Is it possible?

[garycox]

I am new to Land Rovers and have already learned a lot just lurking here. Thanks.

I am thinking I would like to get into a series I or II. One of my concerns is what I read here re top speeds. I would like to be able to safely travel on major highways on occasion.

Is it possible to make a early land rover cruise safely at 70mph? Would just a OD unit get the job done or would more be required? I am not interested in non rover engine swaps, I want something that mostly looks somewhat original.


Thanks for your insights.

Gary

[Rat Patrol]

i wouldn't advise running it that hard for long periods. 65 is as hard as i've pushed mine and that is a bit nerve racking.

[canyonero]

I had a '99 Disco II that I didn't really enjoy on the highways above 50 mph, so my current Series III is even less comfortable at cruising speeds. I guess I just got got used to my wife's Subaru for fifth gear travel...I've always felt that Land Rovers seem to feel instantly better once they turn off pavement and hit dirt, so I'm not sure there's any way to make a Series feel "comfortable" on pavement. I love mine, but don't have to take it on the Interstate..

[leafsprung]

Ive driven everywhere in the US in a series land rover from east coast to west coast NY to LA, dixie to the PNW and never found that I HAD to go 70mph. I regularly take trips in stock 2.0L series ones with 50-55 mph cruise without issue. While a series rover in good shape can pull 70, its not really necessary unless your in a hurry and a land rover really isnt the best car if you are in a hurry.

[SafeAirOne]

I drive my underpowered 109 30 highway miles to and from work 5 days a week at 55mph. Been doing it for years. It's plenty safe and I've never had any complaints from anyone behind me.

Besides, why worry about people behind you? I figure that it's a 2 (or more) lane highway and they have accelerator pedals, turn signals and a steering wheels should they not want to be behind a series rover doing 55.

[Jim-ME]

My Rover with an OD will cruise at 65 but I don't like to push it like that. Even with the OD I prefer 55. I use 4 lane highways as much as I can to allow people to go around. I have been known to pull over on 2 lane roads to let people by. Usually people are staring so much they don't mind going slow for a while. OTOH my son's Jeep with a 4 cylinder engine and a 5 speed really doesn't like much over 55 either.
Jim

[scatterling]

The 109" that I rebuilt will travel at highway speeds without any issues ( except long hills). Nothing fancy ( although all rebuilt) stock engine and gearbox. It does have an overdrive, parabolics and disc brakes. I've had it up to 73 (according to GPS) and it felt stable. It will run at 65-67 comfortably without feeling like it wants to run off the road or fall apart.
I guess it all depends on how you set it up and what upgrades you do.

[TeriAnn]

I regularly take trips in stock 2.0L series ones with 50-55 mph cruise without issue. While a series rover in good shape can pull 70, its not really necessary unless your in a hurry and a land rover really isnt the best car if you are in a hurry.

I love data.

Series Land Rover with stock gearing, 32 inch dia tyres. With and without Roverdrive. Top gear:

MPH____STOCK RPM____ROVERDRIVE RPM

55__________3112_________2479
60__________3402_________2724
65__________3686_________2951
70__________3973_________3178
75__________4226_________3405

Land Rover specs a fresh Series III 2.25L engine with 8:1 head is 70 hp@4000 RPM and 120 lbft @2000 RPM. The factory doesn't specify redline that I have ever seen, but the highest RPM I have seen specified is 4225 RPM. So 75 MPH is close to the guessed at red line. These numbers are for a factory fresh engine and not a high mileage engine like many of us drive.

It has been my experience from driving my 109 with a 2.15 engine for about 20 years that the engine has a highway cruise sweet spot of around 3200 to 3300 RPM where it can happily cruise all day. I think that is why people pretty much refer to Series trucks as being 50-55 MPH highway cruisers. In general the slower you cruise on the highway the better your fuel mileage.

If you look at the numbers with overdrive installed it looks like the perfect solution. And indeed it would be if one did not take into account the anemic output of even a fresh 2.25L petrol engine.

Having put a lot of highway miles on a SIII 8:1 compression engine & an overdrive I have found that even at full throttle sometimes the engine just does not have enough power to push top gear that the higher speeds. And the engine really sucks fuel at full throttle or even close to full throttle.

