever used on any head. [Unfortunately, I used either too much epoxy or the wrong epoxy, as some of the chunks broke loose from the port walls a couple thousand miles later.]
Since I couldn't use epoxy in the exhaust ports, I had to use a bit of creativity to induce the swirl effect.
The final intake ports were treated with my Powre Lynz. I extended this concept to the intake valves as well. Exhaust valves were polished, then electroplated with a catalyst to enhance ionization of the combustion charge.
Though barely noticeable in the pictures, I radiused all sharp edges in the combustion chamber to take advantage of the Coanda Effect to allow the expanding combustion charge to more easily roll around to the back portions of the combustion chamber.
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06-03-2022, 08:43 PM
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#53 (permalink)
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Freebeard, please know that my internet is painfully slow. I spent over 2 hours uploading this video just for you, as I've discovered you have a penchant for air cooled VW's. It is a Salt Lake City evening news clip from 1999 of the GEET Fuel Processor installed on a 1969 VW Beetle. My apologies for the poor quality, it was digitized from a well-work VCR tape.
https://youtu.be/VFgdX8ep3CU
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06-03-2022, 09:07 PM
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#54 (permalink)
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Lots of interesting work going on there.
It's pretty cool to see another person's approach to making the ICE more fuel efficient. I share a few porting mods that you have done. Mine setup is more about directing the fuel from the injector to my pre-chamber for a lean-burn stratified charge. I also incorporate swirl and tumble at low rpm air velocity 2500 to 3000rpm with one of the intake valves opening point delayed.
On my setup the engine is the most efficient at very light load 2500 to 3000rpm with lean A/F ratio's. To clarify this, it's at -1 inch/hg to 1psi of boost while running around 25 to 30 A/F. On the same stock engine in the same car, it would be around 17" inch/hg with a 14.7 A/F ratio.
At light load its around 5psi of boost and 20:1 A/F. Then at high load it's at 30psi with a A/F ratio avg. of 13.5 to 14.5.
The downside of my setup is it's not driver friendly and the average person would hate driving it because of the very lean hole in the light load part of the map. It requires a down shift to get the rpm past 3200rpm and out of the lean burn hole.
I need to make another video of it since it's been a while.
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06-03-2022, 09:29 PM
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#55 (permalink)
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pgfpro, I took the time to read through your Eclipse thread awhile back. I was very impressed. I had thoughts of things I might have done differently, but you made it work for you. Job well done!
I don't buy into the "reducing pumping losses" theory I keep hearing here. I have a Jeep with a 5-speed manual trans. If I'm going down a hill, I can turn the key off to kill the engine. With it in gear, I stomp the throttle, then let off, then repeat (cable throttle, not DBW). For the life of me, I can't feel any difference! My take on it is that you may reduce pumping losses on the intake stroke shooting for WOT (or as close as you can come to it), but you pay it back on the compression stroke, as there is more mass to compress. My finding is that it becomes a wash. With that in mind, I like to target AFRs in the 18:1 range for normal operation. It's lean enough to make sure every hydrogen and carbon atom from the HC fuel molecules mates up with an oxygen, but not so lean as to reek havoc on the combustion process. I am fully aware of a few examples of ~30:1 AFRs successfully implemented by folks like Bob Krupa (Firestorm Spark Plugs); so if everything else is right, it can work.
Thank you for the kudos. It might be interesting to chat sometime. You seem to "get it" way more than most. If you watched the Head Porting videos I posted above, you will understand how I tried to follow the bouncing ball from air cleaner to throttle body to intake port to combustion chamber... I did a custom piston set for one of the Chrysler 2.2 engines designed to use higher-than-reasonable compression for off-throttle power, yet tolerate reasonable boost on pump gas. It was for a rallye car. Here's a picture of the piston.
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06-03-2022, 09:56 PM
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#56 (permalink)
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Pics of my V3 head.
Stock 4G63 heads are normally flat on the top and bottom of the ports.
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06-03-2022, 10:27 PM
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#57 (permalink)
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Quote:
Originally Posted by mpgmike
I don't buy into the "reducing pumping losses" theory I keep hearing here. I have a Jeep with a 5-speed manual trans. If I'm going down a hill, I can turn the key off to kill the engine. With it in gear, I stomp the throttle, then let off, then repeat (cable throttle, not DBW). For the life of me, I can't feel any difference! My take on it is that you may reduce pumping losses on the intake stroke shooting for WOT (or as close as you can come to it), but you pay it back on the compression stroke, as there is more mass to compress. My finding is that it becomes a wash. With that in mind, I like to target AFRs in the 18:1 range for normal operation. It's lean enough to make sure every hydrogen and carbon atom from the HC fuel molecules mates up with an oxygen, but not so lean as to reek havoc on the combustion process. I am fully aware of a few examples of ~30:1 AFRs successfully implemented by folks like Bob Krupa (Firestorm Spark Plugs); so if everything else is right, it can work.
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I've found there is something to it. Take a sub-2000lb car, put a large displacement engine in it, and then repeat the experiment in 3rd gear, and it really amplifies the difference. The taller the gearing, and the heavier the vehicle, the smaller the proportion of total losses from pumping air through the engine.
