Disassembling MG Midget Engine to Find Failure 

"Here's what's left of the bearing, it should not look like that." And I thought we Brits were the masters of understatement. :-)

Personally I like the way Steve narrates his videos. Calm, relaxed...even when something is really torn up :-)

When we were downsizing to move into an independent living facility, I gave my set of Whitworth tools to a man who owned an MG. I had bought them while I was a Triumph Motorcycle dealer.

Steve, you have the proper demeaner for British cars !

I would grind the crank shaft, fit over sized bearings and with new rings and hone the bores, there will be a good Morris engine again for another 50,000 miles. That's what we did at the Morris works back in 1970. If you paint it gold in colour, it will look like a genuine gold seal engine.

You know, Steve...you are my low-cost therapist. Crappy day at work, issues with the kids...whatever. 10 minutes with Steve taking the head off an old MG Midget engine and I'm good. Thank you!

Great video.

I never tire of watching the ubiquitous BMC 'A' series engine being disassembled and reassembled. The one that so many trainee car mechanics and engineers around the world cut their teeth on.

I’m a Brit and I really only watch three car fix you tubers and they’re all Americans, this one of course, mustie1 and puddings fab shop.

Love these small engines. Whether you rebuild this or rebuild another that you have kicking around doesn't matter much. As long as you can get the parts. Do it the most practical way you can.

Yay, more Spridget content!!!

Brilliant as always. Makes me wish I had bought a car like that when they were still cheap and readily available.

GREAT VIDEO , WELL DONE LAD

Steve... You make it look so easy. Thank you for these great videos. I'm always looking forward for the next one.

Very interesting. Thanks for sharing and gl with the rebuild and saving the crank.

Recently finished refurbishing my first engine which was a bmc 1098cc. Was great learning about this engine and it’s easy to see the reason why these engines were so popular

Excellent analysis, I learn something with every video... keep up the good work Steve.

And that, boys and girls, is why leaving out two main bearings when designing an engine is a great way to make it more compact, while at the same time crippling its power potential and durability. Luckily, the Great Main Bearing Shortage Epidemic ended somewhere around 1960. At least in technically advanced nations, that is.

Love the videos when you are inside the engine. Here’s hoping for good news from the machine shop. My guess is it spun the bearing, and then after extreme heat the bolt backed out. Keep the videos coming. Love your work!

Loving these videos! This one is rather cathartic. The little plastic tube is in fact the end of the dipstick sleeve. Apparently it's quite common for them to break, thanks to the heat cycles, and the lower half to disappear into the pan. Replace (for three dollars or so), rinse, repeat. haha

We need videos like this one. Very informative

Nice video. Good commentary, no annoying music and nice simple editing. Keep up the good work!

Love working on British cars. Actually all cars. Really enjoy your channel. Thanks for sharing!!

This channel is great motivation. All I've managed so far is to move some Mini shells to a better location, bring in pallet racking to store all the extra subframes and engines. Once organized I hope to get started on just getting a car started. No restoration yet, just get the pieces together and see what I have to work with. tHanks for all your videos! I'll keep filming...but for now it is just moving parts.

Good video,all well explained and filmed in a simple no nonsense fashion.

very good video, thank you. I have a 1952 MG TD so it is nice to see the engine video

I used to have an Austin A40 with a tuned 1275 A series engine in it, was great fun driving it in the early 70s. I advise that you rub silicone grease into all cylinder head main bolts, thermostat housing bolts and the water pump bolts to stop corrosion. Also it would be a good idea to do the same to the rear suspension bolts and shackles, in fact anywhere you may get bolts rusting and becoming jammed on these old BMC cars. Good luck and thanks for the video.

Good explanation of bearing issue. Go for it Steve.

I really appreciate these whatdonit videos. I would prefer to see this one rebuild than replaced

Thank you Steve for your video, I learn a lot watching these video. I enjoy this kind of video because it helps me understand how to fix my 53 MGTD.

Apart from the silly bit at the beginning what makes this great is that there's no daft music overlay. Top marks.

Great Video! Looking forward to the rebuild video!

Ah great vid. You do the vids on engine dismantling so well. Thanks for doing this Buddy

Wishing you a quick recovery Steve.

Thanks for sharing!

Good videos mate. your garage is a dream!

Steve is like the best Shop Teacher, ever.

The piston for that rod is the one with the indentations, looks like a ball bearing was sucked in, I would inspect the head closely and check for a bent valve.

Great video. I enjoy watching disassemble and diagnostic vids. Keep them coming.

