I should have noted - used engine and tranny not crate. And also the ability and low cost of replacement parts - at least in the US - imo makes it much more sustainable. A friend of mine did a LS swap into a 60's chevy truck - it was impressive how much after market ECU's, wiring harness' etc. there is. Also the shake down and sorting of issues after install were minimal.....

 

Have you had it offroad - crawling type situation? I would imaging it would create a similar situation as launch of the line...... a slip?

 

If you have stock size tires, a mildly built 4.6 with a Cam might get you what you're looking for. I'm running 235/85 r16's on my truck with a freshly built 4.6 and it feels about the same as my 4.0 on stock tires.

honestly, you'd be better upgrading the whole drivetrain to enjoy increased power plus better gas mileage.

 

Probably just stick with stock. Slow but been ok for the last 26 years. Mike

 

Swap in a Defender 1.4 case. Brings back a lot of the pep.

 

Ferrari mechanic customized D1, check it out

 

I appreciate the honest answer. I have a D1 with the 4.0 and I get a similar experience. I was just on a 1200-mile trip to the boondocks that involved about 800 miles on the Interstate where the limit has been raised to 80mph. It's mountainous with a lot of long grades (nothing very steep, but still up-hill, and at over 5000 to 7000 feet elevation. For this trip, I used 91 octane exclusively. My D1 is heavier -- loaded for a trip like that with 3 people and gear, it pushes close to 6000 pounds with the steel bumpers, sliders, roof-rack, etc. I get additional wind-resistance from the load on the roof-rack. It's rolling on 33's with a commensurate lift. It over-indicates speed by 5mph because while I increased tire size, I reduced gearing even more.

It can get up to 85 (actual) on the level. Maybe it could go faster downhill but I don't care to try. If there is a headwind or even a slight grade, it's hard to keep it at 75. That puts me in the truck lane with big-rigs wanting to pass me. Back in the day when 65 was enough, this Rover would be fine, but the cars are going 90 now and 18-wheelers 80mph both with impunity. If I hit a moderate grade, I can struggle to maintain 60 mph. Fortunately, the loaded trucks are also slowed. The thing I don't like about it is I often have the pedal floored for long periods, the engine seems to be bogging down at 3000 rpm in 4th gear or I'm stabbing the pedal as hard as possible to get it to kick down to 3rd where the engine roars at 4000 rpm for long periods.

At 160K miles, I'm thinking my cam is worn, my rings are worn, my valve seals are worn. I'm burning a quart of oil every 600 miles with this kind of driving, and I don't know where this is going. Am I going to have to rebuild/replace the engine at some point? I'm not so concerned about getting a bigger kick in the pants, but driving the Rover flat-out, pedal down, for 8 hours straight worries me. I don't think a cam is going to fix it, but maybe a new cam, lifters, valve job, and rings, or just a whole new top-end. I'm not thinking about hot-rodding it, but just replacing what's worn out. I'd be happy if I could just drive it 65 and under, but it would have to stay local or get trailered then.

 

600 miles to a quart isn’t great, but it’s not horrible either, especially when under a lot of load as you’re indicating. Just based on your mileage of 160k you shouldn’t need major engine work for some time.

 

I agree it's not that much oil loss yet. I'm probably over-anxious because I really depend on the Rover when I'm traveling.

I don't keep detailed records of fuel consumption, but I had a few pieces of good data from my recent trip. On the interstate, I used 21 gallons over 257 miles, or 12.2 mpg. This was just about at top speed unless it was downhill, probably an average of 75 mph with stuff on the roof rack. Overall, I drove close to 900 miles on the Interstates and highways and 300 miles offroad. Overall it was 13.6 mpg over the 1200 miles which is consistent with my experience of ~13 mpg. I've had this Rover since 2011.

When I'm driving a lot in the bush, I take extra fuel, usually a 6 gallon jug that I empty into the tank as soon as possible. I just can't think of a safe way to carry extra fuel, so I minimize the practice. Taking extra fuel can mean longer distances offroad or more time in the field before having to return to refuel.

To bring this back on-topic, I would not want more power if it resulted in a decrease in fuel efficiency. As long as I could control the fuel consumption with the gas pedal, it would be ok. I'd trade 2 mpg for more power on the highway that's littered with fuel stations. But once I leave the roads, lots of power is unnecessary and efficiency and range become much more interesting. Dropping weight would be more desirable than having more flow through the heads at high rpm.

 

As Robert said above, a mildly built 4.6 might get you what you want. Like you said, you will be able to decrease your fuel economy because you can drive it faster. Driving it at the same speed wouldn’t affect your fuel use very much. My 4.6 P38 gets about 2mpg better than my 4.0 D2 on the highway, even though I drive it faster. It doesn’t look a lot less boxy, but it’s coefficient of friction is a lot better.