8cyl / 4cyl idea March 02, 2016, 07:47:04 PM ok,, I may get escorted off the board for this...........so following your SD SO engine timing firing ordernow imagine you prevent certain cylinders from firing fuel,, yet allowing the spark plug to still spark.1-5-4-2-6-3-7-8= sd firing orderwhile in over drive you push a button that picks 4 relays which re-directs the tan wire of cyl 4,2,6,8 to a high wattage resistor of the same resistive value as the injector.The computer thinks it still see's the injector but its actually seeing a resistor. Spark still happens but no fuel is pulsed because the injector itself is not getting a ground from the eec.this doesn't have to be 4 relays,, it could be solid state for faster switching to decrease the time the eec sees the 4 injectors are missing.during the time you have this idea of mine on" your sending fuel and spark to cyl 1, 5, 3 & 7 onlyYour sending spark only to cyl 4,2,6,8.ducking now.............. Quote Selected
8cyl / 4cyl idea Reply #1 – March 02, 2016, 08:53:53 PM Quote from: jcassity;454109ducking now.............. Ducking won't help... What's your point?? Killing fuel just turns those cylinders into a compressor, not a exactly efficient machine to run...If it could work, you'd want to kill every other one in firing order, not all even or odd... Only thing that works(and not all that well) is deactivating valves and injectors... At that point the cylinders equalize having no pressure at mid travel, pressure at TDC and vacuum at BDC... Even deactivated you'll have the drag of pistons in their cylinders, just think how easy it is(not) to crank a engine by hand that has four pistons in place...BTW the computer doesn't care if there's a load on it's injector drivers or not, once oxygen hits the o2, PCM is gonna start throwing codes... Quote Selected
8cyl / 4cyl idea Reply #2 – March 02, 2016, 09:34:37 PM of course I didn't talk about those pesky valves,, or dead weight being slung around,, lolthe one thing I never considered was the 02 and that more than the dead weight is reason enough to say stupid idea Quote Selected
8cyl / 4cyl idea Reply #3 – March 02, 2016, 11:23:53 PM I wouldnt say it was a stupid idea. Dodge and GM has setups similar to your idea. I just don't know the specifics. Quote Selected
8cyl / 4cyl idea Reply #4 – March 03, 2016, 02:21:57 AM I think more would be gained by deleting the IAC so you can actually coast downhill without any engine braking. Quote Selected
8cyl / 4cyl idea Reply #5 – March 03, 2016, 06:58:32 AM As I said it works but only if you deactivate valves... Honda has a V6 with this feature, kills one bank completely so the one remaining runs so hot they'll build up sludge in that head... As far as IAC, isn't going to make much difference in economy, cylinders are leaned out above 1200-1500 on closed throttle so are mostly just pumping air... Injectors "light off" again when RPMs drop below 1200(may be slightly higher or less RPM but that's the logic)... I could see it with the wideband A/F gauge on the Marauder, on closed throttle it'd go lean off the scale, then as speed reduced suddenly jump back to normal 14.7... Interesting thing was you could almost never feel it, but with gauge sometimes detect switch if watching for it... Quote Selected
8cyl / 4cyl idea Reply #6 – March 03, 2016, 05:04:51 PM Like Tom said, the valves would have to be deactivated. There are several manufacturers doing this, including Dodge on the Hemi, GM on their LS & LT engines, and Honda on their V6's (and some 4 cylinders in hybrids).One thing the manufacturers won't advertise is that killing cylinders causes oil burning. The Honda V6, in particular, can run on 3, 4 or 6 cylinders. It does this by selectively deactivating cylinders 1 through 4. Eventually the spark plugs on those four cylinders will become fouled with oil deposits, and the car will start throwing codes P0301-PO304. When this happens, Honda's fix is to replace the rings and spark plugs on those four cylinders (and only those four cylinders). No honing or any machine work, just pull the pistons, clean the ring grooves, install new rings, and put it all back together. They have extended the warranty on these engines to 10 years/unlimited mileage for this issue, and pay their flat rate techs 6 hours on an Accord or 9 hours on a "truck" (Ridgeline, Odyssey, Pilot) to do this job. The oil burning also fouls the catalytic converter, but Honda won't cover that because it typically shows up long after the ring job has been done. Honda also has cylinder deactivation on the 4-cylinders in the Insight and older Civic hybrids. The Honda hybrid system is not as efficient as the Toyota system because the Honda electric motor is coupled directly to the crankshaft - there is no way to decouple them. This means that in the rare instance that the car wants to run on pure electric power the engine is turning too. To minimize parasitic losses Honda deactivates all four cylinders. This reduces pumping losses but still results in a lot of friction, so those hybrids aren't as efficient as Ford/Toyota/GM/Everyone else's hybrids, which actually decouple the engine and shut it down completely while the electric motor is propelling the car.GM trucks with cylinder deactivation burn a lot of oil and have a lot of mechanical problems with their valve deactivation systems, too. It's actually common for truck owners to reprogram their ECU's to disable the feature. They can also prevent the engine from going into cylinder deactivation by putting the truck in tow/haul mode or by plugging something into the trailer connector that tricks the ECU into thinking a trailer is connected (a simple hitch cover with built in brake light will do).GM actually pioneered this technology, BTW, back in the early 1980's with the much-maligned V8-6-4 in the Cadillacs. It was a huge failure back then because the car's computer wasn't powerful enough to run the system. Quote Selected
8cyl / 4cyl idea Reply #7 – March 03, 2016, 06:17:15 PM Yeah but the 8/6/4 gm engines are certainly a sight to see. Quote Selected
