slemke Posted March 17, 2021 Share Posted March 17, 2021 46 minutes ago, jpd80 said: The 500 hp suggestion I made earlier in the thread was simply adding 10% to the GM 6.2 figure, much better flowing head design opens up possibilities. You could have used the LT2 figure from the c8 corvette. Then your number would be ~550hp. Much better flowing heads will be the key. A so so effort will raise lots of questions just like the original 190/210hp 4.6 1 Quote Link to comment Share on other sites More sharing options...
jpd80 Posted March 17, 2021 Share Posted March 17, 2021 2 hours ago, slemke said: You could have used the LT2 figure from the c8 corvette. Then your number would be ~550hp. Much better flowing heads will be the key. A so so effort will raise lots of questions just like the original 190/210hp 4.6 It will probably be a lot more than I said, is Ford is sandbagging with power numbers? Quote Link to comment Share on other sites More sharing options...
theoldwizard1 Posted March 17, 2021 Share Posted March 17, 2021 22 hours ago, fuzzymoomoo said: Koennegsegg has an interesting electronic valve system that could have a future if they were willing to license it or something. But is it cost effective ! Quote Link to comment Share on other sites More sharing options...
theoldwizard1 Posted March 17, 2021 Share Posted March 17, 2021 13 hours ago, slemke said: There is also a YouTube of some guy modifying a harbor freight predator engine to use an electronic valve system run by his laptop. It uses pressurized air to move the valves. Quote Link to comment Share on other sites More sharing options...
fuzzymoomoo Posted March 17, 2021 Share Posted March 17, 2021 29 minutes ago, theoldwizard1 said: But is it cost effective ! I'm not sure. I read a technical write up on it a few years ago. It sounded expensive for sure but as you know if production is scaled up enough the price drops. Quote Link to comment Share on other sites More sharing options...
ESP08 Posted March 17, 2021 Share Posted March 17, 2021 21 hours ago, jpd80 said: I saw a YouTube where they measured the torque required to turn an engine with older conventional ring package and a newer low tension package. With the plugs removed, most engines can be turned over easy enough by hand so the amount of drag is comparatively not that much. I'm not saying there's no friction or resistance, just that it's not as much as most think. A freshly built V8 engine with normal standard tension rings (12 lb ring pull) generally has a rotational torque of 12-14 lb-ft. With an assembled valve train that varies based on spring pressures, certainly increases in breakaway torque as valve springs do have something of a regenerative effect when in motion. I think it's fairly hard to determine with normal hand tools/normal resources how much the frictional losses are just from the changes in lifters/followers/general valve actuation. The OHC valve-train certainly has to deal with MUCH less moving force as OEM Ford GT/GT500 followers/lash adjusters are proven serviceable to over 10,000 rpm while all of the current pushrod engines need significant investment like a shaft mounted roller rocker (Jesel) system, upgraded lifters, thick wall pushrods etc. to stay together reliably much over 7000. Quote Link to comment Share on other sites More sharing options...
jpd80 Posted March 17, 2021 Share Posted March 17, 2021 (edited) 4 hours ago, ESP08 said: A freshly built V8 engine with normal standard tension rings (12 lb ring pull) generally has a rotational torque of 12-14 lb-ft. With an assembled valve train that varies based on spring pressures, certainly increases in breakaway torque as valve springs do have something of a regenerative effect when in motion. I think it's fairly hard to determine with normal hand tools/normal resources how much the frictional losses are just from the changes in lifters/followers/general valve actuation. The OHC valve-train certainly has to deal with MUCH less moving force as OEM Ford GT/GT500 followers/lash adjusters are proven serviceable to over 10,000 rpm while all of the current pushrod engines need significant investment like a shaft mounted roller rocker (Jesel) system, upgraded lifters, thick wall pushrods etc. to stay together reliably much over 7000. Good discussion. A little context on my previous posts. Back in the day, a SBC with 5/64" compression rings and 3/16" oil ring pack could have up to 45 lb ft breakaway torque to rotate the crank. On a modern 408 Windsor with 2mm oil control and 1mm compression rings, that number is reduced to 10-15 lb ft. That I agree is a combination of low tension rings and matching honing techniques, newer piston skirt design but it's all lower friction. I agree, Valve train weight has always been the undoing of OHV pushrod engines, keep the springs light and stay below 7,000 or even 6,000 and valve train load is relatively light. Higher rpms mean heavier springs which then required stronger pushrods and rockers. All of that means higher rotational force that the OHC by eliminating the lifters and pushrods leaving a much lighter actuating assembly. Again agree, Below 7,000 rpm, the performance and compactness of a wedge head pushrod engine shines but the moment we star talking about engines reving North of 7,000 rpm, you simply cannot deny OHC/DOHC comes into it element. Horses for courses. We all hope that the 6.8 is a strong performer, we just don't know what heads and valving is going on it but knowing Ford it will delight some and disappoint others, it's the way of the world. Edited March 17, 2021 by jpd80 Quote Link to comment Share on other sites More sharing options...
