I agree

While this is the general consensus I am no longer certain of it's accuracy. The V6 engine has more than a few shortcomings of it's own here and they are more than significant enough to call into question the previously accepted cost advantages of that design. No doubt, the ever increasing drive for greater power and improved NVH from the V6 engine is the main culprit here having taken the V6 further and further out of it's once most commonly intended role as a lower cost, V-configuration alternative to the V8. As engineers continue to try to mold the V6 engine into something more and more like the V8 in terms of power delivery and NVH the inherent shortcomings of the 60-degree V6 design become increasingly expensive to overcome calling into question wether there is any significant advantage left at all. I've covered several of these issues already in this thread and wont re-list them here.

Again, this isn't a slam dunk by any means. The V6 design has more than a few disadvantages of it's own here and they are yet again numerous enough to question conventional wisdom on the matter. A 90-degree V8 will indeed typically be heavier than a similar size 60-degree V6, but not hugely so. And while a same size V8 will be wider and a bit longer than the typical V6 it will also be substantially shorter. Packaging differences aren't significant enough to create a problem, or lend a serious advantage, on their own.

Also worth mentioning is the fact that the V8's longer crankshaft lends itself to better NVH, something the V8 hardly needed help with but worth mentioning anyway, and the typical bearing arrangement on a V8's crank lends itself to greater durability in any application, another area where the V8 already possessed an inherent advantage by design due to it's cruciform crank but again worth mentioning.

Again not inaccurate, but it isn't sweeping enough. Friction losses will generally be greater, but again we aren't talking huge amounts here since swept area will be roughly the same. Any increased friction loss will be due to additional bearing surfaces and an increase in valvetrain hardware which is again relatively insignificant when looking at the bigger picture.

In the real world these advantages are more than offset by the superior torque chracteristics and improved combustion characteristics of a same size, 90-degree V8 design. We can see this in the real world with the current crop of ~3.5L V6 engines barely besting V8 designs a liter larger or more in displacement in terms of fuel economy, when they manage to best them at all.

Infiniti's own M35 only manages to best the M45 in fuel economy by 2mpg on the highway and doesn't improve on the M45's city rating of 16mpg at all. This despite 50 more hp and 60 more lb ft of torque in the V8 cars corner. And lest somebody think this somehow uncharacteristic Nissan's V6 is one of the most fuel efficient in it's class outside of some of the high performance versions, and this isn't a hi-po version. The Lexus LS460 bests the majority of the recent direct injection crop of mid three liter V6 engines in city and highway fuel economy ratings, again despite a liter more displacement, and in this case, despite the fact that the Lexus V8 produces nearly as many hp per liter as those smaller V6 engines do. Some may want to point to the LS460's 8-speed automatic but the reality is that this primarily helps with city epa ratings and, given the LS460's 1000lb greater curb weight than the cars packing those direct injection V6 engines, I would say it's fair to call that bit of advantage a wash.

The reality is that you have to look very hard to find V6 engines in the mid 3 liter class which seriously best technologically similar V8's a liter or more larger than those V6 engines in fuel economy. When you do find such an example the V6 is virtually always in a seriously more relaxed state of tune than is the V8. That should be telling us something and leading us to ask questions....like what would the same basic V8 design shrunk to 3.5L be able to muster in terms of fuel economy?

 

I don't have the energy to reply to your entire post right now, but your comment on swept area is not accurate.

Looking at the D37 vs the AJ39, the AJ39 has 5% more displacment, but 18% more swept piston area. In addition to the increased bearing friction looses we agree on, there are more parisitic losses in the V8 due to having to actuate more valves.

Believe me I'm a V8 man and I'm terribly dissappointed that with the impending sale of Jag and LR, the AJ-V8 will become merely a footnote in Ford's history. But with that said, the tradeoffs for engines in the 3.5L to 4.0L range come out heavily in favor of V6s over V8s when all factors are considered.

 

I'm going to stick with my statement here. Were talking about a difference in swept area among same size engines of barely more than 10% when all is said and done. And in the real world that makes so little difference as to barely be worth mentioning. They are, functionally, roughly the same. I think our difference here is in what we each find a significant amount for the purposes of this discussion.

