Interesting fact about Jaguar's new S/C V6

[MinisterofDOOM]

I think I'm pretty well-known for my Jaguar love these days. Particularly, for my fondness of the AJ V8 and Jag's extensive use of aluminum.

So, when Jag started offering this new V6 I had heard next to nothing about in every model they make (even the big XJ!) I started looking into it. To be completely honest, my primary reason for research was a terror that Tata may have gotten lazy and pulled from the ancient Book of Ford for a modified Duratec (something Aston did for their V12s, and which is probably the reason Aston V12s get outclassed by Aston[/Jag/Landrover] V8s in a hurry). I had trouble finding much detail for a bit, but a while back I learned something very interesting and very telling:

The new AJ V6 is just an AJ V8 with two cylinders lopped off. Retains the 90-degree vee angle, and all the other design of the V8, but of course varies displacement according to bore and stroke.

THAT is why it sounds so different from everyone else's V6s. It sounds like a tiny european V8 with a lopey firing pattern--because it is.

So, Jag is doing an odd thing, but it suits their image and products perfectly: They're basically selling the same engine plus or minus two cylinders and plus or minus a supercharger (in either guise) in order to provide a scalable engine platform with very little tooling difference. Brilliant. At least, it's brilliant when the original V8 that spawned the engines was already one of the very very best on earth.

I love my AJ!

[Dattebayo]

That's not saying much, because they'd still have to change the CR, timing, coolant and oiling pathways, change the computer, etc to make it all run right.

Am I correct in thinking this or am I not?

Maybe one day enthusiasts will make a modular cylinder kit for engines so we all can just add a pair of cylinders and maybe swap out a cam or two to get some more power... kinda like adding another rotor to a wankel without all the hassle?

[Jesda]

It's too bad the new XE is so bland inside and out.

[Bubba1]

It's too bad the new XE is so bland inside and out.

Agree. Actually the best Jeeeeeaaaaaags ever built had 6 cylinder engines, of course they were straight sixes.

[lne937s]

What makes it interesting in my mind is that it is essentially the same block as the V8 with 6 holes punched in it. The engines are the same physical size. Two cylinders weren't "lopped-off"-- two fewer holes were punched in the block (obviously there are some internal modifications as well). Many of the castings are the same, sometimes with machining being the differentiating factor. They share the same mounts, hookups and many of the same parts.

It always seemed like an inefficient way to build an engine to me from a weight perspective, but it reduces development costs, simplifies production and seems to work for them.

[MinisterofDOOM]

I guess I worded that wrong. I didn't mean literally the same exact block. But, rather, a 6-pot derivation of the same block design. Much like GM did with their straight 4, 5, and 6 cylinder truck engines. It's essentially the same design, adapted to different cylinder counts. It's common with an inline setup but rare with Vs, since different vee angles suit different formats better than others.

For trivia, an example of the reverse of this situation is Ford's "Yamaha" V8 from the oval Taurus SHO. It was really a Duratec 25 with two extra cylinders. It retained the V6's native 60-degree vee angle, no change in per-cylinder displacement so it went from 2.5 liters to 3.4 (rounding). It sounded great, but sadly was more interesting than good.

It's too bad the new XE is so bland inside and out.

I like it...
It's tamer than the XF and XJ, but far more interesting looking than anything German right now. It's stately, like a Jag should be. It's just not excessively loud for the sake of being obnoxious like everything else these days.

But I'm not interested in the XE. I'm interested in the next-gen, all aluminum XF. That's where things will get really fun.

[Bubba1]

But I'm not interested in the XE. I'm interested in the next-gen, all aluminum XF. That's where things will get really fun.

Yeah, especially the expressions on owner faces when they learn how expensive a minor aluminum fender bender will cost to repair.

[MinisterofDOOM]

The XF already has aluminum body panels. What will change is that the entire body structure will move to aluminum with the next-gen, replacing the current steel platform dating back to the S-type with the more modular bones introduced with the XE. The S-type before it had aluminum bodywork, too. As do many Audis. Repair cost hasn't held any of them back. Nor should it, as NOT building a car out of a structurally superior material out of a fear of a POSSIBLE but unlikely outcome is beyond asinine. Should Ford abandon CF on the new GT just in case someone bumps a shopping cart? That is the single most backward piece of logic I've ever heard in my life.

[PapaSmurf2k3]

Its hardly a new concept. GM made the 4.3 by more or less lopping off 2 cylinder from their 5.7 V8.

[lne937s]

Its hardly a new concept. GM made the 4.3 by more or less lopping off 2 cylinder from their 5.7 V8.

It really is a fairly different concept. The Jag V6 is the same size as the V8. The external surfaces of the engine block casting are the same. Engine length and dimensions are essentially the same. Mounting points and many of the parts are the same.

