Cruising speed ?

[Andy Rose]

Hi, I've got a 1970 , 1000 van.. As far as I can see it still has the original diff and has standard tyres. My question is how many miles per hour for each 1000 revs in top gear does it do. I have no tachometer so can't tell the revs, but it does sound very busy at 60 MPH. So I guess I'm looking for advice on what speed is recommended for lengthy motorway trips?

[Hotroddickie]

For regular lengthy motorway trips I recomend a 3.9 Diff or a 5 speed conversion. The stock one in your van is designed for dragging heavy loads around town.
Or you can cruise at 45 - 50 everywhere to save your ears/engine which if Oz is anything like the UK is a lethal Speed on Motorways where most traffic does 70 - 90.
Rich

[Andy Rose]

Thanks for that. Yes, your right, the 50 on a motorway is making a nuisance of yourself and quite dangerous at times. I would like to keep the van original, so I am just trying to work out how hard to push the old girl.

[chrisryder]

In a standard minor, apparently, 97mph is 6000rpm in top (if it could manage it!). But that's with a 4.2:1 diff, and you should have a 4.5:1 diff in your van. I make that 90.5mph at 6000rpm. Apparently 6000rpm is the magic number at which a 1098 engine will pop.

Anyway... cruise at whatever you feel comfortable at! Some engines are happier than others, depends how much it's run in, and whether it's in tip-top tune.

You don't necessarily need a 3.9 diff, a 4.2:1 out of a Minor saloon, convertible or traveller, would make life a lot easier, without sacrificing too much acceleration. If you regularly carry heavy loads in the back, it might be worth living with the original 4.5.

[JOWETTJAVELIN]

The 1275 is happiest cruising at 60, although there is more power 'in reserve' for emergencies.

I have never driven a 1275 that is happy at more than 60-65 cruising.

[Andy Rose]

Magic Thanks very much for the info.. So with my 4.55 dif I should be doing 15MPH per 1000, so at a nerve racking 60 MPH I'm only doing 4000 RPM..and even for my old girl it's not too destructive. Most of the city roads around here are 50MPH and that is only 3500, so no problems at all. The diff has a fair amount of free play, but is quiet in operation. My plan will be, when the diff starts to get too noisey I will put a 4.22 from a sedan in place of the original 4.55.. Thanks again all..

[lowride stepside]

if you'r not lugging a cement mixer , or a tonn of spares round , change the diff , it will pay for it self in petrol alone in no time , let alone wear n tear on the engine . Nice easy job fill it up with new oil , new seals gaskets n brake shoes . Happy days

[Andy Rose]

Yep, a diff change is on my to do list now. Can I ask at what revs max torque and max HP are ?

[lowride stepside]

The 1275 is happiest cruising at 60, although there is more power 'in reserve' for emergencies.

I have never driven a 1275 that is happy at more than 60-65 cruising.

You should try mine cruises at 80 easy, with room for more incase of emergencies ,and thats with an extenal sun visor fitted , Laycock rocks

[les]

Strange how some 1275s seem to run more free than others. Hope mine runs to 80+ if I ever get round to fitting it!

[chrisryder]

My 1098 sits at 70 very happily, and 80 if i'm in a rush. The joys of a 5-speed eh?

It could go faster, but I don't push it... I built the engine, so it could blow any day!

[lowride stepside]

only five

[Andy Rose]

Hi all, I've now fitted a tachometer to the van and find that at 50 I'm only doing 3800 RPM. I would have sworn it was much more than that, my question is, given max HP is at 5100 RPM, would 3500 be a sensible cruising RPM??

[kingzdjc]

Thanks for that. Yes, your right, the 50 on a motorway is making a nuisance of yourself and quite dangerous at times. I would like to keep the van original, so I am just trying to work out how hard to push the old girl.

Sorry but thats rubbish.
Theres no problem at doing 50 on the motorway. I do it with my 803 engine often. Most cars towing trailers only tend to do 50.
The speed limit is 70, it is not a target, so somebody doing 50 has the absolute right to do so. As long as you stay in the left hand lane, other motorway users have two other lanes to overtake.

