Range rover p38 4.6 into a 86 rangie

[wrksux]

as per above how hard is this to do and what kind of cost's would i be looking at, or is there a better alterative to getting some more power out of the engine or say a better transplant

[GRIMACE]

4.6 short block is basically bolt over, than you transfer the heads and ancillaries of your 3.5 to the 4.6...

Keep a track of cost as I too am looking at sum simpler engine transplants.

[lowbox]

if you want to use the front off your old motor you will need a crank to turn the dissie - the 4.6 doesn't have this but you can swap in one from a 3.9 so it's a bit of a PITA but the end result is great.

[Philip A]

if you want to use the front off your old motor you will need a crank to turn the dissie - the 4.6 doesn't have this but you can swap in one from a 3.9 so it's a bit of a PITA but the end result is great.

The distributor is driven from the camshaft.
All you need is a spacer on the front of the crank so that the pulleys are tight as the 4.6 crank is longer than the 3.9 crank. Spacers are available from Graeme Cooper and others. .You will need a cam like the cam in your 3.5 which has a dizzy drive fitted.
Otherwise it is astraight swap as all Rover engine blocks are backwards compatable.
You will not find a simpler conversion than that.
Although the most time you will spend is making the injection work or convrt to carby.
regards Philip A

[Aquarangie]

The 4.6 is a good option and like Phil said, easy to do.

We have a bloke in the RRC with a 4.6 with the same EFI system as yours and runs okay, but the setup isn't ideal as it seems to struggle to rev out past 4000 rpm. The L-ject EFI 'flapper' system is good on a 3.5 but lacks in many ways when you increase the engine size.

Popular EFI upgrades are to convert over to a Motec but it's costly. Megasquirt is also another and much cheaper option but best left to blokes who have an idea about electronics

But overall, the power increase outweighs the niggly little problems in the long term.

Trav

[walker]

I have just installed a 4.6l short motor into my '77 Rangie. It was a fairly easy swap, just takes a bit of time ensuring everything is nice and clean as you put it all back together

Cost: well ended up a bit more than I thought but it's a great motor.

4.6l short motor - $2500
New cam, lifters, timing chain set and all gaskets - $1100 ( I did use all the good, more expensive stuff so you can do it cheaper)
Recondition heads - $250 (doesn't have to be done but if you have it all apart I think it is worth doing)

Total - $3850

[lowbox]

if you want to use the front off your old motor you will need a crank to turn the dissie - the 4.6 doesn't have this but you can swap in one from a 3.9 so it's a bit of a PITA but the end result is great.

The distributor is driven from the camshaft.
All you need is a spacer on the front of the crank so that the pulleys are tight as the 4.6 crank is longer than the 3.9 crank. Spacers are available from Graeme Cooper and others. .You will need a cam like the cam in your 3.5 which has a dizzy drive fitted.
Otherwise it is astraight swap as all Rover engine blocks are backwards compatable.
You will not find a simpler conversion than that.
Although the most time you will spend is making the injection work or convrt to carby.
regards Philip A

Woops brain fade

[jayk]

Where did you get the CAM from to run the dizzy and allow foe the thrust plate at the front of the block on the 4.6?

[armbrup]

Where did you get the CAM from to run the dizzy and allow foe the thrust plate at the front of the block on the 4.6?

You do not need the thrust plate, so you can use the old type 3.9 cam without a shoulder machined andjust leave out the thrust plate.
if you are really paranoid about the cam moving forward, although I have never heard of it happening, you can get a teflon button that screws in the end of the cam, but AFAIK its a lot of stuffing around to set it up.
Regards Philip A

[Lucus]

Later 3.9's/4.0's had the cam thrust plate. My 4.6 runs the camshaft retainer plate. I was unfortunate enought to have a cam that wanted to wander around and self clearance the block (the cam is a heatseeker) so i had to pull the timing cover off and fit the plate. viola noise gone.

PhillpA, im about 2/3rds of the way through converting my ver 3 wolf 3d to a ver4 with coil packs and sequencial fuel and spark driven off a 36-1 crank trigger.

