803 engine - how long do they run?

[JOWETTJAVELIN]

Seeing as it only has a by-pass oil filter, and is bound to be worked hard just to get the car up to speed, my question is how many miles can these units rack up (with general regular maintenance and attention) before needing major work?

Anyone with a 100,000 mile Series II?

[liammonty]

Speaking as someone who 'killed' an 803 (and it didn't take much doing), I think you'd be extremely lucky to get anywhere near that mileage. Even if it was good for 100,000 miles, it would take decades to cover that distance under 803 'power'! The trouble is that the crank is so weak, as are the associated bearings (white metal and tiny), and the thing is so hopelessly gutless and low geared that it's working so hard all the time. It's hard to appreciate just how painful they are until driving one! I couldn't bring myself to spend money on mine after it broke, so replaced it with an ancient 948, which made the car lovely to drive (changed diff as well). I do understand people wanting to keep nice cars original though, but an 803 as a daily really isn't practical. I've heard stories of them having new cranks etc at around 30,000 back in the day, but maybe somebody else will have a tale of how durable they are!

[IaininTenbury]

BMC did that famous 10,000 mile non stop run with an early Series 2 saloon and specially built tender vehicle as a publicit exercise to show how durable the A series engines were. The car completed the distance with no problems and was running more economically after the run than before (nicely run in I expect).
I guess expectations were different in those days...

[bmcecosse]

Aye - but it was just round and round a track with hardly any slope, never mind hill - and virtually no braking or accelerating - pretty much just steady speed running. Clever how they were able to change wheels on the move - including the rear wheels. I assume they must have fitted individual handbrake levers so they could lock each wheel and keep the drive going through the other.

[Neil MG]

Mine hasn't been opened yet (apart from me taking the head off for a look) since 1956 and I have put about 4,000 miles on this year taking it up to 72,000. I have no doubt that correctly maintained engines would easily do over 100,000. The problem is knowing how well the engine was maintained previously!

I use mine as a daily driver with no problems. I also like the feel of the crossplys and wouldn't even think of fitting seat belts or flashing indicators. I love classic car nostalgia, but I don't suggest that is for everyone! Plus I also have other classics if I feel the need for speed or sports car handling!

[IslipMinor]

I've heard stories of them having new cranks etc at around 30,000 back in the day,

My mother bought 'our' 1958 948 Minor when it was 6 years old with 40,000 miles on the clock. The 1 previous owner was fastidious in the maintenance, and we still have his notebook that recorded every 1/4 pint of oil and every gallon of petrol that he put in over his 6 years of ownership. We also have the full service history, which is completely 'by the book', for that 6 years as well.

Despite that, the engine was rebored at 30,000 miles by the PO, and after a couple of years in my mother's time (4 years) we had to fit an exchange crankshaft (all 'standard' journals) at around 45,000, which then went on with no problems up to 99,000, when the whole car was restored and the current 1380 engine fitted. The original 948 was progessively modified, +60 flat top pistons, 12g295 flowed head, Cooper 997 cam (2A948), HS4 carb, LCB etc. And still the crank was perfectly OK with excellent oil pressure, and the bore wear was minimal after 50,000+ miles - I think improvements in oil technology are more responsible for this than anything else, which is why I would never economise on what oil to use in any A-Series engine.

[Neil MG]

[quote="... I think improvements in oil technology are more responsible for this than anything else, which is why I would never economise on what oil to use in any A-Series engine.[/quote]

Agree absolutely! Another major cause would have been (and not without irony) leaded petrol! Regular decokes were a part of routine maintenance. Excessive carbon build up and the potential damage done by less than careful owners and mechanics being a key factor in premature bore wear.

That was the main reason to remove the head (to check the bores) and I have changed the oil four times this year using a high grade 20w50 (API SF/CC)

[IaininTenbury]

Aye - but it was just round and round a track with hardly any slope, never mind hill - and virtually no braking or accelerating - pretty much just steady speed running. Clever how they were able to change wheels on the move - including the rear wheels. I assume they must have fitted individual handbrake levers so they could lock each wheel and keep the drive going through the other.

Indeed, other than the technical acheivment of actually doing it, 10k steady driving dosen't sound too impressive these days really.

[MarkyB]

Service intervals are longer than that these days.

[sudburypaul]

My series 2 is coming up to 43000 miles without a rebuild and showing no signs of excessive noise from the bottom end at the moment. The 803 engine is a bit gutless, coupled with rather strange gearing for negotiating anything resembling an incline, but as I used to do with my old A35 van (which had a 1098 A series engine - ooh the power!) you just get into the habit of setting off earlier. Cruising speed is the main issue on motorways. I have the option of fitting a Midget diff to it at the moment - which I might do as it may alter top speed cruising without affecting low gears too detrimentally or causing any more undue stress on the engine at higher speeds. Who knows, I might be able to cruise at a heady 55mph AND hear the radio at the same time...

