Slow Motorway Speeds?

[Nuffles]

I've had my Moggie for a good few weeks now and have had the chance to do some motorway/dual carriage driving. The speedo says somewhere between 50 and 55mph but having used my Sat Nav (after wiring up a ciggy lighter to power it ) this is more like 45-50mph (50 if I'm lucky). Now having read some stuff on the internet about Minor's I should expect it to go faster than this? I sat at 60 in the Land Rover and that was fine - it would be nice to attain that sort of speed again, or is this simply not feasible with a 1098cc Moggie? The engine pulls well at all speeds (4th will pull all the way from 25-30mph) and starts and runs well. At 45-50mph it seems to be running at a 'good' speed but it desperately feels like it needs another gear. Does the engine not mind revving and can I go faster for long periods? I've overtaken some stuff and it felt like it was topping out at 55mph absolute max although I could be wrong about that. I'm used to the lazy torque of a 15 year old 2.5TD which didn't like revving so it might just be me being naive about petrol engines.

One option is to change out the diff for a taller ratio, but I would lose out on first gear, although I barely use it and prefer to pull away in second except for coming out from side roads onto main roads where I need the 'acceleration'. The other is to source a 5 speed gearbox but I don't know the feasibility of this. Are there any 5 speeds that simply bolt onto the back of the 1098cc engine or do I need a new bellhousing/adapter place? Gearbox mounting points the same? I'm pretty proficient with nuts and bolts jobs so it wouldn't be too much of a problem. Any other solutions?

He's going off to a Morris Minor restorer next week for some welding work for the MOT and he said he's going to take a look at the engine and give it a bit of a tuneup (it's not been running that great in cold weather/night time and misfires badly until it warms up) so hopefully that might give it a bit more top end poke.

In better news I should have some Halogen headlights appearing on my door step in the next few days and I shot this on the way home from Plymouth the other day

[Alex'n'Ane]

You should be able to happily cruise at 60-65. And standard 1098's should be able to reach well over 70, touching 80. There are also some relatively simple mod that can be done to the engine to push this up slightly. The taller ratio diff is a much cheaper option than the 5 speed box, but if you want a 5 speed box, there are bolt on kits available.

[minor65]

The engine will start to rev quite a lot over 40. I personally don't like going over 45/50 (i'm sure someone will comment on that) But i'm just fussy. I'm not completely sure but I think at 60mph the engine as revving at 4000 rpm. Which to me is a bit to much even on a new car.[frame][/frame]

[aupickup]

i do around 60 to 70 on motorways and the 1098 is quite happy at this

[Nuffles]

So revving it is just how it is? Looks like it's just me being funny about over-revving the engine then.

I used to run Nitro RC cars which are only air cooled and are very touchy about engine temperature. Revving high for any length of time is a big no no and you constantly had to tune them to keep them lean enough to perform well but rich enough to keep cool (as the fuel that the engine ran on also lubricated it). This seems to have instilled in me a possibly overactive mechanical sympathy towards engine speeds.

What happens to fuel economy when you cruise at 60 rather than 45? I got from this side of Exeter to Bristol and back (about 100 miles each way) plus extra driving in Bristol and around Exeter on the way home on a tank of petrol, doing 45 on the motorway each way. Would I get noticeably less than that going 20mph faster?

Thanks for the replies so far.

[aupickup]

well obviously travelling constantly at 45 to 50 is better for fuel economy than 60 yo 70

these cars and vans will do 70 quite easily
i thinka lot of folk just think they will only do 45 to 50, mainly the 5 times ayear brigade
i do 10000 miles a year in mine and i dont hang about in it

[linearaudio]

Coming from a diesel cruising at 2000 at 70 to a Moggy doing 4000 at 70 will seem a little "busy"! The general commotion of the thing is offputting, but you get attuned to it and soon realise it's not about to go bang!
The comment about the 5 speed box being a bolt on job is maybe a little conservative. It's a fair bit of expensive bolt-on, no the box doesn't fit straight on the back-the big part of the price is the bespoke bellhousing that is part of the kit (and you don't get the box in the price!). A 3.9 diff is very much a direct swap, raises gearing a handy 14 percent, and they are available from £30 ( If you are a Scot )

[bmcecosse]

Standard 1098 should easily get 70 on a flat M/way - ok , it will struggle a bit on M/way hills. Just put your foot down! At least try to do the 56 mph the truckers do - or they will be constantly on your back bumper - and I for one certainly don't like that. With some mods - the 1098 will do a lot more than 70 Five speed box won't help - because most of the time you will be trundling along in 4th gear - a standard 1098 won't get the best from a 5 speed box - and they are certainly not cheap!

