Michigan Boarder Engine Blueprint and Build

[Slayer]

With a raw water system, the "cold" water it dumped directly into the engine when the thermostat is open. When this is happening at full throttle the pistons are expanding but the cylinder walls are not because of the constant input of cold water. This eats up the required clearance and the results aren't pretty.

The closed system acts as a buffer between the cold water coming in and what the engine sees.

Piston manufactures usually have a marine clearance spec (it's pretty big).

I would suspect then that this is the reason it's so important to allow your boat engine to come to temp before loading it, correct?

[WheelerWake]

I would suspect then that this is the reason it's so important to allow your boat engine to come to temp before loading it, correct?

My thoughts exactly, the pistons are pretty loose - rattling around in the cylinders until they expand some, especially if they are forged.

Luckily for me, I don't have to worry about this, after I launch, I have to park my truck, walk back, navigate the no wake zone, by then the engine is pretty warm.

OEM cast pistons are produced with steel struts in them that keep the piston from expanding so much. This allows a much tighter clearance and keeps the clearance stable for cars that have to start in the winter.

These clearances are nothing compared to lightweight forged race pistons, you run around .010" clearance with them, warm up is very important!

[sgt1970-442]

I truly hope that everyone who owns a Malibu is smart enough to not just go start the engine, back away from the dock idle out 100ft and drop the hammer without getting the engine up to temp.

lots of different metals for expansion factor come into play inside any motor. ring choice also makes a difference, hi tension oil rings verses a low tension is huge. we use a fish scale when fitting the oil ring for lower drag and friction in our race motors. when I checked this on the old pistons, it was more than my scale could register. also bet not many have dealt with sleeving all 8 cylinders with steel sleeves. ring seal was greatly improved over the cast iron bores which equates to more compression and better burn/power. the steel is far more ridged than cast iron. at any rate thank you wheelerwake as I was going to call srp on the piston to wall clearance anyway,,, just gave me something else to add to the questions I will be asking them.

[Woodski]

I have noticed many and actually most ski boats not get warmed up much before a run through a ski course. Generally, I see the owner idle to the course, shut down to get ready then throttle up to 34-3600 rpm headed towards the course. One item on the curculation pump on an open system, the inlet water is not 100% going into the block, the pump tends to recirculate some of the warm water so it is somewhat blended. On a cold start up, the temp will still be low, hence one key reason for the extra piston to wall clearance.

[Slayer]

I bought my current boat from a Malibu dealer who emphasized the importance of allowing the boat to come to temp before bringing the engine above 1,000 RPM. While I was unsure of exactly why, I followed his words and after reading this thread, am super happy that I have.....

Now, to discuss this with the owner of the boat I want.......

[MalibuNation]

Pretty sure the electronics in my boat won't let me got fast until it's warmed up.

I know I'm talking apples and oranges but it cracks me up to see the bass boats with large OB hammer it as soon as they launch ... what are they after ... flying fish

[Sixball]

Yeper. My boat never sees anything above Idle till it hits 160. Both of my neighbors back off the lift and go. I will say all the boats are still running well.

[Michigan boarder]

I do let the boat warm up completely, but the guage never goes much above 120. Even with a new thermostat, still stuck at 120. Maybe with good clean connections it'll change. Either way I'll throw a new thermostat in there again upon reassembly of the cooling components.

[Woodski]

@MB: You will want to do a good service on the t-stat housing unit, clean it up, check all the components, particularly the little springs on the bypass device, etc. That can improve the water temperature control. Also, your temp gauge may simply be inaccurate. An added heater can also change the water temp readings on the gauge depending on how it is plumbed.

[sgt1970-442]

got something delivered today..

wife loves it when I set parts on the granite tops....

[WheelerWake]

I think you should put the before piston on that counter top...

[sgt1970-442]

I think you should put the before piston on that counter top...

only if you have a spare room at your place for me...

[Woodski]

I surprised the CFO with some parts "warming" in the oven and some bearings in the freezer one time. Needless to say my dinner that night included PBJ.... since that is what I was willing to make myself.

[Baddog]

I surprised the CFO with some parts "warming" in the oven and some bearings in the freezer one time. Needless to say my dinner that night included PBJ.... since that is what I was willing to make myself.

Women just don't understand the finer points some time.

When I lived in MN my neighbor was changing his oil in the winter. He had a bright idea to put his 5 little quarts of oil in the oven to warm for a bit so they would flow better. They flowed alright, all over the inside of the oven. Surprisingly, he bought his wife a new oven that very day.

[UWSkier]

I surprised the CFO with some parts "warming" in the oven and some bearings in the freezer one time. Needless to say my dinner that night included PBJ.... since that is what I was willing to make myself.

Dishwashers make outstanding snowmobile clutch component cleaners/degreasers. Slept in the garage with my sled the day I discovered that...

[Michigan boarder]

I think the delivery of the pistons has ended the cold snap. There must be a correlation.

[Slayer]

Dishwashers make outstanding snowmobile clutch component cleaners/degreasers. Slept in the garage with my sled the day I discovered that...

That is simply wonderful!! I used to always pull mine apart, put them in a parts washer to soak for a spell (usually 3 beers), scrub with 3M pads, rinse, then blow them off with compressed air. Prior to rinse, I'd always shoot 'em down really well with brake kleen just prior to blow off. Worked great.

[sgt1970-442]

I see we are all on the same page with the wives.....

on an up note,,,, got a few more things today. its late and I will post some pics in the morning.

[sgt1970-442]

so the crank, rods, bearings and rings showed up. time to get this party started.

you will notice the crank pins are gun drilled. this aids in weight reduction but also helps for matching bob weights for balancing this assembly. this can also be done to the mains to help with crankcase pressures and gives a scavenging affect. the 5.7" scat rods, bushed for floating wrist pins, I-beam in shape and have 7/16" arp rod cap bolts the stock rods have 3/8" bolts with 3/8"x24 thread nuts, and the tensile strength doesn't even come close to the arp fastners.

[MalibuNation]

1/4 barrel of Oberon ok? I boat with the plant manager.

[sgt1970-442]

1/4 barrel of Oberon ok? I boat with the plant manager.

prefer Labatt blue but, free beer is good beer and its a bonus when its cold.

1/4 barrel? i'm just wondering what the rest of you guys are going to drink...

[WheelerWake]

Are going internal or external balance? If internal, what are your plans for the flywheel?

Also, need a photo of that crankshaft on the counter top.

[Baddog]

Are going internal or external balance? If internal, what are your plans for the flywheel?

Also, need a photo of that crankshaft on the counter top.

Best to put it the oven for a bit first. Then quench it in the dishwasher. Good to go on the countertop.

Edited January 30, 2014 by Baddog

[Oberon]

1/4 barrel of Oberon ok? I boat with the plant manager.

Im in!

[sgt1970-442]

Are going internal or external balance? If internal, what are your plans for the flywheel?

Also, need a photo of that crankshaft on the counter top.

internal.