Re: Grease nipples on rocker box 1938 ES2

Are you getting the 1939 date from the printer's reference ? The problem here is that Nortons supplied their standard complete model range instruction manual with the WD side valves which had the earlier patten engine right up until 1945. Inevitably, with more than 100,000 made, most of the surviving paperwork was therefore old model stuff issued with the WD bikes, including the paragraph that you quote. Printer's dates for these went into the 1940s.

Franks lists the procedure for the early 1930s engine and then details subsequent changes, including the fully automatic lubrication for 1938 onwards.

Previously wrote:

G'day, I have recently acquired a 1938 ES2 and have a quick question regarding rocker bearing lubrication. I have an instruction manual for 1939 Nortons and and in the lubrication section is the following:

"Cylinder Head Rocker Lubrication (OHV Engines Only)

These rocker bearings are lubricated by oil mist from the crankcase, but this should be supplemented by grease every 1000 miles. It will be noticed that two grease gun nipples are provided on the side of each rocker bearing boss on the rocker box fixed immediately above the cylinder head."

My bike does not have these grease nipples and there is no sign of anywhere that they should be. In the Norton book by E.M Franks, the grease nipples are not mentioned and it is stated that oil is carried up the push rod tubes. So should these grease nipples be there or not ? If they should, would it be advisable to drill and tap some nipples into the box ? Any suggestions ? Thanks

Hi Glenn,

1938 Model 18 and ES2 engines (if we are talking about the engine that has the pushrod tubes close together, with no barrel fins imbetween, as opposed to the later 48 onwards engine, where the tubes were a bit wider apart - which sometimes was retrospectively fitted by some owners) has a rocker box which has two alloy distance pieces, then an upper rockerbox that retains the rocker arms. Unlike the later post 48 engine, this engine has no seperate oil feed to the rockers, neither does it have grease nipples. Do not worry about this, as Edgar Franks states - the oil mist easily gets up the tubes and you willfind this is sufficient. I raced one of these engines for many years andneverfound this a problem, although Norton's themselves probably recognised that their later 48 onwards design would benefit from it and added seperate oiling, not sure if that was because the breathing was slightly different.

Although I like this 38-47 engine, it did have a fewinherent valve gear weaknesses that made it far less susceptable to tuning than the later engine - the exhaust rocker arm, which is apress fit on to the rocker shaft tends to break if it has a heavy notch in it, from where the exhaust lifter bites into it. Also the cam follower arm in the timing case, which acts on a pivot is notoriously weak, as it sits over the cam with the pushrod recess right on the end - in priniciple a bit like a see-saw. The pushrods are long and heavy, and therefore all that reciprocating weight can break the cam follower. Therefore worth keeping an eye out for both these items at autojumbles just in case Glenn!

(ps - I use to usemy own lighter gauge steel tubing with titanium end pieces on my racing pushrods. I tried duralium alloy tubes once - they only lasted about 2 laps of Oulton Park before they looked like boomerangs!)

Best,

Paul Norman

www.racingvincent.co.uk