Status update and potential improvements
Mudding
Joined: Sep 2018
Posts: 155
Likes: 28
The Rover V8 is a very mature engine with a huge history of tuning and upgrades. Besides Land Rovers, it was used in numerous British sports cars. It was essentially the Chevy Smallblock of the commonwealth countries. There's no lack of aftermarket upgrades and tuning options for it. However, because the market is so mature, it would be foolhardy to expect that you will somehow unlock some hidden performance that no one else in many decades of tuning has managed to do. The Rover V8's potential is well understood. Study it and decide if there is a known-good configuration that suits your desires. Just hoping that a few tuning tricks and various upgrade bits will give you fantasy horsepower or mileage numbers doesn't make any sense when it's all been done before.
A custom build is expensive. There's no way around the fact that re-building an engine is going to involve costly parts as well as 30 to 40 hours labor. The bare engine block you found is probably fatally flawed and if it can be used at all, it will most certainly need flanged cylinder liners. The hours of machine work add and add. Just the labor to swap in a junkyard motor is going to be 20 hours, which by most people's books is thousands of dollars. You can search or ask what people who've done a flanged-liner D2 motor swap have spent from start to finish. I don't see it being done right for a lot less than $10K in time and materials. Spending more hours custom coating parts and dollars for upgraded features to chase 23mpg will easily add thousands more with no promise on the results.
The LS swap is coveted only because of the promise of being able to drop in junkyard motors and depend on them without any further work. Used Rover V8's in the US are hopeless because the overwhelming majority of them were imported during the years that the factory was producing fatally flawed engines. Someone might do a Rover for Rover swap and flip the vehicle quickly, but the life expectancy of a used Rover V8 that hasn't been rebuilt with the flaws corrected is very short and so it makes the labor to swap it a waste. A used LS, on the other hand, can be dependable. It remains to be seen that a swap can be done for far less than properly rebuilding a Rover V8. I would also argue that a properly rebuilt Rover V8 is better than a used LS, and every bit as good as a new LS for this application. The LS really has an advantage over the Rover V8 only at higher rpm which is not particularly useful in a Land Rover. Certainly, the LS has more potential but it's mostly potential that isn't suited to a Land Rover. So it's got to be the price. If an LS swap could be done for $5K, it would win because I don't see a long-lasting Rover V8 replacement happening for a lot less than double that.
A custom build is expensive. There's no way around the fact that re-building an engine is going to involve costly parts as well as 30 to 40 hours labor. The bare engine block you found is probably fatally flawed and if it can be used at all, it will most certainly need flanged cylinder liners. The hours of machine work add and add. Just the labor to swap in a junkyard motor is going to be 20 hours, which by most people's books is thousands of dollars. You can search or ask what people who've done a flanged-liner D2 motor swap have spent from start to finish. I don't see it being done right for a lot less than $10K in time and materials. Spending more hours custom coating parts and dollars for upgraded features to chase 23mpg will easily add thousands more with no promise on the results.
The LS swap is coveted only because of the promise of being able to drop in junkyard motors and depend on them without any further work. Used Rover V8's in the US are hopeless because the overwhelming majority of them were imported during the years that the factory was producing fatally flawed engines. Someone might do a Rover for Rover swap and flip the vehicle quickly, but the life expectancy of a used Rover V8 that hasn't been rebuilt with the flaws corrected is very short and so it makes the labor to swap it a waste. A used LS, on the other hand, can be dependable. It remains to be seen that a swap can be done for far less than properly rebuilding a Rover V8. I would also argue that a properly rebuilt Rover V8 is better than a used LS, and every bit as good as a new LS for this application. The LS really has an advantage over the Rover V8 only at higher rpm which is not particularly useful in a Land Rover. Certainly, the LS has more potential but it's mostly potential that isn't suited to a Land Rover. So it's got to be the price. If an LS swap could be done for $5K, it would win because I don't see a long-lasting Rover V8 replacement happening for a lot less than double that.
Recovery Vehicle
Joined: Jun 2017
Posts: 1,238
Likes: 240
From: Alabama + Vegas + Texas
with hydraulic flat tappets? I thought those were the worse next to solid lifters friction wise? I would think that would net me at least 1-2 mpg alone because of reduced resistance.
i was also considered converting to electric power steering pump.
