Running in the cam

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Dec 28, 2008
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In the thread on belt drive installation a reference was made to Norvill and "tech-talk", interesting stuff. I read about applying 40 ft/lbs to the clutch nut, but caught the article on running in the cam, the essence of which is to get the engine running quickly and avoid:

"Excessively long kicking before starting. Oil will not reach the camshaft lobes until the engine is running"..

Elsehwhere another article on running in a new engine says:

"Remove spark plugs and turn the engine over slowly with the kickstart for 5 minutes to prime the crankshaft gallery with oil, making sure that the oil tank level is kept above the minimum level. Replace the spark plugs and start the engine as normal".

Is 5 minutes of kicking excessive??

Also Norvil advocates the use of a mono grade 50 wt oil (ONLY!!):

"This engine must be used with monograde 50 oil, (SAE 50). It must not be used with multigrade oils of any type".

Hasn't this issue evolved to 20w-50?'

Additionally Norvil advises to run your engine for 30 minutes above 2500 for the cam break-in, but for an engine break-in they say:

"Run the engine for 10 minutes at 2000-2500 revs, but do not ride the bike. Leave the bike overnight to cool".

It appears that you should put a new cam in a fully broken-in engine run it for 30 minutes then remove cam and tappets and place them in your new engine. What am I missing?

Trying to mix advice from different sources will have you thinking along the lines of your last sentence.

For goodness sake, assemble the bloody beast with lubriplate, or wipe the parts down with clean fresh oil (DON'T START ANOTHER OIL ARGUMENT!).

If you fill your crank with oil on assembly, most of it will still be in it when you go to start the engine. 1/4 cup down each rockerbox (slowly) is advised.

With a Mark III, you have the best possible scenario for fresh rebuild startup - the electric starter.

Disconnecct the ignition circuit, pull the sparkplugs, crack loose the main rocker feed at the top right of the head, and cycle the engine with the e-start till you get a bit of oil dribble at the rocker feed (shouldn't take more than a few seconds).

...well, that's what I would do anyway. I'm guessing at least one obsessive compulsive rocket scientist will excoriate me for advocating such a thing...
Engine assembly lube is standard procedure for lube before oil pressure hits.
Flood crank end end enough to drool out journals with rods at BDC.
Oil tank will fill oil to the pump inlet on its own.
Squirt oil at valve train.

Cam run in is the main concern over rings and cogs so Plan A is try keep initial start rpm 2000-3000 for 20 min. This is identical to old American push rod V8's.
Wrap rubber bands or such for throttle hold position and a fan or 2 going, then can diddle the timing for best rpm then back off throttle if rpm raise over 3000.
Oil pressure comes up fast enough not much gained spining engine over but to wipe off assembly lube more before real running loads hits.

Breaking in just rings is opposite, rev up hi as can stand under load to sense the bore heating to avoid melt-galling of micro ridges. Say 1 minute then let cool down then repeat till almost no smoke then give'r increased time hi load rpm
into minutes long periods till no smoke at all.

Stick with the straight grade oil during cam run it as stays more stable than multi grades. Can run what ya like later after the surfaces polished up.

Gearboxes should be flushed after a first good run in too.

Cam running advice always seemed at odds the advice for bedding in rings.
Last time I put an engine together with a new cam and bore I used Graphogen on the cam and then pretty much ignored it.
Got the the engine running and out on the road and under load ASAP with no idling, and no low rev slugging, then used bursts of hard acceleration with cooling off runs in between.

Bores and cam both looking good.
Megacycle sends me these little pots of red cam lube, I wonder if that's graphogen?

Good stuff.
Thanks folks!

My point was that the advice Norvill gives for breaking-in an engine runs counter to the advice they give for running-in the cam; I'm not perfect either.

It would be great to fire off the engine, set the timing and just get going for 20 minutes, and I may do that, but consider that the entire motorcycle is waking up, not just the drive train.

CNW advises that you run the engine untill the oil (20w-50) is warm (8-10 minutes), shut down and drain (engine and transmission), replacing the filter; let cool overnight. re-torque all fasteners, check/set valves. Ride machine 50 miles and repeat; repeat also at 250, 500 and 1000 miles, I believe. I did my Mk III break-in this way and now with 2500 miles on the complete machine it runs to beat-the-band.

The initial 8-10 minutes, with 2 fans going, averaged above 2500 RPM with me opening and closing the throttle so that the engine RPM followed a sort of sine wave graph. I dialed in the ignition first and fast, with an assistant, then just burnt fuel...

I don't like the school that wants you to flog a new engine to redline to break-in the rings; spirited riding after the initial bedding in does that quite well.

I've never been impressed with the quality of cams made in England. Perhaps by making the running in of the cam according to their instructions near impossible, their aim is to avoid warranty claims on less than 'state of the art 'camshafts.
As for priming the crank, I've never had success in priming from the end of the crank. Lately I've been using a small hand held grease gun as an oil can. I throw away the cap , spring and plunger, and fill with oil. I've drilled and tapped a brake line banjo to install a standard grease fitting. The banjo is installed in place of the rocker feed line. The grease/oil gun will work just like the plunger pump on Triumphs to push oil into the galleries, even 50 weight. The pressure relief valve opens at it's blow-off pressure, so their is no concern for inverting the seal.
It is the best way I've found to prime any plain bearing engine as most engines have a oil pressure switch that a grease fitting can be adapted to. I worry a lot less when giving a rebuilt engine to a customer to install knowing that it is fully primed. Cheers Rick
I've heard this stuff from various motor mavens over the years, including Gordon Jennings. Some of it might be true.