8cyl / 4cyl idea Reply #8 – March 03, 2016, 09:43:39 PM Have you replaced active fuel management lifters on a 5.3L lately? I don't think I'd say they've figured it out. The best cure for V8 fuel consumption is to replace half the cylinders with a very large, very mean turbo, a pair of lumpy cams, and a very deep breathing head.My suggestion: 2.3L Ranger duratec with a worked ST head, a T4 d GT35R turbo, and a large FMIC tied to a WC T5 with a quads4rods bellhousing. Quote Selected
8cyl / 4cyl idea Reply #9 – March 04, 2016, 09:11:17 AM Quote from: TheFoeYouKnow;454144My suggestion: 2.3L Ranger duratec with a worked ST head, a T4 d GT35R turbo, and a large FMIC tied to a WC T5 with a quads4rods bellhousing......in an early '80s Toyota Starlet. I've always wanted to put a good motor in one of those and have fun. Already RWD Quote from: Thunder Chicken;454132GM actually pioneered this technology, BTW, back in the early 1980's with the much-maligned V8-6-4 in the Cadillacs. It was a huge failure back then because the car's computer wasn't powerful enough to run the system.Yup. I remember when these were not that uncommon.The 81 Eldorado had a 368 cubic inch version of this. The 1980 model year had the same size motor without the 4/6/8. I would imagine it wouldn't be too difficult to get the old setup to work on a 4/6/8 if one were to come across one.I've been looking for a 79-85 GM E-body (preferably an 82-85 Buick Riviera with either the Olds 307 or turbo 3.8, but am open to others) so I've actually been doing a little homework on these. They're proof positive that the late '70s to late '80s car market is taking off. I've seen clean ones selling for well over 10K USD. Quote Selected
8cyl / 4cyl idea Reply #10 – March 04, 2016, 11:15:56 AM Quote from: Thunder Chicken;454132One thing the manufacturers won't advertise is that killing cylinders causes oil burning. The Honda V6, in particular, can run on 3, 4 or 6 cylinders. It does this by selectively deactivating cylinders 1 through 4. Eventually the spark plugs on those four cylinders will become fouled with oil deposits, and the car will start throwing codes P0301-PO304. When this happens, Honda's fix is to replace the rings and spark plugs on those four cylinders (and only those four cylinders). No honing or any machine work, just pull the pistons, clean the ring grooves, install new rings, and put it all back together. They have extended the warranty on these engines to 10 years/unlimited mileage for this issue, and pay their flat rate techs 6 hours on an Accord or 9 hours on a "truck" (Ridgeline, Odyssey, Pilot) to do this job. The oil burning also fouls the catalytic converter, but Honda won't cover that because it typically shows up long after the ring job has been done. So you're telling me buying a brand new Accord V6 (which we've been considering) and keeping it for 10 years is a bad idea? My family has never had trouble with Hondas (or Fords) but they've all been 4 cylinder Accords or Civics..... Quote Selected
8cyl / 4cyl idea Reply #11 – March 04, 2016, 01:40:33 PM The 4 cylinder Accords (and CR-V's) from 08-12 burn oil too, and Honda has an extended warranty on them as well. In the 4-cyls the Pistons and rings are replaced (still no machine work though).Honda made some changes to the V6 (added direct injection), but other than that it's the same engine. Don't know if the direct injection setup helped the oil consumption and plug fouling. I dunno whether I'd buy one or not, though the new Fusion Sport with the turbo 2.7 could certainly be on my mind...Back to Honda: the R18 engines in the Civics are pr0ne to engine block cracking. Honda has increased the warranty on them to 10 years/unlimited mileage Quote Selected
8cyl / 4cyl idea Reply #12 – March 04, 2016, 01:43:11 PM Quote from: V8Demon;454149.....in an early '80s Toyota Starlet. I've always wanted to put a good motor in one of those and have fun. Already RWD Yup. I remember when these were not that uncommon.The 81 Eldorado had a 368 cubic inch version of this. The 1980 model year had the same size motor without the 4/6/8. I would imagine it wouldn't be too difficult to get the old setup to work on a 4/6/8 if one were to come across one.I've been looking for a 79-85 GM E-body (preferably an 82-85 Buick Riviera with either the Olds 307 or turbo 3.8, but am open to others) so I've actually been doing a little homework on these. They're proof positive that the late '70s to late '80s car market is taking off. I've seen clean ones selling for well over 10K USD.The engines themselves were actually quite strong. It was the hardware and software driving it that had problems. I'd bet somebody skilled at programming could probably make one work quite well with a more modern ECU, such as a Megasquirt Quote Selected
8cyl / 4cyl idea Reply #13 – March 04, 2016, 03:22:46 PM Quote from: Thunder Chicken;454154Honda made some changes to the V6 (added direct injection), but other than that it's the same engine. Don't know if the direct injection setup helped the oil consumption and plug fouling. I dunno whether I'd buy one or not, though the new Fusion Sport with the turbo 2.7 could certainly be on my mind...Well it's pretty much between a V6 Accord and Fusion Sport as far as our next car purchase..... Quote Selected
8cyl / 4cyl idea Reply #14 – March 04, 2016, 10:05:10 PM Quote from: Thunder Chicken;454155The engines themselves were actually quite strong. It was the hardware and software driving it that had problems. I'd bet somebody skilled at programming could probably make one work quite well with a more modern ECU, such as a MegasquirtFrom what I understand, it's based off an input to the ECU with regards to transmission line pressure. The ECU sees a heavy load, all cylinders fire. Looks VERY easy to defeat, according to this thread: http://www.cadillacforums.com/forums/cadillac-seville-cadillac-eldorado-forum/646673-1981-eldorado-6-0-368-v.htmlQuoteThe variable geometry system is a little primitive but does work and save fuel. I added a switch in the transmission pressure sensor to disable the 864 function for driving around town. I could turn the 864 function on for highway running. Worked great! Quote Selected
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