4.6 engine information

we made a video

Absolutely awesome thanks for that. Fascinating to see this with absolutely no other changes.

I know there's the "depends how you drive" argument but let's face it if it is there, I'd use it and something would go bang at some point.

It'd be cool if you could do the next obvious thing and fit a pair of large valve heads. As these can be picked up for £50-100 a pair seems like a no brainer. edited: I see these already have these! Only Merlin lunacy could make a substantial change.

But yeah, you could see how this worked so well as a truck engine as late as the early 2000 but probably less so as a mainstream road car engine as technology overtook it in the 80s and 90s. (even if Rover had a RWD chassis for it).
 
Acceptable changes - It does not count as a ‘substantial change’ if: axles and running gear have been changed to improve efficiency, safety or environmental performance
:thumb::thumb:


That's a real license to do almost anything with a lazy old engine like the RV8.
 
Having had no problems feeding 4.6 power and torque into the P6 chassis for a sustained period now I can only recommend it. Lets face it most of the car is over engineered anyway, and by driving around the known weak link (diff) by not doing burnouts or very hard launches there is no problem using it all.
 
I will disagree with on thing though the "no substitute for cubes". Modern turbo engines instead of the screamers of the past seem to be transforming petrol engines into diesels. My C class makes about the same torque as the 3.5 from 1.6 litres and it does so at 1,200rpm. Let me repeat that - one thousand two hundred rpm. That's why it can pull a ninth gear of 72kph/1000rpm. (45mph - or twice that of the standard P6 4 pot).
 
I will disagree with on thing though the "no substitute for cubes". Modern turbo engines instead of the screamers of the past seem to be transforming petrol engines into diesels. My C class makes about the same torque as the 3.5 from 1.6 litres and it does so at 1,200rpm. Let me repeat that - one thousand two hundred rpm. That's why it can pull a ninth gear of 72kph/1000rpm. (45mph - or twice that of the standard P6 4 pot).

apply the same technology airflow and boost pressures to a 3.5 engine and see how much torque you get then.............
 
Yes of course but a turbo quite definitely is "a substitute for cubes" in the practical sense. I can't say I like it much. I always used to buy entry level premium cars with 6 pot engines for smoothness but these are extinct now. The BMW e34 2 litre 24v six was perfect. modest power, good economy and so smooth.
 
Yes of course but a turbo quite definitely is "a substitute for cubes" in the practical sense. I can't say I like it much. I always used to buy entry level premium cars with 6 pot engines for smoothness but these are extinct now. The BMW e34 2 litre 24v six was perfect. modest power, good economy and so smooth.

Yes you are right in that a turbo will make a good substitute for cubic inches, but it comes at a price, small engines using boost to make the same power as bigger engines pay the price in terms of long term wear and tear, because you have the same loading going through bearings etc a fraction of the size, something has to give
 
Ability of an engine to tolerate extra loads of producing more power depends on how tightly it was originally specified for its planned power output. Some engines seem to have been over engineered for their original marketed output, and will readily tolerate large increases. I have a kit built 'clubbie' with an MX5 1.8L engine (1996 , 90k kms) with a turbo peaking at 7psi, produces 215hp/162kW at the wheels, limited to 7200rpm. Has been tracked a few times, never misses a beat, uses no oil. Nothing internally modified, easy normal driver. Boost comes in ~3500, but smoothly - all depends on the tuning. Bottom end must be well overspecced to handle such large increase in power. Subaru turbos run to 15psi boost, but deliver smoothly, easy drivers.
Big fan of this type of lightly boosted set up if tuned correctly.
 
Ability of an engine to tolerate extra loads of producing more power depends on how tightly it was originally specified for its planned power output. Some engines seem to have been over engineered for their original marketed output, and will readily tolerate large increases. I have a kit built 'clubbie' with an MX5 1.8L engine (1996 , 90k kms) with a turbo peaking at 7psi, produces 215hp/162kW at the wheels, limited to 7200rpm. Has been tracked a few times, never misses a beat, uses no oil. Nothing internally modified, easy normal driver. Boost comes in ~3500, but smoothly - all depends on the tuning. Bottom end must be well overspecced to handle such large increase in power. Subaru turbos run to 15psi boost, but deliver smoothly, easy drivers.
Big fan of this type of lightly boosted set up if tuned correctly.

I would put money on your Mazda engine running that boost outlasting a P6 drivetrain running with a 300lb/ft engine. Really superb motors and oh, that sweet, sweet gearbox!
 
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