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MG Midget and Sprite Technical - Engine out, no immediate obvious problem...

I finally got the engine out today and have separated the gearbox, as well as having removed the clutch from the flywheel. I was going to remove the flywheel but I got endlessly frustrated with the 'removing the final bolt' issue. So I packed it in for the day.

The bell-housing had the usual certain amount of oil on it's insides, but the clutch was dry as a bone and not contaminated. The carbon bearing was absolutely knackered and ground at an angle.

On the clutch, the bit where the bearing makes contact (what's this called?!) was very 'rattly'... I forget since I fitted this, but is it normal for these 7.5" clutches?

On the engine, there is a nice thick coating of oil below the pressure sender hole and the back of the sump is thick with oil.

Apologies for crap pictures, our camera lens broke so I am resigned to iPhone pictures.

What should my next move be in this exciting game of chess?
Rich Amos (1 Sprite 1 Midget!)

http://www.flickr.com/photos/77673728@N00/sets/72157609209564297/
Rich Amos (1 Sprite 1 Midget!)

The carbon release bearing is shot so obviously that needs to be replaced.

The bit that is rattly is generally in my experience at least, rattly.

What was the original problem?
Daniel Thirteen-Twelve

The carbon release bearing is always, always shot on my car whenever the damn engine comes out!

Original problem is that the engine is leaking about a litre or two every 100 miles. REALLY bad. I pulled the engine to see the issue, thought it might be the crankshaft moving too much 'laterally' due to too much tolerance and letting oil out the back, but there really isn't that much oil in the bellhousing for that is there?!

Very confused.
Rich Amos (1 Sprite 1 Midget!)

Why are you using an original distergration type bearing when you have a 7.5" clutch which is a Ford one, why not change over to the Ford bearing type & change the gearbox at the same time?
Brad
Brad (Sprite IV 1380)

Brad,
Why not a 5 speed? Because I spent all my money on another Spridget to race next year ;-).

At the moment I'd just like my oil leak to stop!
Rich Amos (1 Sprite 1 Midget!)

Brad,

The 7.5" clutch with carbon release face is likely Hillman Hunter not Ford. The carbon release bearing can have a long life but recent pattern bearings may have quality issues and people have to remember to not ride the clutch.
David Billington

Considering the issues I've had with overthrow I'm also not disappointed with the length of life of the carbon bearing. Even that one would have lasted a race season, bless it.

Anyway... oil...
Rich Amos (1 Sprite 1 Midget!)

Have we discussed the oil pump cover?
Trevor-Jessie

Actually, no, I don't believe we have fully. Some insight into that would be fantastic, and what I'll need to do to get at the bugger.
Rich Amos (1 Sprite 1 Midget!)

remove the engine backplate

then the oil pump cover OUGHT to be recessed into the rear of the cover

Peter May (it was Chris actually) stated that my rear seal kit would not have any sort of guarantee if this was not fitted and sealed into the backplate with Red Hermetite.

They look as if you could run safely without it, only a tin pressing after all.

But it seems they can be a major leak prevention "big deal"
Bill

So why is that? Why should there be any oil OUTSIDE the oil pump? It's sealed with a gasket, as is the backplate itself. How can oil get inside the tin cover?
Andy
Andy Pie-Crust

Andy

Who knows?

I just know that Chris May said that the only failures he knew of were on cars that didn't have the cover.

I suppose there might be a leak issue, but I cant see it myself

But if Chris and Peter say "do this, not that" what do I do?

I fitted the seal, in accordance, it seals!
Bill

I once tried running with half an oil pump cover when using a Metro Turbo pump (which wouldn't fit inside a standard cover) and it pi...d oil out everywhere.
Dave O'Neill 2

Thanks, I will get the backplate off and take a look I think. I am having a little struggle with the flywheel however. I have managed to get all but one of the bolts off by 'staying' the bolt to be removed against another one, but obviously with the last one it's a little challenging.

Is there any easy way to get this last bugger undone?
Rich Amos (1 Sprite 1 Midget!)

There sure is!!!!

And its SOOOOooooo SWEET, I absolutly love mine, I wish I had bought one years ago, makes taking apart an engine so easy, and fast, all of 3 minutes to take off the flywheel, and the only reason it took 3 minutes, was because I had to remove the clutch assembly 1st. (sweet) ....no blood, to busted knukles, no strained muscles, no brusies, no long breaker bars, or cheater pipes, its just so freaken easy, I cant recommend it enough,,,,truly my favorite of all time tools...even beats maginet on a stick...


