MGB: With maintenance how long will an 1800 last b4 rebuild?

What is the record number of miles on a B before engine rebuild? anyone have a huge number of miles on their B?

That's a trick question. It depends on how severe the use is, how well the rebuild is done, quality of parts installed, type of oil used, etc... ANywhere from 30K to 75k befor eits ready to be rebuilt, maybe 150k before it grenades. I think GlennTowery has something like 400k on one of his cars, but its been rebuilt a couple times.

They last longer today than they did in the 60's. My B has gone 300K+ miles with an average of one rebuild every 100K. It was just rebuilt again after only 10K due to some errors by the previous rebuilder, so I'm discounting that one.

Even with questionable maintenance by DPOs, most MGB engines will go 100,000+ without too much trouble (though it really should be rebuilt before that).

99, 200 on mine and it's still running strong. I bought the car from the original owner so
I know what kind of treatment the car has had since it was new.
Still runs strong and uses no oil. I do change the oil and coolant every year though
just as a precaution. The car is stored during our upstate NY winters.
Drove my TD through six winters here in the early 60's and it's no fun.

George Herschell

80K on mine and running nice !

75,000 on mine and uses no oil. Compression is between 115 and 125 on all 4 cylinders.
BH

I've now done 216,400 miles on my engine. At around 90,000 miles my (motor mechanic) father did a rebore/rebuild because I was moving interstate, not because it appeared necessary yet. Since then the head's been done once (port/polish and combustion chamber mods and unleaded valve seats) and the main bearings and rings were replaced once. Still running on that first re-bore. The motor still runs beautifully, pulls strongly and usually needs no oil, or at most one pint, between its regular oil changes. The car however is carefully maintained, with rarely even 3000 miles between oil and filter changes.

I'd like to expand on Jeff's comment. I suspect that those who drive their MGB daily as their only car will probably not get the mileage from their engine that a weekend driver does. My reasoning is that daily drivers don't get the meticulous attention to every detail that a low-mileage weekend car will. The latter type of hobbyist often maintains his or her car far beyond the average driver. I don't really maintain my daily driver BGT any better than I would have if I drove it new in the 60's. Routine maintenance and repairs only. I don't expect to get more than 80K out of the current engine before it's burning lots of oil, but I do expect far better mileage from other cars that I don't drive as often, but check over before each drive.

When I got my GT it had 128,000 miles on it, the bottom end of the engine was original, but the head had been replaced at some point. Oil pressure suddenly dropped off at 131,000 miles, the car has been a daily driver for at least the last 17 years.

I can run a lot of miles, on a B 4cyl, BUT there things I do to help things out. I change my lifters EVERY 50K in all my 4cl. motors & yes even the real good lifters need to be changed. I tork the head every 10K & adj. the valves & I set the exhaust at .015. I run with 2 oil filters & my oil is clean all the time. The motor in my 73 gt had 50K on her when I put her together & at 150K I plowed a dear & I had to drive 4 miles to get off of I 95 & the motor got to hot, blew the head gasket 1,000 miles later. Rebuilt her in the car with std. rings & rod bearings & rebuilt the head (no cracks) & I have put another 50,000 miles on her. I ran a motor that we built 200,K & I pulled her for a bad TOB, new std pistons & rod bearings & valve job & have run her a lot more miles. Take care of them & you can get a lot of miles out of them, thay are a tough motor.

[quote=ingoldsb]

How many years? 17 on mine since rebuild. Speedo is inaccurate so really don't know the mileage. Still running strong, no oil burning.

Terry and Desmond, those are valid points you bring up but I will argue them lightly anyway just for giggles.

Terry, I tend to think that while weekend drivers aren't driven as often, they are still driven enough to thoroughly warm the engine, etc. Therefore I would imagine that they won't suffer any additional wear over a daily driver on the same weekend.

Desmond, I also see your point and I agree that there are both types out there. I guess most of the people I know with one car, who actually drive the car on a regular basis, are the type who check the oil every time the garage door opens.

I tend to agree with Desmond, but as Steve states, there are both types of people out there. Just happens that most of people I know takes good care of their cars, but I only know a extremely small % of the total MG owners.
i did a total rebuild on my 4 cylinder when I purchased the B in 1992. Reground cam, lifters, bored re-sized rods and new pistons, etc. This engine was still doing great after 100k miles. I did not "Baby" it. Drove it from 1992 to 2004,even on cross country trip(8000+Miles). The engine still had very good compression and ran well. oil changed every 5k and filter on 10k schedule.
As stated earlier, the quality of parts and rebuild are the factors to consider on longevity. My V8 engine has over 130K miles and has survived 4 dyno pulls and performs great.
SAFETY FASTER!