I know that you are, your posts prove this. But I think you need to take a serious look at what is happening with these engines out in the real world because it challenges conventional wisdom and raises questions that cannot simply be answered with what we thought we knew five or ten years ago.

For the heck of it I compared as many models as I could find which offer non hi-po variants of both a V6 and a V8. Not surprisingly this led me to a lot of luxury models, but the data is no less relevant for it and the V6 engines listed in many of these models is virtually the same as can be found in more mainstream models like the Nissan Altima and Ford Fusion.

Infiniti M35: 275hp, 3.5L V6 with 6spd auto........16 city/23 hwy
Infiniti M45: 325hp, 4.5L V8 with 6spd auto........16 city/21hwy

Jaguar S Type 3.0L: 235hp, 3.0L V6 with 6spd auto.....17city/26hwy
Jaguar S Type 4.2L: 300hp, 4.2L V8 with 6spd auto.....16city/24hwy

Lexus LS350: 306hp, 3.5L DI V6 with 6spd auto......18city/25hwy
Lexus LS460: 380hp, 4.6L DI V8 with 8spd auto.......16city/24hwy

Mercedes E350: 268hp, 3.5L V6 with 7spd auto.......17city/24hwy
Mercedes E550: 382hp, 5,5L V8 with 7spd auto........15city/22hwy


I posted the above largely because I thought a few of those watching this thread might be interested in the results....I know I was. Note that design specifics like fuel injection setups, VVT designs and application, etc. were amazingly similar within each brand for the most part. Across the board the hp per liter comparisons were eerily close as well with the largest disparity between six and eight being 7.1hp/liter and the smallest being 4.8hp/liter.

Staying within brands displacement differences range from one liter at the smallest to two liters at the largest, which represents a pretty significant bump, but despite this fuel economy never differs by more than 2 mpg at any point in this impromptu comparo. Even more hp differs by as much as 114 with the closest pairing being 50hp apart. The typical difference in torque, and torque curves, is so vast a comparison is pointless.....just think very, very large.

To be honest I was surprised by the fact that I couldn't find at least one V6 versus V8 comparo that didn't slant more in the V6 engines favor given how much larger and more powerful the V8's were on average. We have V8 engines with significantly more displacement, significantly more torque, and significantly more hp, and yet we have a result that finds surprisingly small differences in fuel economy.

Unless there exists a pretty serious inherent advantage in terms of efficiency for the V8 design this just shouldn't be....at least not with this level of uniformity. Somebody's V6 should stack up better unless there is an inherent reason why they don't.....and by this point I would argue that real world data points to the notion that there is a difference here.

I've tried to poke holes in my own theory and the best one I can come up with is the argument that the assumed improvements in efficiency found in shrinking a V8 from the 4.0-5.5L range found above to 3.5L or so may not come to fruition due to any of several changes necessary to render a V8 in the 3.2-4.0L class. The problem here being that a 3.2L V8 is going to be a very different animal than a 4.2L V8 for several reasons. Either way, the notion merits a bit of thought to say the least.

 

Can't argue with much of what you said, however a 2 MPG higher highway # is a big deal in overall CAFE.

But, I expect the # of V8 engines sold will continue to drop because they are more expensive to manufacture and they are viewed as "evil" by the mass market.

 

A great discussion. Sorry if I missed this in the thread but a wanted to add a few points.

On V6 versus V8 fuel economy, 10% is huge to a company. I think BMW's 335/535 engine is an example of this. BMW already had a small displacement V8 making 300ish HP but developed a turbo six that porbably costs the same as the V8 to improve fuel economy. I would also mention most V6s have more aggressive gearing that hurts fuel economy. I'm guessing this is only a 3-4% penalty.

For production costs, there's something to be said for economy of scale. I'm guessing a production advantage of at least 3 to 1 in favor of the V6. Even a high output V6 can share development/production costs with a mainstream V6. This will give the V6 a significant cost savings over a V8.

Disclaimer, I love V8s and own a AJ-V8. I'm also realistic about the current environment for manufactures and big V6s have seriously eroded reasons for ordering a V8.

 

Since we have included BMW with this discussion here is something interesting with BMW current X5 & the new X6.