Have a looksy, super cheap to, I may buy another one, just to have as back up.

prop

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=31877
Prop

Rich, use a suitably sized allen key with the long bit put through one of the bellhousing bolt holes and the short end jammed into the ring ger. Works a treat.

The oil inside the bellhousing doesn't look to be that much.

Check very carefully for oil leak pathways on the sump and around the rear seal. Hard to see but you can sometimes pick up where the oil has been flowing.
Tarquin

IIRC the oil pump has a small drain hole that feeds oil back into the crankcase, - unless the oil tin can cover isn't seated and sealed properly in which case it drains oil out the wrong side of the back plate.

The amount of oil in the bell housing is pretty minimal and nothing to be concerned with. If you are using/ loosing a litre per 100miles then it isn't going via the bell housing or it would be in much more of a mess than that!
My guess is that it is leaking between the backplate and crankcase, through the rear sump "C" seal or from the oil pressure gauge connection. I presume the front timing gear cover is oil-tight?

Guy
Guy Weller

Knowing Rich I would also guess that some critical nuts and bolts are only finger tight :-)

Or should that be fingerless tight?

Tarquin

Oh Matt, you big joker!

Front timing cover is mess free, yes. I'll investigate getting the fly off and work from there I think.
Rich Amos (1 Sprite 1 Midget!)

Was it actually leaking, or oil disappearing? The former should leave a trail to somewhere, whereas the latter means it's being burnt.

What's your breather setup?

Ant
Ant Allen

Leaking. All over my garage floor and driveway and every road I ever went on!

Breather setup was standard crankcase to HIF, then a rocker breather and a sump breather to atmosphere. Blocked the 2 secondary breathers and still got huge leaks.

Engine has done 8,000 miles since full rebuild.
Rich Amos (1 Sprite 1 Midget!)

> Breather setup was standard crankcase to HIF,

What do you mean by "standard"? The timing cover oil seperator pot is standard for 1275 engines.

> then a rocker breather

That shouldn't be there on a 1275.

> and a sump breather to atmosphere.

Where is this one? Anything in the sump has oil splashing about all over the place. Is it throwing oil out of this "breather"?

> Blocked the 2 secondary breathers and still got huge
> leaks.

The problem with blocking breathers is that blowby builds up pressure in the oil galleries and forces oil out of the weakest seal - usually the rear crank. You need _a_ breather, and it _should_ connect to a pressure just below ambient pressure (in the carbs, airbox or via a PCV depending on the original design), therefore the engine sucks in through any weak seals rather than pushing oil out.

Ant
Ant Allen

I should add - whilst I understand what a breather should do, I'm only just getting to grips with it in A series engines. My sprite has a breather system mismatch, so I've done a lot of research on it to find out what I've got and what I should have. I've not yet come across a HIF carb so perhaps someone can help out with that one.

Ant
Ant Allen

Ant,
This is what I am saying, we have covered this quite extensively already here.

Standard front crankcase tin at the front, connected to the vacuum on the HIF44, just like it was previously connected to a vacuum on the twin SUs.

Sump and rocker breathers are common upgrades made to the A series engine both transverse and inline, especially to racers. This engine is quite 'hot' for a road engine so it was assumed a while ago it would benefit from these.

They were not throwing oil out as they vented to a filter which maintained a vaccuum. When I blocked the breathers, I blocked the sump and rocker breather but left the front 'standard' breather connected to the PCV. As you would have out of factory.

But still huge leaks. It is not as simple as a standard aspiration/vacuum issue as far as I can gather as this usually throws oil into the bellhousing like you wouldn't believe.

Mine is a thick, heavy leak which by the looks of things must be coming from the rear of the engine. I am just trying to eliminate issues one by one as I am very much hoping it's not an issue with my (brand new) pistons and bores.
Rich Amos (1 Sprite 1 Midget!)

Ah ok. Was only trying to help. Still can't get my head around extra breathers being an upgrade. New one on me. Hey ho.

Ant
Ant Allen

Rich,

The reason your leaking is because your only getting vacume at the carb during idle, because there is no vacume in the carb once the butterflys open (AT speed)...granted its getting a bit of swish from the air blowing by, but at road speed your not getting the nessary vacume.

you need to run a hose from the carb to the intake manifold/carb, Then run a hose with a gulp valve at the timing chain cover to the exhauste pipe at a 30 to 45 degree angle...this will provide the vacume you need at speed, the faster you drive, the more vacume.


