Disassembling MG Midget Engine to Find Failure
ฝัง
- เผยแพร่เมื่อ 11 ก.ย. 2024
- Today I take apart the 1966 MG Midget engine to find out what failed. Watch as I tear down this engine from removing the head to checking the bearings.
Don't forget to visit my website for more updates: www.thisweekwit...
This Week With Cars - Episode 0195
#ClassicCars #MGMidget #MG
"Here's what's left of the bearing, it should not look like that."
And I thought we Brits were the masters of understatement. :-)
It was an excellent summary that's for sure :)
It’s typical Iowa or Midwest America
I too had quite a chuckle over that one!
TBF, he should have checked it against a picture in the Haynes manual before judging so quickly.
Not uncommon to see a relatively clean piston top with these, it's caused by oil coming up past the piston. Usually means that there is was excessive big end clearance spraying up too much oil.in the past. The dents on the piston top also tell a story. If a piston smashes into an object at the top of the stroke, the usual result is failure of the big end, that's where the whole chain started.
Personally I like the way Steve narrates his videos. Calm, relaxed...even when something is really torn up :-)
Exactly. And he doesn't feel moved to promote scrotum-shaving or amoxicillin.
Sometimes the shenanigans with some of these guys are too much. I like calm and specific speech way better.
@@targetglen His target audience is probably not the scrotum shavers and STD prone.
Yes he is so full of confidence that nothing seems to faze him, mind you the old engines are pretty simple in comparison to todays rubbish cars.
I agree. No hype or sensationalism.
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.
Many years ago I sold and repaired Raleigh bicycles (when they were made in England) and had a full set of British Standard Whitworth tools. Only way to work on them. 60 years later, I still have them in a wooden tool chest.
BMC A Series Engine. All you really need are 7/16, 1/2 and 9/16 inch AF spanners!
@@john1703 And little hands!
I recently (in the last 8 months) found out about BSW hardware. I bought a 1989 Taiwan made mill with a Taiwan made machine vice on it. Every piece of hardware was US standard except the 2 bolts that hold the front jaw on it. They were 1/2-12 BSW. I had to post on a machinist page and ask for group help. When I tried to thread on 1/2-13 nut it wouldn't fit so I went off to the the hardware store assuming it was metric. I left a very confused person after realizing that was not it either. Turns out that after WW2 the Tai bought up a bunch of British tooling from around the eastern pacific rim and they evidently were still using it into the late 80s to the early 90s.
@@john1703 5/8th s for the rocker cover !
Steve, you have the proper demeaner for British cars !
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!
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.
Cannot recall, should the piston rings go back with the gaps in line, or stepped out or away ?
@@highpath4776 Not in line !! Stagger them .
@@bertiewooster3326 Thought so , Cheers, (particulary final oil control ring.
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.
Yep, I worked on many of these in the 60's. They were in everything, Sprites, A30's, etc, etc. So easy to work on.
@@MrPropanePete Except mini"s with the bloody gearbox bolted underneath. Bit of of a PITA but I've owned 8 of them and probably will get one again :-)
@@mikal8343 I don't know how many 7/16" spanners I lost over the years down the back of that heat shield between the exhaust manifold and the firewall. And cutting my fingers on the radiator shrouds when replacing the fan belt. You've owned 8 of the little buggers, Jeez. Actually, I love 'em too.
@@MrPropanePete My favourite mini horror show is how the rear wheels will bite the fingers of the uninitiated when spinning them to check for bearing noise🤢
Like a trip down memory lane for me retired engineer.👍
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.
Parts are readily available in the UK... You may have to import them to Yankland.
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.
Nice video. Good commentary, no annoying music and nice simple editing. Keep up the good work!
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.
YOu should watch South Main Auto. Some of his diags are pure genius.
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
Great video.
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.
Brilliant as always. Makes me wish I had bought a car like that when they were still cheap and readily available.
Yay, more Spridget content!!!
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
Love working on British cars. Actually all cars. Really enjoy your channel. Thanks for sharing!!
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!
Might have started with a blocked oil feed from the crankshaft to the big end bearing. That would have caused the big end to overheat and spin the bearing.
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.
Great little engines! Remember working on engines without computers or emission controls?
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.
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.
absolutely rebuildable. can be real fun if done right.
Can probably rebuild the crankshaft also.
