I am probably being really dim here, but what kind of benefit do you get from fitting uprated heads to your engine?

I understand that you make ports larger, make the inlets/outlets better for air flow etc. but in real terms what can you expect to gain?

Mark

More power, more torque, (not sure but maybe more rpm potential), even better economy if you tune for that.

[Edited on 20/1/08 by iank]

The head is where all the power is really.

Anything to do with the bottom end is mostly about making it stay together, especially at high RPM which the new high flowing head will alllow the engine to breath at.

Not discounting cam profiles and compression ratio as well

Ahh, so the better flow increases the engines ability to breath and can therefore raise the power and RPM.

The main reason for my asking is I saw this on flea-bay Linky and wondered what difference it would have on my V8...

Although Zilspeeds comment has prompted something in the back of my head to say the first step would be a hotter cam (than the standard 3.9 one).

Mark

re heads very cheap would have cost a lot more to have porting and cutting of v seats done and skim so yes its a very fair price good luck all you need now is a large 4 barrel holley

[Edited on 20/1/08 by imp paul]

I'm sure there is an established upgrade path for the Rover V8, what it is I couldn't tell you though.
Those heads are quoting a specific CR, which can only ever be accurate for a specific displacement. Your engine being a 4.2 could potentially send the CR through the roof if you just bolted these on.
Some rithmetic required first

[Edited on 20/1/08 by zilspeed]

Hmmm

I think I will stick with my original thought in that they are cheap, but I won't go for them. When I get to the point of wanting more power I will go for cams first!

Cheers for the comments guys

Mark

The Rover V8 is heavily restricted by it's cylinder head design in standard form, hence the rather poor specific output of the "cooking" versions.

Someone commented that an engine can be considered as if it was an air pump. Anything you can do to get it to pump more air through increases potential power. So flowing ports, three angle seats, raising CR, manifold tuning, valve durations lift overlap, increased revs and forced induction can all be considered in air flow terms. The more the merrier. With injection and ecu's you can adjust fuelling and sparks to realise the potential of increased air flow. But it all comes down to getting more air to go through the engine.

The inlet tracts on RV8 engines are horrible on the standard EFI setup, all right angles. Bog bros has a picture of R1 carbs on a Rv8, now thats a better spend of £300 as it must make a difference.

You can easily clean up the heads you have got, these do not have larger valves or anything else so not really that special IMHO, a couple of days with the dremel.