Marine Power 6.0 cooling MOD

[kbunch]

We have been posting about the modification developed by Dom Forte and his team for most of this summer. I also modified my engine and thought it may be helpful to post my efforts to assist the next victims.

The thermostat housing is located on the port side, front of the engine under the cooling housing. It is difficult to see and work with as you can't actually see it.

This is a picture of the housing...

[kbunch]

Picture 2 is the thermostats used. The one on the left is the O.E.M stat and the right is a 5.7 LT1 160* thermostat I purchased from SKIDIM.com.

[kbunch]

This picture is of thermostat housing. Note the second hole (return feed) in the housing. The Mod is designed to block the 1 1/4 inch return feed in the back of the housing thereby reducing the volume of engine heated water diluting the coolant from the heat exchanger. You can see the hole to be blocked in the housing in the picture

[kbunch]

You will have to remove the "o-ring" seal on the O.E.M thermostat and put it on the replacement one. the seal is "split" and fits around the thermostat. When you have it apart this will make sense

[kbunch]

These are the parts you will need to complete the mod, blocking the flow. I bought these at the local hardware store. you will have to tweak the parts a bit as you are super limited on space to install. I bought the washer at Lowe's in a bin marked "fender washer" it has to be about 1 1/2 diameter, the toggle bolt was a 3/16x3 and I bought a 1 inch (I think) long Alan 10-24 to replace the 3" long bolt that came in the toggle pack. you will have to trim the ends of the toggle "butterfly" to make it fit in the small space

[kbunch]

And after about 4 attempts this is the completed modification in place

[kbunch]

Post modification I really do not see the reduction in temperature on the gauge on the dash however I am now about 30 hours post modification and have not had a single vapor-lock failure to start. Prior to the mod our engine would vapor lock anytime we were shut down more than 1 1/2 hours, without fail. It is really nice to decide to go, and have the ability. If you have questions feel free to contact me.....

[evil0ne]

Great pictures, we did it blind and this would have helped. Good luck everyone.

[SummerObsession]

My only question is: Can you not buy a new thermostat housing without the "return feed" built in to the housing and use the stock thermostat?

[kko]

My only question is: Can you not buy a new thermostat housing without the "return feed" built in to the housing and use the stock thermostat?

That housing is part of the water pump. If you have this problem why not just use the mod. we came up with? It works 100% of the time and lasts. Dom the mastermind behind this fix has over 1000hrs on his boat with this mod installed with 0 problems. Its quick,easy,cheap and 100% effective why go any further. I think they have a new water pump out I have not seen it yet but I would not even consider it do to the cost involved and with this mod working so well.

[SummerObsession]

OK, I was wondering, that explains it. I haven't looked at mine to see how it is made.

[jjrtar0325]

These are the parts you will need to complete the mod, blocking the flow. I bought these at the local hardware store. you will have to tweak the parts a bit as you are super limited on space to install. I bought the washer at Lowe's in a bin marked "fender washer" it has to be about 1 1/2 diameter, the toggle bolt was a 3/16x3 and I bought a 1 inch (I think) long Alan 10-24 to replace the 3" long bolt that came in the toggle pack. you will have to trim the ends of the toggle "butterfly" to make it fit in the small space

Hey everyone, can you please tell me what the screw, washer and toggle bolt are for in the second to last pic? Trying to do the mod on a 2005 24V and looking for a little more information. Thanks!

[Chuck Jr]

I've had the same issues with my 6.0. This is a great fix. Simple question though: Why can't I simply replace with the correct 160* thermostat for a 6.0? Why the custom application? Do they not offer a 160* thermostat for a 6.0?

[dom w. forte]

I've had the same issues with my 6.0. This is a great fix. Simple question though: Why can't I simply replace with the correct 160* thermostat for a 6.0? Why the custom application? Do they not offer a 160* thermostat for a 6.0?

You can get a 160 for the 6.0l but it wont correct the cooling issue, the hole that is being blocked is putting to much warm coolant back into the block and that makes the engine get hotter and hotter gradually!

[Todd Yost]

I'm trying my hardest to do this mod, but my t-stat is not the same as the oem one in the above pic, I did order the one specified above from skidim and now it is not fitting with my housing....I'm wondering if you can do the mod and then install the oem t-stat? Either way I might have to order a new housing b/c one of the flanges on mine broke when I was trying to take the t-stat out :-(