Interesting Spin on a Series Rover

[TeriAnn]

Let me re-phrase that. I would love to be able to be cruising quite quickly down a road and just head off into a field at speed.

I did that once in Eastern Montana. I do not recommend it. But it is a good test of how well you lash the stuff you keep inside.

A 2 lane road, mountain on one side, large field on the other. Enough of a hill that full floored I was doing about 50 MPH (SIII 2.25L engine). An 18 wheeler came up from behind doing 15-20 MPH faster than I & passed. Unfortunately there was a second 18 wheeler right behind the first also passing AND an on coming 18 wheeler.

There was enough room for the first 18 wheeler to pass but not the second. The driver of the second 18 wheeler didn't like the idea of a head on at a combines speed of over 120 MPH so decided better me than him and started moving into my lane with me along side. I in turn decided that it would be a good time to do a little off road travel and chose to drive off into the field at 50 MPH rather than be a participant in an accident.

To this day I'm still very grateful that there was no drainage ditch.

That was the last of many close calls caused by faster impatient travelers before I made the decision to swap to a more powerful engine. When I got home I started looking for engines that might work in a Land Rover engine bay.

By the way, when you run your numbers, high range on an Ashcroft transfercase is 0.87:1

NP435 - Ashcroft - 3.54 R&P = 3.08:1 at the axle

With your 32 inch dia tyres that's 2100 RPM @ 65 MPH

Unless you have diesel like torque the gearing may be a little high and you low range would be too high for much off road work.

A close ratio NP435 + high ratio kit + 4.7:1 R&P + 35 inch tyres might work better for you, esp. if you ever plan to go off road.

I'm running a T18 + high ratio kit + 4.7:1 & 33.3" dia tyres (255/85R16)
which gives me 2,700 RPM @ 65 MPH. That's about 200 RPM higher than I would prefer but the 4.1 R&P would put me about 200 RPM lower than my prefered 65 MPH RPM and make second gear a little too tall to start off in (I have a granny first). 35 inch tyres would put me at what I believe to be my optimum 65 MPH cruise RPM, but 33.3 is as tall as I can go and easily enter my land rover in a narrow skirt and flats.

If you have the power to push it I think that tallest you might consider is a NP435 + high ratio + 4.1 R&P. And don't consider this combo with the granny first version

I think the granny gear version is only really useful for either gonzo rock crawling or bragging with mall terrain vehicle owners around a pitcher of beer.

I have gear rations on a web page

http://www.expeditionlandrover.info/gearboxSwap.htm

Play with the numbers.

[LaneRover]

you can do that without making it look all goofy

wait a minute... .. does this mean we just started one of the keep it original/do what you want its yours stream hi-jacks?

If done right it wouldn't look goofy - of course if I do it that means it might end up looking goofy.....

[leafsprung]

I think the granny gear version is only really useful for either gonzo rock crawling or bragging with mall terrain vehicle owners around a pitcher of beer.

Considering the relatively high low ratio in the rover transfer case I dont agree. Low ratios give fine control on technical terrain, (even relatively tame stuff) Which is very nice. Even with 4.7 gears and the ford NP435 you only have 74:1 with the c suff on t-case. Which is a nice low range, but for really fine control or rock crawling, double that would be ideal. For comparision the popular "Marlin ultimate crawler" for toyotas gives a 2.28:1 plus a 4.70 in the transfer cases. With other wise stock gearing that gives a 149:1 low-low. The lower the ratio the finer the control. There is a point at which additional lower gearing is no longer useful, but that point is far lower than 73:1.

wait a minute... .. does this mean we just started one of the keep it original/do what you want its yours stream hi-jacks?

No it means that the "long nose" is goofy looking and its body modifications serve no useful purpose.

[Blueboy]

since everyone knows that parts begin falling off at about 72 miler per hour

for me it is windshield wipers.

first time it happened was with my D90 in a, naturally, thunder storm.

have lost 3 in the 109.

with gas the way it is now though, highway trips are more 55 than 70mph.

it was comical though to see folk's faces when a 109 with antique plates passed them at around 75mph - especially the Prius owners.


Jaime

[greenmeanie]

NP435 - Ashcroft - 3.54 R&P = 3.08:1 at the axle

With your 32 inch dia tyres that's 2100 RPM @ 65 MPH

Unless you have diesel like torque the gearing may be a little high and you low range would be too high for much off road work.

The 292 inline 6 is comparible to a stock 350 for torque but has it much lower down the rpm range. Peak is about 1800-1900 rpm. 3.08 is one of the ratios that Chevy offered in their pickups but as I'm an expat I've no idea what one is like to drive.

A close ratio NP435 + high ratio kit + 4.7:1 R&P + 35 inch tyres might work better for you, esp. if you ever plan to go off road.

