Sq4 MkI- new life

[simon.holyfield]

For what it's worth, I think many of us using 20W/50 would see very low oil pressure on a hot engine at tick over. Typically I'll see 15 psi or so after a club run - 40 miles or at reasonable speeds in the UK, but then I have a Morgo in mine. I believe you would see a much lower pressure on the standard pump.

Your test is just running in the garage - it's going to be pretty hot.

[Gui.dorey]

Hi Simes, I have a Morgo in mine.

[john.bebb]

Hi Gui, & All

Gui - good to hear your Sq's on it's way back...

Please could you describe the symptoms of "wet sumping" which made you to suspect & return your pump to Morgo?

I've a weird prob with mine - there is considerable loss of condensate(?) after a run - this ceases when the motor is cold - the loss is not from the sump plate nor the crankcase halves...

i'm certain is neither the main oil adapter nor the rocker/p-gauge banjo...

'tis a great shame - other than this my Sq's running lovely to ride...

but much spoilt by dumping an oil slick each time it's used



Any suggestions please?

Cheers, John

[simon.holyfield]

Your picture makes it look like that leak is under the drive side John. Is that right?

[Gui.dorey]

Please could you describe the symptoms of "wet sumping" which made you to suspect & return your pump to Morgo?

Hi John,
It should be in one of my threads, but you know I always had a lot of oil coming out of the primary breather on every run. One suspicion was wet sumping, so I just took the primary cover off and also the sump plate, and left it over night. One could see the oil was seeping past the Morgo and going into the sump. It wasn’t much but enough to have a spoonful or two over night on the bowl I placed underneath the bike.

But fixing the Morgo didn’t fix the main problem. During every ride I still had oil coming out of the breather. After chasing all types of suggestions, the conclusion was that too much oil was seeping past the plain bearings because their clearance was too large leading to the final disaster.

It doesn’t have to be the same on yours. There were other things going on, such as 0 oil pressure when warm. However, if oil is coming out of the primary breather during a run, it means there is more oil in the sump and primary case than the the Morgo can pump back to the tank.

Cheers,
Gui

[paul.jameson]

I have never run a Square whilst on the stand for long enough for it to get hot enough for the oil pressure to drop. In hot weather I either keep the bike moving or turn off the engine until it is needed again. So I can't speak from experience of having done the same as you. But, I did change from SAE40 to 20:50 on the Healey late last year and quickly noticed a greater tendency for the oil warning light to come on after doing a run when the engine revs dropped to tickover. So it may be no more of an issue than that.
The only suggestion I can think of is to warm the engine up such that you get low pressure at tickover, turn off the engine and remove the timing side cap over the end of the front crank. Start the engine again and see if oil is coming out of the pressure relief valve or around the edges of the machined washer on the end of the crank. Blip the throttle and see what happens then. This should provide some clues as to where the oil is going and whether or not you have a serious but elusive problem. By serious but elusive problem, I am thinking of a crack in the crankcases opening up when the engine is warm or something like that.

[john.bebb]

Hi Folks,
Thanks for your input & suggestions: -
Simes - the pic is deceiving – the leakage is definitely from “distributor corner” …
The options are; - 1/ rocker & p-gauge pipes & banjo. 2/ oil tank feed/return adapter.
3/ timing chest (crankcase) breather ((I believe Gui refers to this as the “primary” breather)).
& 4/ the dynamo/distributor housing… 5/ I’d rather not think about Paul’s last suggestion!!!

Gui – I recall watching at Healey’s (some decades) ago, a test motor running as fitted with a clear plastics timing cover – to investigate “oil damming” and to develop remedial piping &/or baffles…
… the swash was quite turbulent but flow paths were clearly visible – including the formation of a static reservoir up in the d/d sprocket corner – of course, the size of this reservoir was rpm dependant but was clearly seen to extend as to compromise the timing chest (primary) breather on occasions… now some oil is of course required for the dynamo/alternator shaft bearing…
and such is the only way the distributor helixes etc receive lube.

Paul – I thank you but sincerely hope it’s not your suggested scenario as in your last sentence!
FYI – I use Halfords “Classic” 20/50W motor oil
I may well try the relief valve check - & video it – please what would you expect to observe when throttle is blipped? (… apart from oil splatter on the camera lens).

Items #1 & 2 are assumed “not guilty” – I’ve rebuilt such a fair few times & am now satisfied with the integrity thereof (after rework to remedy poor manufacture).
Item #3 is nigh neither visible nor accessible without taking the gearbox out or similar drastic spannering… & mine is extended with flexi tubing such that it vents at the tail of the motorcycle…
Item #4 – CAREFULL – both valve & ignition timing settings may go AWOL…

So rationalising that the drip rate as observed in present circumstances is a bit too rapid to be solely from condensate, thus there must be a small fluid reservoir formed somewhere – which cannot return to the sump… and taking into account that prior to this Easter it had spent ~ 18 months & over 5k miles being virtually oil-tight: -

My current hypothesis is; –
I should not have tried to get away with fitting Heli coils blind in the dynamo/distrib housing…
I might try a bodge with RTV down the bolt holes – but such may not achieve full resolution.
I expect I’ll be on the ‘phone tomorrow to Bennet (I-H-S) for a chat and to offer him
some beer vouchers in exchange for a replacement 220556 housing.

I shall try to remember to update as appropriate. Cheers All – Ride SAFE.

[Gui.dorey]

John, I meant the timing case breather of course. Not primary. Just meant one thing and wrote another.

[paul.jameson]

John,
My reply was to Gui, rather than you so at least you can stop worrying about cracks.

[Gui.dorey]

Well, I tried my first run, but didn’t get far. Cold start on first kick and she settled to a nice tickover. Rode out of the driveway and changed to 2nd, but the she didn’t seem to have any power and didn’t want to rev up. As soon as I opened up the throttle, the engine wanted to splutter and die. I managed to get to an open country lane, but as soon as I changed up, she didn’t want to rev and had no power. I rode a couple of miles hoping she would clear out, but didn’t, so turned around. By this time the bi-starter was pushed fully in. Tried playing with it, but pulling it out would bog the engine down. Now it was getting worst, and basically was limping back in bottom gear at 20 km/hr. Stoped and adjusted the distributer, advancing it a little, but no change. Eventually the engine started misfiring, spluttering and dying. It would restart, rev up while on the stand, but in gear, any oppening up of the throttle would not increase the revs and cause it to die.

It seemed it was starved of fuel, and as the petrol level was on the low side, I thought maybe the gauze in the tank was clogged with crud. Nothing major was there after disassembling the pet cock at home. So now I’m wondering if the carb has a jet clogged or something, but didn’t have the heart to take it off for inspection.

I have the air needle 3 turns out, which always worked well before.

Any thoughts?

Cheers,
Gui