Boy o boy did this video trigger a trip down memory lane. Growing up all I could think about was owning an MG. Graduating from HS in 1975 my Dad said he'd buy the car I was responsible for the insurance. We bought a 1970 MGB. After a year of paying insurance my Dad, the insurance agent, and I discussed how I could lower the cost..I went from no fault to at fault...and yup within the year I totaled the car. All I could afford after that was a 1964 Austin Healy Sprite, replaced that with a 1972 Midget ...and eventually found my way into a 1969 MGC-GT (standard not automatic). That MGC was one crazy ass car. Between my MG and AH owning friends it was amazing the work we could do (including rebuilding engines) with a basic set of tools.

real nice video .. excellent presentation ..

great stuff Steve, thanks

Great little engines! Remember working on engines without computers or emission controls?

Generally BMC made great engines, it would be a shame to have to discard this one. I vote for saving it, if this is at all economically feasible to rebuild.

Thanks, that was an excellent video.

I bought a fiat x19 years ago it run fine for about two weeks although only driven once but after the engine going bad, I striped it down to find the remains of feeler gauges that had been forced into crank and snapped of that looked not dissimilar to your engine bottom end

Really interesting

Great video Steve. Which ever way you chose to deal with this, either by rebuilding this engine or building another from what you have sitting around, I look forward to seeing what comes next. If tge crankshaft is shot then its an open and shut case.

Very nice video!

I learned. Thank You.

I had one of those, consistently overheated, used oil, but it looked good!

Thumbs up Steve.PS i always get covered in oil. Cheers.

The correct way to remove the head from a BMC A series ids to remove the rocker shaft and push rods before removing the head. If the push rods are left in place as per this video it is easy to bend them or for them to fall out allowing them to get mixed up when they should alway go back where they came from.

Great stuff

I bought a ‘77 TR-7 with a blown engine for $500 in ‘84. When I tore it down, I saw the connecting rod had gone through the side of the block. I would guess the previous owner had a similar failure with the nuts coming off the rod bearing cap. I bought an ‘80 engine and dropped it in. That was a fun car and had many interesting repairs and driving it from Chicago to Los Angeles and back three times. It was a fun little car.

Excellent diag video, interested to see you rebuild this engine.

When I was a much younger man, I had a 1964 MG Midget. When I got it, the previous owner said it had just been rebuilt by a reputable shop (He gave me the receipt). It was never a speed demon, having a 948cc engine. But the girls sure loved it.

Hi Steve great content 😊

I am looking to buy an MG midget.....I have put together small block chevys and these seem simpler, but I would bet that getting parts is tougher. I am following this series and Steve really seems to make very good videos. I hope he reads this as I want to thank him.

WOW! talk about oil starvation! What the hell happened to that rod, bearing and crank to make look like toast? Terrific video. Great narration. Lots of engine experience/

Pausing it before the teardown begins. I'm guessing rod bearing because that's what all my knocking a-series engines used to fail with 🙄

This little engine was obviously run way longer than it should have. This sort of failure was a subsequent of ignoring ominous noises. As the old adage, credited to the Chinese philosopher Sum Ting Wong, says "small noise, stop now". It appears from here that the rod nuts were not tightened properly at a previous assembly, or overtightened to near stripping. Considering the thread mismatch to American fasteners, someone may have just used compromised nuts just to get the job out. I hope a complete autopsy is forthcoming to find what caused the nut to fracture as the forces involved should leave telltale "footprints" on other components. On a side note, can anyone explain the origin of the Mowag name cast into the block of these engines? Brings back memories of yesteryear. Great little engines. Robust, reliable, once you resign yourself to dealing with Joseph Lucas, also known as the prince of darkness. and a joy to work on. Got a kick out of the valve at the back corner of the head, the heater valve. Love that English engineering.

Eric of I do cars calls that metal debris "Reynolds Foil". Thanks for the video - if the crank is not reclaimable, get one out of another of the engines you have lying about - and maybe a rod too, that one can't be too good after the beating and the heat.

The famous A Series bypass hose. Source of much frustration when it's in Mini

I rebuilt a number of these engines when they were still in production. The engines were designed and built to be cheap to produce. Most of the owner's manuals for these engines, Sprite, Midget, and Spitfire, recommended new rings at 50,000 miles. Later engines of about 1600cc were the same block originally used for 948cc, just cast with a bigger bore. Many people driving in hot climates had cooling problems and went to a custom radiator. British machining during this time was not very accurate and that led to a lot of problems. A complete rebuild (in the US) usually resulted in a longer lasting engine and much more reliability than the original.

You were lucky as the big end cap stayed in place, it could have been far worse than a scored crankshaft. Lets hope it can be reground. Looking forward to the rebuild.

Yes, more please.

This small engine looks like a toy to Steve......! 🤣🤣 but what next is his briefing and explanation that strike everyone's attention....