Once thats finished its either getting a thor manifold of a supercharger.

[RangingRover]

PhillpA, im about 2/3rds of the way through converting my ver 3 wolf 3d to a ver4 with coil packs and sequencial fuel and spark driven off a 36-1 crank trigger.

Will be interested to know how much difference (if any) the coil packs make once they're on. Don't think I can be assed doing it on mine, but if it works well, it might go on the very long term list.

[armbrup]

The biggest difference with coil packs is that you ten have the ability to tune a 3 dimensional electronic advance map.
However car makers probably spend more time and money doing this that anything else.
As an example the greatest gains from a Unichip on my 3.9 came not from the mixture compensation, but from the electronic advance curve, which enabled MUCH more advance on light and medium throttle and also on full throttle where the advance could be taken to knock and then backed off at every load point. ( although I doubt that they spent as much time as necessary on this)
With a 4.6, you also have the option of knock sensors wher ethe ECU can recognise Knock and retard just enough to cancel it. I do not know whether the Wolf has this.
But you can still get good gains yourself by experimenting, but a long dyno session is necessary to get maximum gains, and even if you get only 50% of factory gains you are still ahead.
Regards Philip A

[andrew e]

can you use any coil packs? rover ones arent that common, and weckers want big$$$. can you use ones say off an LS1, which are common as, and sell for 150-200 on fleebay?

[Lucus]

Im using some whizz bang coils the i got from fleabay when i bought the ecu.

Im sure you could use ford v8 coil packs or something similar. Im running 4 coil pack i wasted spark config. Im also using two m and w two coil ignitors.

Have a look at the EDIS coil packs that the guys from trigger-wheels use.
im using one of there trigger wheels:

http://trigger-wheels.com/store/index1.html


with the 36-1 trigger disc my ecu know knows with 10deg where the crank shaft is. this means the injector can be trimmed to fire as the valve opens rather than onto the back of a closed valve. Im will also be firing two plugs off each coil so this obviously means a much fatter spark (and hopefully a bigger plug gap) Im hoping the more accurate fuel timing will mean less fuel drop out in the intake tracks and the fatter spark will mean a better burn.

Im looking to increase the torque of the engine and i figure this is a good place to start.

PhillipA the wolf 3d ver 4 has auxillary inputs that can be configured to advance/retard timing. This would be ideal for a knock senor. However i dont plan to run these as i dont run heaps of timing if i can avoid it.

[armbrup]

i think you can use ost popular EDIS coils as long as their current draw can be handled by the ECU outputs.
Re the knock sensors
I think its a bit more complex than that.
I recall reading a story in one of the mags about a GM engineer sitting in the back seat of a Commodore with headphones on checking that the computer was hearing the knock via the knock sensors. They generally use an amplifier and headphones to listen for knock, as do dyno tuners.

Apparently it is a black art to set up knock sensors so that the ECU hears them and interprets the signal generated by the piezo crystal.

Probably this is to refine the final 10-20 %.

I think the only way to really have an engine set up for optimum tune would be to fit the latest ECU eg The Thor 4.6 Motronic, with all the standard sensors, but maybe buying a new 38A ECU with the security and body stuff disabled.


The Wolf and others are good but nowhere near as sophisticated as a Bosch Motronic.
For example the Motronic measures the resistance of every plug on every firing and can detect any single misfire. The ECU also can tell the strength of the firing of each plug, and balance the power of each cylinder individually.
This is a defacto balancing of the engine, and Rover actually increased balance tolerances because the ECU balances each cylinders firing impulse.
Pity the hardware of a 4.6 is not as good as the software.
Regards Philip A

[Lucus]

I think the only way to really have an engine set up for optimum tune would be to fit the latest ECU eg The Thor 4.6 Motronic, with all the standard sensors, but maybe buying a new 38A ECU with the security and body stuff disabled.