Slight inclines, high altitude driving or headwinds will keep you from achieving the high speeds. But a tail wind or slight decline & you are there.

To take proper advantage of an overdrive at high speeds you really need to power range of a 200 or 300tdi.

If you are going for the higher speeds, you really should have the steering in very good condition, proper alignment to within factory specs, wheel bearings properly adjusted and wheels properly lug balanced. The trucks can be very stable at 75 MPH or if they need attention can be unstable and hard to control much above 50 MPH.

Bottom line is that a healthy well adjusted stock truck can do 75 MPH under certain driving conditions but you are right on the edge of the engine's ability and maybe not the best place for a long distance cruise.

My recommendation for a stock rig is 55 MPH freeway speed is your best bet for long drives. 65 MPH works for those times when you are in a hurry and driving a short distance but your fuel mileage will noticeably suffer.

When you have to open up the throttle to get the engine to push the overdrive at higher speeds your fuel mileage can really suffer. And under many conditions the power is just not there to push the overdrive at high speeds. There are reasons that Land Rover gave up on the petrol 4 cylinder engine and went with the tdis. I suspect highway cruising ability was one of them.

[jac04]

I installed a Roverdrive on my Lightweight with great intentions of being able to cruise at 70mph. Fresh engine, suspension & steering components. Basically, read what TeriAnn wrote. It will cruise at 70-75mph no problem except for steeper grades. However, I find myself still cruising at 60-65mph and enjoying a much more 'relaxed' drive and better fuel economy. The vehicle seems much happier at those speeds as well. Like Ike said, a Land Rover isn't the best vehicle to drive if you're in a hurry.

[kwd509]

Interesting thread, to redirect for a brief moment; Is it true that the older 2.25 three bearing diesel will come apart if it is regularly asked to do more than 50 mph?

[Partsman]

Gary if you just have to have 70-75mph in your Land Rover, might I suggest swapping out your 2.25liter petrol either for a tdi or a six pot and installing 3.9 diffs, with this combo you can achieve the speeds you're looking for. Now that that's said, I should point out that these motors were never engineered to run these conditions, and it might well behoove you to look into a more modern vehicle for your higher cruising speeds. Read carefully everything that TerriAnn has written above, as she does know what she's talking about, her website should put to bed any doubts you may have on that end of things. http://www.expeditionlandrover.info/
Remember above all else, be safe and have fun! That's what these vehicles are all about.

[antichrist]

Besides, why worry about people behind you? I figure that it's a 2 (or more) lane highway and they have accelerator pedals, turn signals and a steering wheels should they not want to be behind a series rover doing 55.

You would think.
I've lost count of the times on nearly empty multi-lanes that I've watched people in my rear view mirror gain on me rapidly, them doing 70 or so to my 55/60, only have them to slow down and drive along right behind me for miles.

My 88's I've always driven 55-65 on the highway without issue.

[mearstrae]

OK, my 2 cents worth... I have a Series Hybrid with a 3.5 and over drive, since it's a R.R. drive train it has higher gearing than most. It is capable of doing (belive it or not...) about 80 (or more) mph on the highways. But... It isn't a good idea, these are not roadcars they are working trucks (or more to the point working tractors...) and are not safe at high speeds. The suspension isn't suited nor are the brakes. Leaf springs, high center of gavity and drum brakes are a recipe for disaster, let alone; even if you run radial tires....

'95 R.R. Classic LWB
'76 Series III Hybrid 109
'70 Rover 3500S

[Billy5]

Hmm. Well heres my take..lol. I bought a series for what it is. It is basically a tractor with a body on it. They weren't designed with highways in mind ( from what I am gathering in my short time). I have no intentions of trying to make it what it wasnt supposed to be. I could spend thousands on new springs etc..but I ask myself why? But I have had mine up to 62 mph wide open with overdrive by gps. I really dont think these engines really like sonic revs. So my happy spot is around 50. Shes happy singing along, engine smooth etc. and I feel very comfortable at that speed. I go into the right lane and stay there. I cant ask more from a 40 year old, off road truck...

[Terrys]

The three previous posts are right on the money; the 88 is not a safe vehicle much over 60. A 109 is a different animal with regard to handling, but no better, if not worse, at stopping. Add in the dynamics of an old front end with likely issues, and they just aren't stable at high speed.