GM essentially removed cylinders from a V8 engine block. Jaguar essentially punched two fewer holes in the same V8-sized block.

[Bubba1]

I guess I'm more cost conscious about car ownership than you, MoD. I won't ever purchase an aluminum bodied DD like a Jeeaaaag XF, as I have friends in the body work biz as wells as friends that have owned aluminum bodied cars (emphasis on past tense for the owners). As far as comparing aluminum with the CF on the new Ford Gt. You're comparing Apples with oranges. Unlike an XF or Audi A8L which at the end of the day are DD sedans, how many people do you know park their Ford GT's in mall/grocery store parking lots on a regular basis or commute in them? And if you're gonna pay that much money for a supercar, affording CF body work, which is even more expensive than aluminum, is not likely a concern.

[MinisterofDOOM]

I just don't wreck my cars.

[lne937s]

BTW, I found an image of the crankshaft of the jag v6, which is kind of telling of what is going on. If you look at the tail end of the crankshaft between the main bearings where the 4th bank of cylinders would go on the V8, there is just a counterweight and blank space. There were rumors you could just "unblank" the rear set of cylinders on the block and change out the head/crank to make the v6 a v8, but I heard that is not actually true due lack of cylinder liners, machining differences, etc.

[PapaSmurf2k3]

Seems like a good bit of extra weight in the driveline.
Great for manufacturability, not so much for maximum performance.

[MinisterofDOOM]

BTW, I found an image of the crankshaft of the jag v6, which is kind of telling of what is going on. If you look at the tail end of the crankshaft between the main bearings where the 4th bank of cylinders would go on the V8, there is just a counterweight and blank space. There were rumors you could just "unblank" the rear set of cylinders on the block and change out the head/crank to make the v6 a v8, but I heard that is not actually true due lack of cylinder liners, machining differences, etc.

Something's not quite right about that. This isn't just a V8 with two cylinders removed from their bores. It is a V6 BASED ON a V8. The block doesn't have two empty holes sans cylinder liners; it is two cylinders short. Physically reduced in size. Photos all reflect this--it is a much shorter block with a different cam cover bolt arrangement suiting the cylinder count. Just pulling two conrods and two pistons off a V8 crankshaft and replacing them with a weight would be crude, wasteful, stupid engineering. This is like the Chevy Papasmurf mentioned--Based on a V8 and shortened. I spend all day looking at the V8 variant and the 6 is notably shortened.

My guess is that weight is nothing more than a balancer. Since this V6 inherits the AJ135's 90-degree vee-angle, it won't be as naturally balanced as either the AJ135 or a traditional 60-degree V6. That crankshaft weight could serve to dampen that imbalance some. Its placement angle supports that, aligned rotationally with the middle row of cylinders, which could help offset the reciprocating mass difference vs the outer rows.

This is an AJ135 V8:


This is a 3 liter AJ V6:


A bank shorter. Look at the cam cover fasteners--there's no room for a 4th row of ignition coils, nevermind the cylinders beneath them. Look at the exhaust manifolds. Just look at the proportions. The V6 is much more square, where the V8 is longer longitudinally.

Its hardly a new concept. GM made the 4.3 by more or less lopping off 2 cylinder from their 5.7 V8.

And Dodge did the opposite to create the Viper V10. It traces its roots way back to the '60s when it was Chrysler's "small block" alongside the much bigger Hemi.

[lne937s]

You are looking at those engines from two different angles, but if you look at the back of the V6, between the end of the heads and the flywheel, look at that blank space on the back of the block, The heads do not extend to the back of the block and only cover the front three cylinders. In essence, that blank space on the block is where the other cylinders would go in the V8. The block is basically the same as the v8 with the heads only covering the first three cylinders and the rear bank of cylinders blocked off. There is still the rear set of main bearings to support the extra cylinders from the v8 in the v6.

When an acquaintance of my who works at Jaguar/Land Rover told me this was how they were building their v6, I couldn't believe it. But they really developed the v6 by taking the v8 block and putting cylinders and a head to cover the first three pairs of cylinders, with the back pair blocked off. This is why both engines are the same length. This is not like the 4.3l Chevy v6. It may seem like "crude, wasteful, stupid engineering" but that is exactly what Jaguar did.

to quote a R&T article on the topic that I dug up
http://www.roadandtrack.com/car-culture ... r-porsche/

As if someone had capped off the rearmost pair of cylinders on a V-8 block, put a different crank and shorter heads in, and said, "Voila! V-6!"

[RicerX]

This thread has too few F-Type pictures.



Now back to your regularly scheduled posting, already in progress.

[Jesda]

The interior is so... 1998.

[RicerX]

The interior is so... 1998.