You have to remember what driving was like back in the day when these cars came out.....they where twisty, windy, roads with lots of stopping and slower speeds....rarly did they see long interstate cruise driving....AKA why do you think we got 4 speed trannys instead of 5 speeders, plus the current evac system was adquaite for this type of slow speed, stop and go, constant back and forth movement of the gas pedal.....In todays world, If we get to drive a twisty windy road even for 5 minutes aday on a daily driver...its a blessing from god himself. my car see's long straight highway driving and modern city driving about 96% of the time...Ill bet yours does to. no where near like back in 1972.



bottom line...you need more vacume at speed, idle your fine

prop

Prop

Hey rich,

Another thought....I wonder if the machine shop, lathed/ground/milled... "Away" the scrol seal groves on the crankshaft, that would certianly make for alot of leaking.


prop
Prop

Prop,
My system uses an HIF44 carb, with the breather hose from the front canister to the purpose-designed connection on the carb body. It works well for mine and I think it is the same set-up as Rich is using.

Guy
Guy Weller

Prop,
Noone else gets this kind of leak on a day to day issue with the same set up so I can't really imagine it is just that.

FYI, it leaks a hell of a lot on the driveway when idling.
Rich Amos (1 Sprite 1 Midget!)

Sure it isn't leaking from a cracked pressure guage pipe? That will pump out a steady stream of oil at tickover!

My car gets through about a pint between oil changes - every 3000 miles.

Guy
Guy Weller

Hey Ant,

Dont be to hard on rich, it took me along time to understand the evac system as it does many others, adding additional breathers is a common mistake during the learning process. At the time it seems like a good Idea, until you learn otherwise.

prop
Prop

Rich if your getting that at idle, I think you got other problems....maybe a cloged oil gallary, did you you pipe cleaners to clean out the galleries, maybe the shop broke thur some of the gallaries during the machining process....or the grooves where machined off the scrol seal as I stated eairler, maybe the shop saw the hole at the front of the engine which looks like a hammer hit it, (some are smooth holes others are rough and jaged) and the shop welded it up. maybe the rings are not gapped correctly, and were to loose and you got ALOT of blow by...then agian maybe the carb has one to many pieces and is actually blocked off, not sucking, or not sucking enough...have you got a manifold leak, that would reduce the vacume at the carbs.

I think your wise to break down the engine and see whats going on.

well I got to get to work...see ya later

prop
Prop

I have officially been 'propped'. I can assure you the vacuum theories do not confuse me one bit.

What does confuse me is where the leak is coming from and thus I will let you guys know when the fly comes off.
Rich Amos (1 Sprite 1 Midget!)

Yep - congratulations Rich
8^)

Follow the Propisms - and you'll wonder why it all seemed so difficult.
Steve Clark

Prop has to come up with the most original theories I have ever heard.
Most problem solving follows a route of simple tests but Prop always wants to take the most drastic action first, ie " pull the engine to see if someone has ground off the scroll seal on the rear main"

Prop put a vacuum gauge on your inlet manifold you will find there is a vacuum in the inlet manifold 90% of the time. Its only on full throttle acceleration you loose vacuum as soon as you throttle back you will get a decent vacuum in the inlet manifold, hence the breather is connected into it.

However Prop I do enjoy your contributions to the forum, I am suprised you ever manage to find time to work on the midget.

Image of my breather set up that works fine 1275 breather from the front cover to the carb.

Mike
M J Pearson

Image hopefully
M J Pearson

if it doesn't work this time I give up


M J Pearson

Rich,

It's been a long time since I had an A-Series apart, but I'm pretty sure there are several blanking plugs on the back of the engine. Some of them are blanking off the oil passages.

I had to pull a fresh rebuild for this once. I had replaced the blanking plugs with pipe plugs and didn't pick a good thread sealer. It leaked a lot.

Charley
C R Huff

2 oil plugs at the rear along with 2 water plugs...

The only (decent) way of getting the oilplugs out is to drill and tap and then get them out that way.

Gary used to use about the same oil consumption; when I stripped the engine there was nothing obvious in there that was causing it to use so much. Never did a compression test so it could have been blow-by but the rings looked ok..

You need to find out where it is leaking from; now that its out that will be harder than when it was in ;-)
Toby Anscombe

Toby,
It is far more enjoyable to do with the engine out - no more crawling around on my filthy garage floor - even if I am now poking around in the dark wandering where it's come from. I haven't cleaned it though so still have the big traces of oil. Fingers crossed.
Rich Amos (1 Sprite 1 Midget!)