The Wolf and others are good but nowhere near as sophisticated as a Bosch Motronic.
For example the Motronic measures the resistance of every plug on every firing and can detect any single misfire. The ECU also can tell the strength of the firing of each plug, and balance the power of each cylinder individually.
This is a defacto balancing of the engine, and Rover actually increased balance tolerances because the ECU balances each cylinders firing impulse.
Pity the hardware of a 4.6 is not as good as the software.
Regards Philip A

True true. I couldnt justify the time and expense to set up a 38a on an engine thats basically a dinosaur. I've made a hobby of tuning the wolf.
At the end of the day my rangie is 14years old. Its only a toy.
I dont get to swing spanners and nut out faults anymore at work so the rangie has taking the place of that.
Im happpy to try new stuff on it just to see what happens

BTW my new setup is based upon a motronic setup.

[RangingRover]

The biggest difference with coil packs is that you ten have the ability to tune a 3 dimensional electronic advance map.

What do you mean by three dimensional? I already control the advance curve of my dizzy in a table using MAP and rpm....

[armbrup]

I should have said,"compared to a mechanical dizzy".

I also have a rudimentary map on a Unichip from my dizzy, but the EDIS is so much more accurate on timing and gives stronger and more accurate spark.
A dizzy is reliant on the camshaft accuracy , which is reliant on the timing chain which streches over time.

AFAIK the main reasons for EDIS are that the carmakers had to guarantee emission compliance over 50 k miles in the USA without servicing, and they couldn't with a dizzy because timing chain stretch changed the timing . Also slop in the chain can cause variations on revving and overrun. You will note that modern cars have a camshaft sensor as well as a crank sensor.
It would be impossible to run the engine with very high compression right up against knock with a dizzy, as car makers do today.

How have you set up your timing map? On a dyno with headphones?

One of my main concerns with going full electronic is that the time and money necessary to get any real gains from a timing map will eat up any fuel savings for years.

At present I run a 14CUX with a Thor manifold on a 3.9, with a Unichip trimming fuel and controlling timing, and now o2 sensors to control part throttle A/F ratio to 14.7:1.

Regards Philip A

[Lucus]

Are you running cats PhillipA? Any reason your not going leaner than 14.7 at cruise?

[cloughy]

Are you running cats PhillipA? Any reason your not going leaner than 14.7 at cruise?

Because the O2 sensors offer closed loop and set the A/F ratio themselves

[Lucus]

Are you running cats PhillipA? Any reason your not going leaner than 14.7 at cruise?

Because the O2 sensors offer closed loop and set the A/F ratio themselves

I get the concept of closed loop. The oxygen sensor dont set the a/f ratio they only provide a voltage (0 to 1v for a narrow band and 0 to 5v for a wideband sensor) to the ecu. The ecu sets the a/f ratio.

My point being that most cars without cats can safely run leaner than 14.7 at cruise and thusly save fuel.

[cloughy]

Are you running cats PhillipA? Any reason your not going leaner than 14.7 at cruise?

Because the O2 sensors offer closed loop and set the A/F ratio themselves

I get the concept of closed loop. The oxygen sensor dont set the a/f ratio they only provide a voltage (0 to 1v for a narrow band and 0 to 5v for a wideband sensor) to the ecu. The ecu set the a/f ratio.

My point being that most cars without cats can safely run leaner than 14.7 at cruise and thusly save fuel.

Yep, sorry for being simple, its obvious the oxy doesn't set the ratio, Its just a signal, but if the ECU decides that in closed loop the A/F ratio is 14.7:1 there is not much you can do about it, as when you decrease inj, cycle on the unichip, the ECU will only up the fuel

[Lucus]

Is the unichip able to bend the oxy signal?

The ver4 wolf allows you to set the target voltage for cruise so you are able to set a lean cruise. I have found that my 4.6 likes to cruise around 15.5/15.7.

It makes the most power and torque around 12.9/13.0 a wot. Likes to idle rich though which frustates me but having changed cams probably doesnt help

Hey Mods. can you move the posts about engine management to a new topic, as we have pretty succesfully hijacked the poor blokes thread!

[armbrup]

I get the concept of closed loop. The oxygen sensor dont set the a/f ratio they only provide a voltage (0 to 1v for a narrow band and 0 to 5v for a wideband sensor) to the ecu. The ecu sets the a/f ratio.