The only thing that is dangerous at doing 50 is the other road users that think the motorway has 'slow lanes' and 'fast lanes' which is doesnt, and that 70 is the minimum speed on the motorway, not the max.

[Alex'n'Ane]

Anyone driving a car that is going so slowly that forces lorry's to move out into the middle lane, which slows down all the traffic on the motorway (selfish) and is frankly more dangerous.. Driving at 56, same speed as lorries is very common in these cars though, they sit very happily at it, and its not dangerous etc.

[kingzdjc]

Anyone driving a car that is going so slowly that forces lorry's to move out into the middle lane, which slows down all the traffic on the motorway (selfish) and is frankly more dangerous.. Driving at 56, same speed as lorries is very common in these cars though, they sit very happily at it, and its not dangerous etc.

Again rubbish. If you have an 803 engine you will know many of them cannot go more than 50 nowadays. These engine are 55 years plus. 50 on a motorway is NOT dangerous, and certaintly not selfish. My minor has been on the road A LOT longer than many of the vehicles on the road today, so tough luck really.

The MAX speed for lorries is 60. This is the MAX not a target. Many of these larger lorries SHOULD be doing 50 and no more. THEY are the ones that are dangerous when they exceed this.

There are 3 lanes on the motorway. So if those in the middle lane want to take over, they can go in the outer lane. In no way does this slow down traffic. In fact, it has been proven that those that SPEED over the limit of 70 contribute massively to traffic jams on the motorways, as they usually drive at variable speeds.

IT IS VARIABLE SPEEDS THAT ARE SELFISH AND CAUSE JAMS, NOT SOMEONE DOING 50!

This bugs me just as someone who says horses etc shouldnt be allowed on the roads??? Why not, they were here first, those that come after have to adapt.

[JOWETTJAVELIN]

Well, I wouldn't like to be sat at 50 with lorries thundering past. To be safe you need to be going just faster than the lorries, or at least the same speed.

The fact is that early-mid 1950s cars were not built for sustained high speeds as motorways didn't exist in this country - that's why there were so many breakdowns back then, cars just weren't up to the job.

[kingzdjc]

Well, I wouldn't like to be sat at 50 with lorries thundering past. To be safe you need to be going just faster than the lorries, or at least the same speed.

The fact is that early-mid 1950s cars were not built for sustained high speeds as motorways didn't exist in this country - that's why there were so many breakdowns back then, cars just weren't up to the job.

Personally, I dont mind lorries thundering past me. You get used to it. Theres nothing unsafe about it. If the lorry wants to overtake it can do so, doing 60, so what exactly is unsafe?

Its not as is ALL lorries are in the left hand lane anyway. Many lorries frequently use the middle lane.

Yes, cars in the 50s werent built for motorways, but many 60s cars, when motorways were around, didnt travel any faster really. So speed has nothing to do with it. Think of the autobahns in germany. You get someone doing 60 in one lane, and 150 plus in another. Guess what, theyre no more dangerous than motorways over here. Slow speed in one lane has NOTHING to do with safety.

Also cars back then didnt brake down because they werent built for high speed. They broke down because lack of maintainance by their owners.

[bmcecosse]

Driving at 50 on an Mway IS dangerous - and extremely selfish. You slow a truck to 50 on an incline - and a whole line of trucks will be brought to their knees - and will start trying to overtake each other, completely blocking the Mway for other traffic. And of course, you are also getting Minor Owners a very bad reputation. I avoid the Mway whenever I can - it's MUCH more pleasant to drive on a nice peaceful A or B road, where you can make your own speed, and stop where you wish. At 50 mph up here - the trucks would be 1mm from your bumper and when they did pass - the trailer wheels would be so close you would automatically cut over into the shoulder..........
Seriously - what you suggest is just not reasonable......

[les]

I find motorways boring in a minor---just sitting there listening to the thing screaming. Surely no one can enjoy that. I think A and B roads are best for these cars and the occupants Plus you can do 30 safely, if you want!