I know it may be futile but I’m trying to prove that newer isn’t always better and this is a project that I just decided to do
Inside the motor itself, the 4.0 and 4.6 motors have less than 1 horsepower of resistance because a human man can hand turn a motor, so if you magically elimited all friction inside the 4.0/4.6 motor, you'd improve hp by less than 1 and mpg improvement would be small.
If you spend thousands of Dollars chasing those small gains, you might end up disappointing yourself, especially when considering that you aren't going to eliminate 100% of resistance in either the motor or drivetrain/powertrain.
If most of your driving is above 70 mph, then chasing some aerodynamic improvements might make some sense, however, very few people drive enough highway miles for their average speed to be over 50mph. If you fall in the majority group of daily street driving and occasional off roading, then your average speeds are going to be far below 70mph so the biggest bang for your buck at lower speeds is a weight reduction plan.
Take off the spare tire. Remove the entire trailer hitch assembly. Remove the interior headliner. Remove the roof rack rails. Remove the interior hatch/door panels. Remove the cosmetic front grill. Install magnesium BMW wheels with lightweight tires to replace the Rover wheels/tires. Remove the carpet and floor mats. Another advantage here is that removing pieces is free. Moreover, removing the front and rear sway bars will actually improve your offroading ability.
If you want to test what electric power steering will do for your MPG, simply disconnect the power steering pulley from its shaft lock such that it free spins instead of turns the PS pump. That simple experiment will tell you if any small MPG gain is worth spending the money to add electric PS.
None of the above really hits the sweet spots for Disco 2s, though.
Track/off road straight pipes that replace the cats, however, will improve your exhaust flow, as will buying a $50 Dremel and taking your time grinding your exhaust headers to match your exhaust ports in your heads, especially if you slightly enlarge the flow ports in both.
Tough to beat a new $250 Crower cam in the motor, too.
...and if cold weather isn't a threat to freeze up your throttle body, then blocking the hot water passages through it will lower your intake air temperature.
Years ago I built a 1988 Chevy 350 for my truck specifically for fuel economy, cam, ported head, headers, intake, everything. 1-2mpg improvement. Fast forward a generation and I have EFILive and tuned both my 99 Tahoe and 02 Camaro to run 17:1 at low throttle openings - again minimal improvement.
Have recently driven late model F150 trucks that achieve 22-23 mpg. They are lightweight, have low rolling resistance tires, cylinder deactivation, high compression, long runner mpg optimized intakes, etc. The discos have similar power and better economy than their competition (V8 SUV's) for the generation. The Disco is heavier, stronger, with a lower cg (due to the heavy frame/axle/suspension), better visibility (due to high profile, square shape, glass angle) and superior survivability due to the design. The LR3 and LR4 are similar size and shape, get slightly better fuel economy due to the advance engine design and programming.
You can't make a brick get good gas mileage without a diesel engine, that's just physics. At least with an LS swap you program the ECU with EFILive for optimum economy. One last idea - Tahoe hybrid drivetrain?
Have recently driven late model F150 trucks that achieve 22-23 mpg. They are lightweight, have low rolling resistance tires, cylinder deactivation, high compression, long runner mpg optimized intakes, etc. The discos have similar power and better economy than their competition (V8 SUV's) for the generation. The Disco is heavier, stronger, with a lower cg (due to the heavy frame/axle/suspension), better visibility (due to high profile, square shape, glass angle) and superior survivability due to the design. The LR3 and LR4 are similar size and shape, get slightly better fuel economy due to the advance engine design and programming.
You can't make a brick get good gas mileage without a diesel engine, that's just physics. At least with an LS swap you program the ECU with EFILive for optimum economy. One last idea - Tahoe hybrid drivetrain?
Thread Starter
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Three Wheeling
Joined: Jul 2018
Posts: 85
Likes: 3
From: Las Vegas, Nevada
1-2 mpg, no way.
Maybe, maybe 3-5 crankshaft hp.
Electric ps pump, you can ask Alex, he had removed his ps pump altogether at one time, and I think he had a very small gain in mpg.
As far as newer not always being better, it actually is, because everything you want to do is newer technology than the long outdated 4.0/4.6
Maybe, maybe 3-5 crankshaft hp.
Electric ps pump, you can ask Alex, he had removed his ps pump altogether at one time, and I think he had a very small gain in mpg.