Regular changes of 20/50 mineral oil at about 3000 miles is the main prescription, plus regular top-ups due to some sump incontinence.

Paul

[David53]

Just do regular oil changes and drive the car with care and you'll be fine. The 803 may be a little underpowered but the A Series is a tough little engine even in 803 form. If you want to cruise motorways and go hill climbing buy an MGB!

[rayofleamington]

I think improvements in oil technology are more responsible for this than anything else,

I couldn't agree more - hence some moderns having service intervals of 20,000 miles and no expectation of engine rebuilds before 100,000 miles! Improved tolerance capability, Bearing technology and FEA techniques have also helped..

Old fuels were part of the reason for needing regular dekokes but also oil leakage from the valves and rings was also a significant factor. Modern fuels can help remove carbon build ups from oil ingestion...

[JOWETTJAVELIN]

Re 803 performance: once the engine has thoroughly warmed up, (and it does take its time) I actually find it a fairly nippy little thing to buzz about in. The gearing is really the problem; you set off in second (first has no concievable use apart from 1 in 3 work), flick it into third and then the BIG step up to top. I find the performance adequate when you take into consideration the fact that it is such a small engine and 56 year-old technology.
As I have recently graduated from university and there's not much doing on the job front I rarely go near motorways now. In any case, it is unreasonable to expect an 803 Mog to go on the motorways regularly anyway.

About longer service intervals, these are ill-advised in my opinion. The oil is still subject to the high temperatures in internal combustion engines. It also still breaks down over time and mileage. The thing with modern, fuel-injection engines is that the oil doesn't get as diluted with petrol as much as carburetted engines, however 10k miles between changes is not, I think, a good idea.

[liammonty]

Oil really is very much better these days- otherwise, therre wouldn't be so many engines still running beautifully after 100,000+ miles, having had (manufacturer recommended) oil changes at only every 10,000-20,000 miles. The facts speak for themselves. I'm all for regular oil changes in cars like my Minors and my air-cooled VW, but with a fully synthetic, highly developed, expensive oil in a modern car, it is crazy to stick to 50 year old oil change intervals! My wife's VW diesel Goplf ahs it's FIRST service due at 18,5000 miles, and I'm sur eif it posed aa real risk leaving it that long, there is no way VW would do it- just think of the potential warranty claims!

[MarkyB]

I just had my modern motor serviced ( a pretty penny it cost too ) the service indicator now says it will need a big service in 117,000 miles!
It will be interesting to see how this changes over time but this thing shines a light through the oil to see how dirty it is, and the computer takes into account the type of driving the car is used for.

[JOWETTJAVELIN]

I just had my modern motor serviced ( a pretty penny it cost too ) the service indicator now says it will need a big service in 117,000 miles!
It will be interesting to see how this changes over time but this thing shines a light through the oil to see how dirty it is, and the computer takes into account the type of driving the car is used for.

And if computer says 'no'?

[dellerie]

803 engine will run for as long as it has a supply of petrol from the pump/tank.

[bmcecosse]

The computer will likely say 'SERVICE' after one year - no matter how clear the oil........ My daughter's Clio is like that - fortunately (thanks weelung ) I know how to reset it!

[liammonty]

"803 engine will run for as long as it has a supply of petrol from the pump/tank"

Not so-I had half a tank of fuel, with a working fuel pump and oil in the sump. Engines don't run too well with ruined big-ends, even with a plentiful supply of petrol!!!! I accept that the 803 was OK in its day, but nobody could ever refer to it as a strong engine- that's why BMC made so many mods to it when they brought out the 948, which is a hardy little engine. If it was great to begin with, they wouldn't have needed to increase shell sizes and strengthen the crank! If you trawl the literature on it, you'll struggle to find much positive said about it- even the road tests of the SII Minor when it came out weren't terribly complimentary, as the engine had more or less the same power than the 918 sidevalve, but was far lower geared, and less robust. As I said, I agree with people who have 803s and want to keep them in their cars, but I can't agree that it is a great and durable engine!

[dellerie]

"803 engine will run for as long as it has a supply of petrol from the pump/tank"

Not so-I had half a tank of fuel, with a working fuel pump and oil in the sump. Engines don't run too well with ruined big-ends, even with a plentiful supply of petrol!!!! I accept that the 803 was OK in its day, but nobody could ever refer to it as a strong engine- that's why BMC made so many mods to it when they brought out the 948, which is a hardy little engine. If it was great to begin with, they wouldn't have needed to increase shell sizes and strengthen the crank! If you trawl the literature on it, you'll struggle to find much positive said about it- even the road tests of the SII Minor when it came out weren't terribly complimentary, as the engine had more or less the same power than the 918 sidevalve, but was far lower geared, and less robust. As I said, I agree with people who have 803s and want to keep them in their cars, but I can't agree that it is a great and durable engine!

i never said it was! i was making light harted banter about it...

my split screen moggy has a 948 fitted and so does my A30. both 803's were replaced within a year of ownership.