Advanced user advice needed. Rebuilding 3,5 V8

[Maznaz]

Hi,
I am restoring Range rover classic. I live in Latvia and rover v8 engines in my side are far from well known. Better say they are more like exotic

I studied few books regarding rover v8 (tuning rover v8, rover v8 engine etc.) so I think main things and problem areas of engine and it rebuilding are a bit clear.

Main idea that car will not be as daily cruiser, more like weekend fun wechicle. Engine is removed and ready to rebuid. Engine is 3,5 in rather good condition fited with standart Stromberg CD75 carbs.

Main question fow to improve fuel consumption? I know it is rather funy
As I described earlier it will not be put in daly run so LPG as possible fuel cos cuting option is not interesting.

My main idea is to put late SU carbs with free flow filters, modified exaust, exaust mainfold from late 3,5 efi. pulsar remuved. More precise timing. Improved oil sitem. Inspection and rebuild of all "standart" things - gaskets, seals, bearings, piston rings, cylinder bore honing etc.
Things I am not sure - new chamshaft I guess some "tuned" one. or std. OEM. Timing - duplex or like standart - only with strenghtened theet. New lifters - rhod??? Distributor, plug leads.

It will be very nice if you could advice how to get best results without spending fortune. AM I planning in right direction?

Sorry for bad english hope you understand everything

Maris

[kiwicar]

Your aproach should be to do a good carefull rebuild of the short block, get the mains align board to ensute the crank will spin freely and also ensure the crank is properly straight. The same with all the other reciprocating components, make sure all the deck heights are the same and if it were mine I would lighten the rods and ballance the bottom end and the rods and pistons, a quick hone and a new set of rings on the old pistons would be good.
Mildly port the heads (open the throats out, I am assuming you have the later SD1 type heads if not buy some the P6 ones are junk) and match the chambers. Choose a mild cam (215 to 225 degrees at .05 lift and as big an Lobe seperation angle as you can get) with as much lift as you dare, but check for piston to valve clearance. Headers good, some have found that a deliberate mismatch at the bottom of the exhaust port to the header that leaves a step out of the port is good for power and economy, SU's better than strombergs not as good as efi but either way feed it with cold air fron outside the engine bay, don't stick filters directly over the exhaust headers. Basically a mild tune up with a reasonable cam should improve things provided you don't boot it hard, you want to keep as much torque as you can. you need to get the compression as high as you can, but I have no idea how good your petrol is.
Is it a 4 or 5 speed manual or a 3 or 4 speed auto? this will make a big difference.
Best of luck
Mike

[Maznaz]

hi,
it is 11D engine form RR. originaly fited with 4 speed manual.

thanks Maris

[kiwicar]

The biggest improvment with fuel economy will be to add an fairy overdrive box to the 4 speed, if you are looking at a restoration project then this is not a bad thing as I am pretty sure it was a factory option on the later 4 speed boxes. The only problem will be finding one, on the good side you could still get rebuild kits for old ones about 5 years ago, they may still be made (sombody bought out the rights to them. GKN more recently did an overdrive for the 5 speed. Another route would be to install the transfer gears from the 3 speed auto transfer case as they are about 25% higher than the 4 speed manual ones.
best of luck
Mike

[Maznaz]

hi,
many thanks Kiwicar
please advise, I have LHD car, also box is LHD spec. will overdrive unit fit from RHD box?

[kiwicar]

should be no problem, the transfer cases were the same left and right hand drive (the overdrive unit goes in the power takeoff hole and is driven by and drives back into the box here.) The gear leaver for it will be better placed on that side aswell, if you go GKN then the whole set up is electronic so all you need is a switch on the dash.
Mike

[jefferybond]

Hi,
Main question fow to improve fuel consumption? I know it is rather funy :)
As I described earlier it will not be put in daly run so LPG as possible fuel cos cuting option is not interesting.
Maris

One way to improve fuel consumption is to increase the compression ratio. I assume yours is a 9.35:1? You could fit vitesse pistons to get 9.75:1, which will make it more efficient, and give more power.

You could even go to Rover P6 pistons, which I think are 10.5:1, but this might need high octane fuel to run properly.

Jeff

[katanaman]

High comp might work but in something as heavy as a Range Rover you could end up with detonation meaning you have to back off the ignition which = higher fuel use again.