Modern Jaguar build quality issues?

[RoverP6B]

Just seen this:

http://twitter.com/dontbuyajaguar

Really doesn't look good - and Jaguar doing nothing to resolve the issues.

[RoverP6B]

I actually quite like the modern Jags, I just don't think much of the engines. I'd still have a dark red X351 with the S/C V8 though.

The bodged V6 is a stopgap while they develop the new "Ingenium" straight six...

[RoverP6B]

A V6 isn't much of a compromise if you do it properly (see Ferrari/Fiat Dino/Lancia Stratos, see also Alfa Romeo Giuseppe Busso Arese V6), but the packaging advantages of the V6 are receding as the transverse-engined FWD platforms are mainly going all-four-cylinder, and there's also a demand to downsize from V8s and V12s, so Jaguar and Mercedes-Benz are returning to the inline six layout (which can also be adapted to/from a V12 as and when required).

http://wot.motortrend.com/1504_cats_out_of_the_bag...
http://www.roadandtrack.com/new-cars/videos/a8645/...

[RoverP6B]

A V8 in itself is a bit of a compromise, it's not an inherently balanced layout, the only way of making it at all balanced is to fit a massively counter-weighted 90-degree crank. A V6 can only be balanced, I understand, with a 120-degree bank angle - but if you've got room for that, you may as well go for a flat six. The solution, therefore, is to halve the bank angle to 60 degrees and either put up with the vibration or add balancer shafts to damp them out. A 90-degree V6 that is just a V8 block with the two rearmost cylinders blanked off is not in any way ideal. The only reason Jaguar went down that route is because the supply of Duratecs from Bridgend was ending and they needed something to fill the gap while they developed the Ingenium straight six.

Packaging a straight six need not be a problem. The advantages of the layout are such that it's worth making space for it.

[RoverP6B]

esso said:

How does a 75 degree V8 with a flat-plane crank work?

Short answer: it doesn't. The vibration you get from a narrow-angle V8 (especially with a flat plane crank) is significant. Quite how Yamaha sorted out their 60-degree V8 for Volvo I really don't know. Jaguar tried a 60-degree V8 (based on the V12) for the original F-type project back in the late 60s but they couldn't get the vibration down to acceptable levels.

[RoverP6B]

Here's the thing: with those TVR engines, the Speed Six, with a softer cam profile and a quiet exhaust, would swap nicely into an old Jag or somesuch doing duty as a refined cruiser. In fact, I've an idea it began life as a Jaguar AJ-6, albeit then being redesigned out of all recognition. Likewise, a 3.9 litre Rover V8 can sound thunderous in a TVR Griffith or Chimaera but soft and burbly in a Range Rover Classic. The V8 in the Ford GT is derived from that in the Crown Victoria and Lincoln Town Car.

The TVR AJP-8, on the other hand, is good at only one thing: making a lot of power and noise. There is no way that it could ever be made refined.