Sq4 finally completed...

[roger.fellows]

Next in line for grounding are the silencers. More difficult to rearrange.

[paul.jameson]

I am surprised that the person you spoke to at Morris Oils apparently did not recommend using their Running-in oil. When I spoke to them this was recommended on the grounds that modern oils - including their Golden Film - are just too slippery to allow an old engine like ours to run in. Certainly, I have been more comfortable using Running-in oil in my rebuilt engines of late, but I stripped the top end of my KH recently and could still see the honing marks on the cylinder walls. I could also see where the rings had gone up and down which was a comfort. This was the engine I spoke to Morris's about, following which I re-honed the bores, fitted new rings and ran on the running - in oil for 700 miles. I have certainly done 8000 miles since and the bores look less worn now than a 1000 mile bore in the 1970s did.
To summarise, at 12000 miles now my bores look just about run in, following use of Running-in oil for about 700 miles, some 8000 miles ago. If you use standard oils during the running in period, expect nothing in the way of running in.

[Brian.Fosh]

Hi Paul/Simon.

I'm certainly enjoying the Sq4. It is quite an experience. Although not my first, it has been 27 years

The Morris SAE40 runs at 50psi from cold and stays at this during normal running on the road but drops to 25psi at tickover when hot. (I'm using a Morgo pump and I adjusted the oil pressure valve spring to limit it to 50 psi after Drags spring was giving me an off-scale reading of 120psi. ( the gauge, subsequently proved within 3psi mid range on a calibration rig).

Given my engine is so fresh and all the bearing clearances still quite close, the drop in pressure at tickover gives me the impression that it wouldn't take much wear in the mains or rockers to cause the pressure to drop quite a bit more. I do wonder how long it will be before I join you with similar pressures and choice of oil.

However, I do use the smaller of the two pipes to feed my rockers after Drags expressed their changing thoughts to me when I picked up the parts to make my own ... which I believe is how Drags also now supply. I still get a healthy bulge of oil at each rocker at tickover, just not a jet like one of those "peeing boy" garden statues
It would be interesting Simes to temporarily block/restrict your rocker feed and see what improvement you might get at your gauge.

The engine is freeing off and its tickover rising after each run, which leads me to believe things are bedding in nicely. However, I do agree with you Paul about Golden Film as I'm not new to it. I ran 9000 miles with it in a BSA sloper and did several tough motorway runs, 3 Belguim trips, TT, 2 isle of wight etc. I had lapped that bore with an adjustable hardwood plug that I turned, and got to know the oil characteristics from its adjustable oil feed to restrict excessive smoking. I sometimes increased the feed while I rode, e.g on long motorway inclines to stave off seizure. I ran the bike on the edge of seizure quite a lot (These bikes had no oil control ring and pistons were not low expansion). I was impressed at how the oil cared for the bore and piston when I swapped between a standard and high compression barrel/piston set to give me motorway speeds...

So while I find Golden film does let an engine run in with my inclination towards long runs and mileages, I wholly agree it is pretty protective stuff and may not be the best for running in over shorter journeys and club runs etc

Regards, Brian

[simon.holyfield]

However, I do use the smaller of the two pipes to feed my rockers after Drags expressed their changing thoughts to me when I picked up the parts to make my own ... which I believe is how Drags also now supply. I still get a healthy bulge of oil at each rocker at tickover, just not a jet like one of those "peeing boy" garden statues
It would be interesting Simes to temporarily block/restrict your rocker feed and see what improvement you might get at your gauge.

I've made a list of the bits I need - you can be sure I will report back when I have had the chance to swop the pipes over; I suppose I could restrict the existing 3/16" rocker feed pipe down to the cross-section of the 1/8" pipe, and see what happens. It would certainly be quicker, maybe a throttle/pin in the rocker box union...

[Brian.Fosh]

Well, I've covered around 1200 miles on the bike now.

Out of the blue, I received a second Log book from the DVLA 2 weeks after the first. Both have the same registration but different document serial numbers. The second says "non transferable" and no longer has a section on the green tear-off for new owners to declare its age.

I spent half hour comparing the two, a bit like one of those "Where's Wally" pictures. The answer by the way, is Swansea.
(For our overseas Friends, Swansea is home to the UK's vehicle registration offices)

Then came a panic last weekend... 1st of April by coincidence... while I tidied the paperwork away in a folder, sitting in my chair with the bikes rear plate facing me...The DVLA's cover letter with the first log book declared a registration plate number one digit different to what is now on the bike.

It can only have been their typing error on the letter as what is on the bike is correct to the logbook (both of them!).


