Classic cars forum & vehicle restoration.

[ka]

I still think my comment has relevance, if you are not able to differentiate between stiff front springs/seized shock absorbers and engine surging, a second opinion is well worth pursuing. I do not question you mechanical ability, but an alternative view is always worth the effort.
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KA

Better three than four.

[peter scott]

Hi Ralph,

To me the description "surging" suggests that the engine periodically increases its speed/power without you changing throttle position.

I think this is highly unusual. A more common complaint is that the engine periodically loses power due to misfiring. The last time this happened to me I traced it to intermittent earthing of the contact breaker base plate within the distributor.

Peter
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http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon

[Ralphg]

Hi all,

I'm sure that it'll be embarrassing end to this and I'll be red faced at the end.

The surging occurs all the times and lasts for maybe a second on and off, more under load than coasting on the level. I've not tried it with the choke partially out. The main needle is for high altitude as we live at 1860m. The piston moves up 7 down easily with the engine running & accelerated The piston "clunks" down easily when lifted and the oil is the thinnest that I can get here but maybe heavier than 3-in-1 which I'll try to get hold of. Sewing machine oil will most probably be easier to get. The lowest grade of fuel is ULP 93 RON and I add lead replacement to it at the specified amount. The fuel is new.

I've looked carefully at the distributor, there is no discernible movement in the shaft and the rotor does not touch the contacts. I've bypassed the condenser with an electronic unit, however it makes no difference either way. The brass contact on the rotor is fixed firmly and does not move at all. The points have been checked on several occasions and are right.

I've not been out in the car for the passed week or so due to the heavy rain making the hill up from the house difficult. We need the rain badly so the car takes second place at the moment.

Ralph

[goneps]

Ralph,

Two weak mixture jet needles were specified for the Series E. Even at sea level virtually all Morris Eights that I know of run rich; I've been running my Eight Tourer on a weak needle for as long as I can remember, and even with a new jet the jet nut has to be wound well up to get the correct mixture.

Jet needles for the Series E are:
Rich M9
Standard EK
Weak MOW
Weaker MW

I'd suggest you'll most likely need the MW to compensate for the altitude. It's unlikely this is the cause of your problem, but it's another factor that needs to be right. Running rich usually just wastes petrol, decreases the already modest performance, and gives uneven idling (hunting) when hot. If you can start the car from cold, even in summer, without using the rich mixture control (choke) then you're running too rich.

From your latest description of the symptoms I think it would be sensible to fit a new coil and condenser, just for the sake of eliminating another possible source of trouble. Both can cause surprisingly illogical symptoms when they start to fail.

All this is pure guesswork, of course. It's difficult enough to diagnose such problems even with the vehicle to hand; nigh impossible from a distance.

Richard

[Ralphg]

Hi Richard,

Many thanks, I see that the needle that I fitted is M7 as specified for the SU but for the Series 1, so I'll get hold of Ian and see if he can supply me with the one that you suggest. Checking the running mixture with a Colortune plug it is definitely running a little rich but I don't think that's the problem. Just keep plugging away??

I'm trying to source a coil locally, friend says he thinks has has one somewhere, I do have a spare but it leaks oil so that's no good. The condenser has been bypassed by the electronic unit.

As I said, I've checked the distributor shaft for play and there's none, I'll check the points again and finally ask a friend here to have another look at the car with him driving and see what he thinks.

Ralph.

[ukdave2002]

Ralph

Don't forget that your electronic ignition will have a condenser of exactly the same value that the distributor has, and it to can of course fail, that said it will be a more modern component not fabricated in the style that condensers were some 70 years ago, that we still insist on for distributors.


Incidentally I presume you have removed the original condenser ( electrically ) when fitting the electronic unit?

Dave

[goneps]

Ralph,

Thinking back on what's been discussed thus far, is your engine in fact a Series E? Although in theory it should not apply to overseas cars, the post-war factory exchange engine scheme resulted in many hybrid engines in which a Series E or MM Minor (USHM1 or USHM2) short block was married to the original UB head, manifold, carburettor, sump and oil pump.

Is your car actually an export model, or a home market model that someone has privately imported? One way of telling is that export models were fitted with smaller wheels with larger section tyres, namely 5.25 x 16", whereas home models had 4.50 x 17" wheels and tyres.

Is your engine a complete Series E unit, or is it an E short block with UB flat head? Even if it has the E head, it still might have the earlier UB manifold and carburettor (my own car was run in this configuration for several years with a borrowed E engine). If the latter is the case, then M7 is the correct jet needle for weak mixture. The E manifold is wider than the UB-type manifold, and unless your car has the indented wing (originally to accommodate the air silencer) the E manifold/carb probably won't fit.

I suggest you post some clear pictures of the under-bonnet arrangements so that the power plant can be correctly identified. I need to see both sides of the block in detail, and of course the head and manifold/carb. Also, measure the diameter of the carburettor choke, which is 1" for the UB engine and 1 1/8" for the Series E. Because of the interchangeability with components from later models many of these cars have been subjected to what we'd nowadays call "mix and match" exercises by various owners—in addition to the aforementioned manufacturer's confusion of factory exchange units.

Richard

[Ralphg]

Hi Richard & Dave,

I've not been able to master the posting of pictures into the Forum from Photobucket.