Needs to be done every 25,000 miles or sooner when driven at USA speeds... tranny also...
@@BuzzLOLOL Not at all! All you have to do is maintenance, as and when required. Neglect doing this, and you loose!
@@regsparkes6507 - Nope... at 26K miles the rods are knocking... valve springs breaking and dropping valves into the engine... tranny synchros and bearings shot... been through all that several times... even the owners manual says replace the rod bearings at 25K miles... lube front suspension every 1,000 miles... that's 2 times just to get from one side of USA to the other... dropped a Buick 215"/3.5L aluminum V8 and 5 speed into my Midget decades ago... that also lost about 20 lbs...
cdn1.mecum.com/auctions/ln1021/ln1021-467556/images/img2182-1632513245217@2x.jpg
Steve is like the best Shop Teacher, ever.
GREAT VIDEO , WELL DONE LAD
I really appreciate these whatdonit videos. I would prefer to see this one rebuild than replaced
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.
Apart from the silly bit at the beginning what makes this great is that there's no daft music overlay. Top marks.
Silly bit at the beginning?
@@ThisWeekWithCars Yep, there's a plague on TH-cam where people think they're Michael Winner. You usually click to 5 minutes into a video to get back the needless music introduction. The best video's have absolutely no introduction and get right on into it. Other than that its a great video.
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.
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.
'53 MGTD is one of my dream cars.
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.
That’s only worth doing if the car is a particularly rare or valuable one like an ex-works race car or something similar (and even then, competition cars are likely to have had different engines fitted). For the most part, there’s little financial incentive to do so, though it’s nice to keep it if possible.
Steve’d need to get a ‘Heritage Certificate’ from the archives at the British Motor Museum to find out the original engine number; it’s not recorded on the car, but in this case, it isn’t the original engine anyway, as it’s a 1275cc instead of a 1098cc.
very good video, thank you. I have a 1952 MG TD so it is nice to see the engine video
Have you seen my teardown of a MG TD engine: th-cam.com/video/rfQw7l2p0bA/w-d-xo.html
Wishing you a quick recovery Steve.
Great video. I enjoy watching disassemble and diagnostic vids. Keep them coming.
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.
MOWOG stands for (MO)rris and (WO)lseley (G)roup, although what the G stands for is sometimes contested but that is what the BMIHT is claiming it stood for.
The famous A Series bypass hose. Source of much frustration when it's in Mini
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.
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
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 🙄
Did you every come up with a plan to prevent the failure? Knowing how long to go before a rebuild or using a better bearing? Anything you would recommend?
@@Dancing_Alone_wRentals Root cause of the problem is lack of oil changes from the sludge in the bottom of the sump/oil pan.
@@timbutton4990 tHanks. Makes perfect sense. I always changed oil but never really paid attention as to why. Never put miles on cars years ago. I had a lighthearted approach because nothing ever went wrong.
Excellent analysis, I learn something with every video... keep up the good work Steve.
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/
Blocked in the rod shaft I assume, there is a away of fitting the bearing shells
This small engine looks like a toy to Steve......! 🤣🤣 but what next is his briefing and explanation that strike everyone's attention....
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.
My neighbors had a TR7. It broke in the first year. Three years later they were still waiting for parts to come through the dealer system when they disposed of it.
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.
That's true, low grade grey iron used for political reasons, and mass production did not match machining outputs as we do nowadays. The bigger engines [1500 up] were "B" series, a similar but bigger block all round. One issue that does not surface now was the quality of the shell bearings Copper Lead was preferred for the higher performance B series engines, and it was find until the oil quality degraded the lead, then the copper quickly ate into the crank. So fit your crank shells, measure the sizes and grind the crank journals individually to suit. Much better result.
Good video,all well explained and filmed in a simple no nonsense fashion.
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.
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.
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.
With the ridge he found at the top of the cylinders that block needs bored and then will need new larger pistons as well, so great time to make it a stroker engine if he feels like it!
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.
Good explanation of bearing issue. Go for it Steve.
A series engine parts and whole engines are readily available in the UK. You may need to import to Yankland.
Thumbs up Steve.PS i always get covered in oil.
Cheers.