theoldwizard1 Posted March 22, 2021 Share Posted March 22, 2021 On 3/17/2021 at 12:18 PM, ESP08 said: The OHC valve-train certainly has to deal with MUCH less moving force as OEM Ford GT/GT500 followers/lash adjusters are proven serviceable to over 10,000 rpm while all of the current pushrod engines need significant investment like a shaft mounted roller rocker (Jesel) system, upgraded lifters, thick wall pushrods etc. to stay together reliably much over 7000. The key to the mind blowing near;y 9,000 RPM NASCAR pushrod engines are special valve springs ! The Spring That Revolutionized NASCAR 1 Quote Link to comment Share on other sites More sharing options...
Stray Kat Posted March 22, 2021 Share Posted March 22, 2021 Hang on a second.... turning an engine with a particular ring pack over by hand is one thing but that’s not really what goes on dynamically when an engine is running. Those forces of combustion are both pushing the piston into the thrust wall and at the same time acting on the rings by blowing them out into the cylinder wall. Big difference there. I don’t know the math formula to figure it out. I guess it’s not even necessary to know as intuitively one is correct by saying thinner lighter rings and lighter piston assemblies will reduce parasitic losses. Quote Link to comment Share on other sites More sharing options...
ESP08 Posted March 22, 2021 Share Posted March 22, 2021 1 hour ago, Stray Kat said: Hang on a second.... turning an engine with a particular ring pack over by hand is one thing but that’s not really what goes on dynamically when an engine is running. Those forces of combustion are both pushing the piston into the thrust wall and at the same time acting on the rings by blowing them out into the cylinder wall. Big difference there. I don’t know the math formula to figure it out. I guess it’s not even necessary to know as intuitively one is correct by saying thinner lighter rings and lighter piston assemblies will reduce parasitic losses. Right, but the discussion was going in the direction of rotating the engine by hand. Quote Link to comment Share on other sites More sharing options...
slemke Posted March 23, 2021 Share Posted March 23, 2021 14 hours ago, theoldwizard1 said: The key to the mind blowing near;y 9,000 RPM NASCAR pushrod engines are special valve springs ! The Spring That Revolutionized NASCAR I’ll bet they aren't cheap either. At some point an ohc architecture becomes more cost effective. Does it even matter on an inline engine? Quote Link to comment Share on other sites More sharing options...
jpd80 Posted March 23, 2021 Share Posted March 23, 2021 7 hours ago, slemke said: I’ll bet they aren't cheap either. At some point an ohc architecture becomes more cost effective. Does it even matter on an inline engine? You'd be wrong about the price of springs, in 2012 prices, it was about $28 per spring or around $500 a set. The big issue with spring failure was manufacturing defects, the coiling of the wire creates a rough surface that generates surface flaws that eventually failed in service. In 2012, the inspection process had upwards of a 25% rejection rate until changes in the fabrication process reduced defects, improving the quality. Quote Link to comment Share on other sites More sharing options...
slemke Posted March 24, 2021 Share Posted March 24, 2021 16 hours ago, jpd80 said: You'd be wrong about the price of springs, in 2012 prices, it was about $28 per spring or around $500 a set. The big issue with spring failure was manufacturing defects, the coiling of the wire creates a rough surface that generates surface flaws that eventually failed in service. In 2012, the inspection process had upwards of a 25% rejection rate until changes in the fabrication process reduced defects, improving the quality. About the same price as a set of 32 springs for a Coyote on Amazon. So no real cost savings. Spring sets for an LS are $150 or less. Can always find something more expensive. I wouldn’t call them cheap, but not exotic expensive either. Maybe we will get some 8000 rpm monster after all. SOHC 2 valve may still be a lower cost solution than pushrod for high rpm applications. Quote Link to comment Share on other sites More sharing options...
theoldwizard1 Posted March 25, 2021 Share Posted March 25, 2021 On 3/23/2021 at 6:33 AM, jpd80 said: You'd be wrong about the price of springs, in 2012 prices, it was about $28 per spring or around $500 a set. The big issue with spring failure was manufacturing defects, the coiling of the wire creates a rough surface that generates surface flaws that eventually failed in service. Are you refering to the PSI springs or typical valve springs. IIRC, there is some fancy metallurgy used in the PSI springs. Quote Link to comment Share on other sites More sharing options...