As far as the cam break-in goes, the manufacturers of flat tappet cams tell everyone to run them in at a minimum 2500rpm to work harden and polish the cam, not just Commando owners. It has nothing to do with the presence or lack of oil. The highest pressure the cam lobe and tappet sees is at idle. Keeping the rev's up initially lets them bed gradually. Redline makes a break-in additive with zinc to counter micro-welding.

Nobody in their right mind would propose redlining a new motor to seat the rings. Not the least because it isn't rpm's that seats rings, it's cylinder pressure behind the rings that's pressing the ring against the cylinder wall. That takes throttle. The rings are much harder than the cylinder, but there's much more cylinder than ring surface. Light pressure appears to polish the cylinder and leave the ring intact. It would be a moot point if the rings were supplied with a honed surface. And there's always the ole BonAmi.

Redline Assembly Lube is a gel that's great for everything in the motor including the cam and o-rings. Big veterinary syringes are perfect for priming the crank and oil galleries, but some engines are self-priming, (wetsump) :o
Ah yes Bon Ami, I've an unopened can of it and really trying to find a reason not to dust bores with it on a dry install. Could wd40 bores to help dust stick. wd40 is gone by first ignition so good as dry and what Total Seal used to recommend but now sells a dry power to put on instead, hm. A couple decades ago nano abrasives packs were sold to dump into oil to polish up for better mileage. This traces back to WWII Hurracanes stopping experiment of dumping nana size abrasives into path of following fuel injected Me109's and instead of slowing enemy down they gained even faster.
I've cleaned a number engines Commando to V8's with a sock full of Bon Ami in one hand and a pumped up water sprayer in the other aimed at carb mouth.

Total Seal Quickseat Dry Film Powder - JEGS
Quickseat is a powder Total seal has developed for quicker, more effective ring seating. Simply spread Quickseat on the cylinders and assemble the engine... ... _cleanser/
Our Bon Ami 1886 formula uses a soap made from purified tallow and soda ash. To this simple soap, Bon Ami adds powdered feldspar. Feldspar is a naturally occurring mineral that has a hardness of about 8 on the Mohs scale of hardness. Yet the soap surrounds the feldspar grains lubricating them so they do not scratch most surfaces. Space men use Bon Ami d/t its safe materials for everything.

Of course all of this is academic if you can't get the dang thing to fire off or stay running, then you kick your self and cam to death I guess.


My memory is not what it used to be, I miss spoke when attempting to relay the CNW break-in routine, here is what Matt sent me:

Reason for my e-mail is that you need to make a correction to a post that you made on the forum.

In regards to breaking in the engine, we Never recommend using 20-50W initially as you stated. Always a 20W or 30W straight weight Non Detergent oil (I only use 2 quarts at start up so that it warms up faster). The oil type is absolutely critical and I just assume you make the correction instead of me going in there to mention it.

Not sure about the transmission drain after the first start-up either. We never do and I don't think I told you that it was necessary. Sure it cold flush out some initial debris and wouldn't hurt, but again its not some thing we do on our machines or state in our start-up procedures.

The important thing is not to run the engine for to long right away (statically)....only until the oil gets a bit warm which could be 5 minutes or a little more. In order for the rings to get seated properly the engine will need to be under load and that's why the first 50 miles is important, again with Non Detergent oil. 3 quarts this time.

Straight from the source.

Here is something I read from Castrol Oils for Airplanes Piston Engines.

What is a Straight grade oil?
"Straight monograde oils are designed to be used when breaking-in a new or recently overhauled engine. They are formulated from mineral base stocks, typically further enhanced by a low concentration of anti-oxidant and pour point depressant for improved low temperature performance. These oils are also referred to as Running-In or Break-In oils. They are designed and formulated to provide the correct level of lubricant breakdown and controlled cylinder wear to help lap and seal the piston rings. Straight monograde piston engine oils are approved against SAE J1966 specification (superseded MIL-L-6082E). Some engines use these oils beyond break-in so if in doubt please refer to your engine manual/manufacturer. "

Here is the website FYI. ... rentPage=1
Ah so - no talk of motorsport delights w/o the oil type boog-a-boo lurking.
I'm sold on single grade mineral oil for -run in- but I think the NON-Detergent part is a mistake or mis-understanding. Of all the times the engine may be most polluted by assembly lube and carbon blow by before rings and valves and what not mate and seal, HI Detergent oil makes best sense to me. What am I missing?

I do an initial start up and warm up for just a few minutes with cheap 30 grade then replace in with 15-40 Rotella farmer-equipment-mower-truck do everything oil. Rings, in last 4 open-closed engines has seated smokeless within first gallon-50 miles. Then couple more Rotella flushes at 100 miles then 5-600, then permanent oil. Make that 5, as I got a Magnum 18 hp Kohler boxer twin rebuild this fall-spring too. Brit Iron seasoning-hardening made me brave enough to take on mower job myself and win.

OH YEAH, just in case throttle sticks as you stumble away from bars,
THINK kill switch first and fire extinguisher next.

hobot - delaying facing my 5th Combat pensive engine test by doing all kinds of other nasty labor intensive but mostly mindless tasks I can't fail at.
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