Thread: 3.9 to 5.0 litre

Originally Posted by Slunnie

However, others do see the reason for it.

Thats what I'm asking.What advantage does an old type cast iron V8 have over an old type alloy V8?,seems like lots of work for 400cc. Pat

In the words of the Prosche Cayenne ad...

If you have to ask why you need 450BHP to drop the kids off at school your not thinking hard enough..lol

I can definitely see a big power increase from the stock Rover 3.9 to the stock GMH 308

But It costs about 3000 for the kit from marks adapters
Then you have to start changing major components to strengthen everything

As i said its much easier to modify the motor that's there its cheaper and will keep it factory to the eye

The reason im keen on the rover v8 is im putting one in a 67 Cortina as my next project
There is no other motor that i would fit to this car full stop
Lightest v8 i can afford
Plenty of power
Plenty of perrformance parts
Heaps of poeple that dont mind sharing there knowladge about them
And i have one in my land rover and love it

Originally Posted by PAT303

Thats what I'm asking.What advantage does an old type cast iron V8 have over an old type alloy V8?,seems like lots of work for 400cc. Pat

Parts availability. Cheap performance upgrades. Virtually indestructable (no slipped liners, etc), great looking intake manifold, neater engine.

There are a few advantages...

The VB Commodore made from 1978 till 1980 came with 4.2 or 5.0 litre engines, meeting the requirements of the day in terms emissions etc.

A whopping 87kW and 114kW respectively.

VB Commodore Specifications

Cast iron technology is old technology, however strong it may be. I don't dismiss it as an option because of that, rather on the terms of mass and how such an increase will effect the dynamics of the LR into which it is fitted.

You could always just buy a later Range Rover with the Jaguar V8 engine. I recall they were in the order of 500HP, totally modern and not at all agricultural.

Ron.

I have sort of changed my mind on this.
I used to be dead against it, but really a 5litre GM is only about the same weight as a (cast iron) Tdi, especially if you put alloy heads and manifold on.
So no one rubbishes Disco tdi's for bring unbalanced etc.

I personally would prefer a Gen111 to either as they are light and I believe in large capacities they are more reliable as they are designed from the outset to be 5.7 litres or so. I have just finished re reading Tuning Rover V8s and all the problems that the 4.0 and 4.6 have.

The big thing is that large GM flywheel not fitting in the ZF bellhousing.
I reckon you could cut and shut a manual gen111 bellhousing and a ZF bellhousing to make a hybrid, but noone yet seems to have done it.

GM fans I assume that a Gen111 does NOT have the 2 positions drilled for the starter motor that a 350 has for large and small flywheels. I have searched and searched with no result.
Regards Philip A

Back to original question.
You can fit almost any engine, will it comply? That is another question and you will have to check with local requirements.
Simplest from my experience is to keep block and hat that stroked.
Do at least a 4.6 or 4.9L, do the injection system(Haltech or equivalent) and some head work etc.
That way you keep the same engine no, no one will know unless they stripp down the motor or drive it.
There is a huge difference with road manners from a 4L to 4.6, especially in high compression version.
With sufficient funds you can do almost anything the question begs? Why would you? For $8k you get a stroked thumper that will pass engine no inspection and make the car go as it perhaps always should have.

I like going with the KISS principal and its worked for me.

Alternatively, wait till the market section has one where all the work has already been done, they do appear.
Good luck.

Originally Posted by RoverP6B

Cast iron technology is old technology, however strong it may be. I don't dismiss it as an option because of that, rather on the terms of mass and how such an increase will effect the dynamics of the LR into which it is fitted.


Ron.

Any different to the mass increase when fitting a bullbar, driving lights and a winch? Heaps of Landrovers / Range Rovers with those extras added and no complaints about dynamics being effected.