advice on running in a rebuilt engine

Dunromin

Seaman
Joined
Apr 29, 2011
Messages
58
I'm finally ready to put my 470 mercruiser in the water after a rebuild including rebore, pistons, rod and mains bearings, head job etc. Can anyone offer instructions or point me to a link that will help me run it in?
 

Doernuth

Petty Officer 1st Class
Joined
Jul 6, 2010
Messages
332
Re: advice on running in a rebuilt engine

merc manual #3 Section 1A Page 5 I believe is the proper procedure. Or ask the engine builder what the procedure is?

Links to download in the Adults only forum at the top of the page!!!
 

CobiaXL

Banned
Joined
Mar 8, 2010
Messages
353
Re: advice on running in a rebuilt engine

I assume this engine has NEW flat tappet lifters and cam?If so proceed..Use oil with zinc(No synthetic)..With the distributor removed,Prime the oil pump.I used a old screwdriver cut off and inserted into my dewalt drill.Spin on high till ya get oil at top of engine(Oil will flow out of push rods,Make sure there is oil coming out of every push rod.It may take a couple minutes if you planning on using 20/50w Valvoline racing oil.Properly breaking in an engine requires running it without a load for 30-45 minutes. During this time, the engine should run around 2,000 rpm, occasionally varying the rpm between 1,500 and 2,500. However, the engine shouldn't be allowed to idle because the oil pump isn't spinning fast enough to provide enough oil pressure at those low rpm levels.Good luck
 
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