I don't think it would be a very good idea.
kinda new to this Boat engine thing..since I'm building a new motor for a JET boat and things seem to run so cold is it a bad Idea to fill the block??
I don't think it would be a very good idea.
If your water temp is too low, then why not plumb your cooling system so as to have the ability to increase water temp, such as a gate valve at least? My boat runs at 165*-185*, depending on rpm. That's fine by me.
Filling the block has its place(s); if you're talking about filling to the bottom of the waterpump holes on your iron block, you can bet that you'll be asking your motor oil to handle more of the cooling responsibility and that oil temp will rise as a result.
If your water temp is too low, then increase your water temp.
LO
I agree, I would not fill the block to increase water temp. Actually I'd worry more about oil temp instead of water temp, as long as the oil temp is 180-210 I wouldn't worry about the water temp!..
Thanks for all the info.....