Tom H wrote:
I have obtained a copy of Volvo Penta's oficial "laying up" guide from the Volvo stand at the Southampton boat show.
It says on AF in the engine "Leave the liquid in the system, it provides good protection against freezing and corrosion"
It also gives instructions as to how to suck it into the engine.
I ran the engine for about 20 minutes on a continous circulation of 20 litres of 50/50 mix untill good and hot (2/3 way from cold to hot on the guage and steaming liquid coming out of the engine.
Is that enough to protect me for winter or am I getting paranoid and going to lie awake at night listening for the sound of a cracking block?
thanks
If yours is a "closed cooled" engine, you're fine with what you did.
If it's a "Raw" water cooled engine and you started with 50:50 anti-freeze, You'll need to determine how much fresh water
was in the block and add that to the 50:50 you started with and figure that you no longer have 50:50 sitting in the block (since you mixed with the 50:50 you started with)
Since the water in the block of a raw cooled engine doesn't completely circulate out it's hard to say what concentration you have unless you get an anti-freeze tester and measure it to be sure.
Below is the freeze-protection capability of both ethylene and propylene glycol mixes.
(I'm going to assume that you're using non-toxic propylene glycol)
http://www.engineeringtoolbox.com/propy ... d_363.htmlHere it is for ethylene glycol too in case you're using it...
http://www.engineeringtoolbox.com/ethyl ... d_146.htmlThe main point to consider here is that you do not get perfect mixing when you start out with 50:50 and mix it in an engine where the thermostat doesn't open very much at idle (because the engine is not producing a lot of power and hence doesn't produce a large heat load. In addition, the circulating pump doesn't move a lot of water at idle. So it's at least plausible that you might not get perfect mixing and then have possibly some areas in the engine that are 30:70 or less....
If you look at the chart above for Propylene glycol, a 30:70 mix will "slush" at only 7*F and 30% ethylene at 2*F
If you live someplace that sees temps well below zero....like say, -20F, both the propylene and ethylene glycols will be frozen at the 40% level.
You might
be at 40% (or less!

)if you started with a block full of clear water and THEN used a 50:50 mix to circulate.......
The answer? with a RAW water cooled engine,
If you insist on using anti-freeze to "winterize" your block and manifolds, drain them FIRST!Cheers,
Rick