Mercruiser BB Thermostat Housing conversion?

[Danny_Ocean]

Mercruiser 330/454, raw-water cooled (standard cooling).<br /><br />I'm converting from log-style manifolds to center rise. Now that I'll only be using two hoses per manifold/riser, my existing thermostat housing has four extra water outlets. Can I block-off the unused outlets or must I upgrade to the new-style thermostat housing?<br /><br />Thanks in advance,<br /><br />D. Ocean<br />Pompano Beach, FLA

 

[yoced]

Re: Mercruiser BB Thermostat Housing conversion?

Danny, I may be coming late to a conversation, but I am a little confused - how is it that you are running two hoses to each side but have four leftover ports on your thermostat housing?

 

[Danny_Ocean]

Re: Mercruiser BB Thermostat Housing conversion?

The old-style (log manifold) thermostat housings have six outlets. Four built-in to the body of the housing and two on the "cap" that covers the thermostat. In order to mimic the new-style housing, I will be unplugging the 3/4" pipe-thread hole on the top/front of the housing and inserting the brass "T" from the new-style housing. That will give me a total of eight outlets. According to the diagrams in my manuals, when using center-rise manifolds, the hoses from the brass "T" go to the risers and the hoses from the thermostat "cap" go to the bottom of the manifolds. So, I'm left with the four outlets on the body of the housing to deal with. Not sure if they can be capped-off or must they be "looped".<br /><br />D. Ocean<br />Pompano Beach, FLA