Land Rover question

[wuvvum]

Does anyone know what the gearing is (in mph/1000rpm in top) of a non-overdrive Series III 109 on standard wheels & tyres? A mate has bought one fitted with a Perkins 4.236 (redline speed: 2800rpm) and I've been trying to work out what the top speed is likely to be. I suspect not very much. Although it is likely to prove a useful bit of kit if he ever comes across any houses that need pulling down.

[dollywobbler]

Paging Mr Scruff!

[pogweasel]

I looked at a Perkins engined one. 42mph, flat out. No thanks!

[Albert Ross]

Pog's right on the nail. Best to fit an overdrive, but get a remortgage first. Or, get a scrap Disco and rag the 200 Tdi out, and then the diffs, and get a scrap 110 rear axle, to swap all the innards out of it into the 109 rear axle casing. Slap it all in, and make a flying machine.

[Pete-M]

15.93 mph / 1000 rpmSo, you're looking at:Tyre diameter of 28.913", Final drive ratio of 5.4:1.15.93529541446208 mph @ 1000 rpm23.90294312169312 mph @ 1500 rpm31.87059082892416 mph @ 2000 rpm39.8382385361552 mph @ 2500 rpm47.80588624338625 mph @ 3000 rpmThat is going to be one noisy, noisy, incredibly slow and tedious bastard. Therefore you must buy it before he does. It's the Autoshite way! You must then do a 100 mile a day motorway commute in it, whilst taking pictures of everything going past. Perhaps you could mount a webcam on it and broadcast shite spotting reports live on the internet. You'd be spending plenty of time in there, why not make it fun?

[Albert Ross]

Where did you get a tyre diameter of 29 inch Pete?

[Pete-M]

I figured it'd probably be on 205/80/16s or thereabouts. Have I cocked up somewhere?

[Albert Ross]

Yup. 109 would have a 7.50x16 on it, never smaller, but the crossplies are smaller diameter than the radials. Some had 9.00s, but they're rare and bloody pricey. Diff ratio of 4.7:1, Transfer ratio in high range of 1.148:1....I know mine on the standard tyres and diffs, with the 2286 diesel in it, will cruise around 60 ish with overdrive in, I don't like to thrash the 3 bearing engine, it's the original from 1970.............!110 diffs are 3.54:1 ratio, might be easier to find a Stage 1 axle, but like £350 for a used one is beyond most people.