jpd80 Posted March 25, 2021 Share Posted March 25, 2021 (edited) 3 hours ago, theoldwizard1 said: Are you refering to the PSI springs or typical valve springs. IIRC, there is some fancy metallurgy used in the PSI springs. My point was that the NASCAR springs that were developed to survive at 8,000 rpm were not as expensive as some may think. Changes were made to the process to eliminate the rough surface on the wire when formed, that eliminated the surface flaws causing spring failures. A big part of that change was: 1. Super Clean wire from Japan which was virtually free of inclusions and flaws that caused spring failures 2. A change in forming process that forced any flaws into the centre of the wire Contrary to popular beliefs, the answer wasn’t just stiffer and stiffer springs, it was actually correcting an imperfect manufacturing process that people had lived with for decades. Edited March 25, 2021 by jpd80 1 Quote Link to comment Share on other sites More sharing options...
ESP08 Posted March 25, 2021 Share Posted March 25, 2021 (edited) 3 hours ago, jpd80 said: My point was that the NASCAR springs that were developed to survive at 8,000 rpm were not as expensive as some may think. Changes were made to the process to eliminate the rough surface on the wire when formed, that eliminated the surface flaws causing spring failures. A big part of that change was: 1. Super Clean wire from Japan which was virtually free of inclusions and flaws that caused spring failures 2. A change in forming process that forced any flaws into the centre of the wire Contrary to popular beliefs, the answer wasn’t just stiffer and stiffer springs, it was actually correcting an imperfect manufacturing process that people had lived with for decades. In the pic below is a comparison between 1.42" install height 4.6 4V springs: Left - PAC 1500 series - super clean wire stock, polished and nitrided surface (the NASCAR stuff) Middle - Associated Springs/Manley Nextek - super clean stock but no special surface treatments Right - Stock spring If you zoom in and you can see how the spring surface gets progressively rougher Edited March 25, 2021 by ESP08 2 1 Quote Link to comment Share on other sites More sharing options...
edselford Posted March 30, 2021 Share Posted March 30, 2021 To get the kind of volume ford needs to justify this new 6.8 V8, ford is probably going to replace the 3.5 ecoboost V6 on all hybrids on the F150! This also means that the future hybrids on Navigator and Expedition hybrids will also get the 6.8 V8. Maybe utilizing the atkenson cycle combustion to increase efficiency. The supercharged versions for the Mustang and Raptor F150 would not utilize the atkenson cycle. edselford Quote Link to comment Share on other sites More sharing options...
rmc523 Posted March 30, 2021 Share Posted March 30, 2021 45 minutes ago, edselford said: To get the kind of volume ford needs to justify this new 6.8 V8, ford is probably going to replace the 3.5 ecoboost V6 on all hybrids on the F150! This also means that the future hybrids on Navigator and Expedition hybrids will also get the 6.8 V8. Maybe utilizing the atkenson cycle combustion to increase efficiency. The supercharged versions for the Mustang and Raptor F150 would not utilize the atkenson cycle. edselford So you're just making things up? 1 Quote Link to comment Share on other sites More sharing options...
jpd80 Posted March 31, 2021 Share Posted March 31, 2021 14 hours ago, edselford said: To get the kind of volume ford needs to justify this new 6.8 V8, ford is probably going to replace the 3.5 ecoboost V6 on all hybrids on the F150! This also means that the future hybrids on Navigator and Expedition hybrids will also get the 6.8 V8. Maybe utilizing the atkenson cycle combustion to increase efficiency. The supercharged versions for the Mustang and Raptor F150 would not utilize the atkenson cycle. edselford But see, your logic falls apart when the 6.8 is effectively a replacement for the 5.2 V8, I think the intent is to keep the 6.8 exclusive so it doesn't affect Ford's CAFE numbers. The idea of a hybrid 6.8 is interesting but I wonder if Ford is really thinking of replacing the 3.5 EB / Powerboost. Hooefully, we get some more detaiks soon..... Quote Link to comment Share on other sites More sharing options...
slemke Posted March 31, 2021 Share Posted March 31, 2021 6 hours ago, jpd80 said: But see, your logic falls apart when the 6.8 is effectively a replacement for the 5.2 V8, I think the intent is to keep the 6.8 exclusive so it doesn't affect Ford's CAFE numbers. The idea of a hybrid 6.8 is interesting but I wonder if Ford is really thinking of replacing the 3.5 EB / Powerboost. Hooefully, we get some more detaiks soon..... I think we would see a coyote hybrid first. I was actually a bit surprised the powerboost did not use the coyote. From a marketing perspective it makes sense to use the most expensive gas engine in the lineup and expand on it. it will certainly be interesting to get more details on the 6.8l. I think to be viable, it would need to have greater availability than just replacing the predator. Are the materials and mfg costs that much less to offset the engineering effort? Quote Link to comment Share on other sites More sharing options...
