Winterizing straight inboard

ScubaAl

Member
Joined
Jul 31, 2001
RO Number
5559
Messages
48
Hello Boaters,

I need a little help, I have a 1978 Cruisers Villa Vee with twin GM V-8's, raw water cooled. This boat is a straight inboard with a velvet drive transmission, its not a IO. In searching for information on how to winterize the motors every article I find talks about warming up the motors by attaching "muffs" to the outdrive. I found nothing on a straight inboard.
I'm thinking about 2 different options. One would be to remove the water intake hose from the thru hull, put the hose in a pail of antifreeze and start the motor. When antifreeze comes out the exhaust shut down. One concern would be the fact that the thermostat would not have opened up. Problem? I don't know.
Option number 2 find and pull drain plugs on blocks and manifolds. Then some how fill block and manifolds with antifreeze after they are drained of water. I'm thinking the manifolds would be pretty easy to fill, but I'm unsure as to which hose to pull and fill on the block. Then there's the whole thermostat thing again. Oh and in filling the block, would this get into the transmission cooler?
All this work would be done on land after the boat is hauled out. I don't believe I would have access to running water.
So, anyway to my question. Anyone have a step by step instructions on winterizing inboards or website that has the necessary info?
Thanks for your help, Al
 
You're option 1 is probably the best. Would be helpful if you had access to running water so you can warm up the engines, open the thermostat, and then run the antifreeze thru while fogging the engine. You could just pull the thermostat out for winterizing. Good luck.
 
I go for #1. It's not a big deal to take the thermostat out.

Even if you warm up the engines first, there is no guarantee that the thermostat will be open when you put the hose in the bucket.

Don't forget to change your oil before winterizing. Warm up the engine some before changing oil. It helps the oil flow easier when it is warm. Doesn't have to be hot.
 
Thanks for the help. I guess just pulling the thermostat would really not be that big of a deal. I do always change the oil before haul out, usually on the weekend before the boat comes out.
Al
 
I run 2 gallons full strength antifreezee thru by placing a funnel in the raw water intake and pour the antifreeze in while the engine is running. At that point, I'm not concerned that the thermostat is closed. Then I open up the block drains on both sides, clean out the scale so they drain completely and then back fill with 3 1/2 gallons 50/50 antifreeze to be sure the blocks are filled with the correct mixture. The inital antifreeze gets everything but the blocks. When I backfill, I remove the thermstat and fill my 454 Crusaders that way. Another option would be to drain the water out of the blocks and manifolds, pull the thermostats then run 50/50 thru the water intake s while the engines are running. I know lots of guys who warm the engines to operating temps, then run 4 gallons st antifreeze thru without draining anything. If you do that, drain some anti-freeze/water mix out of the blocks when you're done and check the freeze point.
 
Warm up the engine before your boat is hauled out. Drive it over to the lift and winterize it while the marina hauls the boat. I have a single inboard and that's exactly what I do. if your marina does not allow you to do that, then winterize it immediately after it is hauled while the engine is still warm. I happen to have a grocco strainer which allows for a very convenient place to pour in the antifreeze, but I'd use the bucket method if I didn't. I have my 4 gallos of antifreeze lined up and pour them in the strainer as I'm squirting winterizer down the carb (I'm sure it's a hoot to watch me do it). I then open the drains and pull off the hose at the water pump and trans cooler just in case some passage didn't get entifreeze. I would not pull the thermostat.

I also change the oil, filter, trans fluid, & add gas treatment the week before so I don't have to worry about it during haul out. Don't forget to winterize your head and/or sink if you have one.
 
I was at the boat this weekend, too rough to go out so I did some minor maintenance. I also checked on the location of the drain plugs on the block. Looks to be kind of a pain to reach, but I think do-able.
The idea (good one) of warming the boat up before the marina hauls it out doesn't work for me as I live 200 miles away. The haul out would be done during the week while I'm at work.
So it looks like I will be doing more or less what GS suggests. Water intake hose in antifreeze to protect trans cooler, raw water pump and manifolds. Then I will remove the drain plugs, drain block. Remove thermostat housing and back fill.
I have no problem pulling the thermostat, but looking at this diagram COOLING SYSTEMhttp://www.marinemechanic.com/New-Folder2/v8-cool-flow.htm It looks like I could just remove the hose from the water pump and it would fill the block? With the plugs out I could began backfilling and when antifreeze comes out, close the plugs
Some years back I had a Ford 351 that I winterized that way.
One more thing, would there be a problem to began fogging the motors as they suck up the antifreeze for the manifolds and trans cooler?
Thanks everyone, Al
 
I can't fill the blocks on my Crusaders without removing the thermostat.(GM Blocks).
 
Greg how come you cant fill the blocks without removing the thermostat? Are raw or freshwater cooled?
 
I'm Raw water cooled, but it is the design of the thermostat housing that prevent me from just back filling thru the hoses. (Crusader 454 XLs)
 
Gregory - if you pull the large hose that runs from the circulating water pump up to thermostat and pour AF down that hose, won't it fill the block. It does on my GM 5.7L and I do not see why it would not on other engines. Cannot see how the design of the thermostat housing would come into play once the hose is removed and you are pouring AF down the hose. But I have not tried to winterize a big block GM engine that way.
 
No, all water enters above the thermostat so if it's closed, it will bypass the block. My old 5.7s (Crusader) had the same setup as my 454s. I used to be able to do it the way you suggest when I had Mercs.
 
Greg: I have a fresh water cooled crusader 427 and for the last thirty years I was under the same impression. This year I put in pink anti freeze without removing the thermostate. Drain the block of water, then close up and pour pink anti freeze into the filer or have it taken up by the raw water pump. I put in five gallons. Shut down and opened the cocks. Anti freeze flowed out, from the block, from the manifolds and the oil cooler. It would appear that the system fills the block first before filling the manifolds. The oil cooler gets it first as well. Really quite simple. I didnot catch what went out the exhaust. After checking I added another two gals for safety. Them drained the block and manifolds. That was messy but I picked up the waste with a wetdry vac and disposed of it. I am comfident that my block is winterized, and that using the pink I have added a degree of rust prevention. My block has the original manifolds, elbows and will be celebrating its next season with 2800 hours. Regards Bill
 
Bill, thanks and congratulations on your 2800 hrs On those Crusaders. THey must be well taken care of. How did you get the antifreeze to go into the block if the thermostats were closed? My Water flow diagram (94 454 Crusader XL), shows raw water bypassing the block until the thermostat is open. For filling with antifreeze after draining, my manual specifies to remove the thermostat housing and fill the block with anti-freeze.
 
Greg: I was surprised that it worked. Considering my engines age perhaps the systems differs from yours. However, the block must recieve coolent first, also the thermostat only really functions when surrounded by liquid. Therefore I assume that without the liquid in the block there is no pressure behind the pressure relief and the coolent flows in to creat that pressure, then it goes to the manifolds. In the manual it shows the pressure relief open when the thermostat is closed. Bill.
 
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