I'm unsure if Honda was the first to do this, but starting in ~2003, some of their engines would disengage the camshafts from the valves when decelerating, leaving all of the valves closed, so the air inside acted fully as a spring, returning most of the energy of compression back to the piston (the only major losses being the heat lost from compression to the cylinder walls, plus normal frictional losses).
Later on, the R-series engines' party trick was that, during cruise, the throttle butterfly would swing wide open, and the engine would be throttled by varying valve lift and timing. Their engineers reported they were able to see average improvements of ~6% fuel economy.
I personally run around an 18:1 AFR in my engine. Combustion definitely slows down as you go lean, even as little lean as that is, as evidenced by it needing an extra 6-8° of ignition advance to reach peak BSFC and torque. Slower combustion means more heat is lost through the cylinder walls, and more force is applied at suboptimal crank angles. HCs don't really improve (they're basically zero already) but BSFC and fuel economy still improve. I always chalked this up to gains from running with the throttle more open but I have no way to be certain.
The original engine that I swapped out was capable of around 100mpg on the highway, and it leaned out to a rather absurd 24:1 AFR under certain conditions. When it dropped into lean burn, you'd have to dig deep into the throttle, basically running it wide open, and just maintain speed. It had a very compact combustion chamber and, when running this lean, it would switch to asymmetrical valve opening and direct the charge over an indexed spark plug to make sure it ignited.
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06-04-2022, 12:43 AM
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#58 (permalink)
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Quote:
Originally Posted by pgfpro
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What was your strategy, and how do you feel it worked for you?
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06-04-2022, 01:59 PM
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#59 (permalink)
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Quote:
Originally Posted by mpgmike
What was your strategy, and how do you feel it worked for you?
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This head in the pics hasn't been tested yet. One thing to keep in mind is I built the Talon to be a multi-purpose car.
It had to be fast, 0 to 60 mph in less then 2.7 seconds and low 9 second 1/4 mile car.
It had to be an extremely great winter driving condition vehicle.
It had to able to drive on mountain dirt roads and also a dirt track race car. In which it has won our local dirt drags two times now.
and it had to get at least 40mpg combined and 45mpg freeway.
The pics of the head above will be used on my 71 Camaro project. This setup will make around 1400HP with a 2.0L 4G63 engine that will be a compound setup with an 88mm feeding a 59mm or a 51mm turbo. The fuel to make this power will be GEM 42. It will also have a 92 pump gas setting that will be my street tune at around 700HP. It will also have a waste solvent tune in it that will make only 400HP. So the pics of the my V3 head has to be more on the HP side vs the FE side. This is a stock cast 1G head that probably is in the top 5 highest flowing in the world I have flow numbers but I'm not going to post them because I don't want to get to rapped up in flow bench racing.
So, to answer your question my main strategy is to guide fuel to my prechamber in combination with my spray guided pistons. On my setup all the FE gains came from the prechamber ability to run a very lean A/F ratio. As far as intake pumping losses on my setup I have tested NA lean burn (16inch/hg) vs the turbo pre chamber lean burn (1.5inch/hg to 1psi) and I can see a 20% increase in FE running the turbo setup. These test we're done on three different engines 1.5L D15 Honda, 1.6L D16Z6, tested on my Del Sol in my write up on here, and my 2.0L 4G63 that is being used in the Camaro and Talon.
IMO 8psi or 16.29inch/hg of intake vacuum is measurable force the engine feels, so it has to take away from the engines efficiency. How much does it help to my 20% gain in FE I don't know because there are other factors going on here ie gain in air pressure to help with swirl and directional flow to the pre-chamber, and great engine delt P to get ride of all exhaust to have a clean
combustion charge on the next cycle and one more added feature is utilizing the air for combustion cooling purposes. I can make a 30psi hit and watch the coolant temps go up to 206*F and then run it in lean burn and within 3 minutes coolant temps drop to 180*F and the exhaust EGT's will drop drastically. One of the questions I get most is " running that lean aren't you worried the engine is going to melt lol my reply back is while in lean burn you can watch the coolant temps drop 10* and I can pull over and touch the exhaust manifold. Infact its so bad I have a turbo manifold blanket to keep the heat in.
The Talon isn't the best platform being AWD and a Auto even though it has lock up converter. But I Love this car. On my Honda Del Sol with not as a refined Turbo Lean burn setup I could get 65 to 70 MPG Freeway depending on what route I took. The Del Sol had a very poor cd. but it still did amazing for what it was.
For what it's worth I'm not an expert or engineer. Its just my hobby to build race engines and now FE engines. I don't have anything to sell. The technology I'm using is old as me so its really not anything new.
I've been ask to show pics of my pre-chamber and I can't do to fear of patent infringements. Lets just say my PC looks similar to a very large company that is involved in F1, even though I wrote a post on a very large F1 forum that this company would most likely be seen and have one or more teams using their PC before the F1 hybrid era. pre 2014.
So once again I'm just a good old boy from Idaho playing with cars
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Last edited by pgfpro; 06-04-2022 at 03:08 PM..
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06-04-2022, 02:04 PM
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#60 (permalink)
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In Lean Burn Mode
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Crap forgot a couple pics.
Dirt Drags
Camaro 4G63 engine
Camaro
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