new to this tonight!,anyone with experience of putting 1990 3.9 into series 1 p6 v8?.from what i can tell its the distributor wiring that i need help with,what wires go where etc.i have got coil from 3.9,dizzy is 35dlm8,gonna swap sump,pick up,front crank pulley etc,can i keep original water pump?.Also have pipes for oil cooler off pump still on engine but no cooler attached,can i just plumb these together with joint of some kind? Somebody must have done this swap before me. Any help,tips ,greatly appreciated.
engine swap for 3.9 into p6 v8 series one 1970
- Thread starter devoandy
- Start date
You pretty much don't have a choice when it comes the the waterpump,...using the P6B issue is essentially the only option as clearance will prevent any other pump from being used.
In order to do so, the timing cover on the 3.9 will need to be changed, as the waterpump footprint is totally different. You can use either a P6B timing cover with an oil pump spacer plate to accomodate the taller oil pump gears, or you can use an SD1 timing cover.
The best option is the SD1 cover.
The oil pump front cover off the 3.9 engine with the oil cooler feeds can be replaced with another new oil pump front cover, which are readily available.
Does your distributor have the 2 pin or 3 pin module?
What type of inlet manifold/carburettor/s are you planning on using?
The starter motor on the 3.9 will require replacing as the location of the solenoid will impinge on the P6B suspension mounting. All starter motors fitted to the four wheel drive vehicles are essentially of the same design, so none are suitable.
Either of the Lucas starter motors fitted to the P6B will work with a 1990 3.9.
Ron.
In order to do so, the timing cover on the 3.9 will need to be changed, as the waterpump footprint is totally different. You can use either a P6B timing cover with an oil pump spacer plate to accomodate the taller oil pump gears, or you can use an SD1 timing cover.
The best option is the SD1 cover.
The oil pump front cover off the 3.9 engine with the oil cooler feeds can be replaced with another new oil pump front cover, which are readily available.
Does your distributor have the 2 pin or 3 pin module?
What type of inlet manifold/carburettor/s are you planning on using?
The starter motor on the 3.9 will require replacing as the location of the solenoid will impinge on the P6B suspension mounting. All starter motors fitted to the four wheel drive vehicles are essentially of the same design, so none are suitable.
Either of the Lucas starter motors fitted to the P6B will work with a 1990 3.9.
Ron.
Thanks for info,still need a bit more though.I have got a 2pin dizzy,but what wires go where still a question.Where would i get another oil pump front cover?,Is it the length of water pump (ie the front to back bit) that stops the fitment of said pump? or other prob?.I plan to retain original inlet and twin su set up,though i might need a different needle size. Also, thought i might have been able to fit kenlowe fan to create extra space betwween engine and rad?. It seems the devil is in the detail!. Any more info out there! :?
TwinPlenum3500S
New Member
Is it a 3.9 EFi? Why carbs?
TwinPlenum3500S
New Member
Injection .... you get better fuel economy, relaibility and useability. A 3.9 Range Rover is not the original engine, so why the fascination with originality ... I dont get it. A 3.9 EFi is a superb choice to liven up and modernise a Series 1. Lower compression, hence no pinking, need for fuel additive, wont go out of tune, no points .... paint the plenum and rockers grey as per the early P6 and enjoy entering the modern age.
Oil pump front covers are available from Rimmer Bros or I would imagine any Land Rover / Range Rover spare parts supplier. From my understanding, the only difference between the cover on the P6B and those used in LR/RR is the spigot size for the oil filter. After the SD1 was introduced, the size changed and then remained that way.
The P6B waterpumps are referred to as "short nose" pumps for that very reason. All others whether they be SD1 or LR/RR have much longer noses, and this then results on clearance problems between the engine and the radiator. There is also the major problem of the pulleys no lining up should a waterpump other than a P6B issue be used.
Even if you replace the engine driven fan with an electric one, the pulley on the waterpump must still be in the same plane as those on the crankshaft and alternator, not to mention power steering pump if you have one, so that will still dictate the type of waterpump that can be used.
Retaining the original inlet manifold and SU carburettors will require different needles at the very least. The aircleaner and filters used will influence the type of needles fitted. If you use the SU flame trap system as fitted to the P6B, then you will need to fit an engine breather at the off side rear of the lifter gallery as the 3.9 litre engine does not have one fitted at that point.