As far as newer not always being better, it actually is, because everything you want to do is newer technology than the long outdated 4.0/4.6
Well I suppose so. But the complexity of newer technology can outweigh its benefits in the form of increase maintenance and costs. I’m just thinking that maybe theres more improvement somewhere. This is going to be a highway vehicle. Cross country trips regularly
Thread Starter
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Three Wheeling
Joined: Jul 2018
Posts: 85
Likes: 3
From: Las Vegas, Nevada
Years ago I built a 1988 Chevy 350 for my truck specifically for fuel economy, cam, ported head, headers, intake, everything. 1-2mpg improvement. Fast forward a generation and I have EFILive and tuned both my 99 Tahoe and 02 Camaro to run 17:1 at low throttle openings - again minimal improvement.
Have recently driven late model F150 trucks that achieve 22-23 mpg. They are lightweight, have low rolling resistance tires, cylinder deactivation, high compression, long runner mpg optimized intakes, etc. The discos have similar power and better economy than their competition (V8 SUV's) for the generation. The Disco is heavier, stronger, with a lower cg (due to the heavy frame/axle/suspension), better visibility (due to high profile, square shape, glass angle) and superior survivability due to the design. The LR3 and LR4 are similar size and shape, get slightly better fuel economy due to the advance engine design and programming.
You can't make a brick get good gas mileage without a diesel engine, that's just physics. At least with an LS swap you program the ECU with EFILive for optimum economy. One last idea - Tahoe hybrid drivetrain?
Have recently driven late model F150 trucks that achieve 22-23 mpg. They are lightweight, have low rolling resistance tires, cylinder deactivation, high compression, long runner mpg optimized intakes, etc. The discos have similar power and better economy than their competition (V8 SUV's) for the generation. The Disco is heavier, stronger, with a lower cg (due to the heavy frame/axle/suspension), better visibility (due to high profile, square shape, glass angle) and superior survivability due to the design. The LR3 and LR4 are similar size and shape, get slightly better fuel economy due to the advance engine design and programming.
You can't make a brick get good gas mileage without a diesel engine, that's just physics. At least with an LS swap you program the ECU with EFILive for optimum economy. One last idea - Tahoe hybrid drivetrain?
I guess there’s trade offs everywhere. Thank you so much for everything.
Thread Starter
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Three Wheeling
Joined: Jul 2018
Posts: 85
Likes: 3
From: Las Vegas, Nevada
Most vehicles have 15 to 20% loss from crank output to wheel output. This means that if you magically eliminated all drivetrain resistance you'd improve mpg by some amount less than 20%.
Inside the motor itself, the 4.0 and 4.6 motors have less than 1 horsepower of resistance because a human man can hand turn a motor, so if you magically elimited all friction inside the 4.0/4.6 motor, you'd improve hp by less than 1 and mpg improvement would be small.
If you spend thousands of Dollars chasing those small gains, you might end up disappointing yourself, especially when considering that you aren't going to eliminate 100% of resistance in either the motor or drivetrain/powertrain.
If most of your driving is above 70 mph, then chasing some aerodynamic improvements might make some sense, however, very few people drive enough highway miles for their average speed to be over 50mph. If you fall in the majority group of daily street driving and occasional off roading, then your average speeds are going to be far below 70mph so the biggest bang for your buck at lower speeds is a weight reduction plan.
Take off the spare tire. Remove the entire trailer hitch assembly. Remove the interior headliner. Remove the roof rack rails. Remove the interior hatch/door panels. Remove the cosmetic front grill. Install magnesium BMW wheels with lightweight tires to replace the Rover wheels/tires. Remove the carpet and floor mats. Another advantage here is that removing pieces is free. Moreover, removing the front and rear sway bars will actually improve your offroading ability.
If you want to test what electric power steering will do for your MPG, simply disconnect the power steering pulley from its shaft lock such that it free spins instead of turns the PS pump. That simple experiment will tell you if any small MPG gain is worth spending the money to add electric PS.
None of the above really hits the sweet spots for Disco 2s, though.
Track/off road straight pipes that replace the cats, however, will improve your exhaust flow, as will buying a $50 Dremel and taking your time grinding your exhaust headers to match your exhaust ports in your heads, especially if you slightly enlarge the flow ports in both.
Tough to beat a new $250 Crower cam in the motor, too.
...and if cold weather isn't a threat to freeze up your throttle body, then blocking the hot water passages through it will lower your intake air temperature.
