I started building an LS engine about 5 years ago (still havent fired it up) and the first 3 years the cylinder heads were just on the block with a few bolts in each head hand tight. When I finally got around to torquing the heads down, I pulled the heads off to clean the surface, and could see rust starting on the outside edges of the block surface working its way towards the cylinder bores. The cylinder bores still looked like they were freshly machined and it turned over with no issues.

Thanks for all of the feedback. Keep in mind that my knowledge is limited and the more questions I ask the more limited I find it to be. That being said, I was concerned about the springs in certain cylinders being completely compressed for months at a time. FYI, I do not have a crazy spring pressure. I am very relieved to find out that this is not a worry I should have. Btw, I didn't come up with this on my own. I saw something on this topic years ago when I was on fakebook. I usually change the oil and filter in the fall, fog it till it stalls and also remove the plugs and fog the cylinders. This is the first year I have filled the cooling system with RV anti freeze. I store my boat in the basement so freezing is not an issue, but going for the anti corrosion protection. Thanks again for all your comments and help.

I’ll start this by saying I’m not knowledgeable at all compared to a lot of the guys on this website….

When it comes to winterizing - I’ve changed the oil in the fall to get any moisture out prior to it sitting. I’ve changed the oil in the Spring to get RID of any moisture that accumulated over the winter. I’ve left the tanks empty. I’ve left the tanks full. I’ve fogged the motors like I was trying to eradicate a hornets nest, I’ve not fogged them at all. Frankly - I’ve never noticed much difference.

So these days I don’t worry about it too much. Every Fall I change oil, filters, fuel filters, drive lube, plugs and pump them full of antifreeze. I have close cooling but want the system full of anti-freeze. I wait until Spring to change the Fuel Filters and the Water Pumps so they are fresh. As noted, I turn the motors over every couple weeks but that’s easy - I just hit the button while I’m dicking around with other things.

Don’t overthink it, but definitely keep the questions coming. Lots of smart people here.

This guy on YouTube had a few videos on one of Lake Speeds Nascar engines with Lake Jr. they dynoed and tore apart.
Had sat for almost 20 years they claim. Rockers not backed off.
In the first 5 minutes or so of this video, they tested all the springs and they were still within 5 pounds of new.
This was 2nd video of the ordeal.

Do you see sufficient oil pressure or any oil pressure at all when you do that at cranking RPM only?

Rotate it every month or 6 weeks with a 3/4 socket on the balancer bolt mostly to turn the rubber impeller to a new position so the same blades aren't bend over all winter.. On the discharge side of the pump they are completely bent over. Been doing this for 35 years and they last 3-4 years. I change it at 2-3 years depending on the water pressure they are putting out, cause the pumps a hassle to get to. I have gauges on my dash to watch the pressure so i can tell when they are getting worn.

Cap'm, I never even considered the sea pump. I guess it's not wrong to turn the engines a little at a time every so often. Sounds like overkill as far as the valve springs go. The pumps are a PIA on probably every boat. How come there's not a better pump that can be mounted up high in plain site with easy access? Something to look forward to I guess. Thanks for your comments.

Honestly - I’ve never paid attention.

My water pumps are a pain in the ass, but I change every year. I only put about 15 hours a year on them and some years they have shown notable wear. I’m not willing to risk getting stuck one afternoon. Hell, I change them in my Donzi’s Mercury XR6 every year.

I can honestly say,my old whipple motors didn't get rotate for over 3yrs.I will say,the springs were micropolished isky 8005a's.motors are still running.

I don`t know if I would rotate my engine dry every so often.. as a matter of fact I woudln`t . an impeller is cheap.