I'm well aware of the reasons for an engine's specific characteristics, and how they are altered for different applications.
For the 90, the V8 will have valve timing altered to give more torque at low RPM, at the expense of top end power. However in any LR application, the R V8 can't be described as a high performance engine, because it wasn't.
The V8 was the 'high' powered option in the Stage 1, Ninety, One Ten, 127 and all 3 Defender models, as well as the Disco 1, Disco 2, Range Rover (classic) and Range Rover p38 models. Clearly you do not know your LR model history very well
Any other engine option for all of these was less powerful, either as a smaller petrol engine or a diesel.
It really isn't about tuning for this discussion. The RV8 hails from the 1950s. It is never going to make the most specific horse power!!! But that is missing the point of 'displacement'. You rather sound like one of the ****s over on Pistonheads obsessed with power per litre.
Displacement generally gives you more torque. And torque at speed means more power over the rev range.
A graph I put together a while ago.
The Jeep 4.0 is very akin to the 3.9/4.0 RV8 in power. And obviously the 4.6 RV8 makes quite a bit more power than the 2.5 KV6.
The KV6 is a very good engine (we've had 2!!! One in an 825 Sterling and an MG ZS180). The 177hp variant is shown in the graph above. And while it makes comparable PEAK power to a 3.9 RV8 or 4.0 Jeep engine. It makes substantially less power across most of the rev range due to making less torque. This is the advantage of displacement (or forced induction, which is a topic in its own right). Changing the gearing can help offset a lack of torque, but you can only achieve so much and revving an engine hard to extract the power will not do much for fuel economy. As the KV6 Freelander 1 demonstrates quite well, being that it does very similar mpg to any of the Rover V8's, despite the lower displacement and much lower curb weight of the FL1.
So, despite the RV8 being 50 years older than the KV6, it is a far more useful engine for many applications. Which is why Rover/LR/whomever, never fitted it to the heavier larger vehicles.
If all you care about is specific output, then the 1.8 K-Series produced a maximum of 190bhp from Rover, more than the KV6 and is smaller and lighter again..... rather making a mockery of your KV6 statement.
And you only need to look at Honda to find the likes of 120bhp/litre specific output from a production 2.0 n/a engine. But frankly, they would be completely awful in a 90. The KV6 would probably have been pretty good with the right gearing and is not so dissimilar from the performance and output of the BMW 2.8i M52 engine.
Yes in a TVR the R V8 did make some good power, but even TVR binned it eventually, as it wasn't capable of the sort of output power a modern multi valve engine can produce, that's not being anti R V8, it's just a fact that a 2 valve per cylinder engine doesn't make as much power as a similar sized multi-valve engine.
That is a very naive view, oh and completely wrong. TVR had stop using the RV8, because supply of them was stopping. Whether they should have sourced something else or developed their own engines is not really this discussion.
As for OHV 2v engines. Do you live under a rock in a dark damp cave?
For sure multivalve engines have far more curtain area and a wider total powerband. So can generally make high specific outputs.
You can find new designed OHV engines from Ford, Chevrolet & Chrysler in many different vehicles and trucks.
You can buy a Camaro with a 6.2 litre OHV 2v engine with 650hp!
The new Z06 corvette will have 670bhp.
But head over to Dodge and their 2v OHV V8 rocks with 707bhp in a pickup or SUV and 807bhp in the cars!!!!
OHV engines have many great advantages over DOHC ones. Smaller, shorter, lighter, cheaper to build, less complex.