The X5 has a 4.8 v8 with 350hp/350tq.

There new X6 has a TTDI 4.0 v8 with 400HP/450TQ.

Actually BMW's new TT4.0 V8 produces more power/tq then the following trucks:

Toyota Tundra 5.7 V8 - 381hp/401tq
Chevy Silverado 6.0 v8 - 353 hp/373tq
Dodge Ram 2nd gen Hemi 5.7 v8 - 380hp/404tq

With Ford promoting Ecoboost (Turbo's) for there I4's and V6's I can see the Ford revamping a new V8 to be smaller, lighter and to include Direct Injection w/TT's for a new generation of v8's.

 

This topic has gotten way wide of "A New V8 from Ford?". And few actual
facts about the "Boss/Hurricane/EcoBoost/What-will-they-call-it-next-week" engine have emerged other than it's supposed to be a V8 (Well, duh!).

In another forum or blog, a bore-spacing figure of about four-and-a-quarter inches was quoted as having been reported "by those in-the-know". This solves what many see as the only blemish in the "modern" (defined as anything more than two valves per cylinder) modular engines. I agree for the most part--gear-driven OHCs would be preferable to chain-driven OHCs, as Ford did in their terrific Indy V8 of around 1965. I don't know if the world-beating Cosworth-Ford DFV 3.0L V8 of Formula 1 fame used gear drive to rotate the camshafts, but I suspect that it did. Anyone is free to correct me there! But chains work pretty well, and chain-drive is doubtless much, much cheaper.

I have read that the first versions that will be sold are SOHC units destined for the 2010 F-150 and perhaps the Expedition. Can anyone confirm or refute this?

I have further read that these will be two valves per cylinder, which I hope will not be true! Can anyone confirm or refute this?

Following the truck chassis two-valve version sometime later will be a four-valve version for the Mustang, and probably a three-valve version, too. Can anyone confirm or refute this? Has anyone got any model-year data for these introductions?

Speculation abounds that somewhere in here Gasoline Direct Injection will be introduced to up either the economy, the power, or both. Can anyone confirm or refute this?

In some thread there's a grainy black-&-white photo of a page from Hot Rod Magazine showing what's supposedly a Ford SOHC V8 partially disassembled--looks like a two-valve "Y" block with cross-bolted main bearings and vertical-drop intake ports like the current modular 4.6 three-valve. Strange valve covers. Anyone have any info on this one?

Finally, Jack Roush is currently campaigning a yellow S197 with a "Ford Experimental" engine at dragstrips beginning last Fall. They have no qualms about letting the fully assembled engine be photographed--there are pictures of it in dragmags and on the www. I've read nothing about it other than it's nicknamed the "777" because it is 7 liters producing 700 HP at 7000 RPM naturally-aspirated, per the scant articles accompanying the photos. Can anyone provide factual details beyond the displacement?

Thanks to each and every forum participant that can provide truthful answers to any of these questions!

I will update this posting often, as this effin' software times-out waaaayyyyy too soon!

Greg "Eights" Ates

 

This topic is NOT about the Boss / Hurricane, but about another V8 that has been speculated about, possibly another update to the Mod family.

The DFV did indeed have gear driven cams.
There were gear drive conversions for the old 427 cammer.
It is unlikely that gear driven cams would be used in production engines, they are too expensive, too heavy, too noisy and do not provide any performance benefit for street engines.

Most everything else you mentioned has been discussed on other MustangSource topics.

 

Yes the Boss 6.2L and 5.0 Mod-volution are 2 different entities

 

Geez, tell me about it, not to mention transmitting alot of harmonics along the way as well. My brother wanted a geardrive for his old Nova and I got him one for his birthday. It was cool for about 2 seconds then after several distributor R&R's along with super-gluing his fillings back in, he was sorry he ever wanted one. The only way I could see something like a gear drive working in a modern production car would be the implementation of some very expensive composite materials to dampen out all the unwanted characteristics.

 

Bob, as we know from race engines, gear driven cams can be designed and maufactured to work extremely well.

However as your brother found out, throwing in your engine some cobbled together gear drive from an aftermarket company can be a disaster.