[bmcecosse]

3.9 final drive for £ 30 !!!! Oooohhhh - that's Cheeeeeeeeeap !! My 3.7 was £80 - plus 'gratuity' to local Cops Charity Box for 'encouraging' the seller to stump up after 4 weeks waiting

[Nuffles]

I'll keep my eye open for a 3.9 diff sometime in the future then. Hopefully the engine will perform a bit better once it's come back from the Morris Minor man. My only reservation towards the 3.9 diff is that I will lose a bit of first which although I don't use it 80% of the time it's useful for steep hill starts (of which there are many in the rolling countryside of Devon) with 3 passengers. It is my daily/weekly driver and I spend a lot of it on fast A-roads and country lanes and comparatively very little stop-start city driving so a 3.9 diff would probably have more positives than negatives. Unless my knowledge of ratios is incorrect it will have comparatively little effect on first gear compared to fourth? It would be nice to get even a 10% increase in road speed for engine RPM as that would push me up to 55 and from there it's not many more RPMs to 60.

Thanks for the continued help guys

[bmcecosse]

Just don't run it constantly over 6000 rpm - or the crank breaks!

[linearaudio]

Just don't run it constantly over 6000 rpm - or the crank breaks!

6000 from a standard 1098? Wishful (or not) thinking!

By the way, I love the photo with the thatch cottage, very in period, no yellow lines/pavements/overhead lines
Suck it and see with the diff- you certainly won't lose money on it if it isn't to your liking!

[Nuffles]

How fasts that? I've never had a rev counter on any of my cars before Well there was one on the Range Rover but it was a field car so I never really paid much attention to it.

Thanks about the photo btw, I've had a lot of positive feedback on it from both Facebook and DeviantArt

[linearaudio]

6000? Somewhere around the ton!! EEK!

[mike.perry]

If my Series MM is capable of motorway cruising at 60 with the trailer on the back then a 1098 Minor should be capable of over 70 even if things start to rattle a bit.
I would not recomend a 3.9 diff for Devonshire driving, about the only place to take advantage of it is along Slapton Ley. If I was driving around that area I would be thinking of dropping the diff to 4.55 for improved hill climbing.
Not looking forward to driving to the Nat. Rally at 45mph running in my new engine.

[Nuffles]

It pulls like a train up most of the hills around here. Low down torque is all there, it's just high RPM that I'm anxious to push. On main roads I'm seldom down to third even on the steep ones and second is only needed for tight junctions. First is nice for hill starts obviously but I definitely wouldn't want to gear down any more than is already in there. If a well priced 3.9 diff comes up I'll pick it up and give it a go. I can always sell it on again if it's not to my liking.

Are these all indicated speeds you guys are quoting or verified by sat navs? I hit 70mph going down Haldon Hill on the way home from Newton Abbot where I picked him up but that was only what the speedo said and in reality was actually about 60-65. The revs sounded very high and I wouldn't really want to push the engine to that speed in normal driving. How likely is it that It's had a lower geared diff put in it in the past? Is there any way to tell without getting the diff out of the axle?

[bmcecosse]

It is possible the final drive ratio is wrong - after several years I found mine was a 4.55 - should have been a 4.22. You can jack up a wheel - and then turn the prop shaft 10 times and note how many turns the wheel makes! Worth checking if your air filter is all clogged up if you think it's down on top end power.

[Nuffles]

Wouldn't the jacked up wheel turn twice as fast as the diff though? I shall have a go at that sometime and see Thanks.

[chickenjohn]

You should be able to happily cruise at 60-65. And standard 1098's should be able to reach well over 70, touching 80. There are also some relatively simple mod that can be done to the engine to push this up slightly. The taller ratio diff is a much cheaper option than the 5 speed box, but if you want a 5 speed box, there are bolt on kits available.

Agreed, I have driven my Traveller at 60-65 often on dual carriage way/motorways for years now with no ill effect. My car is standard, it will cruise at 70, but starts to sound a bit strained at this speed. BTW, I have driven the car for 45,000 miles like this and the engine is still sweet at a total of about 98,000 miles now. Just change the oil and filter often.

60-65 in practise is only a few tens of minutes slower than a modern car at 70-80mph over a long journey.

By the way, I have "calibrated" my Traveller versus a known German performance car at 60-70mph and am convinced the speed readings are accurate.

[bmcecosse]

Yes - the jacked up wheel turns twice - just divide by two! Plenty of roadside flashing signs to calibrate the speedo against - usually have a 'sad' face just below the speed reading - dunno why that is . Or - follow some trucks on the open road - they should be doing 56 mph exactly!