Breaking in a camshaft and running outer springs question

[NCAmother]

I plan on only running the outer springs when I break in the cam on the 850t.  What I noticed is the lower spring cup is loose without the inner spring in place.  Is it ok to leave this lower spring cup installed or should I remove it? Thanks!

[TOMB]

 Just a guess.
I don't think they did it that way to factory I'm going to guess they just put  the engine in the bike assembled or test run on a engine stand started up and rode the s*** out of it right around the racetrack or the city streets but I'm just guessing

TOMB

[TN Mark]

Where did the idea of ‘breaking in a camshaft’ come from? I’ve never heard of such a thing.

[Moparnut72]

Very important with flat tappet cams. Automotive engines prior to roller cams needed to be run at 2,500 rpm for 20 mins after a new cam is installed. Otherwise there is the risk of having one or more flat lobes on the cam. I don't know how the factories did it but I think they had electrically powered equipment to "run" the motor for the required amount of time. I know my neighbors weren't thrilled when I broke in the cam on in my high performance 360 Mopar with open headers before I took it to the muffler shop. 
kk

[RinkRat II]

     Moparnut is correct!

   It's not a good idea to leave out those parts. Assemble the engine as it should be, when you fire it up, immediately run it to2500rpm and hold it there to allow the cam and lifters to run in. Three cycles of 10 minutes will allow heat/cool cycles for the best break in. Use a good break in oil and change it after your 30 minutes.  My $.02

     Paul B 

[Don G]

How radical is the cam profile and what is the supposed spring load? If you using basically stock or mild cam lifts and springs, no special extra work is required, start up and ride briskly.  DonG

[s1120]

Very important with flat tappet cams. Automotive engines prior to roller cams needed to be run at 2,500 rpm for 20 mins after a new cam is installed. Otherwise there is the risk of having one or more flat lobes on the cam. I don't know how the factories did it but I think they had electrically powered equipment to "run" the motor for the required amount of time. I know my neighbors weren't thrilled when I broke in the cam on in my high performance 360 Mopar with open headers before I took it to the muffler shop. 
kk

Ya back in the day the church we shared a driveway with was not all that happy when I was braking in cams on my old Mustang drag car!! :)  :) 

As for the springs..  Unless they are some real stiff custom springs, I would just install them the way they are. Only time I ever took out the inners were if I had some crazy seat pressure.

[John A]

The cam is lubricated by splash so that is the reason to not let it idle at break in. I like GN paste, a molybdenum grease for metal forming by Dow as an assembly lube. If the lifter starts to skid without rotation it goes bad quickly. My advice is the same as most, just put it together so that it will start right off without cranking much and keep it above 2500. If it’s done stationary have some no nonsense fans blowing on the cylinders and it’ll be fine. The only time I had one fail is when the engine didn’t start right off on a GM six cylinder with a Comp cams sports cam. Simplest engine in the world and I had the ignition timing off. It made more power on five cylinders and that cam than it did on the replacement stock cam on six cylinders . I like it when you hit the starter, it makes a half revolution, lights off  and runs right up. I have a Norris cam in a Guzzi that has well over 150K miles on it and is still about perfect, that was a success!

[NCAmother]

Thanks everyone, I don’t know the spring pressures, they were on a set of swap meet heads.  The cam is mild, crane cam similar to old norris-ss cam.

[Moparnut72]

I've been thinking about it. I wouldn't run it without the spring retainers nor the 2nd springs either. I don't know the exact setup here but on an auto engine I would be afraid there might not be enough pressure to get the lifters to rotate resulting in wiping out the cam and or lifters.
kk

[pressureangle]

I have done a lot of homework with regard to Guzzi cams and lifters prior to installing a Web 86b cam in my '85 LeMans, which required sorting the details of Ford Y-block lifters and the associated lobe tapers.
Guzzi, as seems to be standard practice in Europe, has true flat tappets and untapered cam lobes with the lifter bores offset from the lobe centerline to induce rotation. This mitigates to a large extent the problem American 'flat tappet' cams have with contact pressure, as we have a radius ground into our lifter bases and a taper on the lobe which although creates rotation, gives only a single point of contact where the true flat surfaces have a line of contact across the entire lobe face. Loading is much reduced for a given spring pressure. That said, and knowing something about the metallurgy and oil spasms involved, I would set up a good fan to cool the engine and give 3 cycles of heating/cooling no less than 3 minutes each, and at the 'standard' 2500rpm, plus and minus 500 rpm. If I was pretty sure the carburetion would permit it, I'd just go ride it and keep it over 2000 rpm if you have some open roads to do so. Recent research has shown that the entirety of the 'flat tappet cam debacle' of the last 20 years has been due entirely to poor production quality control, with cam lobe taper and lifter base radius basically being all over the place to the point that a significant number find pairing that gets outside survivable dimensions.
However, it's still required to get the new pieces to love each other properly. 2500rpm is the generally agreed speed to cast enough oil off the crankshaft to keep new bits lubricated during the initial break-in period.