As for the bike... I struggled but have seemingly now resolved the engine missing after long runs, normally at about 30 miles or so.
After replacing plugs, HT leads and condenser and taking Paul Jamesons advice to clean up all the connections and solder joint through the low-tension side of the electrics, I replaced the distributor cap and the HT coil... Which finally seems to have done the trick.

The bike ticks over much less erratically now with its new car type 6v coil instead of the one from Drags. I picked up the replacement on ebay for Austin Sevens etc... but it does draw far too high current. The charge doesn't balance now until around 55mph with the lights on.. but for now it's running sweet in daylight hours.

Happy biking all

Brian

[Brian.Fosh]

I took it out in today's wonderful weather

....but STILL misses after around 10 miles now.

What to do eh? I'll update here as I progress...

I think I'll try a new set of plugs and caps, maybe a different make like Bosch top end or copper cored etc etc, and then look closer at the distributor.and its bushings.
I'm wondering if an insulator gasket for the carb might help.

The thing is, I'm running a MK1 with Mk11 high compression pistons with skimmed head and barrels.. It was never my intention to get more performance out of it, it just fell that way with what was available and what needed to be done. This is adding an unknown set of variables for me.
There's an exhaust crackle on the overun if I accelerate hard and change up, but no yellowing or bluing of the downpipes.

So far I've replaced the plugs twice, Condenser twice, HT coil, Distributor cap and HT leads, stripped and cleaned the carb, re-soldered the points supply at the condenser end and cleaned all the low tension connections and opened up the points gap.

I've run with and without tetra-ethyl lead in the fuel but pre-ignition from low octane rating doesn't seem to be an issue.

I tried to richen it for cooler running but could only get a far too big 140 Main jet to replace the 120. This was just too big a step and it was unresponsive when snapping open the throttle or even just opening the throttle for normal acceleration. I've now obtained a 125 Main Jet, yet to try, and am looking to increase the Air compensation jet similarly.

Regards to all,

Brian.

[Brian.Fosh]

Dwelling on my problem with missing , I think i'll go for still colder running plugs.
I was first on original spec plugs but had missing within a few miles..Lodge CN
I then realised i'm running abnormally high compression for a MK1 with its now skimmed head/barrel and late pistons.

In fact, T&L skimmed the head for me and questioned me afterwards if the engine had lost a piston on one corner as it needed more skimming than they would have liked to bring it back to flat thanks to one corner in particular.. (They were right, it had lost the front nearside rod)

So I then went to MK2 cooler running plugs with Mk1 thread/reach.. B5HS and B6HS.. but these plugs are still designed to get quite hot.

...and I still get very white plugs.

So I've ordered up substantially colder running plugs, a set each of B8HS and B9HS.

Let's see how I get on.

Best regards to all

Brian

[chris.shearwood]

Hello Brian,
Your symptoms of very white spark plugs and problems occurring after 10 to 30 miles running could possibly be accentuated by a partially blocked fuel cap vent. Are you certain the vent is clear?
I think your bike looks really nice, regards, Chris

[Brian.Fosh]

Thanks Chris. I checked the vent and alas, it is clear.

I've jumped from B6HS plugs to B8HS and all was fine until my newly fitted HT coil went open circuit on the low tension side today, after just a couple of hundred miles...Which I confirmed by using my headlamp bulb to track the power through the circuit.
The bike was holding a comfortable 70 on the busy A5 in to Milton Keynes at the time.

After the quick arrival of the RAC, in a car support Van, and his determined hunt for an HT coil, much like an Easter egg hunt..which rather impressively WAS found, I pointed out it needed to be 6v and the chap departed very disappointed after calling in a retrieval truck for me).

Anyway.. in the extended wait that followed, my son drove the HT coil I removed last week out to me.. and I was duly able to ride home fine... after telling the RAC of course.

it beggars belief the poor quality of cheap pattern parts that flood the market these days, my new coil being filled with oil but the coil itself can be felt rattling within... just like the widget within the can of Draught Guinness I just devoured.

Regards to all, Brian

[Brian.Fosh]

I opened up the new HT coil that left me stranded.
It looks like it wasn't supposed to rattle internally but the coil had broken away from its bakelite top as the whole weight was supported at that end only.

Sure enough, the copper wire to the Low tension coil was broken.

It could have happened in transit anytime on its long journey to me I guess, but none-the less, one hard bump on the road and it would likely have broken any way. It's a shame because the rest of the design is actually quite adequate and the workmanship was fine.

Regards, Brian