WHY DO I LOVE IT?!

[Bubba1]

The interior is so... 1998.

Yeah, it does look 90's. The big styled vent aimed at one's right armpit doesn't seem quite right. Perhaps it looks better in person.

[Jesda]

I hope the materials make up for the lack of imagination. Aside from the platform and the upcoming Ingenium 6, the rest of the car feels like a derivative afterthought.

[lne937s]

To me, what the interior reminds me of is how the mid-90's Aston Martin DB7 started out as an F type prototype that got shelved (you can see multiple similarities in the design). When I look at the interior of the current F Type, I think it looks like what a mid-cycle DB7 refresh would be with modern electronics.


I do have to give Tata credit. They actually had the guts to make a car that had been thought about, postponed, shelved, etc. for decades. Some of the styling and engineering (like the V6 made on a V8 block with the back cylinders blanked off) may not seem like ideal, but they are small in the premium segment making successful premium vehicles that aren't just a bunch of re-purposed parts from lesser cars. The Ingenium 4 cylinder is interesting and I wonder how they are going to reach scale to make it successful (maybe shared with some Tata cars in India?).

[hudy]

You cannot just slap some pistons and a head on the V-6 and call it a day. Completely different. Also the V-6 has a balance shafts at the rear and in the front.You can see the teeth for the balance chain drive near the flywheel. The front balancer is driven by the fuel pump chain. Also, you can only get forced induction now. No NA variants available in any engine(V-8, V-6, and I-4). Like already mentioned, it is a V-6 based on a V-8.

Cool thing is the supercharged V-6 in a 2013 Range Rover is faster than the NA V-8 2012 Range Rover. I don't feel like it was a compromise on the LR4 or Jag XJ either. Plenty of power and sound pretty cool. Can't wait for this summer with the Manual trans F-Type coming(V-6 only at this point). Also getting AWD in the F-Type. Jag/LR coming hard with new product over next few years is pretty cool.

[MinisterofDOOM]

Also getting AWD in the F-Type.

Is the single worst thing I could possibly imagine for the model. I can't fathom what Jaguar was thinking with this. AWD as the ONLY, SOLE, EXCLUSIVE, NON-OPTIONAL drivetrain layout in the V8 R? Unbelievable. NOBODY who has EVER driven an F-type has EVER thought "Oh, gee, I wish this thing weighed 180 more pounds and wasted some of its power on the wrong end. EVER. Jag have lost their gorram minds. As an option, sure. But AWD ONLY? It makes my head hurt just thinking about it, but Jaguar managed to actually DECIDE IT IS THE RIGHT WAY TO DO THINGS. Mindblowing.

If I was a very, very rich man, a V8 F-type would have been extremely high on my list. With AWD, it is now not even ON the list.

I sure wish this industry obsession with AWD would just die already so we can go back to driving real cars that push with the back and steer with the front.

[Bubba1]

Is the single worst thing I could possibly imagine for the model. I can't fathom what Jaguar was thinking with this. AWD as the ONLY, SOLE, EXCLUSIVE, NON-OPTIONAL drivetrain layout in the V8 R? Unbelievable. NOBODY who has EVER driven an F-type has EVER thought "Oh, gee, I wish this thing weighed 180 more pounds and wasted some of its power on the wrong end. EVER. Jag have lost their gorram minds. As an option, sure. But AWD ONLY? It makes my head hurt just thinking about it, but Jaguar managed to actually DECIDE IT IS THE RIGHT WAY TO DO THINGS. Mindblowing.

If I was a very, very rich man, a V8 F-type would have been extremely high on my list. With AWD, it is now not even ON the list.

I sure wish this industry obsession with AWD would just die already so we can go back to driving real cars that push with the back and steer with the front.

With your venting about AWD, it seems you missed the best point, Tata is talking about a man pedal in the F-type!. That's huge and the main reason I, and many other enthusiasts, never considered buying a modern Jeeeeaaaaag sports car. Well that and their downright terrible reliability and awful depreciation rates. As far as AWD, it's not like Jeeeaaag is throwing in the towel and converting their entire lineup to AWD (like Subie or Audi), or converting everything to CVT (like Nissan) . Plus, they've dabbled in AWD before. I seem to recall the X-type was available in AWD. That said, having driven so many AWDers, I don't hate them. I freely I admit I prefer RWD for myself. But for a family member with long daily commute in a snow prone area, I wouldn't mind them driving an AWD vehicle during the winter.

But with CAFE standards getting tougher, I envision the infatuation with AWD levelling off or shrinking due to its being thirstier for fuel than 2WD.

[lne937s]

http://blog.caranddriver.com/block-part ... ce=twitter

saw this in Car & Driver and it reminded me of this discussion