rear crankshaft scroll.

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wearthefoxhat
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rear crankshaft scroll.

Postby wearthefoxhat » Sat Apr 06, 2019 8:34 am

One of the deciding factors on buying my traveller was the the 1098 engine hade been rebored to ÷ 20 with new pistons and rings fitted and a new rear crankshaft seal was fitted as well. The test drive was fine and I saw no obvious leaks.
The car was delivered by transporter. I gave it a basic service as the oil level was on the minimum- of oil plugs filters etc. On filling up with new oil , it immediately poured out of thre rear of the rocker cover. The cover had been over tightened and the gasket had squeezed out causing the leak.There was also sillicone there to stop the leak (bodge repair) A new gasket cured this.
There is an oil leak from the rear seal, down through the jiggle pin. One drop every few minutes when engine is running but drips constantly when stopped. The leaked oil pool is about the 3 inches in diameter. the block was professionally rebored and i have receipts for this and the new pistons. The rebuild was done buy the previous owner. I have the receipt too for the oil seal conversion kit, which i have since read on here is inefectual to be polite.
So where do I go from here? Ref crankcase breathing, i have the right angled pipe on the rocker cover which is clear and I have since fitted a tube from that, to the small tube on the air filter case.
So, Is the conversion an add on which can be removed? Will the original scroll still be there? Are new scrolls still available? I have a spare low mileage engine but it has sat for a good few years but does turn over by hand .
Loads of questions but any guidance would be great.

philthehill
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Re: rear crankshaft scroll.

Postby philthehill » Sat Apr 06, 2019 8:53 am

The scroll will still be on the crankshaft.

The fitment of the oil seal is an add on and when removed the rear of the crankshaft/scroll can be returned to original spec.

I fitted a lip seal to my 1400cc 'A' Series engine but it was soon removed. Only if you have the Maestro engine with the factory installed lip seal can there be any guarantee that the lip seal will be effective.

Remove the seal kit, clean everything up and re-fit the top part of the oil catcher Pt No: 2A51 (MOSS) (Item No: 17 & called cover rear in exploded BMC manual view). You may not have it but they can be obtained. Adjust to give 0.003" clearance (all around) between crankshaft and top catcher.

You may have to rob a rear cover off an unserviceable block. It may be worth doing a search on 'e' bay - or you could borrow the top cover off your spare engine.


biomed32uk
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Re: rear crankshaft scroll.

Postby biomed32uk » Sat Apr 06, 2019 9:59 am

As Phil says take it off, I tried and fortunately the engine never made it into the car as the seal just did not fit properly.

Reinstate the original scroll with all of the parts, getting the cap within .002 - .003 all round is crucial, if the bearings are in good order, there is no excessive blow by, which there should not be by the sounds of it and the breathing is set up correctly there should be very little oil that gets by.

I get the odd drip after a fast run - fast for a Minor anyway.

IslipMinor
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Re: rear crankshaft scroll.

Postby IslipMinor » Sat Apr 06, 2019 11:31 am

'wearethefoxrat'

Rather than repeating the details of the various Minor crankcase ventilation systems in this topic, please read through the previous one 'Fume Vent Dumping Oil'.

It sounds like you have the earlier 1098 ventilation system that does not, by design, work when the car is stationary, and is not really very effectively when moving either, which is one of the reasons it was changed to the 'closed circuit' system on the later 1098 cars. The main reason was pollution - the early 'draught tube' system dumped oil and fumes directly into the atmosphere, under the car and on to the ground!

Do you have all of the following:

• A non-vented oil filler cap
• A tube connecting the outlet from the rocker cover to the air filter casing (already confirmed?)
• A tube connected to the front side tappet cover running down the side of the engine on the same side as the exhaust

Some pictures would be very helpful to make sure we understand what is fitted to your engine.

Although the rear oil seal conversion has a poor reputation, I though that was more on higher revving, modified engines? It's a great shame, as a good 'seal' on the rear of the crankshaft would be a solution well worth paying for.

