Sq 4 MK II massive oil leak

[pauldridge]

Thanks to all of you for the suggestions regarding my oil leak, And the prize goes to those of you who suggested a wet-sumped crankcase. At your suggestions, I pulled off the sump plate this morning, and damn if almost a quart of oil didn't come out of there.. nice, clean, non-sludgy oil by the way. I buttoned it up, and then filled the empty oil tank, only to find a decent little puddle in short order, right under the timing cover low point. Pulled that off, and discovered the P.O. had gotten the paper gasket crimped right at that low point. Fortunately, I had in had a full gasket set, so replaced the gasket using a light smear of Loctite 518 as someone suggested and put her back together (that stuff reminds me of the old British Hylomar so often touted).

It took a few kicks, and finally na encouraging shot of starter fluid to get her going, but once she cranked, she just settled down to a smooth idle almost immediately, ex-choke (Solex carb). After about 2 minutes of running, I don't see a drop of oil (well, at least not the massive puddle as before), so I am a happy camper. Soon as I secure the gas tank and seat, I'll be off on my maiden voyage, thanks to all your help.

And in answer to questions about the oil pump... yes, my '53 SQ 4 MK II does have the geared pump with simplex drive chain. I've ordered a Morgo pump from British Bike Bits at almost half the price of other sources. Hope that's not one of those "if it looks too good to be true...." situations.

By the way.. someone suggested drilling and tapping the sump plate for a drain plug, but the sump screen fits right flush against the top side of the plate, so I don't see any way for that to work, other than welding some sort of external bung on the lower side of the plate, so the drain plug doesn't protrude into the screen? Maybe the better solution is just to ride the bike regularly so I don't have to worry about wet-sumping (and/or install the Morgo pump.

Phil

[paul.jameson]

Bob,
The transition from MK I Square to MK II Square is one of the oddest in Ariel history. Nominally, both versions were available for the 1953 season which started, as usual in September 1952, in time for the Autumn Motorcycle shows. But, only 3 MK I versions were built with the 1953 XH engine prefix, all of which went first to the Earls Court Show. Data published by Ralph Hawkins suggests that these are the only 3 MK Is produced for the 1953 season. But, there were many more MK Is built in the September - December 1952 period which used the 1952 engine number sequence but were fitted in frames with the 1953 frame number sequence. Some of these went out in Wedgewood Blue. I suspect your bike was one of these, complete with oil gauge in the 1952 style tank. (If you look at the 1953 catalogue details in the Knowledgebase, you will find that the specification for the 1953 MK I is sketchy, to say the least.)
The first MK IIs appeared early in 1953 - none left the works in 1952 - and I have not found any reference to a Mk II appearing at the late 1952 Earls Court Show. The second Mk II went to France, described as "Show finish", but that was late January 1953. Presumably, either there was difficulty in producing the MKII engine initially, or the works decided to get rid of the old MK I stock before the new machine hit the showrooms. Either way, my 1953 Mk II (ex Ralph Hawkins) did not have an oil gauge, or the hole in the tank to fit one. Again presumably, the lack of an oil gauge reflected more confidence in the new gear pump of the Mk II than the old plunger pump of the MK I. I am happily running a plunger pump on my 1936 4G. When either my Healey 1000/4 or my swinging arm Square Four get to road worthy stage, each will be fitted with a Morgo pump. I don't trust the Ariel gear pumps.

Apologies Phil, for that diversion from your oil problem.

[paul.jameson]

Phil,

Fit the Morgo pump and that is an end to the wet sumping problem. You say that the oil in the sump was nice and clean. What about the inside of the timing case? If it was clean, you may be ok. If not, you will certainly need to strip your engine to clean out the crankshaft sludge traps. These are very small, so any black deposits in the engine get stuck in them and cut off the oil supply to the big end. At this point, the con-rod exits the crankcases. The Healey brothers reckoned that it took 500 miles from changing to detergent oil before a big end blocked and a loud bang resulted.

So, if in doubt, strip the engine. Many people have taken the risk, including Club Chairman Lester Grant and former Square Four Spares Organiser David Jones. Both blew their engines up. You have been warned.

[pauldridge]

Thanks Paul,
the seller, who turned out to be a difficult man to deal with in the end, did claim that he rebuilt the engine some 2,000 miles ago, and supports it with Dragan invoices for pistons, rings, bearings, etc. I'm well aware of the concerns about clogged oil passages, but I do feel that this bike has had very little use since overhaul, and the inside of the timing case is clean as a whistle, as is the bottom of the oil tank and the sump plate and screen. Although I've done lots of car engine rebuilds, motorcycles are a bit murkier on my expertise CV, so I'll likely take my chances and set aside a teardown for now, and restrict my riding to short jaunts on cooler days. There are 5 other bikes in the shed for long distance or more spirited riding. I do plan on the Morgo pump and Dragans oil filter kit.

Today I rode the bike for the first time, and was thoroughly pleased with the performance.. throttle response was nice and linear throughout the range, the bike felt nice and tossable in the corners, and the engine was smooth as silk. The only objectionable issue I found was the limited rear suspension travel (minor), and abysmal (near non-existent) front brakes. Hoping I can do something to juice these up a bit (metallic shoes.. arcing to better fit the drum?)

All in all, I'm really happy with the bike, and looking forward to bringing it back to its full glory!

[Paul_Linden]

For info here are pics of the inside the coupling case of my 57 square four before and after cleaning during the rebuild. The black grunge in the before picture was all over the inside of the engine, the cases, oilways, etc. I estimate that after I'd cleaned it all off I would have enough to fill a one pound jam jar. That's a lot of gunge!

[nevhunter]

That's pretty sludgy. If it's only a couple of thousand miles and hasn't been really hot, I wouldn't be very impressed with that contamination. Short trips can cause that too as water condenses but In the places you have it , It would have been hot. That crap centrifuges out in the crankshaft oil galleries and is what blocks them, sometimes. I would have thought that modern oils would keep it cleaner than that. The sludge traps in my singles never show any contamination but I take the tank of and shake metal nuts and kero to clean it out, each time I oil change Nev

[robjameson]

If you want to fit a cartridge oil filter, the Draganfly kit contains a bracket allowing you to bolt on to the rear engine plates to hide it.

However, the filter and housing, are a very common item, used on norton commando 750/850 models, and widely available on eBay at much lower prices than the drags ones, if you are confident to fabricate your own bracket.

I'd still check the sludge traps if I bought a square four!

[simon.holyfield]

There are a few pictures of my oik filter installation on my blog. It lives under the gearbox.

[simon.holyfield]

http://ariel-square-four.blogspot.co.uk ... filter?m=0

[chris.shearwood]

the seller, who turned out to be a difficult man to deal with in the end, did claim that he rebuilt the engine some 2,000 miles ago

Phil,
Can you ask the seller exactly how he cleaned out the sludge traps? His reply might give you a good indication whether or not he actually did clean them. I wouldn't ride the bike without being absolutely sure those traps are clean.
Regards, Chris