1988 Bayliner 5.7 OMC engine thermostat?

[34 ford]

Hi,
I have a 1988 Bayliner 5.7 OMC engine. It has a Holley aluminum intake manifold.
I took it apart to check the thermostat. But there was no thermostat.
The original OMC thermostat will not fit in to the intake it would bottom out, and
the thermostat housing will not mate to it.
My question is if I put an automotive stat in, which will fit. Do I have to put water in the block, because
it was drained last fall. Or will the water circulate enought, until the stat opens?
Or should I run with out a stat?
Thanks for the help.

 

[Kainon]

Re: 1988 Bayliner 5.7 OMC engine thermostat?

The OMC housing should bolt up, GM Standard.

So with a Marine Thermostat, there's other ports that come off and go to the Exhaust manifold, and the auto style doesnt so that's a concern.

There are Thermostat Spacers out there, like an Older Mercruiser one if memory serves, maybe even an aftermarket AUTO one too..
http://www.michiganmotorz.com/thermostat-housing-spacer-p-1116.html (quick google search)

an auto thermostat is typically a 195F, you can get 180F(for hot rods) but what you want is a 160F ( on the bottom the OMC will be stamped 160F should be.. )

If the OMC one doesnt fit, try a Mercruiser one.. ther are more like a standard auto one.

Running without the stat isnt a good idea, but yea you can to test, but without it proper running temp wont be maintained.

If you DONT run water through the engine when starting it, you will destroy the RAW Water Pump (regardless of the one you have and even for 10 secs maybe less) and possibly the engine depending on how long you run it..