Well I am trying to do things on the cheap. the 14CUX will only run 14.7 closed loop. I do not think it could be altered by a Unichip.The Unichip only bends the TPS and MAF signal (as well as the timing signal), while the O2 sensors take the ECU into closed loop, basically overriding the MAF and TPS until set percentages are reached..

When you look at the signal from the sensors, it constantly varies as the ECU shortens and lengthens the injection duration.
At idle you can see it cycle up and down from 0 to 1volt, but at higher revs it just lights up all the lights on the Jaycar LED tool as it cycles up and down quickly. But the central tendency is towards 0.5volts which is the minimum output of a powered Titania 4 wire sensor.

I tried it as a last ditch attempt to cheaply get better fuel economy without going to a aftermarket ECU.
And it seems to have made more of a difference than any other mod. I appear to get about 10% better around town and more? on the highway.

While the 14CUX is going so well , I cannot justify maybe 1K-2k on an aftermarket ECU and wideband O2 reader.. ( although I am an inveterate "project" person, and have read the Megasquirt stuff many times over)

You may be able to disagree with me , but from what I have read there are diminishing returns on economy vs A/F over 15:1. so there is no way I could recoup the savings in petrol.
Regards Philip A

[Britswed]

I run a P38 motor in my comp truck(87 rangie) it was origanally a 4.0ltr now out to 5.0ltrs roughly.I looked at all different ways of running the motor(as in Rangie coil packs,crank shaft sensor & cam sensor)I eventually bit the bullet and went motec,from memory we had it firing like a two stroke with only the crankshaft sensor connected.The motor was always super smooth with plenty of grunt.It now runs a camshaft sensor as well and it loves water(never stops)

But like everyone says the easiest way is to get a 4.6 and run your 3.9ltr injection system & maybe upgrading the ECU to Unichip or something similar to get the most out of it.

Mal

while iam at it i need new injectors as the rover ones just dont supply enough fuel.Any recomendations???

[armbrup]

while iam at it i need new injectors as the rover ones just dont supply enough fuel.Any recomendations???

I am surprised as the Rover green bands are 23.5Lbs per hour, vs Holden 5 litre at 18.5 lbs.
Have you checked the max duty cycle?
I bought some 4hole injectors from here and they were good to deal with.

http://www.fiveomotorsport.com/Injector_SetsENGLAND.asp
You will note that the red injectors are Ford motorsport and for a 5 litre Mustang.
I am sure you can find bigger ones on the site.
Regards Philip A

[Britswed]

while iam at it i need new injectors as the rover ones just dont supply enough fuel.Any recomendations???

I am surprised as the Rover green bands are 23.5Lbs per hour, vs Holden 5 litre at 18.5 lbs.
Have you checked the max duty cycle?
I bought some 4hole injectors from here and they were good to deal with.

http://www.fiveomotorsport.com/Injector_SetsENGLAND.asp
You will note that the red injectors are Ford motorsport and for a 5 litre Mustang.
I am sure you can find bigger ones on the site.
Regards Philip A

We are now running custom High Compression Ross racing pistons in her and have done some other work,so basically the standard injectors just cant keep the supply she needs for what i want it for


Have sent them a email thanks for that .

Mal

[Euan]

The ver4 wolf allows you to set the target voltage for cruise so you are able to set a lean cruise. I have found that my 4.6 likes to cruise around 15.5/15.7.

The megasquirt has got an Autotune (closed loop) function, that has made very easy to set the target exhaust/oxygen voltage at cruise 110 kph, by leaning it right out, until just before it gets rough and needs more MAP to hold that speed. Hence I have been able to get excellent fuel economy (for a Rangie). Although I had to play for a far while with the acceleration fuel schedule to get rid of the stutter when you power away from that region of the map.
And when the autotune has stoped trying to amend that region of the map in varying environments then you know the other corrections are right.
As it is a low comp eng I’ve also been able to get away with a lot of ignition advance on, in that region.