theoldwizard1 Posted March 31, 2021 Share Posted March 31, 2021 21 hours ago, edselford said: To get the kind of volume ford needs to justify this new 6.8 V8, ford is probably going to replace the 3.5 ecoboost V6 on all hybrids on the F150! This also means that the future hybrids on Navigator and Expedition hybrids will also get the 6.8 V8. Being old, I have a touch of CRS disease so I may be wrong ! Doesn't the current EcoBoost 3.5L use 12 injectors ? 6 "typical" and 6 HPDI ? IIRC, the engine runs on the PFI "most" of the time and the DI only kicks in under high load/WOT. This keep particulate emission low. Big cost savings getting rid of those 6 high pressure injectors and all the associated plumbing ! 1 Quote Link to comment Share on other sites More sharing options...
blksn8k2 Posted March 31, 2021 Share Posted March 31, 2021 Since we seem to have moved into the wild-assed speculation phase, what if Ford decides to make the 6.8 in both iron and aluminum block versions? The iron block could be the replacement for the 6.2 in truck applications while the aluminum block version could replace the 5.2 in the GT500 and could also serve duty in the 2022 Raptor. It's not as if Ford hasn't done something similar in the past. Both the 4.6 and 5.4 mod motors were examples of very similar strategies. 1 Quote Link to comment Share on other sites More sharing options...
edselford Posted March 31, 2021 Share Posted March 31, 2021 No, hybrid with 6.8 is an educated guess based on statements made by Canadian union president “Windsor will have stable volumes” with the 6.8 I sort of agree that it could include a cast iron block for F250/F350 and an aluminum block for F150, Mustang, Navigator and Expedition. Yes I do remember ford making 4.6/5.4 with both at the same time! Yes, allot we don’t know but it’s fun to speculate. edselford Quote Link to comment Share on other sites More sharing options...
slemke Posted April 1, 2021 Share Posted April 1, 2021 Maybe this becomes Ford’s equivalent of the 392 hemi and they shove it in anything that it will fit as a premium running out of ice special edition. The 3.5EB would still be available...I don’t see it being dropped unless Ford has a 3.6-4.5l EB v8 in the works also. I’ll speculate it will be SOHC, high revving (7500+ rpm) 2v per cylinder making 650hp in top tune. Naturally aspirated and aluminum block to save weight and give better handling balance than the predator v8. who is keeping track of the guesses? 1 Quote Link to comment Share on other sites More sharing options...
jpd80 Posted April 1, 2021 Share Posted April 1, 2021 13 hours ago, theoldwizard1 said: Being old, I have a touch of CRS disease so I may be wrong ! Doesn't the current EcoBoost 3.5L use 12 injectors ? 6 "typical" and 6 HPDI ? IIRC, the engine runs on the PFI "most" of the time and the DI only kicks in under high load/WOT. This keep particulate emission low. Big cost savings getting rid of those 6 high pressure injectors and all the associated plumbing ! Knowing Ford, all those added costs are already being factored into the price and passed onto customers. The back to basics 7.3 was a mental reset by Ford as it zoned in on what was really needed in SD trucks and vans, the needs and statutory requirements in segments like F150 and utilities dictate complex solutions that in time will be supplanted by electrification, Ford seems comfortable with current ICEs until electrification really takes hold. 14 hours ago, blksn8k2 said: Since we seem to have moved into the wild-assed speculation phase, what if Ford decides to make the 6.8 in both iron and aluminum block versions? The iron block could be the replacement for the 6.2 in truck applications while the aluminum block version could replace the 5.2 in the GT500 and could also serve duty in the 2022 Raptor. It's not as if Ford hasn't done something similar in the past. Both the 4.6 and 5.4 mod motors were examples of very similar strategies. 7.3 in various power ratings seems set to replace the 6.2 in Super Duty and E Series, the 6.8 is shaping as the replacement for the low volume high performance 5.2 V8 that is Currently restricted to just Mustang. 7 minutes ago, slemke said: Maybe this becomes Ford’s equivalent of the 392 hemi and they shove it in anything that it will fit as a premium running out of ice special edition. The 3.5EB would still be available...I don’t see it being dropped unless Ford has a 3.6-4.5l EB v8 in the works also. I’ll speculate it will be SOHC, high revving (7500+ rpm) 2v per cylinder making 650hp in top tune. Naturally aspirated and aluminum block to save weight and give better handling balance than the predator v8. who is keeping track of the guesses? I'm thinking that the 6.8 V8 is most definitely a remedy for the 392, the potential is huge. 2 Quote Link to comment Share on other sites More sharing options...
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