Special Break In Oil, Yes or No

Yes I know this topic has been beaten to death before but there has been a lot of changes in the oil market. Had to replace camshaft and followers on my MK3 and also full rebuild including new piston rings. Previous owner rocker spindle flats were assembled backwards and no insulating washers on intake valves which probably killed the cam which was also replaced by previous owner.

Have previously successfully just used regular 20w50 castrol non synthetic motorcycle oil for rebuilds that did not include replacing the camshaft. I really don’t want to replace the cam and followers again. There are several choices of break in oil with high zinc/phosphorous. What have people used successfully? Let's try to stay on topic.

Firstly, I hope you used a good quality assembly paste on the cam lobes?

My understanding is that it’s the initial start up of a new cam that causes most damage. The assembly paste protects against this.

Personally, I never use a running in oil.

I have used this on various shiny brand new camshaft startups including big block V8's, small price for big protection.

Thanks for the responses. The cam and cam followers were covered in assembly paste. I plan on squirting some oil down through the head covers to additionally prime the cam and cam followers just before startup.

I used running in oil on my 750 after I had a rebore as the shop that did the bores were most insistent
My bike uses negligible oil and never smokes so maybe they were right!

I used Comp Cams assembly lube and VR1 20/50W. 15 years later still tight and smooth.

I used some for the first time in a Kohler K-series lawn tractor major rebuild 2 winters ago. This was a 500cc single. The stuff I used was Driven BR30 5w-30 conventional break-in oil. It contains ZDDP for the flat tappets. I changed it out after 5 hours run-time. That engine normally runs straight 30 weight in the summer. Without taking the engine apart again I really don't know if it was a good thing but it runs like jack the bear and has about 35 hours on it now.
Russ

Absolutely, use the br for 500 miles. I didn’t and had to re ring. Most oils are to good these days.

baldy said:

Have previously successfully just used regular 20w50 castrol non synthetic motorcycle oil for rebuilds that did not include replacing the camshaft. I really don’t want to replace the cam and followers again. There are several choices of break in oil with high zinc/phosphorous. What have people used successfully? Let's try to stay on topic.

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When the Norton oil tests were performed here by Comnoz, the mix of products tested included a couple different break-on oils - Driven BR 15W50 conventional and Motul 10W-40. Neither of these oils were impressive with respect to load carrying capacity, but one thing that did stand out was that they were both very high in “Total Heat from Friction”. I recall that in subsequent oil discussions Comnoz suggested that Castrol GTX 20W-50 conventional would be a good break-in oil due to its high “Total Heat from Friction” values in combination with its impressive load carrying capacity of 257 lb vs the Driven and Motul break-in oils with load capacities of 163 and 140 lb respectively. So on balance the GTX might be a superior product relative to the other break-in oils for a Norton application.

It’s interesting that you recounted above employing Castrol 20W-50 conventional oil for breaking in several engines with satisfactory results. According to the oil testing results Castrol GTX conventional oil ticks all the check boxes you’d seek in a Norton break-in oil. I recently used it in a Harley related project for break-in with satisfactory results . It’s a relatively inexpensive oil so I’d recommend to keep on using what you’ve been using all along if it happens to be GTX 20W-50.

noooooooooooooooooooooooooooooooooooo.

Breaking in was a myth recognized over 30 years ago. If ya ride ya bike like ya did as a teenager back in the 70"s, then your break in period will be completed quickly. That's what you want. Find a winding hilly road and give it some gas. That will allow power and back off periods to get the results you need. Those that live on flat ground just need to pretend they are going up steep, bendy hills and use throttle accordingly. Start off with a good quality oil which you will use for the life of the bike.

Dereck

I recently rebuilt the top end on my T140 and I did something that I used to think horrific...

I did what our old friend Hobot used to rave about...

I assembled the pistons into the barrels with WD40. Cams and reground followers got copious assembly lub, but the pistons and rings only got WD40.

And when I started it up I kept the revs in the 2-3k rpm range, no idling. So, if we assume it took 5 seconds to fill the sump and create proper splash lubrication, and if we assume 2,500rpm, then the pistons rings went up and down over 200 times with only WD40. Thus, they should be bedded in.

Then I rode it, taking roads that require constant speed changes and gear changes and rode it ‘briskly‘ at 5,000-5,500 rpm.

The oil? Top drawer Bel Ray V Twin 10-50 synthetic. I wudda used Royal Purple but I need the oil to be wet clutch compatible.

The problem I have with the ‘use less good oil to help the bedding in’ argument is that we’re only bedding in the rings and bore. Everything else in the engine still wants the best oil it can get (especially the cam and followers). So my thinking is, if we’re not careful, we can sacrifice the cam and followers in pursuit of bedded in rings !

And the argument that modern oils are ‘too good’ for these engines is just plain wrong. Modern oils designed for modern liquid cooled, roller tappet engines are simply NOT good enough for our old relics. But don’t take my word for it, read comnoz’ excellent oil test thread...

i found this interesting, but with everything "a grain of salt"


Agree with others, break in oil may do more damage than good. I'd just use whatever oil you intend to use, it just might take a little longer to fully seat the rings. Only caveat is synthetic oil. I've been told to use dino oil to break in if using synthetic oil

I'm (hopefully) nearing a break in of an overhauled engine. I use GTX 20-50 Classic, engine build poop (I think it is wot AN sells
I'd have to go look, it sure is sticky). Yes, know about the minimal oil in the jugs approach since it was in Cycle Magazine 100
years ago but just a thin coat of GTX not man enough to do the WD route. Only thing I can recommend is to pre-lube using a
squirt can and hose into your oil system so everything is oiled up and OP comes up rapidly. Then start as per FE keep your revs up
for a fifty mile run.

My question would be what are your oil changes for the new motor? 50, 250 and 750 before going to normal changes?