Did a complete rebuild at 36K -- upgrades for autocross -- bottom end then needed rebuilding at 125K

Interesting subject. The trend with new cars is for engines to last longer and longer without major work. I attribute that to the better fuel control with electronic fuel injection and to the use of lead free gasoline. Excess fuel in the mixture causes both cylinder wall washing which promotes ring wear and also thins the oil which promotes addtional lower end wear. In a MGB if you can keep the mixture as lean as possible and use lead free gas you should be able to extend the engine life far beyond the normal mileages when they were new. I'd think that on the whole cars from warmer climates or those not driven in the colder months would probably fare better due to less time running on the choke and the resulting rich mixtures. At least with SUs or Strombergs you don't have an accelerator pump shot to richen the mixture each time you step on the gas so that helps a lot. With well tuned needle selections for the carbs they should be good for between 75 and 100K before major work is needed.

Had Max for 36 years and well over 400K miles. He's always been a daily driver except when I lived overseas. I always had to pull the engine at around 60K or so to do a new clutch and sometimes a rebuild. It really is who does the work. Which is the story of our cars history.

If a top mechanic like Hap or some others rebuild the car then 80K or better. Someone who just slaps it together or is ok but not meticulous then much less. Even if you think you're doing the right thing unless you have experience with the builders or speed shops it weighs heavily. I had a great mechanic do the rebuild time before last and the car just ran and ran incredibly. I used to do routine maintenance every weekend until that build when I just drove the car and checked the oil.

However, last time I had someone local who does this as a hobby assemble the engine. Not good as freeze plugs blew and rings were pul in up-side-down. Had to re-ring it within 2000 miles. The head, my Huffaker head, was murdered by a good speed shop (I was told they were good) and it came off the car twice for leaky valves. I finally just sent it to Sean Brown. Now its back to being the monster it was when it came from Huffaker. He said the speed shop had put the guides in the wrong places - intake in exhaust and visa versa.

So the moral is spend the money for the best engine builder you can which this board can help you with. It will save time and money and your engine in the long run. Always balance the engine and make sure there aren't any exhaust leaks when you reassemble. When I followed this course I just drove the car and never thought about it.

Glenn,

Curious how you plumbed 2 oil filters. Is one in the standard position and one spliced in oil cooler lines?

Thanks,
Shareef

On 160 K Km, that is close to 100K Mls, I had to do the first rebuilt on my 1800 engine. After the rebuilt, I used better oil and changed it with the filter at 3K Mls intervals. Now it has loged about 175 K Km and is still going strong.
May be it also depends upon the style of driving that becomes a little more relaxed when growing older:smoking::drinking:

I would say it's done after 75k. Things will be worn out.

My GT has 216,000 on the clock but was rebuilt at least once before it left California in 1996. It runs great.

My convertible has 136,000 on it and the head has been replaced but the bottom end is untouched as far as I know (and I have service records back to Day 1). The hot oil pressure is on the low side and I may have to do at least the rod bearings soon but compression is good and oil use is acceptable.

My B's engine was knackered by the time it hit 60,000 miles. By 65,000, it had blown up :( Of course, very little had been done to it, other than oil changes. Otherwise, the engine was left alone. No wonder at least one plug would foul, and it was down on power on hills. Those damn DPOs! Oh well, the engine was getting rebuilt anyway.

My car has 100k on it. It has been freshened though. Compression is great. Oil pressure is great, about 75 at cruise, 50 at idle. I only put a couple thousand miles a year on it so I'm sure I'll be good for a while.

Everybody says doesnt burn oil, etc. That's not the real BAD wear problem.
The real bad one to watch out for is low oil pressure. It usually from bearing wear or bad oil, and very rarely a tired oil pump. That situation (running with low oil pressure) gives rise to scored crank journals, spun bearings and, and finally hole in the block.
The best way to detect the problem is to listen for rattle on starting. (Worst thing to do is rev up the motor while it's rattling.) It reveals large clearances (slop) which rattle before the spaces are filled with oil.

My 71 has 106,000 on it now. It has had its oil changed every 3000 miles. It does not smoke or leak. I usually have to add 1 quart of oil between oil changes. It carries 75 pounds of oil pressure. I think it depends on proper care and sane driving. I have logged 103000 miles on a Model A Ford with regular (2000 mile) oil changes. Model As have no oil filter, so more frequent oil changes. At 103K It did not need rebuilding, just the replacement of one exhaust valve.
Bruce