You will also need to fit the P6B exhaust manifolds as those on the 3.9 exit towards the rear and so will not fit within the confines of the P6B engine bay.
I am pretty sure that the coil for your distributor requires an unballasted 12 volt feed, where as the supply to the coil on the P6B runs through a ballast resistor.
Ron.
The P6B waterpumps are referred to as "short nose" pumps for that very reason. All others whether they be SD1 or LR/RR have much longer noses, and this then results on clearance problems between the engine and the radiator. There is also the major problem of the pulleys no lining up should a waterpump other than a P6B issue be used.
Even if you replace the engine driven fan with an electric one, the pulley on the waterpump must still be in the same plane as those on the crankshaft and alternator, not to mention power steering pump if you have one, so that will still dictate the type of waterpump that can be used.
Retaining the original inlet manifold and SU carburettors will require different needles at the very least. The aircleaner and filters used will influence the type of needles fitted. If you use the SU flame trap system as fitted to the P6B, then you will need to fit an engine breather at the off side rear of the lifter gallery as the 3.9 litre engine does not have one fitted at that point.
You will also need to fit the P6B exhaust manifolds as those on the 3.9 exit towards the rear and so will not fit within the confines of the P6B engine bay.
I am pretty sure that the coil for your distributor requires an unballasted 12 volt feed, where as the supply to the coil on the P6B runs through a ballast resistor.
Ron.
vaultsman
Well-Known Member
TwinPlenum3500S said:
You're right...and certainly right in this case about originality...if the guy wants to go 3.9...so much more efficient with Efi.
But some of us love carbs and the P6 history that goes with them.
Love your car..great work..but...modernise a P6B to something recognisably different? Why? IMHO
vaultsman
Well-Known Member
TwinPlenum3500S said:
You're right...and certainly right in this case about originality...if the guy wants to go 3.9...so much more efficient with Efi.
But some of us love carbs and the P6 history that goes with them.
Love your car..great work..but...modernise a P6B to something recognisably different? Why? IMHO
Hello TwinPlenum3500S,
Your lovely fuel injected P6B is only one of two that I have ever seen. Locally I have never seen one! and that makes yours all the more special as there are so very few of them.
There is certainly no problem in using SU carburettors with current unleaded fuel, the only "no no" is the ethanol blended fuel. The 35DLM8 is an electronic distributor, so no points there. I am sure that a lot of people like the simplicity of carburettors, and the feeling that they can go on holidays maybe to some exotic part of the world, steering their P6 or P6B firm in the knowledge that should something decide that it is going to misbehave, then the fix will be within their toolkit.
Running an electronic ignition with carburettors means a very reliable engine. Set the timing, mixture and idle and you are away. Just the normal routine maintenance from then on. A modern 3.9 with a good cam will certainly transform the P6B, and as you said,..no pinking, no fuel additives, no points, and won't go out of tune.
Ron.
Pilkie
Active Member
SydneyRoverP6B said:
Ron,,
TP's car has been built to his own modern spec,loosing its originality!
Ok if you are into doing that,no problem,and it is no doubt a very nice car!
You do some things to old cars in OZ to keep them running with Jap engines and boxes that are inspired!! Needs must and all that!!
It is one of the things that Rover was going to introduce to the P6, so its a natural progression in a way! But you couldnt buy one from the dealer!
A few have been fitted with fuel injected V8's! If you are really into economy over originality then go for it!!
The nonsense about unleaded causing problems in the V8 is an ongoing argument!
All V8's can happily run on it with slight adjustments!
pilkie wrote,...
In Australia, all Rover V8 engines built from 1986 onwards can happily run on unleaded fuel without any need for modifications to ignition timing or for the need to use fuel additives. Engines built prior to that date can have issues both with the ignition timing,...usually requiring it to be retarded, and the need to use fuel additives to prevent valve seat recession. I have read conflicting information on the need for additives, both from Land Rover and fuel companies within Australia. So to be sure, I used one in my original 1974 3.5 until it was replaced.
Certainly devoandy will have no such problems with his 1990 3.9 litre, which will run perfectly on unleaded fuel.
Ron.
