Engine Break-in

[FreeBeeTony]

Getting ready to launch the Rapido Vortec next w/e.

I know this has been discussed many times............but I gotta ask again.

What's the best procedure for breaking-in a new/rebuilt engine?

Since install last fall it's probably been run 30-45 min on the muffs in the driveway. What should I do/not do when I launch? Should I get on it right away for short spurts before I reach my slip?

Wanna do it right.

 

[Don S]

Re: Engine Break-in

Here is a C&P from the Mercruiser owners manual.


20-Hour Break-In Period
IMPORTANT: The first 20 hours of operation is the engine break-in period. Correct
break-in is essential to obtain minimum oil consumption and maximum engine
performance. During this break-in period, the following rules must be observed:
• Do NOToperate below 1500 rpm for extended periods of time for the first 10 hours.
Shift into gear as soon as possible after starting and advance the throttle above 1500
rpm if conditions permit safe operation.
• Do NOT operate at one speed consistently for extended periods.
• Do not exceed 3/4 throttle during the first 10 hours. During the next 10 hours,
occasional operation at full throttle is permissible (5 minutes at a time maximum).
• Avoid full throttle acceleration from IDLE speed.
• Do NOT operate at full throttle until the engine reaches normal operating
temperature.
• Frequently check engine oil level. Add oil as needed. It is normal for oil consumption
to be high during the break-in period.

 

[FreeBeeTony]

Re: Engine Break-in

Thanks Don.............

 

[Coors]

Re: Engine Break-in

tony, I thought you had splashed long ago.

 

[FreeBeeTony]

Re: Engine Break-in

I blew the engine that was in the boat (that I had installed Vortec heads) at the end of last season. Wound up breaking a valve, hit the piston and basically took out the whole engine. I had replaced the lifter in on that valve and thought I had found the original problem.........the only thing I can think of is there was a problem with that lifter bore.......

Anyway.........I wound up buying a Vortec longblock from Rapido, installed new manifolds, risers, starter, coupler..........basically have a new engine.

With my luck, the engine will run great and I won't be able to afford the gas.........

 

[Lou C]

Re: Engine Break-in

The break in instructions Don posted are basically the same as what's in my old OMC owners manual...
I don't let the price of gas stop me from havin' fun, I filled up at Seymour's Boatyard dock in Northport LI and it was $4.79 for gas.....(that's where the pic in my avatar was taken)
good luck with the new motor...

 

[FreeBeeTony]

Re: Engine Break-in

Question.........

What is meant by "extended periods"?

I can run across the bay at various speeds..........then there is a fairly long stretch of no-wake zone..........probably take 30 min or so to get through.
Is this OK or sould I avoid doing this for the 1st 10 hrs or so?

Going out for a spin now..............

UPDATE:

Just got back from the ride..........backfired through the carb a few times at ~3000RPM's, even stalled once. Am attributing this to water in the fuel. I changed the fuel filter/water seperater before I put in in the water.......even added some dry gas. The more I ran it the better it seemed.

Right now I need to gain confidence.........feels like I am starting all over again. So far so good!

Have only gone up to 3400RPM's so far.

 

[FreeBeeTony]

Re: Engine Break-in

bump

 

[Don S]

Re: Engine Break-in

15 minutes, especially at idle. I hate to see new engine run at idle for more than a few minutes.
Can you find a lake somewhere where you can do the breakin?

 

[FreeBeeTony]

Re: Engine Break-in

No lakes here Don............just trying to figure out how to break it in and go fishing at the same time!

 

[Lou C]

Re: Engine Break-in

I know what you mean about those no wake zones...they can be a pain...like when you are in em and then some guy blows by in a 40 footer half up on plane pushing a 2 foot bow wake, and bounces you around...
You might be able to get through there, by varying your engine speed from idle, up to 1500 and back down, I can run at 1200 and not leave a wake anyone would notice...but the 'authorities' in some places can be pretty strict about that...where I am (North Shore) it doesn't specifically say 'no wake' just 5 mph limit, so you still may be able to vary your engine speed up and down and not exceed that by much...
Are you down on the South Shore, or up here on the North Shore?

 

[Coors]

Re: Engine Break-in

Just keep playing with the throttle, some load, no load.
just not a constant rpm, or the rings will seat to that.
Vary the rpms, which involves putting a load on the engine-forces the rings against the cylinder walls.

 

[FreeBeeTony]

Re: Engine Break-in

Continuing break-in........up to 4000RPM's now.

Variyng between 1500-4000..........so far so good!!