We need videos like this one. Very informative
the matching divot marks in the head on cyl 1 point at a hard metal object bouncing and getting caught by the piston multiple times before finally making it past the exhaust port? a small ball bearing.
after any catastrophic engine failure, i'm told to inspect or replace intakes and exhaust. this was not your root cause is understood.
Thank you.
Good videos mate. your garage is a dream!
I’d like to know more about the Willys in the background
When I saw that....I was thinking there is a video to look forward to.
Thanks for sharing!
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
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.
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. 👍👍
Sorry but regrinding that crank is asking for trouble even if it could be reground. Regrinding weakens the crank without even considering the heat damage. The original crank is not the strongest around which is why a nitrided crank was considered essential for any serious power upgrade.
The rod is buggered too… if the block is OK then it needs a rebore, crank, rods and a set of pistons…
@@JBils41 Yes I had forgotten about the rod. Yours is probably a better solution.
real nice video .. excellent presentation ..
Ah great vid. You do the vids on engine dismantling so well. Thanks for doing this Buddy
Has kevin from junkyard digs still got the spare engine he borrowed for the blue mg from Cole the corne star
Interesting idea!
@@ThisWeekWithCars would make a good video
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.
The BMC engine was a great little worker, you must change the oil regularly.
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.
Would love to see an engine rebuild, even if that one doesn't work out...
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 learned. Thank You.
I'd like to see you get back to that race car replica tune up. Cheers
Years ago I had a 1969 B that had started to smoke. I didn't have the time to rebuild it myself so I had an import shop do it. They did a great job except that after I paid for it the mechanic told me I was going to need a clutch very soon. I asked what was involved to which he told me the engine has to come out. "Did you remove it to rebuild it?" "Well, yes..." Anyway, I'm looking to buy a green 1969 B that has a questionable 1800 but I have to make sure I can get parts here in the mid-west. Your tear down was my first look inside a midget engine. I just now noticed the license plate. I'm about 40/50 miles south. How available are parts in IA? I'd prefer not to go online but if that's the only option... Thanks for the video.
Great Video! Looking forward to the rebuild video!
Thanks, that was an excellent video.
The old Clarkson quote seems appropriate here ,"My big end ended up in a bucket" - still that looks like one very wounded A series
I've never seen anything like that on an A series engine in all my years as a mechanic !
Excellent diag video, interested to see you rebuild this engine.
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
I had one of those, consistently overheated, used oil, but it looked good!
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.
had a spitfire with transaxle great little car so much fun
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
Great Videos, but even if you have another motor, it's most likely used, so why not rebuild this and show us just how you rebuild the old MG/Sprite motors. I'd love to see more.
I’ve never seen less body movement from any TH-camr. Steve has got to have a robot double!
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.
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.
The Sprites were great little cars, but always deserved a better engine than the old A-series anyway!
Very nice video!
Great stuff
call abacus racing in va beach, talk to chuck. thats the man when it comes to these motors.
I find it amazing that with a missing bolt on the end cap, that engine didn't throw that rod.
The bolt shouldn't have fallen out of the rod until I turned the engine over on the engine stand.
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?
@Steve.. What great life decisions/choices have you made and or what do you do for a living or what have you done that set you up to live the car guys "dream" garage/lifestyle? You have amassed a massive collection of vehicles, have tools most of us dream of having and a garage that I'd live in. I'd find a video extremely interesting explaining and going thru as much detail as you can go without getting to personal what it took, the struggles, hard-work and what types of choices you've made in your life that were able to put you in the position you find yourself in today... I think it might inspire or send some younger people down a path that they may have never thought of taking? Thanks.... I'll copy and paste this comment on newer videos in Hope's that it will reach you and hopefully get enough likes that you'll have no choice but to do a video or a series of videos on your success...
Hi Steve great content 😊
May be a good time to hop one of those up. Go a little nuts. Have a little fun.
great stuff Steve, thanks
Looks like its been rebuilt ..Always hand test unladen crank for binding progressively when torquing down
That got uglier and uglier as it went along. I doubt that crank can be saved, especially as it almost certainly has been ground once already! As usual, Steve, I love your calm, methodical approach to these things...
Oil in the bell-housing probably indicates a shot rear crankshaft seal as well.....
That was my first initial thought
MGs don't have a conventional rear seal like North American cars. They use a scroll seal and are famous for leaks. If an MG isn't leaking oil, it's empty.
Yes, more please.