[NCAmother]

I have done a lot of homework with regard to Guzzi cams and lifters prior to installing a Web 86b cam in my '85 LeMans, which required sorting the details of Ford Y-block lifters and the associated lobe tapers.
Guzzi, as seems to be standard practice in Europe, has true flat tappets and untapered cam lobes with the lifter bores offset from the lobe centerline to induce rotation. This mitigates to a large extent the problem American 'flat tappet' cams have with contact pressure, as we have a radius ground into our lifter bases and a taper on the lobe which although creates rotation, gives only a single point of contact where the true flat surfaces have a line of contact across the entire lobe face. Loading is much reduced for a given spring pressure. That said, and knowing something about the metallurgy and oil spasms involved, I would set up a good fan to cool the engine and give 3 cycles of heating/cooling no less than 3 minutes each, and at the 'standard' 2500rpm, plus and minus 500 rpm. If I was pretty sure the carburetion would permit it, I'd just go ride it and keep it over 2000 rpm if you have some open roads to do so. Recent research has shown that the entirety of the 'flat tappet cam debacle' of the last 20 years has been due entirely to poor production quality control, with cam lobe taper and lifter base radius basically being all over the place to the point that a significant number find pairing that gets outside survivable dimensions.
However, it's still required to get the new pieces to love each other properly. 2500rpm is the generally agreed speed to cast enough oil off the crankshaft to keep new bits lubricated during the initial break-in period.

Did not know about the European offset lifter bores.  Thanks for the cooling cycle advice, been thinking similarly.

[Moparnut72]

I follow Uncle Tony on tube somewhat regularly, he had a video recently regarding cams and lifters. It seems there have cams and lifters coming into the marketplace without proper tapers and radii resulting in failures. Offset lifters and cam lobes sounds like cheaper and easier way to accomplish the same thing.
kk

[guzzisteve]

I have done a lot of homework with regard to Guzzi cams and lifters prior to installing a Web 86b cam in my '85 LeMans, which required sorting the details of Ford Y-block lifters and the associated lobe tapers.
Guzzi, as seems to be standard practice in Europe, has true flat tappets and untapered cam lobes with the lifter bores offset from the lobe centerline to induce rotation. This mitigates to a large extent the problem American 'flat tappet' cams have with contact pressure, as we have a radius ground into our lifter bases and a taper on the lobe which although creates rotation, gives only a single point of contact where the true flat surfaces have a line of contact across the entire lobe face. Loading is much reduced for a given spring pressure. That said, and knowing something about the metallurgy and oil spasms involved, I would set up a good fan to cool the engine and give 3 cycles of heating/cooling no less than 3 minutes each, and at the 'standard' 2500rpm, plus and minus 500 rpm. If I was pretty sure the carburetion would permit it, I'd just go ride it and keep it over 2000 rpm if you have some open roads to do so. Recent research has shown that the entirety of the 'flat tappet cam debacle' of the last 20 years has been due entirely to poor production quality control, with cam lobe taper and lifter base radius basically being all over the place to the point that a significant number find pairing that gets outside survivable dimensions.
However, it's still required to get the new pieces to love each other properly. 2500rpm is the generally agreed speed to cast enough oil off the crankshaft to keep new bits lubricated during the initial break-in period.

Wow, what an explanation. Excellently put into words. That is an art!! 

[TN Mark]

Wow, some fantastic information on this thread for sure.

The initial question was regarding a Moto Guzzi 850T.

Did the Moto Guzzi factory ever  run each engine at 2500rpm for 3 separate heat and cooling sessions? Or did they slap them together in their most efficient fashion, bypassing the greasing of swingarm and head bearings, to get the bikes shipped out.

I bought my first Moto Guzzi in 1978 and simply never remember hearing or reading about a Moto Guzzi Tonti frame motor needing the cam run in.

I replaced the cam in a G5 and a Convert though. I used copious amounts of assembly lube, broke the bike in as I would any new motorcycle and simply changed the oil after about 500 miles. That's always worked well for me. 

[NCAmother]

Spring pressures are 111# and 250#

[Speciality]

In 50+ years of working on my own bikes I have never heard of running in a camshaft. I live in the UK and have only had European and Japanese bikes. You learn something new every day….

[pressureangle]

Well, like anything else, there is more than one way to skin a cat; engines produced for 'public consumption' have to have a break-in scheme that doesn't frighten the owner. Typically, factories put a new engine through about one minute of what you'd call 'abuse', and throw it to the customer with oil that meets expectations. The first minute of running sets 90% of the required break-in.

In 1982 I saw Team Kawasaki assemble the top end of Lawson's Daytona 200 engine, start it and wing it a dozen or 20 times to some at the time incredible RPM in neutral, give it a look over and send it out on the track.

There's a huge number of ways to arrive at the same end but the expected usage and initial construction dictates some of the break-in. Looser engines built for racing can be beaten quickly. Something with a 100k mile warranty needs a little more time and tenderness.

Camshafts in particular- when everything is working properly, there is no metal-to-metal contact anyway. Flat tappet bases keep oil in place better than radius tappets. High speed keeps oil in place and puts more where it needs to be. Low RPM and low oil film simply lets the 'rough' new parts smooth out so they're not subject to scuffing when oil film breaks down.