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Old 01-12-2015, 10:00 AM   #93
Art
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City: SF Bay Area
Vessel Model: Tollycraft 34' Tri Cabin
Join Date: Feb 2011
Posts: 12,569
Quote:
Originally Posted by Marin View Post
Depending on the configuration of one's wet exhaust system, cranking an engine without starting it could lead to overfilling the wet elbow/muffler with the result being backing up some water into a cylinder or two.

While I don't believe in cranking on the starter to lube a regularly used engine's innards, I also suspect Ski's assessment is correct in that it probably won't hurt anything enough to be the cause of an engine needing an overhaul.

So if one chooses to do this, they should make sure that pumping raw water through the boat's cooling system with no exhaust present to clear the water will not cause any problems.
Good points, however...

In reality... there are times when for one reason or another a boat's engine has trouble starting or maybe even simply refuses to start while cranking. For those reasons the amount of crank time may reach 10 X, 20 X or higher comparative to the relatively quick two to four times of 5 to 8 seconds each that attains oil pressure via starter action for pre lube of bearing journals and surfaces. Always best to be sure a boat's wet exhaust is set up to handle lengths of cranking for whatever reason.

Note: Following is history on a high performance 1967 Buick Wildcat classic engine; to which I do as mentioned in my posts above. I use this car/engine in both gentle and not so gentle driving techniques, depends on my mood and road/weather opportunities at hand. Purchased this all power/AC “Luxo-Muscle-Car” in 1998 with 71,321 on her. Original owners purchased her new when they were in their early 70’s. Man, they had balls! – LOL Wife was 101 yrs. when she passed. Car had been in garage for 11 years and basically kept up by her son taking it out a few times per year. When I got my “Cat” she needed, tires and detail/cleaning as well as engine, trany and brake service… then my new-monster was ready ta GO!

Sixteen years of "Sunday Drives" flew by...

Summer 2014 I had a decades accomplished race motor engineer (builds race car engines for "Sears Point Raceway" - 30 minutes from my home) rebuild my 1967 Wildcat 430 cid, 360 hp, 10.5 to 1 compression engine block... at 47 years age, 125,250 miles use... bearings had no bad-surface effects, flat tappet lifters had little to no cupping, cam lobes stood proud. Reason I rebuilt was due to several pistons having oil ring failure and three cracked piston tops. Blow back had become untenable. I had him use the best materials/equipment for rebuild to original specs. He told me that he was impressed with remaining quality of engine internals. And, that in 2014 the metals in the new parts/equipment being installed was much improved compared to 1967.

IMO: Regarding classic engines having no catalytic converter in exhaust... ZDDP zinc does continue coating bearings and flat tapped surfaces with a barrier that limits wear, and, starter actuated pre-lube oil pressure rise does help bearing surfaces at cold starts; especially after long duration shut downs.

Please don't get me wrong. I don't perform a starter actuated pre-lube if motor has only been shut down for hours to even several days. I do it when a motor has been sitting for long period of time.

There are three very important items to use with well built, excellent running engines:

1. Good lubrication products – with additives as deemed correct
2. Good cooling system – with additives as deemed correct
3. Good fuels – with additives as deemed correct

Other than that! - - > Go Baby – GO!!
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