In that I am keeping the suspension fairly stock other than putting on parabolics 35" tyers will be too much. She is getting power steering but that tyre dia on stock width axles has got to make a large turning circle huge. That puts leaves me with experimenting with gear ratios. As you say on your very informative site tyres are good for fine tuning but I should really get the gearing sorted correctly first.

If you have the power to push it I think that tallest you might consider is a NP435 + high ratio + 4.1 R&P. And don't consider this combo with the granny first version

This is probably what I'll end up with in the end. It would be cheaper, however, if the 3.54's worked so I'm trying them first. If I go 4.11 I'll be doing the Toyota thing with axles from Jim.

I have gear rations on a web page

http://www.expeditionlandrover.info/gearboxSwap.htm

Play with the numbers.

Thanks for the input everyone.
Cheers
Gregor

[LaneRover]

No it means that the "long nose" is goofy looking and its body modifications serve no useful purpose.

Agreed.

Now if they had used an old straight 8 or the Merlin from a WWII fighter....

But they didn't. Maybe the extra space in front of the engine is used for storage of all the stuff that you usually keep in the back of your Rover in case of breakdown

[thixon]

I'm certainly don't fall into the "has to be original category."

But I have to ask this question. Am I missing something? What's cool about this? I'd feel like an even bigger dork than I already am if I rolled up to a rover gathering in one of those things (forget about trying to explain it to someone on the street asking questions). You'd be better off buying an auburn boat tail kit, and making that into a 4x4.

I just don't get it. I'm a little thick, so someone explain this to me so I won't feel like such a doofus.

Hey Lanerover, it always makes me feel better when I see your posts. I have one truck that is'nt running. When I see that you have four your're working on, it kinda makes me feel less in a hurry to finish mine. Thanks.

[TeriAnn]

Considering the relatively high low ratio in the rover transfer case I dont agree. Low ratios give fine control on technical terrain, (even relatively tame stuff) Which is very nice. Even with 4.7 gears and the ford NP435 you only have 74:1 with the c suff on t-case. Which is a nice low range, but for really fine control or rock crawling, double that would be ideal. For comparision the popular "Marlin ultimate crawler" for toyotas gives a 2.28:1 plus a 4.70 in the transfer cases. With other wise stock gearing that gives a 149:1 low-low. The lower the ratio the finer the control. There is a point at which additional lower gearing is no longer useful, but that point is far lower than 73:1.

Stock C suffix low range first is 40.7:1 which is way too high for a lot of off road driving that I do. Its OK for easy to somewhat moderate off road trail driving and lot of folks seem happy with it as the low ratio. I hesitate to suggest a low range first gear ratio to someone without knowing where they like to drive.

You mention that 74:1 is a useful gear & even twice that would be better. My take is that this kind of gearing is only useful for hard core rock crawling and requires a non stock throttle linkage to a foot pedal. My low range first is 70:1 and I could not keep my foot steady enough to use that gear off road until I went with semi solid engine mounts and cable linkage.

I normally don't do gonzo rock crawling so for most off road travel I do, low range first doesn't get used. My second gear low range is 34.14:1 which is way too high for most of the technical work I tend to do. For the kinds of technical driving I enjoy doing, a gear around 55:1 would be about perfect. A close ratio T-18 would give a 47.1:1 low range first and a close ratio NP435 would have a low range first of 55:1 low range first with C suffix transfer case & 4.7:1 R&P.

For the kinds of off road driving I prefer to do a close ratio NP435 at 55:1 is about perfect. I wish I had known about the NP435 back in 1999 when my conversion was done. But for people who do highly technical rock crawling I agree the Granny first gear ratio as better. But just remember that ratio step between granny first and second gear is a dozy.

No it means that the "long nose" is goofy looking and its body modifications serve no useful purpose.

To me the thread topic appears to be more like a cartoonists rendering of a 1948 Willys Jeepster look alike

[thixon]

To me the thread topic appears to be more like a cartoonists rendering of a 1948 Willys Jeepster look alike

X2

There's

[leafsprung]

My take is that this kind of gearing is only useful for hard core rock crawling

Lower gears are VERY useful any technical trail with steep accents or decents, negotiating a tight trail with lots of trees, off camber sections, icy sections where you are trying not to slip a wheel etc. Low gears allow fine control of your speed. Definately not strictly for "gonzo rock crawling"

and requires a non stock throttle linkage to a foot pedal. My low range first is 70:1 and I could not keep my foot steady enough to use that gear off road until I went with semi solid engine mounts and cable linkage.

When the gears are lower the variations in throttle change your speed less. Besides if you are creeping along you dont need throttle . . .unless your gears are high enough that your engine wont pull them at idle. With 116:1 and a mechanical rod linkage, I do not have the issues you are experiencing. If you had a doubler on your t-case you would use it more than you think.