In Australia, all Rover V8 engines built from 1986 onwards can happily run on unleaded fuel without any need for modifications to ignition timing or for the need to use fuel additives. Engines built prior to that date can have issues both with the ignition timing,...usually requiring it to be retarded, and the need to use fuel additives to prevent valve seat recession. I have read conflicting information on the need for additives, both from Land Rover and fuel companies within Australia. So to be sure, I used one in my original 1974 3.5 until it was replaced.
Certainly devoandy will have no such problems with his 1990 3.9 litre, which will run perfectly on unleaded fuel.
Ron.
Me again, been having a think, Sydney rovers tips seem to be the way forward. Reckon i will get an sd1 front cover,retain p6 water pump,assume this compatible with sd1 cover? Next Get a new oil pump front cover,use my 2 pin 35 dlm8 distributor,(exact wiring details still needed please).Retain p6 twin su`s,inlet,exhaust, manifolds,starter,does this sound correct so far? I have got the original coil from the 1990 3.9 range rover,was advised to use this with the 35dlm8 dizzy?.Got a spare p6 motor,so am swapping bits as needed,oil pick up ,sump,crank pulley. Reason for swap is my p6 got low oil pressure with a top end knock,big oil leak,etc,plus i got 3.9 with 60k on it, so this seemed the best option . Have i missed any important details out!?.Been impressed with response from you blokes out there so far,dont let me down now,as i am feeling enthused again. Will post my progress (or not) as the transplant happens,cheers.
TwinPlenum3500S
New Member
Manifolds?
Hello devoandy,
The original P6B and the SD1 timing covers have exactly the same water pump footprint located in the same place relative to the engine. The heater return and thermostat bypass hoses fit in the same position too.
It would be a good idea to fit new oil pump gears too. A new pair for a 1990 3.9 litre engine will fit straight in.
The coil from the 1990 Range Rover is needed as it is designed to work correctly with the 35DLM8 distributor. The suppy to the coil must be 12 volts with the ignition switched on. A ballast resistor must not be used. Looking at the module on the distributor, it is my understanding that the wire closest to the edge of the module goes to the negative on the coil, while the other goes to the coil positive.
You can double check to be sure with Rimmer Bros or your local LR/RR spares centre.
The alternator and its mounting bracket from your P6B engine will also move across to the 3.9. Now that reminds me,...double check that the threads in the ends of the 3.9 heads are the same as those in your 3.5 heads, as there are differences. Heads made prior to 1994 can be 3/3, 3/4 or 4/4..that is the number of bolt holes at each end of the head.
Ron.
The original P6B and the SD1 timing covers have exactly the same water pump footprint located in the same place relative to the engine. The heater return and thermostat bypass hoses fit in the same position too.
It would be a good idea to fit new oil pump gears too. A new pair for a 1990 3.9 litre engine will fit straight in.
The coil from the 1990 Range Rover is needed as it is designed to work correctly with the 35DLM8 distributor. The suppy to the coil must be 12 volts with the ignition switched on. A ballast resistor must not be used. Looking at the module on the distributor, it is my understanding that the wire closest to the edge of the module goes to the negative on the coil, while the other goes to the coil positive.
You can double check to be sure with Rimmer Bros or your local LR/RR spares centre.
The alternator and its mounting bracket from your P6B engine will also move across to the 3.9. Now that reminds me,...double check that the threads in the ends of the 3.9 heads are the same as those in your 3.5 heads, as there are differences. Heads made prior to 1994 can be 3/3, 3/4 or 4/4..that is the number of bolt holes at each end of the head.
Ron.
Hello sydney rover,
Thanks for all your top advice,i think it is going to prove invaluable over the coming weeks.I now feel confident of the task in front of me. Hoping to get it all sorted before the autumn, so will post regular updates for other p6 owners to benefit from my experiences!. Devoandy.
Thanks for all your top advice,i think it is going to prove invaluable over the coming weeks.I now feel confident of the task in front of me.
Hoping to get it all sorted before the autumn, so will post regular updates for other p6 owners to benefit from my experiences!. Devoandy.
Hello Devoandy,
I am pleased that I was able to help.
I look forward to reading how it all goes.
Ron.
I am pleased that I was able to help.
I look forward to reading how it all goes.
Ron.