Rover v8.... crap power...time for a tech topic?
Discussion
This has prob been done at some stage,but today whilst in WH Smith i was flicking through some mags,and an issue of practicle performance cars caught my eye with the front page as per this topic..... had some differing cars all fitted with rv8's in various states of tune,but all making pretty low numbers,now the top one tested was a cobra with some JE heads if i recall,and that made approx 265.... the mag stated that the rv8 heads were very poor in design,and that its pretty hard,not to mention very costly to get anything decent power wise out of them,compared to say a chevy or mopar 2 valve head engine of the same capacity.... now my question,why is the rv8 so inneficient? why are the heads so bad? and what did tvr power do to the engines from standard to make them tvr spec?
And as a final thought,ive seen wildcat heads mentioned on here,what are they and how do they differ from the standard versions?
And as a final thought,ive seen wildcat heads mentioned on here,what are they and how do they differ from the standard versions?
There is a follow up planned.
I was going to that shoot out but the engine wasn't ready. The main problem with all these rolling roads is that while the relative performances are right, the absolute figures are so open to variation that it makes life very difficult. It fell into the Will's argument but I am working on doing an engine dyno vs rolling road comparison with them.
I was going to that shoot out but the engine wasn't ready. The main problem with all these rolling roads is that while the relative performances are right, the absolute figures are so open to variation that it makes life very difficult. It fell into the Will's argument but I am working on doing an engine dyno vs rolling road comparison with them.
combine said:
Forget the mags , go to a race meeting , Rv8's at Rockingham today with 400bhp , and some very good drivers - the Dunlop tuscan challenge , its a great engine !
Im not slating the engine,im certainly happy enough with mine,and amongst my paperwork theres a dyno print out showing 286hp which i think is about right for what it is....... but im just interested in the questions this particular article raised,pretty suree there are some tech minded people on here who can shed some light on the rv8's plus and minus points of its design I read the magazine and I felt the cars were on the whole a pretty poor bunch only one made respectable power for the capacity (the Ginetta with a 3.9 and 240ponies), some sort of re-match is required I feel.
The rover can be made to produce reasonable power but getting 300bhp plus out of it is pretty expensive, as others have already said the head are indeed poor and the intake manifolds are also poor. As we know the std airflow meter chokes the intake and the clockwork spark system isn't much cop.
there are several 5ltr cars running around with 330-350 ponies these days which is getting ,more like it and I managed 270+ from my 4ltr build on std valve sizes so it can be done.
The rover can be made to produce reasonable power but getting 300bhp plus out of it is pretty expensive, as others have already said the head are indeed poor and the intake manifolds are also poor. As we know the std airflow meter chokes the intake and the clockwork spark system isn't much cop.
there are several 5ltr cars running around with 330-350 ponies these days which is getting ,more like it and I managed 270+ from my 4ltr build on std valve sizes so it can be done.
http://www.pistonheads.co.uk/sales/817522.htm
they can make sensible power, but it does cost money. the heads are the weak point, but its still a strong engine that sounds terriffic.
mine made 404bhp and did 20,000 miles before being rebuilt forracing in the challenge gpb. now 360/420.
nothing wrong with that from an engine designed in the 1940s!
they can make sensible power, but it does cost money. the heads are the weak point, but its still a strong engine that sounds terriffic.
mine made 404bhp and did 20,000 miles before being rebuilt forracing in the challenge gpb. now 360/420.
nothing wrong with that from an engine designed in the 1940s!
There's nowt much wrong with the RV8 design in se - but in determining reasonable goals you'll have to remember it was originally meant to be a GM 'ultra small block' V8 with 3.5 litres capacity. With that brief in mind, the head design was probably perfectly adequate. The problem comes with increasing the capacity when the biggest valves you can get into the heads without really esoteric trickery are 43/37 mm - which is what ultimately restricts the sort of power you can reasonably get. For about four and a half litres capacity on a pushrod engine which you won't want to rev beyond 6,000 rpm too much, too often the airflow of well ported big valve heads is still adequate, but go much beyond that and all you're doing is lowering the point in the rpm range at which maximum bhp will happen with a corresponding increase in torque. Of course what sort of power you can get from the RV8 heads is largely dependent on cam choice, i.e. how much all round driveability you're willing to sacrifice. 
Edited by 900T-R on Monday 4th May 10:35
Guillotine said:
http://www.pistonheads.co.uk/sales/817522.htm
they can make sensible power, but it does cost money. the heads are the weak point, but its still a strong engine that sounds terriffic.
mine made 404bhp and did 20,000 miles before being rebuilt forracing in the challenge gpb. now 360/420.
nothing wrong with that from an engine designed in the 1940s!
You're selling the beast then Andy, how come?they can make sensible power, but it does cost money. the heads are the weak point, but its still a strong engine that sounds terriffic.
mine made 404bhp and did 20,000 miles before being rebuilt forracing in the challenge gpb. now 360/420.
nothing wrong with that from an engine designed in the 1940s!
Just caught the tail end of this one, as i am new to the tvr (last week got one) and the engine is a range rover v8 the ecu still thinks its a range rover at 2 tons when its not so the torque is different i have been to rpi engineering in norfolk and have a my chip remapped so better torque, i will try the plug and play device tomorrow and report, i am not a tecccy but have been out in a chim with one fitted and what a diference pull away in 5th from 10 mph...
jamiethetruth said:
Just caught the tail end of this one, as i am new to the tvr (last week got one) and the engine is a range rover v8 the ecu still thinks its a range rover at 2 tons when its not
That one has been publicly debunked by John Ravenscroft at TVR a dozen of years ago - his categorical statement was that no TVRs ever left the factory with ECUs containing Land Rover maps. If the Eprom still contained the Range Rover map you wouldn't be able to rev any higher than 5.250 rpm for starters. Boosted LS1 said:
The best thing about the rover is it weighs next to nothing so bhp & torque should be considered along with the weight. Good engines imo.
Agree - BMEP may suck by current standards, but torque/weight/volume ratio is excellent and power/weight/volume ratio still good. 
900T-R said:
jamiethetruth said:
Just caught the tail end of this one, as i am new to the tvr (last week got one) and the engine is a range rover v8 the ecu still thinks its a range rover at 2 tons when its not
That one has been publicly debunked by John Ravenscroft at TVR a dozen of years ago - his categorical statement was that no TVRs ever left the factory with ECUs containing Land Rover maps. If the Eprom still contained the Range Rover map you wouldn't be able to rev any higher than 5.250 rpm for starters. Andy's engine is fabulous and sounds a dream. But paying for it must have been a nightmare. It takes planning and experience to come up with something as gorgeous as that.
Have you thought of supercharging? SC Power do a 'bolt on' for 4, 4.5 and 5 litres, the latter two including heat exchangers. The power increase is quite remarkable and the 5 litre comes in around about Andy's level. And I don't think I'd like to take his car to a Sainsburys car park whilst the supercharged engine is remarkably docile.
Howard, of White Elephant fame, took one to the continent for Sprint and loved it.
Have you thought of supercharging? SC Power do a 'bolt on' for 4, 4.5 and 5 litres, the latter two including heat exchangers. The power increase is quite remarkable and the 5 litre comes in around about Andy's level. And I don't think I'd like to take his car to a Sainsburys car park whilst the supercharged engine is remarkably docile.
Howard, of White Elephant fame, took one to the continent for Sprint and loved it.
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