The V6 has a smaller bore, and shorter stroke

AJ126 V6 = 84.5 x 89.0 x 6
AJ133 V8 = 92.5 x 93.0 x 8

Yes the external dimensions of the V6 and V8 block are the same (cast in the same mould) but the internals are very different, there is no "blanked off cylinders" in the V6, there is just some voids at the front & rear. Internally it is a V6, the blocks are different, you can't fit a V8 crank/rod/pistons into the V6 block.

 

Thank you for clarifying that. Still makes no sense that they did it that way from a weight, materials and packaging standpoint to me. It must have allowed them to use the same accessory drives, mounts etc. but at large cost in bulk and weight, plus the inherent balance issues of a V8 based V6. Weird design decision IMHO.

The V8 itself is pretty impressive engineering in many respects. Still would prefer actual forged rotating assembly to what we have here but can't have it all for 100k apparently.

 

The story I heard is that the R&D guys were told "put together a V6 for testing" and they had the block cast that way to utilise as many parts from the V8 as possible, just to build a testbed quickly & cheaply. And then when the results were good they were told "that's great, we're gonna build it" and it they were like "oh, ok then..."

The number of major shared parts between the two engines is quite extraordinary...

Front cover, rear cover, timing covers, lower sump assembly, oil pump***, water pump, oil filter, flex plate, timing chains, bolts, engine mounts, VVT system, high-pressure fuel pump & hoses, plus lots of other bolt-on stuff.

*** from MY15 the V6 has a new "twin-stage oil pump" which is not shared with the V8, read into that what you will...

 

Hmmm . . . makes one wonder about the vintages of the F-Type flambé cases reported here.

 

Guys, it could just be a marketing decision driven by what else is out there. For the people who want a big motor RWD car, how many are track people? I think most of them. Because really, if you are driving your RWD car in a way that RWD drive matters on public roads then you might be taking things too far.

So for those who do want it for the track: Why are you not buying a Z06 or Viper? Because if you want a street legal track machine, those cars are a better match. The standard tires are better. The motors are stronger.

I think this decision is JLR NA understanding who is likely to spend money on this car and not incurring support costs for a drive train that would be lightly ordered. Yes, some enthusiasts may complain but ultimately a good number of those who purchased in the US would have bought a Viper or Z06 over the RWD R for obvious reasons.

And I'm in that boat. I'm not a HPDE enthusiast and I'm interested in the F-type. I like the "AWD and plenty of electronics to keep me safe" model. And if I were looking for an HPDE car? Z06 or Viper hands down.

 

At least some of the fires were caused by these issues:2015 Jaguar F-Type, XF, XJ Recalled For Potential Stalling & Fire Hazard
2015 Jaguar F-Type, XF, XJ Recalled For Steering Failure, Fire Risk


Btw: not related to tuning unless the reduction pulley was misaligned.

 

In case it might be helpful, here is a comparison of pictures posted on another forum of the V8 (AJ133) and V6 (AJ126) blocks:







The similarity of the blocks and differences in the bores of the cylinders are readily apparent as are the "missing" cylinders.

 

Thanks. That diagram makes me feel better because at least the "missing cylinder" space is empty as opposed to solid metal.

 

Well that'd never happen...

 

It looks like it's about 1/3 metal back there to me. Odd that they eliminated the rear cylinders.

 

Profitability=beancounters, who oversee marketing. Design and Engineering is below these groups. When BMW changed their "Ultimate Driving Machine" slogan to their "Joy" campaign or whatever it was, it actually reflected the non-enthusiast market they were looking to grow into, it''s just that that market wanted to believe they were buying the Ultimate Driving machine so the campaign was a flop and they switched back, but the cars did not. The 5 series was a particular casualty. I am fearful the XF is heading there, but the new body architecture may save it. Broadest appeal to masses sells more cars. Enthusiasts will need to pay more of a premium for the sport features.