Toby,

your right, i drilled mine out then tapped them NPT & fitted plugs with a tad of sealeant.

Ant,
try a leak down test, see if that shows up anything amiss, easy enough to do yourself or the local garage couple rip you off for the privilage.

Brad
Brad
Brad (Sprite IV 1380)

Brad,

Any reason you went NPT rather than BSPT as BSPT would be far more common in the UK.
David Billington

Hey rich,

An easy way to remove the flywheel, is to load the engine in the back of the pick-up and haul it to a shop and let them hit it with an impact wrench, Ive done that a time or 2


Propism is the new one world language....LOL.

The reason I was pointing out the most drastic solution was rich didnt have hardly any problems with oil leaking BEFORE he rebuilt his engine 7000 miles ago, I belive something went a miss in the machine shop, because everything he is decribing isnt an issue...

Im probably wrong and turly hope I am, and the problem is nothing more drastic then a piece of finger bone inside the breater pipe...lol.

but I am looking forward to what rich finds

prop
Prop

I love how you assume everyone has access to a 'pick-up' Prop ;-)
Rich Amos (1 Sprite 1 Midget!)

Prop would love to pop across and help Rich but he has to spend some time on his own car

one day

soon

maybe


I suppose it couldn't be finger bon....

err no

forget I even considered it

Where he may be on the right track is with the bridge piece at the "wrong side" of the flywheel

I think it needs to be very closely set to the scroll on the crank to help keep the "suck" inside the engine and there is always some tolerance with bolt holes, vis. Prop's questions about the head casting holes last week. The smaller the gap at the three holed piece the less oil will be able to slip past unseen as the scroll does its duty.

Just a thought and may be worth a look

If I were you, getting that far in I would have a big think about a seal, they can be awkward to fit, never provide a perfect solution but are a better bet than doing nowt.

But I would say that, I like mine!


Bill

Alright, I have the flywheel off, and the backplate removed.

http://www.flickr.com/photos/77673728@N00/sets/72157609209564297/

There was a considerably oily 'rear' of sump as you can see, along with a collection of oil below the flywheel mount (whatever that's called). The 'U' seal of the sump was disintegrating, and I pulled off little flecks of it.

Is it my rear sump seal?
Rich Amos (1 Sprite 1 Midget!)

Rich,

In some of those pictures your spigot bearing looks to have a section missing. Worth replacing it while the engine is out anyway.
David Billington

Rich, also note the crank end face where the flywheel mounts looks clarted up with Loctite? Make sure this surface and the mating face of the flywheel are perfectly clean and ONLY use Loctite on the female threads (if you use it at all...). I also like to lap the flywheel to the crank, but that requires removal of the dowels which is often difficult.

Mark.
Mark T. Boldry

Thank you. I see what you mean by the spigot - how do I remove that? I stopped here because I stared and couldn't see much else that I could dismantle!

Am I right in saying it's the sump leaking not the crank largely?
Rich Amos (1 Sprite 1 Midget!)

At this stage you should consider making a cradle to mount and start the motor up. If the oil problem is huge 10 seconds running will show the weep. Then any changes you do can be retested till your happy its been fixed. The spogot bush is an interferance fit, so a logitudinal cut will get it out.
f pollock

Rich,

A common way to remove the spigot bush is to pack it with grease, insert a close fitting shaft and hit that with a hammer. That generates hydraulic pressure and forces the bush out. Hold some cloth about the shaft just in case some grease is thrown out. A new bush should be soaked in engine oil overnight before installation.
David Billington

If the stick and grease trick dosnt work, they make a "blind hole puller", or you can tap it and use a slide hammer ...other wise its a bear.

Im surprised by the amount of wear on the clutch release bearing...(the carbon ringy thing...or whats left of it)...how worn was that when you installed after the last rebuild 7000 miles ago. I think your on track with the oil pump area.

I have just a crazy wayout thought, what are the thurst bearings/bushings like...if they are worn, maybe there is some latreail movement in the crankshaft....I know thats out there, but there is certianly some wear at the input shaft/piolet bushings areas as noted by others.

I have to agree with F pollock...build a stand, and get the engin running and track it down from there if nothing is really appearnt...Infact Id still do it before install, just to make sure

As to the Pick up truck comment...I tend to forget that trucks in the UK are an oddity, here in the breadbasket of the midwest...they are as common as dogs, its rare to see more then 3 houses in a row without at least one pick up truck/suv/van in the drive way.

prop
Prop

A jig is a fantastic idea but I neither have the space (it's not a large garage!) or the metalwork skills to do this, as much as it would be a nice thing to have! I will remove the sump, have a peer underneath and see what else I can fathom from that.

