Thread: 4.6 v8 into '85 County 110

Hello Clive,

I have a 4.6 running in my Rover P6B which originally had a 3.5 litre engine.

In both cases I am running twin SU carburettors, with the 4.6 delivering not only 50% more torque but also better fuel economy. I see 10.5 litres / 100km normally, with a best of 9.7 litres / 100km.

I had no problem in bolting my 3 speed transmission to the 4.6, the bolt holes are all still in the same place as my 3.5 which was cast some 30 years earlier.

The 4.6 will totally transform your 110,..you won't be disappointed.

Ron.

I put a 4.2 litre motor from an LSE Range Rover in my '85 County, a great combo. The mob that did it could have put in a 4.6 but I was'nt towing anything & they recommended this motor.
There are reports the 4.6 is a bit "lumpy" & I would have thought a 4.0 with the electronics would have plenty of oomph.
PM sent.
BTW I offered to help out when you drowned your engine up Healesville way & never heard back. Did you get it all sorted?

Just remember that the 4.6 block will only be part of the expense if you are replacing an old dying 3.5 block.

You should have the timing cover/oil pump rebuilt to ensure oil pressure,assuming you use the old setup.
The heads will need a rebuild, including new rocker shafts, rockers, pushrods etc. Lots of money.
The dizzy will need a rebuild.
Carbys will need to be rebuilt.
It could add up to thousands.

IMHO the cheapest way to do it would be to buy a complete low mileage 3.9 dressed engine which would include heads etc, and have the upgrade oil pump etc, if from a late S1 Disco. AFAIK the bellhousing will bolt up no problem. The only problem should be with the routing of the top radiator hose, a minor detail. Also you will have to improvise wiring to the alternator etc. You may also be able to get some money for the injection.
make sure that any engine is complete with Alternator , PS pump, starter etc etc as these things are expensive.
Regards Philip A

Originally Posted by PhilipA

Just remember that the 4.6 block will only be part of the expense if you are replacing an old dying 3.5 block.

You should have the timing cover/oil pump rebuilt to ensure oil pressure,assuming you use the old setup.
The heads will need a rebuild, including new rocker shafts, rockers, pushrods etc. Lots of money.
The dizzy will need a rebuild.
Carbys will need to be rebuilt.
It could add up to thousands.

IMHO the cheapest way to do it would be to buy a complete low mileage 3.9 dressed engine which would include heads etc, and have the upgrade oil pump etc, if from a late S1 Disco. AFAIK the bellhousing will bolt up no problem. The only problem should be with the routing of the top radiator hose, a minor detail. Also you will have to improvise wiring to the alternator etc. You may also be able to get some money for the injection.
make sure that any engine is complete with Alternator , PS pump, starter etc etc as these things are expensive.
Regards Philip A

Yep id go the 3.9 from a late 95 on S1 disco and run the EFI as well and keep it on LPG

Originally Posted by PhilipA

Just remember that the 4.6 block will only be part of the expense if you are replacing an old dying 3.5 block.

You should have the timing cover/oil pump rebuilt to ensure oil pressure,assuming you use the old setup.
The heads will need a rebuild, including new rocker shafts, rockers, pushrods etc. Lots of money.
The dizzy will need a rebuild.
Carbys will need to be rebuilt.
It could add up to thousands.

IMHO the cheapest way to do it would be to buy a complete low mileage 3.9 dressed engine which would include heads etc, and have the upgrade oil pump etc, if from a late S1 Disco. AFAIK the bellhousing will bolt up no problem. The only problem should be with the routing of the top radiator hose, a minor detail. Also you will have to improvise wiring to the alternator etc. You may also be able to get some money for the injection.
make sure that any engine is complete with Alternator , PS pump, starter etc etc as these things are expensive.
Regards Philip A

Also, from memory, you would need to put a larger Dia exhaust system to get the most out of the 4.6

Go the 4.6

There's no substitute for cubic inches!

It will rock

The long stroke 4.6 will produce more low down torque which is what's needed for a heavy 4x4. The 3.9 is smoother due to its bore/stroke ratio and can be tuned, and is ideally suited to something like an MGB. Also, importantly, you should really get a 4.6 block with top hat liners already installed, which I believe the TRS short engines have.

Of course if money is no object :- Go the 4.6 .
A $10,000 motor in a $4000 car. I was being the rational man.

Why not a Gen 3 ?
Would be MUCH cheaper than a well prepped 4.6 in a manual, as adaptors are readily available, and if you want torque, that will give torque.

They weigh the same , the drivetrain will take it, and the ECus are readily available , tunable . There are specialists around who will wire it up reasonably.
Regards Philip A