 

well the v8 to v6 war i have seen cases where v8 did better on milliage, like a good friend of mine had a merc mountainer, one with a v6 one with a v8, his v8 had better mpg do to being able to get the boat moving, so basicaly, there is a happy medium for every motor, before power waste gas, and after pwer saves gas

 

fwiw...the philosphy at ford seems to be going away from v8's in amajor way, in no small part to congress/bush making into law an epa standard of 45? mpg by 2020...this will have MAJOR impact on engine design...count on it. this is the law of the land and will require mega investments to meet the criteria. ford has already announced that turbos will be a major part of their engine designs. this is deja vu for anyone old enough to remember the 70/8's...turbo motors were the norm for lots ofmanufacturers...turbos make sense...and with the advances made in design and durability, turbos will be seeing a major resurgence in the coming years...


food for thought...


jackg
06 sts6

 

V10: Well spoken, V10, but where are the facts about EITHER of these engines?

I've seen blogs where the 5.0 is to be a somewhat modernized 4.6/5.4 V8, and other blogs where the 5.0 is to be the smallest displacement version of a new non-4.6/5.4 V8 that will debut in trucks at around 6.2 liters with the capacity to be stretched to over 7.0 liters. And which one of these is the very real V8 in Jack Roush's dragracing Mustang--or is this yet a third V8 design? And will the current 4.6/5.4 still be offered in various Ford/Merc/Linc models?

Greg "Eights" Ates

 

Well, the guys most folks look to for this kind of info....Fourcam, blue II, Igor, etc....are all essentially reporting the same things as of late.

......The 5.0L is an updated modular with DI, VVT, and a 3.6X bore and not the small displacement Boss/Hurricane that it might have been. Perhaps the most confusing tidbit here is that the 5.0L seems to have adopted the Boss name that the 6.2L Boss/Hurricane family left behind. According to the above this engine is to be pulling Mustang duty by the 2011MY.

.....The 7.0L in the Roush Mustang is a part of the larger Boss/Hurricane family, although I haven't seen much info on it lately to say the least.

....4.6L is dead by 2011 at the latest with the 5.4L to follow soon thereafter.

Granted these are still rumors, take them for what you will. But at this point it seems unlikely that the basics could be very far off and that all of the above people, some of whom are true insiders, could have gotten it all so wrong.

 

Scratch that 5.4L tidbit above. Fourcam has stated elsewhere that not all Mod motors will be dead by 2012. Although, I cannot say if by this he means that some form of the 5.4L will continue or if he is simply including the new 5.0L engine since it does find it's basis with the Mod motor even if it is, effectively, a new engine.

 

Sorry about the triple post. I forgot to give credit to Boomer, our resident keeper of the 2010+ Mustang flame, for already making all of the above info available to us elsewhere in this forum. Your efforts are very much appreciated bro.

 

I try to keep it as up to date as I can

 

Ford did drag out the poor ol' 302 Windsor for several years after the advent of the Mod 4.6 in such rides as the Explorer if I recall. Keeping the 5.4 after the Hurricane hits the streets will be a bit redundant, but probably makes some sense given switch over costs (whatever re-engineering various trannies and platforms would require, ramping up Hurricane production while smoothly ramping down 5.4 production, etc.).

But it seems the writing's on the wall that the Mod motors, as we know them, are probably nearing the end of their life span. A significantly modded Mod 5.0 might carry on in the Stang for a bit, but that may likely be the series swan song.

 

I suspect it will take 5 years to completely roll over to all the new Ford engines.

The 6.8 V10 Mod motor will be gone as soon as the Hurricane / Boss is in production.

The 5.4 Mod should also be rapidly replaced in trucks with the new big V8. I suspect that the 5.4 will linger on for several more years in Ford's BOF SUVs, Navigator & Expedition. There is supposed to be a revised 5.4 Mod for those vehicles that will run on E85.

In the F-150, the 4.6 will probably get replaced buy a turbo 3.5. The 4.6 will linger on for as long as Ford still builds the Panther cars, it's unlikely it makes any economic sense to put more modern engines in those car. The Explorer will go to unibody and V6s. The Expedition may keep the 4.6 for a while, but like the F-150 a turbo V6 should eventually replace it.