I don't know if old MG's have matching numbers or not but if they do do the one on this match ? If so I would say rebuild it. Its only a rod bearing that spun and not a main so the block should be OK so it would be worth the effort to save the cars originality IMO.

had a spitfire with transaxle great little car so much fun

Depending on how groved the crank is I personally would have the crank regrowned . Just a little less work to put it back together. You could get another engine but that one might take more work to rebuild than this one. Great video Steve it takes me back a good few years, thanks. 👍👍

These engines were in everything from a Morris Minor, Austin Healey Sprite/Midget, Minis and many others 850cc to 1100. As kids we would swap them out in a afternoon

May be a good time to hop one of those up. Go a little nuts. Have a little fun.

That was interesting to see what the damage to the engine was. Let's hope you can salvage the crank and get it running again.

Very interesting video. I'd like to see more with a follow up on what you decide to do. Any ideas on what the cause of failure may have been? Big end bolt insufficiently torqued up?

even before the sump came off, the ball bearing that was bouncing around for 20 or so revolutions caused the shells in no 4 to take a little damage, carry on running and this happened.

Hi Steve . "Nothing on a big ship " .... but this isn't a big ship ! I'm sure you 'll do what it takes . Thanks Steve

I’d like to know more about the Willys in the background

I have just stumbled on your site & love it. I own a 1970 MG Midget in Australia that has been bored out to 1300cc slightly modified camshaft, extractors, power boosted brakes, plus an oil cooler as in the MG B and it purrs along. Red with the black lower door panel & 14 inch chrome MG B wheels. I wonder if you know if there is anyone in your circle that has two pivoting quarter glass windows that are not rusty or bubbly on the locking handles, plus I need the chrome finishers that are around the heater demister vents above the dash. Appreciate your help. Brian. Noosa Australia.

I'd like to see you get back to that race car replica tune up. Cheers

I've never seen anything like that on an A series engine in all my years as a mechanic !

I wonder if the failure point was the rod nut? I had an old 348 Chevy engine that had the same thing happen after I rebuilt it. Ever since I always use new rod bolts and nuts in a rebuild.

A series engine parts and whole engines are readily available in the UK. You may need to import to Yankland.

That crank journal was really beat up. Could be out of round or too much to grind. Is it hard to find a good block somewhere?

Would love to see an engine rebuild, even if that one doesn't work out...

Has kevin from junkyard digs still got the spare engine he borrowed for the blue mg from Cole the corne star

Awesome :)

I’ve never seen less body movement from any RU-vidr. Steve has got to have a robot double!

I suspect the thrust bearings also ate it and would explain the oil in the bell - the rear seal was being pushed out due to crank moving forward and rear

its been may years since i saw rod bearings paper thin.i could imagine it did make some noise missing a rod bolt.at least it stayed on the crank instead of thru the block.

call abacus racing in va beach, talk to chuck. thats the man when it comes to these motors.

Looks like its been rebuilt ..Always hand test unladen crank for binding progressively when torquing down

The BMC engine was a great little worker, you must change the oil regularly.

The old Clarkson quote seems appropriate here ,"My big end ended up in a bucket" - still that looks like one very wounded A series

If it is the origonal engine block it would be nice to keep it if possible, otherwise it matters little. The earlier models had castellated nuts and a split pin if I recall correctly, otherwise should be nyloc or similar.

I find it amazing that with a missing bolt on the end cap, that engine didn't throw that rod.

That's ingested something - the divots in the piston are mirrored on the head, and it was hard enough to splay out the edges of the piston. Too much coincidence that that was the cylinder with the failed bearing, so maybe that's what started the sequence of failures.

I've driven a fair number of old, kind of worn out, high mileage cars in my life, but the only time I've ever actually broken anything in the engine (as opposed to the engine simply getting loose and suffering blow by) was when I was young, aggressive, careless, and really over revved an engine, but even then I scored the cams but I did not break a connecting rod, crank, or main bearing. Was I just lucky, or is there something in particular you have to do to break an engine in this particular manner? I've always been good about maintenance, is it simply clean oil that prevents these problems?

With oil in the bell housing check the rear main oil seal before anything else. What were the cylinder compressions before you started stripping down or didn't you bother to check. It's the head gasket that sticks the head down and not stud corrosion. Why not use a stud extractor rather than just 2 nuts locked together? It amy damage the threads but you're going to replace the head studs anyway. ALWAYS remove the oil pan before inverting the engine so that can see what is actually there without having to search inside the crankcase and pistons! It's 99% certain that the cause of the problem was failing to torque the con-rod bolts correctly. In case you ask I was a Development Engineer working on these engines for a number of years so I know them quite well.

Ouch!