With what you have described, I am not sure that I would want to take very much on trust about your engine 'build', but what is the best solution for you?

First, some basic checks:

What oil is being used?
Current oil level
Compression test

When you remove the oil filler cap when the engine is idling, what happens? Are there any/many fumes coming out of the top of the rocker cover?

Where do you live? There may be someone reasonably near to you, who could help to diagnose the problem and help with identifying the solution?

If the crankcase ventilation system is working as it should, and you are still getting a serious leak from the rear of the crankshaft, the only likely solution is to remove the seal conversion and replace it with the standard components as previously described. That requires either the engine out, with or without the gearbox, or the gearbox removed on its own, leaving the engine in situ, if that is easier for you.

Do you have any warranty from either the previous owner or the engine builder?
Richard



wearthefoxhat
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Re: rear crankshaft scroll.

Postby wearthefoxhat » Sat Apr 06, 2019 1:40 pm

Thanks guys for the fantastic informative replies. I think going back to the original scroll is the best idea. good to know that the top part is available from moss. I'm off to the footy now Preston North End (My team) v Sheffield united.
I will take photos and post over the weekend.
Meantime on various questions...
Non vented oil filler cap ...yes
tappet cover side vent fitted ....yes
Tube fitted from rocker cover to air filter casing..... not when I bought it but now fitted at service.
Oil used ..... Halfords classic 20W 50 mineral oil
Oil level was filled to the max mark. now about 1/16th of an inch lower after only a few local miles.

Went to start the car to check fumes from oil filler cap
But pull start doesn't work. Doh. I fixed this yesterday by resetting and tightening the cable joint behind the bulkhead. Worked a treat 6 times no problem but obviously not tight enough.!!!
will report back soon.

Thanks again.

oliver90owner
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Re: rear crankshaft scroll.

Postby oliver90owner » Sat Apr 06, 2019 2:29 pm

Might not even be the correct dipstick? Engines over-filled with oil are not a good idea. Perhaps needs checking out?

philthehill
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Re: rear crankshaft scroll.

Postby philthehill » Sat Apr 06, 2019 3:29 pm

Richard
The main problem with the oil seal conversion is not engine revs but ensuring that the outer face of the crankshaft flywheel flange is perfect with no corrosion or any form of damage.
Corrosion and damage to the flat surface will tear the lip seal and make it useless in next to no time leading to failure of the seal which results in oil leaking into the bell housing.
The Maestro 'A' Series engine had a much deeper flywheel mounting flange with a precision ground outer face for the lip seal to rub against.

Phil


Mark Wilson
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Re: rear crankshaft scroll.

Postby Mark Wilson » Sat Apr 06, 2019 8:53 pm

Well, I was going to apologise to the OP for a minor digression - but as I now know he's a fellow PNE fan I'm sure he'll forgive me (although we unfortunately didn't manage to win today. I don't live in the area now so couldn't go, but I will be there on Tuesday for Leeds...)

So, my digression, before I digressed. The mention of the jiggle pin reminded me that when I rebuilt my engine and box, which are now in the car but untested, I forgot to fit the jiggle pin :oops: . Is it important enough for me to split them again? I intend fitting the prop shaft tomorrow, so if its needed it would be a good time to bite the bullet.

Mark

philthehill
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Re: rear crankshaft scroll.

Postby philthehill » Sat Apr 06, 2019 10:36 pm

The only reason that the jiggle pin is there is because BMC expected the 'A' Series to leak oil into the bell housing and it has to get out somewhere. The jiggle pin is supposed to keep the hole clear of oil and clutch dust with all it jiggling about.

Personally I would not remove the gearbox just to fit a jiggle pin.


alanworland
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Re: rear crankshaft scroll.

Postby alanworland » Sat Apr 06, 2019 10:41 pm

The jiggle pin is there to do just that - jiggle! and keep the hole open allowing any leaked oil to escape so as to not contaminate the clutch.
As long as the holes kept clear I can't see not having one being a problem.

Alan
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Mark Wilson
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Re: rear crankshaft scroll.