I will also at some point try and do the spigot bush and pray.
Rich Amos (1 Sprite 1 Midget!)

Rich,
Another thought: I think that when stationary, the oil level in the sump is below the line of the crank bearings. i.e. the rear oil scroll is not submerged. Therefore when these leak it is mostly when the engine is running. There will be some dripping of residual oil when parked overnight, but not a great deal.

If your car is continuing to dribble a lot of oil when not running then this would suggest a leaking sump - probably the rear "C" rubber gaskets.

If it appears to be pumping out oil when running then do check the connection to the oil pressure gauge as I mentioned way back at the start of this thread. The other possibility could be leakage from the oil feed pipe to the filter or the oil pressure relief valve cover.

Guy
Guy Weller

Hey rich,

an engine stand can be vary easy to make out of wood 2x4s

Build the stand out of 3-4 wooden 2x4s make a wooden brace the same angles as the engine mounts to then use your front engine mounts screwed to the bracing,,,,attach the tranny,,,use some 2x4 scrap to level the tranny/engine,,,then bail wire it down, borrow a rear tranny spline, so the oildosnt leak out..add jumper wires to the wiring of the car, hook up the rad sort a loose and fast along with the exhauste pipe...and fire it up...shouldnt take but 2 hours to build, when your done, tear it down

the way these little engines like to leak...you would be well a head to reconsider

prop
Prop

Guy,
Thanks very much. I have a sneaking suspicion it could be much be the 'c' seal, it looked really wrecked. It may also suggest why the oil basically poured out no matter how much I put in - down to a level. Also suggests why the bellhousing isn't soaked as it may be with a rear scroll issue.

Also, the pressure guage connection was *definitely* a contributing factor (but not the whole issue, as shown by the oil right under the C-seal). The piping was drooling a little bit and it is definitely in need or sorting out.

I hope, HOPE this may be the answer and I might be on my way. Only thing is, when I get the engine out, I want to do 100 things to the bay before I put it back in!

Rich
Rich Amos (1 Sprite 1 Midget!)

C-seal, Do you mean the gasket area, under the scrol seal area that attaches with the 3 screws???

Hoping for you rich, good luck, maybe a little RTV around the 3 screw housing when you get it re-installed

prop
Prop

No, the 'C' seal of the sump at the rear.
Rich Amos (1 Sprite 1 Midget!)

Im not sure what that is rich???

prop
Prop

The seal at the back of the sump where it fits round the crank:
http://www.flickr.com/photos/77673728@N00/3049726079/
Rich Amos (1 Sprite 1 Midget!)

I get a feeling (without going back into forty miles of a dozen threads) that we discussed this cork gasket before someplace

It looks to be the likeliest cause Rich, that one looks toasted (and crumbly)
Bill

I was pulling it off in bits like soggy carboard. It looks likely to be the cause.
Rich Amos (1 Sprite 1 Midget!)

There has been discussion, and dare I say it - differences of opinion - about whether to trim the ends of the C seal when fitting. I think the later rubber / neoprene seals appear to be too long when fitted and the ends extend up enough to make one wonder if the paper sump gasket ends are going to lie flat. And I cannot now remember - trim or not to trim? I think I didn't trim, and used a silicon bead around the sump in place of the paper gasket.

Another thing - when cleaning up the sump face check with a straight edge as they usually distort upwards a little around each bolt hole. Careful "dressing" with a ball-pein hammer will return them to flat or even slightly depressed so that they tighten flat when done up.

Guy
Guy Weller

Fit the end seals tight into their recesses first, trim them so both ends stand up proud of the sump face, maybe 2mm for the plastic ones and 3mm for cork as cork seems to be more compressible. Then lay the flat gaskets in place with their ends on top of the seal ends, keep them in place with grease or some Hermetite or Loctite jointing compound. A tiny smear round the end seals won't do any harm either. Then fit and tighten to the torque setting (which is amazingly low). It's always tempting to overtighten but that just distorts the sump face as Guy says.
David Smith

I got you rich, Know I know where your at!!!....I used the rubber ones...fitted 1st, then shaved off with a razor knife, and tacted the ends with some oil resistant RTV sealer...that was 3 years ago, I was a bit supprised how stiff the rubber ones got...still worked fine, but they where made by payne. thats hard to beat.

prop
Prop

This thread was discussed between 16/11/2008 and 24/11/2008

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