Inside the motor itself, the 4.0 and 4.6 motors have less than 1 horsepower of resistance because a human man can hand turn a motor, so if you magically elimited all friction inside the 4.0/4.6 motor, you'd improve hp by less than 1 and mpg improvement would be small.
If you spend thousands of Dollars chasing those small gains, you might end up disappointing yourself, especially when considering that you aren't going to eliminate 100% of resistance in either the motor or drivetrain/powertrain.
If most of your driving is above 70 mph, then chasing some aerodynamic improvements might make some sense, however, very few people drive enough highway miles for their average speed to be over 50mph. If you fall in the majority group of daily street driving and occasional off roading, then your average speeds are going to be far below 70mph so the biggest bang for your buck at lower speeds is a weight reduction plan.
Take off the spare tire. Remove the entire trailer hitch assembly. Remove the interior headliner. Remove the roof rack rails. Remove the interior hatch/door panels. Remove the cosmetic front grill. Install magnesium BMW wheels with lightweight tires to replace the Rover wheels/tires. Remove the carpet and floor mats. Another advantage here is that removing pieces is free. Moreover, removing the front and rear sway bars will actually improve your offroading ability.
If you want to test what electric power steering will do for your MPG, simply disconnect the power steering pulley from its shaft lock such that it free spins instead of turns the PS pump. That simple experiment will tell you if any small MPG gain is worth spending the money to add electric PS.
None of the above really hits the sweet spots for Disco 2s, though.
Track/off road straight pipes that replace the cats, however, will improve your exhaust flow, as will buying a $50 Dremel and taking your time grinding your exhaust headers to match your exhaust ports in your heads, especially if you slightly enlarge the flow ports in both.
Tough to beat a new $250 Crower cam in the motor, too.
...and if cold weather isn't a threat to freeze up your throttle body, then blocking the hot water passages through it will lower your intake air temperature.
Yes I am attempting to optimize it for highway use. I plant to travel and tow a travel trailer occasionally. I figure I may just do a piston coating and a good custom roller cam at least, I’ll probably just do that. These are just ideas. I figure if I am going to shell out 1600-2000 dollars for an engine I minus well upgrade it. But thank you for your insight.
Thread Starter
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Three Wheeling
Joined: Jul 2018
Posts: 85
Likes: 3
From: Las Vegas, Nevada
Yes I am attempting to optimize it for highway use. I plant to travel and tow a travel trailer occasionally. I figure I may just do a piston coating and a good custom roller cam at least, I’ll probably just do that. These are just ideas. I figure if I am going to shell out 1600-2000 dollars for an engine I minus well upgrade it. But thank you for your insight.
Recovery Vehicle
Joined: Jun 2017
Posts: 1,238
Likes: 240
From: Alabama + Vegas + Texas
...ignore aerodynamics, though. Your aero drag is a function of frontal cross section which basically doubles when you pull a trailer outside of the draft zone. Any minor improvements to Aero drag made with underbody panels or lowering the Disco would be lost in the aero noise of pulling a trailer.
There are some good aftermarket cams out there. If you are rebuilding the motor then it makes sense to upgrade to one of them. I did!
The best and cheapest ways to improve the 4.6 motor include:
all metal Cometic head gaskets so that you don't need to tophat your motor or pin your sleeves,
ARP studs,
new cam/rod/main bearings,
Crower cam,
blueprinting your piston ring gaps,
Porting your exhaust headers to match your heads,
straight pipes replacing cats,
throttle body heater bypass (when feasible),
inline thermostat mod,
cleaning/testing your fuel injectors, and
new spark plugs/wires/coils.
A cheap automatic engine bay fire extinguisher is also highly recommended. I just bought one for my boat for less than thirty bucks. You'll spend more going to see a movie than that...
There's lots of weight that you can remove for highway driving, but again, that won't matter if you are pulling a trailer.
TReK
Joined: May 2011
Posts: 2,768
Likes: 396
From: kitchener, canada
If you want mpg why do all this trouble.
Get yourself a well proven 300 tdi diesel slap it in the disco and enjoy getting 900 km to a tank of diesel that costs less than premium fuel
that's your best idea
Get yourself a well proven 300 tdi diesel slap it in the disco and enjoy getting 900 km to a tank of diesel that costs less than premium fuel
that's your best idea
Thread Starter
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Three Wheeling
Joined: Jul 2018
Posts: 85
Likes: 3
From: Las Vegas, Nevada