engine reliability

[jensen]

Hi Vince,

In theorie it's a simple conversion, practicly it was alittle more difficult.

The theorie / wishes / engineering considerations stated in 2003 where as follows :

1. All the oil should be filtered before entering the engine, no unfiltered oil entering the engine.
2. As less as possible machining on crank cases, it’s difficult and I can’t change it back in the original state.
3. Because the oil pump is rather a volume pump than a pressure pump the oil filter should have a low flow resistance and a large surface.
4. Changing the oil filter should be really easy, without opening the engine or removing importand parts.
5. Should be able to work with 10W50 full synthetic oil, and the oil filter should be easy to buy.

From a logical point of view there is only one place that meets the criteria above and that is a place before the oil pump, so I decided that the oil filter should be placed underneath the pump itself, as a part of the pumphousing.

Another advantage was that the the oil is drawn down by gravity to the lowest point (oilfilter) and thus the oil pump itself is not working different than in any other standard engine.

I bought several used oilpump housings to experiment, and finaly I machined a three part oil pump housing where the top (part in the engine) stays the same.

I removed the centrifugal oil filter, replaced the oilfilter shaft by a direct pipe with a diapragma to regulate the flow between crank, clutch and head and dismissed the oilfilter chain.

After years of optimising and further development (I destroyed / machined at least 12 oil pump housings) I got what I wanted, I even included a pressure sensor and a temperature sensor. On top of that the engine also gained an extra horsepower due to removing the oil filter and the chain (and less noise from the engine).

I hope that this answers the question,

Jensen

[e3steve]

I have fought with two problems over the last 30 years! <br />One, poor electrical supply, (fit a BMW field coil 3 phase alternator) and piston wear at the high speeds British motorways demand.<br /><br />I need the engine to be reliable at cruising speeds of 70 -80 mph or its playtime for the idiots who populate our roads.<br /><br />On every engine I have seen that is used fairly hard, the rear face of the pistons show wear and tearing of the skirt. This is the area that seizes in extremis.<br /><br />Obviously, this is the thrust face of the piston, the very area that is shielded from the cooling air stream. The way the engine spins also throws the spray from the big end oil supply towards the front of the cylinder.<br /><br />It is easiness itseself to fit an augmented oil supply to the rear face of the pistons.<br /><br />Tap into the oil pump at the oil gallery with its plug. lead an oil line around the back of the motor and into the 'well' of the gearbox. This is hidden by the tin cover for purists.<br /><br />Drill and tap into the rear sloping face of the crankcase. This can be done with engine insitu, but is, obviously better done on a stripped engine. A 'T' piece unit will llow the feed to be taken to each cylinder.<br /><br />However you do it, (I actually used the oil breather inserts under the carbs) arrange for a small diameter pipe to angle upwards and rearwards into the cylinders. The oil presure is more than sufficient to squirt fresh oil directly at the high friction area at the rear of the cylinder and does NOT affect oil supply to the rest of the engine.<br /><br />I have also fitted an oil cooler unit for serious peace of mind, but can assure one and all, that you will have a much happier engine if you undertake this mod.<br /><br />John Dugen<br /><br /><br />

The penny's just dropped: your CB was on eBay, with a YouTube video link, a couple of years back? Surely there can only be one CB77 with a BMW alternator and an oil cooler (under the starter motor, I seem to recall?).