Morris Minor Owners Club

Hello,
On my 948cc 1958 2 door saloon with original engine I have done about 95000 miles. It's not unleadded converted.

For the last while It feels like the bottom end has gone. It is very rumbley on accelerating and no power on hills whatsoever.

I had to replace the distributer some time ao (it's the correct one) and ever since then, it's not been a problem. I had driven it everywhere. Essex to Devon was no problem at constant 65mph.

Changing the time makes no difference. All electrics are ok. Sometimes it is better than others.
No oily water, so not the head. The top of the engine is not presurised. It's not smokey or using oil.

There maybe something else to consider. It's always had a sticky valve on starting which has then been ok after about 1/4 mile. I'm wondering whether a valve permanently sticking open effectively gives 3 working cylinders and therefore the rumble.

Next. I have a spare 1098 engine and gearbox. Can you do a straight swap?
Thanks
Nick

Rumble suggests the bearings have worn. How is the oil pressure? Valve stuck open does indeed give a 3 cylinder engine - even worse if it's an inlet valve, which is admittedly less likely... Take the rocker cover off and watch the engine idling.....
And yes - 1098 engine + box is very much a drop in replacement.

Hi,

I belive Oil pressure is ok. No light on or coming on on very low revs.
Thanks
Nick

Gauge readings would be useful - and a compression test!

Hi,
Finally managed to find a little time to look at the car.

Took rocker cover off - all valves moving up and down ok. No stuck ones.
Can't see the oil "seeping" out of rocker assembly in many places.
Rocker cover caked in gungey black and emulsified brown oil.
Breather pipe totally blocked with light brown emulsified oil.
Some water even maybe in the rocker cover. Condensation??

Have not done compression test, but removing 1 or 4 HT lead slows the engine, 2 or 3 has little or no difference at idle.
Can will get to 50 or 60, but takes much longer than usual. Power is gradually getting worse and worse,.

It's using water, but water doesn't seem contaminated with oil.

My diagnosis - head gasket gone or partially gone between 2 and 3 cylinder.
Would this maen a bottom end ruble on lower revs too? The engine would be out of ballance maybe?

I would appreciate your thoughts.

Thanks

Nick

It would indeed be horribly out of balance and 'rumbly'..... I suggest head off and grind in the valves - clean the rocker gear etc, change the oil and filter - making SURE the filter is correctly assembled inside the case - re-assemble and try it with new spark plugs. Don't worry about 'unleaded' - it's really not necessary.

Head off, investigate, decoke and lap in the valves as BMC suggests. Bottom-end wear would just make a lot of noise rather than a loss of power.

Problems hill climbing ? Possibly clutch ( adjustment needed or replacement ) , or even dragging /stuck (rear) brakes, renew or clean distributor arm and check auto advance/retard.

More info if it helps having got the head off.

Decided to get recon head as not confident lapping valves.

1st time I've taken a head off as well. (Yeas I labelled all the push rods and nuts etc so they go back the correct order)

The engine always was (Last 5 years) poor power on starting (no trouble starting it) but always 2 cylinders, the 3 then 4 over 2 minutes warming up time. Power when warm, no issue.
More recently (6 months) power getting worse and worse. Hardly go up the smallest hill more than 25MPH.
Oil all emulsifies, condensation in the rocker cover. Water micky brown, but nothing really oily there, though it was using water.
Very rumble engine especially on low revs.

I assumed head gasket, but having got the engine apart today, gasket intact, if a little warn round water and oil channels, but definitely ok round the cylinders.

Now the car had been off the road for 30 years before I got it 95000 miles now, 85000 then.
When I got the rocker cover off last week, when I noticed all the light brown oily gunge emulsification there was almost rust mixed with the oil.

These rusty particles were also on top of the cylinders -I had flushed the engine and drained the oil before taking the head off.

The bores are not scored, they are clean lovely and shiny and very smooth. I have cleaned off the top of the cylinders so no grot remains.

I’m hoping my problems lay in valves in my original head that were passed it and not sealing, hence the poor power, rumbles and sounding like a tractor rather than bottom end gone. I always had speed, just a long while getting there.

Taking the HT leads off 2 or 3, barely made a difference in engine note or revving.

Thoughts would be appreciated if you can offer that kind of advice

Ta

Nick

What is the ridge like at the top of the bores and what sort of play are you getting with the pistons?

And how much did you pay for a replacement head?

It's only a couple of hours to grind in valves ! Reccon head - hmmmmmmmmm - wouldn't be me !! And - you should NOT have cleaned off the piston tops - best to leave well alone. It may burn oil now. Make sure the top of the block is perfectly clean where the new gasket will sit - but DO NOT rub it with emery etc! And check the studs are all firmly screwed in - and fit a new bypass hose - NOT the ghastly concertina thing......

bmcecosse wrote:... but DO NOT rub it with emery etc! ...

I don't mean to hijack this thread but can you explain why this would be so bad please?

Because it will rub 'low points' on the block! The temptation is to rub away madly between the cylinders....... What would be acceptable is to wrap a sheet of emery around a flat piece of timber - and carefully work that across the block - but frankly there is no need, just carefully scrape the surface - the square tail of a 12" steel rule works well !

nick........ for the price of a recon head you could have probably bought a know good second hand engine.At the milage you have,unless the old engine has been worked on,there will be a lot of wear on the bottom end,pistons, oil pump,cam etc,and it dos'nt take much more time or effort to swap an engine than taking off and replacing a head.You may find that you still have the same ,although not as bad, problem. Then you could rebuild your old engine step by step learning how to do all the work yourself as you go,its the best way to see how the engine works.Then when,if, you need to lap valves in ,in the future, you will know what to do. Hope the head sorts your problem good luck with it.

Hi and thanks for the responses.

Trusted morris dealer for the head - happy with that.

Tiniest of ridges at top of cylinder bores. The kind you can just feel with you nail, hardly with end of finger.

No play in the cylinders.

Why not clean the ends ofthe cylinders you can see? There was rust - flakes - on them which I though would score the bores when the engine was run again.

No I'm not sanding or emerying the head. I'm just wiping clean and using carb cleaner top remove any grot. (Here's hoping that's ok)

All bar 1 of the studs out and screwed in well. I used 2 nuts against eachother and then released then nuts when the stud was in fast. (the opposite of how I got them out)

Any ideas on the 1 remaining water elbow stud?

I seem to have broken a tiny but of casting of the exaust manifold on 1 end, looks like it's been cracked and therfore not part of the fixing for many years. Put it back and hope or get a recon?

Really do appreiate your advice. Will be next week before I starts re-assembly.

The head gasket was NOT blown, by the way - at least not between cylinders. Definiely water in the oil, though.
Ta
Nick

Did you take any pictures?
They always go down well

" Trusted Morris dealer " oh my........ Best to leave pistons well alone - but too late now! Doubt the exhaust manifold will be a problem.

You only need to leave a 'ring' of carbon around the crown of a piston when decoking, the rest can be removed.

Yes -that will do fine - but why bother at all?