Postby Mark Wilson » Sun Apr 07, 2019 8:18 am

Thanks Phil & Alan - phew!

ampwhu
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Re: rear crankshaft scroll.

Postby ampwhu » Sun Apr 07, 2019 8:50 am

I did the same! fitted my newly built engine a month ago and forgot to fit the pin in the bottom of the gearbox. did wonder if I should attempt to fir one, but with the green light from the experts on here, i'll just put a thin screw driver up the hole every now and then.

Declan_Burns
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Re: rear crankshaft scroll.

Postby Declan_Burns » Sun Apr 07, 2019 9:21 am

You can retro-fit a jiggle pin without removing the gearbox. Just put it in backwards from the bottom and use a screw driver to spread it so that it doesn't fall out.
Regards
Declan


Regards
Declan

wearthefoxhat
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Re: rear crankshaft scroll.

Postby wearthefoxhat » Sun Apr 07, 2019 5:16 pm

Delay in proceedings guys as the starter pull switch is goosed. it stopped functioning intermittently, then it got to the "pull it out to it's limit and prey stage"- at which point I adjusted the cable which worked briefly and now nothing. When I depress the centre push button from the engine side, it is completely dead. so I guess i need to order a new switch. I did try rocking the car in gear just in case the starter was stuck but no difference.
Oh the joys.....

paul 300358
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Re: rear crankshaft scroll.

Postby paul 300358 » Sun Apr 07, 2019 5:54 pm

You could connect the two terminals with a jump lead or have you got a starting handle?

wearthefoxhat
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Re: rear crankshaft scroll.

Postby wearthefoxhat » Sun Apr 07, 2019 6:07 pm

Your right Paul but I'll order the new switch for peace of mind. I do have a starting handle but I've never used one! I imagine myself not letting go and dislocating a shoulder!!

philthehill
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Re: rear crankshaft scroll.

Postby philthehill » Sun Apr 07, 2019 8:34 pm

If you use the starting handle keep your thumb out of the way otherwise there is a good chance if the engine kicks back you will end up with a broken thumb/hand.


oliver90owner
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Re: rear crankshaft scroll.

Postby oliver90owner » Sun Apr 07, 2019 11:38 pm

Thousands upon thousands of engines were hand cranked millions of times (not each engine!) back in the earlier days of motoring and agriculture. Very few breakages occurred - and usually to those not taking the proper precautions.

My mum finished up with both arms in slings due to the same Alliss Chalmer tractor, back in the war days. Doctor was not happy that she had continued doing the same work after breaking her wrist the first time!

I have a four pot 7 1/4 litre tractor engine (among others) that was only hand cranked from new. I am not afraid to crank it over - but I have set the timing correctly - so that it does not kick back - and would never ever try to ‘swing’ the engine over, as the inertial trip (on the magneto) would disconnect and fire the engine early as the cranking speed increased! I’ve only witnessed one broken arm when a lad ‘swung’ a large crawler engine (yes, an Alliss!) but have had to avoid a short ‘flying’ handle when it disconnected after a back-fire on a 1950s baler engine that Dad was attempting to start.

pgp001
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Re: rear crankshaft scroll.

Postby pgp001 » Mon Apr 08, 2019 12:58 pm

I used to start our single cylinder Field Marshall tractors & Fowler crawlers on the handle all the time, its a bit of a knack but quite easy once you get the hang of it. Thumbs over rather than under the handle is an absolute must though just in case.

We used to start our 1946 6LW Gardner engine Scammell on the handle sometimes, but that was done by two of us pulling on a rope tied to the handle.

Phil

wearthefoxhat
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Re: rear crankshaft scroll.

Postby wearthefoxhat » Wed Apr 10, 2019 8:17 pm

New starter switch fitted (after a few swear words). Refitted the starter pull cable and...snap ! The end which screws into the cable attatcher was frayed So I ordered a new cable. starts a treat off the button from the engine side so all is ok on that bit.
Life is never boring with an old Morris.


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