To Crank or Not To Crank

[mgbeda]

Hi Folks,

Now that I've got my engine mounted in the frame I had intended to spin up the oil pump (at 1/4 turn crank increments as recommended by Bruce), put the distributor back and then use the starter to crank the engine until I get oil pressure that way.  And then I figured every couple of weeks I'd crank it with the starter until I see oil pressure, to keep things loose.  I figure with the sparkplugs out it'll crank fairly fast.

Then I read this on the internet:

"Once fired, bring RPM right up to 2000 rpm, keep RPMs moving between 2000-3000 rpm, do not idle and do not go under 2000 rpm. Do this for 20-30 min. This is to break in the cam, the cam's only oiling is from splash oiling"

http://answers.yahoo.com/question/index?qid=20090928233800AAt6rUG

So now I'm wondering if it's a bad idea to crank it with the starter until I'm ready to actually start the engine.  I'm sure I won't get anywhere near 2,000 rpm, even with the plugs out.  Will the cam essentially be dry if the engine doesn't get to 2,000 rpm?

What do you think?

Thanks,

-mB

[The Tassie Devil(le)]

So now I'm wondering if it's a bad idea to crank it with the starter until I'm ready to actually start the engine.  I'm sure I won't get anywhere near 2,000 rpm, even with the plugs out.  Will the cam essentially be dry if the engine doesn't get to 2,000 rpm?    What do you think?    Thanks, -mB

In a word, YES.   DO NOT CRANK WITH THE STARTER UNLESS YOU ARE GOING TO ACTUALLY FIRE IT UP.

Sorry for the shouting, but you risk damaging the bearing shells, cam lobes and lifters, plus scraping the cylinder bores dry.

Now, the way the oiling works apart from the oil in the galleries to the engine parts is that the cam lobes, lifter faces, cylinder bores, rings, timing gear, and everything else that doesn't have a direct oil path is by splash feed.   

That is, the oil that is splashed around by the rotating crank, throws oil everywhere, and onto everything.   Plus, the "air" inside the sump becomes an oil mist and coats everything it touches.

Plus, on each revolution, oil is sprayed onto the cylinder walls, under the pistons to lubricate the walls, piston skirts, gudgeon pins, and also act as a coolant for those parts.

Just cranking will not create this "Mist"

Bruce.

[Scot Minesinger]

The cam has a break in and MTS told me the same thing when I bought the new lifters, run it for 20 minutes never less than 2,200 rpm.  After I replace them, I am to crank the engine to start it and immediately run for 20 minutes @ 2,200 rpm.

If you want to keep the engine lubed for long periods of not running, you can spin the oil pump with distributor out with a drill and long extension with female flat blade screw receptacle.  Then also turn engine over by hand 720'.  Do this say every three months or so.

[MY 59]

it is a funny feeling to first start an engine and then vary the RPM for 20 minutes!
find top dead, set distributer, check fuel, then crank the starter......BOOM she starts and then rev her up to 2,000!
when I did it in both my Fairlane and Caddy (engines built by me and my brother) your eyes are hovering over temperature guage, oil light etc watching out for anything going wrong! all the while slowly varying the revs around 2 - 3,000.

[The Tassie Devil(le)]

If I am doing it for a customer, I make sure that he or she is not around.

I run in the cam at 2,500 RPM for 1/2 Hour.

Bruce.

[D.Yaros]

it is a funny feeling to first start an engine and then vary the RPM for 20 minutes!
find top dead, set distributor, check fuel, then crank the starter......BOOM she starts and then rev her up to 2,000!
when I did it in both my Fairlane and Caddy (engines built by me and my brother) your eyes are hovering over temperature gauge, oil light etc watching out for anything going wrong! all the while slowly varying the revs around 2 - 3,000.

It would not seem funny/disconcerting if you ever saw what they do with a brand new engine in auto assembly plants.  The first time I saw them "crank it up" I was shocked!

[Scot Minesinger]

The way dealers drive around in new cars too around the parking lot, like they are in a race for their life, is shocking as well.

[mgbeda]

Thanks guys.  I guess I'm lucky I didn't make a big mistake.

-mB

[aggie2012]

I don't want to hijack this post, but I have a question on basically the same subject.

Marty at MTS said I could run the engine at 2000+ rpm for 25 minutes, or run it in 2 15 minute intervals with a 10 minute break for a little cool down.

When I was breaking in my timing set and cam last week, I blew a hole in my radiator and had to stop after 15 minutes. When I have everything back together, do I run it another 15-20 minutes, or do I have to start over?

[The Tassie Devil(le)]

The running-in time all depends on the ability for the cooling system to handle the temperatures that come with running any engine at "high" sustained speeds so it doesn't overheat.   There would have been a reason why the radiator self-destructed.   A standard engine in a standard vehicle as was designed should never have such a problem.

With one engine, I had to run the cam in in 10 minute intervals, with extended cooling time in between.     In this case, I ran it for a total of 35 minutes.

The thing with running the cam and lifters in is to ensure that the oil splashing from the rotating mass is sufficient to fully coat the cam lobes and lifter bases, and for the minute particles of oil to enter the microscopic porous surfaces of the cam lobes and lifter bases.

This "coating" then remains in location, enabling the engine to be idled down for prolonged periods.   But, I would never recommend any engine to be put at idle for long times, but in stop-go traffic, there is a lot of idling.

This is why high mileage engines last so long.

Bruce.