Not sure how many vintage tech guys we have here other than Darkman, but will ask anyway Finding that the current oil i am using in my T160 is letting the very hot oil pressure drop a little too much for my tastes i was wondering what others use, i am currently using Westway 20w50 semi synth and was thinking about using a 20w60 in the hop of maintaining hot viscosity/pressure when very hot....so what do you use?
My tick-over is low around 900rpm at a guess, but it just dropped to about 5 psi after a longish run...just looking for a older thicker type of oil that will get me through the summer before i look into the bearings.
mmmm if the pressure is that low, I would think about the bearings sooner rather than later or there could be an expensive rebuild in the offing. I though the pressure should be around 20 psi at least. is the oil light coming on??
Don't use the oil light just a gauge..it was very hot and could have been the PRV stuck as i have used it since and it was showing the usual 40 to 60psi and there also could be som fuel contamination hence changing the oil.
I don't know what oil is recommended for the T160. My thinking is that when the engine was designed, essentially way, way back before (semi) synthetic oils, only mineral oils were available - Castrol GTX and Duckhams Q20-50 being the regular oils of choice (apart from Castrol R which usually went in the petrol tank by the teaspoonful. Mmmmmm ... highly aromatic!!). These oils worked well enough in my 5TA, Dommi 500 and '69 Bonnie way back when. Also, I'm sure I read somewhere that modern synth' oils do not always suit older type engines as they are too thin by comparison with mineral oils. Could it be that one step back will provide two steps forward? Discuss. Just thinking out loud!
I use either castrol or silkolene 20/50 classic oils in my bikes and change it every year even if i do low miles as its not expensive to do, with the triple i would definitely check the prv for dirt and also fitt a new oil pump.
The good stuff IS still available ... https://www.classic-oils.net/All-Products-by-Manufacturer/Duckhams/
Thanks for the input guys, i fitted a new Hyde pump when i refreshed the bearings and the crank was dressed as it was within limits but i suspect the may be i little clearance, didn't trust the company i was going to use to get the mains concentric at the time it will see gauge needle stuck against the stop on cold start 15-20c yet will normally only see 20-40psi hot at around 2.5-3 k rpm (guessed as i dont have a tacho and more used to twins) I dont subscribe to the must see 70psi at 3,000rpm brigade for various reasons, i am using Westway 20w50 which is a semi synth and i also am inclined to think most modern oils are too thin at the specified temps despite the viscosity...if you think about it oil development goes hand in hand with modern engine development and today's motors are manufactured with very tight and precise clearances and different materials. I have been looking at Millers oils as they do a 20w60 designed for classics like Aston Martin and Ferrari so i think i will try that and see.
Another vote for Duckhams Q 20/50. I run it in my 500/T100P. I also used this in all of the Jaguars that I ran in the 80s and 90s it was the only oil that would stay in the XK engines when used hard. These engines always used oil, with other oils the motor would use a pint in 125-130 miles but Q would give up to 250 miles a pint. Duckhams for sure.
Throw the gauge away and forget about it! I think the oil pressure light on the t160 is set to about 6psi.
Its set for pretty low but i dont trust idiot lights, and i wont run any motor without an oil pressure gauge ...its saved more than one engine in the past, even most of the cars i have had have got pressure gauges fitted I have ordered some of the Millers 20w60 recommended for older high performance engines.
At the risk of stating the bleedin’ obvious...... Viscosity is a measure of ‘runniness’. The multigrade number describes hot to cold performance. Older engines built to wider tolerance with a bit of wear might accept a notch thicker oil. After that, the choice is about oil longevity (synthetic best) and additives from detergents to friction modifiers. So, by my reckoning, the question is simply about viscosity not temperature (which is assumed).
Tricky-Dicky. I always use the silkolene But when I rode the Harleys I used to get screaming eagle that ran cooler than normal oils supposedly. Ride Safe Joe.
Since none of.us are.chemical.engineers,.we have to.go.by the numbers. In that context, one oil is as good.as.another. ...J.D.
As i said in my earlier post despite the viscosity figures i have always found the older oils seem to keep better oil pressure at higher temps in older engines, which IMO is down to the way modern engines are designed and the oil that developed for them as the friction modifiers used these days have differing effects with older engines.
Exactly right, it's no use expecting old engines to maintain high oil pressure at tickover, they never had much even when new. Fitting pressure gages to these old motors will just frighten you. I have 66 bike and a 1974 car both running perfectly but l know if I fitted gauges l would crap myself! Sometimes ignorance is bliss!
