The V8 Owners Forum -

Hi guys

I am looking at buying a land rover stage 1 V8 to take me to my static caravan in cornwall and back a few times a year and i know the std stage 1 engine is de-tuned to 90bhp which doesn't help with the mpg between 10-13 mpg and i have hered that whilst uprating the engine to early range rover speck 135bhp it will slightly improve the mpg to around 20 mpg by replacing the cylinder heads to range rover cylinder heads is this true and if so will i need to change the cam aswell.

i am not looking for a rocket ship with diesel mpg but 10-13 mpg is just stupid.

what do you all think

If it has a high mileage I would look for a 3.9 instead, and change the transfer gears to the RR 0.996, that would give the best possible mileage.

The stage 1 pistons are low compression, they would need changing to get RR spec compression, the heads were the same as the late 3.5s, SD1s. I believe the cam hs different timing also. I had a 1980 RR with a 3.9 cam, 0.996 transfer gears (HC engine) and was very impressed with it. My 85 110 was originally the same as the stage 1, very sluggish and noisy.

My 110 now with 3.9 and auto, disco transfer box is doing around 18mpg, about as good as you would probably be able to get from the stage 1

paul c wrote:My 110 now with 3.9 and auto, disco transfer box is doing around 18mpg, about as good as you would probably be able to get from the stage 1

ah right i see something to think about then

cornish rattler wrote:Hi guys

I am looking at buying a land rover stage 1 V8 to take me to my static caravan in cornwall and back a few times a year and i know the std stage 1 engine is de-tuned to 90bhp which doesn't help with the mpg between 10-13 mpg and i have hered that whilst uprating the engine to early range rover speck 135bhp it will slightly improve the mpg to around 20 mpg by replacing the cylinder heads to range rover cylinder heads is this true and if so will i need to change the cam aswell.

i am not looking for a rocket ship with diesel mpg but 10-13 mpg is just stupid.

what do you all think

The single mod which would improve consumption most would be to up the CR. To about 9.75:1

Take the restrictors out of the inlet manifold[if they are still in] and you should get 132bhp.

nickm wrote:Take the restrictors out of the inlet manifold[if they are still in] and you should get 132bhp.

132 bhp would thier be an improvement on mpg i would be happy with around 20 mpg

Not too sure if mpg would improve.My brother has a stage 1 and he used to get 18mpg with the original 3.5 with restrictors removed.He now has a 4.6 in it and the mpg is the same.

cornish rattler wrote:

nickm wrote:Take the restrictors out of the inlet manifold[if they are still in] and you should get 132bhp.

132 bhp would thier be an improvement on mpg i would be happy with around 20 mpg

There might be a tiny improvement in MPG at steady speeds - but it will be worse if you use the extra grunt.

DaveEFI wrote:

cornish rattler wrote:

nickm wrote:Take the restrictors out of the inlet manifold[if they are still in] and you should get 132bhp.

132 bhp would thier be an improvement on mpg i would be happy with around 20 mpg

There might be a tiny improvement in MPG at steady speeds - but it will be worse if you use the extra grunt.

Hi dave

Right ok i see, so would removing the restrictors make the mpg better or worse on long runs

Hi
Anything that improves engine efficiency has the potential to give better MPG, removing the restrictors will improve eficiency however weather you get better MPG is down to your right boot, you may just get every where quicker and see no improvment. It is a rover 3.5 on carbs (though SUs are pretty good carbs) in 2.5 tons of vehicle with the aerodynamics of a medium sized shed, be honnest with me how many miles per gallon do you expect to get?
If you want good MPG, stick a 4.8 chevy LS motor in it with a decent 5 speed box andrange rover diffs in both axels or a T5/6 six speed and the existing axels and the auto transfer box ratios and you may see 22 to 26 to the gallon on a run if you drive it carefully, however you can but a lot of petrol for the cost of doing that.
Best regards
Mike