The engine looks like a complete Series "E" reconditioned unit from Morris Motors USHM1 motor together with a 4 speed box. The car is definitely an export model fitted with 16" wire rims and had the 5.25 x 16 tires on. These are not obtainable here so I've fitted something close. The wing is not indented and I'm looking at modifying this to accommodate the air silencer. I have the aluminium air silencer and oil bath filter.

I've ordered the MOW (MW not available) needle from Ian and that should be here in 2 weeks, so until then there's not much I can do on that score.

The Electronic Transistor Ignition unit does away with the condenser completely and as I said earlier, I'm trying to locate a 6 volt coil here but as you can imagine, they are rare.

[img]http://s1077.photobucket.com/user/Ralphg1/media/2016-01-01%20Morris%20Engine%20left%203_zps12ndgk46.jpg.html?sort=3&o=0[/img]

Not too sure how the above works so perhaps you can Email me on raubenheimer@icon.co.za and I'll send you the pictures.

Thanks once again, Ralph.

[Penman]

Hi
You copied the top "email" link instead of the bottom IMG link.






_________________
Bristols should always come in pairs.

Any 2 from:-
Straight 6
V8 V10

[goneps]

Good pictures, Ralph, and thanks to Penman for posting them.

That's unquestionably a complete Series E engine with appropriate manifold, including its two-brush dynamo with the electrical system converted to fully regulated. An interesting facet is that the E engine mounting has been retained and the chassis arrangements modified to suit; the usual practice is to fit the UB-type bearer and timing cover with the original mountings. It looks neat, however, and appears to have been competently done.

As far as I can tell that's the correct carburettor for the Series E, since you haven't stated the choke diameter. If indeed that's the case then the MOW needle should be an improvement on your current needle; if you subsequently decide it's still too rich the MW should be available from Burlen in England, who are the SU specialists.

I presume the float level has been set correctly as per this diagram?

If you can get the engine to run for long enough, the best way to check the mixture is by studying the spark plugs. While the bottom of the thread may appear sooty the ceramic insulator around the central electrode should appear clean, preferably with a pale chocolate hue. However, this may be influenced by the particular brew of your local fuel—I recall that the Sasol ingredients of SA fuels were corrosive and causing a few problems for older vehicles during my time there. Brief experience with a 10% ethanol blend in this country gave the plugs an alarmingly white appearance. You'll have to experiment with this.

When doing this test, check all the plugs because it's not unusual for one cylinder (invariably no. 3 on these engines) to run weaker than the others. Set mixture by reference to whichever cylinder runs weakest. If you run too weak for extended periods the exhaust valves will burn out.

A final observation—those tyres look decidedly undersized. Apart from lowering the already low gearing and giving optimistic speedometer readings, I doubt they'll help the ride comfort. Even different brands of the same size cross-ply tyres can give remarkably varying degrees of ride quality. In the unlikely event that 5.25 x 16 cross-plies are not available in the main centres, it would probably be an investment in the long run to import them yourself.

Since your car also has the Series E 4-speed gearbox it's likely that your speedometer readings are already well astray, unless some remedial measure has been taken. There's a discussion of this topic in this thread:

http://www.oldclassiccar.co.uk/forum/phpbb/phpBB2/viewtopic.php?t=15230

Richard

[welder]

[goneps]

Ian,

There's no hole in the filler cap because there's a vent on top of the tank, where it's inaccessible without dropping the tank. Good point, however, since we've been clutching at straws—could be easily checked by running with the filler cap off.

Richard

[petelang]

I'm always suspicious of those braided flexible hoses as any perishing of the rubber cannot be seen.
I have had a similar problem which was just such a pipe becoming porous allowing fuel to run back to the tank due to pump sacking in air. In your case it is after the pump so would be more inclined to show leakage but maybe something else along the fuel lines? Maybe pick up pipe in the tank?
When first switching on the pump, does it pressure up straight away?
Peter

[Ralphg]

Hi all, after sometime I've manged to progress somewhat.

I had a problem with the fuel gauge not working and got info on how to check this, turned out the dash unit works so it indicated that the sender unit was faulty. Had to remove the tank to get to the screws of the side mounted unit and found that there was about 3 kilograms of sand in the tank and the float was completely corroded. That's not sorted out.

as far as the "surging" is concerned it seems that it may well be the coil and as these are not available in SA I'll pick a new one up from Ian Harris whilst I'm in Scotland in August together with a few other bits that I need.

Will see what happens when I get back in September, thill then, thanks to everyone for the help.

Ralph

[goneps]

Ralph,

Progress of sorts, which is encouraging.

Are you sure that the sand in the tank has not been the cause of your problems? Frankly it's a wonder the engine ran at all.

As regards the fuel gauge, the dash unit will not work correctly unless it's properly earthed. It's a good idea to connect a small earth lead from the threaded attachment post to a known good earth close by. If the gauge is not properly earthed it will read either full or empty regardless of tank contents, depending upon whether you have the earlier G33 or later G35 system. Components of these two systems are incompatible and therefore not interchangeable. I mention this in case you attempt to find another tank unit—it must be the right one to match the gauge, or you'll need to change the gauge as well.

Richard