Yours, htown16's and everybody else's input is appreciated and will not be dismissed. The 20W or 30W non-det oil recommendation was received from Matt Rambow and detailed in the cNw engine break in procedure I'm following. In any event, the engine will not be run until the temporary oil press gauge is installed. It's nice to see that the great oil debate continues. Thanks again!
Jerry,
Not being a journeyman Norton owner, I had to pick a plan and move forward. The way I see it, nobody was discredited. I appreciate all advice. Jerry
I'm not sure I follow you Greg, when do you use the conventional? I have Classic in my commando now and used GTX regular quite a bit in the old days but am not sure I would use it on a flat tappet engine now since most of the ZDDP has been removed. Just trying to understand your reasoning as I may have overlooked something.
When I build a bike, I fill it with Conventional Classic (high Zinc). From the first oil change on, I use standard Conventional GTX.
The concern I have is that I believe, but have no direct proof, that over the years Castrol GTX has had a lot of its additive package changed over the years to allow it to be used in cars with catalytic converters, a concern that did not exist in the early 1970s. I am by no means an expert but the more recent gtx products are sn or sp rated while classic is sj. classic has zddp greater than 1000ppm. gtx as a sn or sp oil must have less then 800ppm to comply with this rating. Basically from SL formulations to SM and later formulations, Zinc additives were halved and detergents were substantially increased due to EPA mandates. Castrol GTX back in the day had way more zinc than it does today and Classic is more equivalent to that older formulation than GTX is today.
See: https://www.accessnorton.com/Oil-Tests/NortonOil.php While Castrol GTX is not near the top of the list, it is much higher than Rotella T6.
So, your name for solid lifters is flat tappets? How about hydraulic lifters that are not roller lifters? I quit rebuilding car engines when street cars still used solid lifters or non-roller hydraulic lifters. I've personally never heard of flat tappets other than related to Norton engines, so I searched. There are thousands of hits that show flat tappets as non roller tappets and having both ends flat (or the cam end slightly radiuses) - that is not a Norton tappet.
Gawd......................Please forgive me. I'm more sorry than ever for starting this thread.
I've had both Smiths oil pressure and oil temperature gauges on my Interstate for over 40 years, I view them as long-term fittings, I like the reassurance they give me.
