Cooling concerns........

[HOWARD O]

I am thinking that I shouldn't be running this boat in the cold water at all anymore until I get this squared away. It has had no thermostat since the new exhaust was installed and while I'm sure it's fine in the summer and in Florida, but here the water temp gauge doesn't budge....I have no oil temp gauge.

I have been doing some researching and am still at a loss how to get a thermostat to work in this boat, mostly because I am ignorant on what to do. Here are some photos of the crossover and the lines. Even after I run it fairly hard and shut it down, the temp gauge doesn't come up anywhere past 100*. Only part that is barely warm are the top of the risers and the valve covers.

This doesn't have to turn into another 7 pager :) , but looking for suggestions on how to warm up this motor! I know enough that continually running a cold engine is bad, very bad. :yes:

[MOP]

The Tstat goes under the housing in picture #1, if you do mixed salt and fresh running use a 160. Probably take you 1/2 hour to put one in.

Phil

[HOWARD O]

I know where the thermostat is supposed to go and Cuda went throught that already, however he ran into some issues of getting enough water flowing through the block. Engine was overheating immediately. You were actually helping him out in this thread, perhaps it might jog your memory.

http://www.donzi.net/forums/showthread.php?t=47346&page=6

If it were as simple as just dropping a new thermostat in there, I'm game......but a little birdy is telling me it ain't going to be that simple!

[gold-n-rod]

I've wonder all along if cold operating temps were affecting your performance, i.e., bogging and running rich. Maybe the 2 are related. :confused:

[MOP]

I have a different type Tstat housing out in the garage that I need to look at, there needs to be a bypass for some flow until the Tstat opens. I ran it on my engine with no issues.

Phil

[HOWARD O]

I've wonder all along if cold operating temps were affecting your performance, i.e., bogging and running rich. Maybe the 2 are related. :confused:

I was originally thinking that but now that it's improving with the fatter jets and good gas, not so sure now. Before I launched the boat, the temp would come up some on the hose. After launching, I thought something may have happened to the gauge, it didn't move. So I did the simple test of grounding out the sending unit and the gauge swept all the way up.....working fine. That's when I put 2 and 2 together and realized it either didn't have a t-stat or that it was stuck open. Water is cold, well below 50* I'm sure.

With no t-stat in there, the temp isn't going up no matter what I do in this water. I am surprised that the well water (my hose), is that much warmer than my river though.

I love this stuff! My old Donzi, now my brother's, doesn't have a t-stat either.....but he is in SoCal and generally runs in somewhat warmer water. :kingme:

[HOWARD O]

I have a different type Tstat housing out in the garage that I need to look at, there needs to be a bypass for some flow until the Tstat opens. I ran it on my engine with no issues.

Phil

Well, that's right, the manifold needs water constantly and it wouldn't get it with the current setup and the t-stat installed. There is a plug in there, but it's after the fact and apparently for a temp sender. Did I read correct that there can be holes in the thermostat to let some water through at all times? Or am I confused?

http://www.donzi.net/forums/attachment.php?attachmentid=26731&d=1169398007

[DonziJon]

I would NOT run the engine below 140*. That would be the very minimum in salt water. In fresh water you have a lot more leeway...160-185*. Running 160-185 or higher in salt will cause salt buildup in the engine. NOT Good at all. You don't mention trying a thermostat after the new headers. Put one in and try it. If it doesn't do the job..one way or the other, take it out and put it in a pan of water on the stove with a cooking (candy) thermometer and see when it opens.. Running the engine COLD is not good..short of an idle. John

[DonziJon]

Well, that's right, the manifold needs water constantly and it wouldn't get it with the current setup and the t-stat installed. There is a plug in there, but it's after the fact and apparently for a temp sender. Did I read correct that there can be holes in the thermostat to let some water through at all times? Or am I confused?
http://www.donzi.net/forums/attachment.php?attachmentid=26731&d=1169398007

You are correct. There IS a bypass right next to the thermostat. John

[BlownCrewCab]

Yes....If you get a non bypass crossover from stainless marine the T-stat has 3-3/16 holes drilled in it, so t allways flows water to the exhaust, even when closed. I think I have one out in my tool box, I'll see if I can find it and get a pic.

[HOWARD O]

Yes....If you get a non bypass crossover from stainless marine the T-stat has 3-3/16 holes drilled in it, so t allways flows water to the exhaust, even when closed. I think I have one out in my tool box, I'll see if I can find it and get a pic.

I'll remove that housing in the morning, see what gives. If it IS a bypass crossover, then simply installing a good thermostat "should" work. If not, go with the "bypass" type thermostat or go this route below?


http://www.donzi.net/forums/attachment.php?attachmentid=26448&d=1168134588

[HOWARD O]

I would NOT run the engine below 140*. That would be the very minimum in salt water. In fresh water you have a lot more leeway...160-185*. Running 160-185 or higher in salt will cause salt buildup in the engine. NOT Good at all. You don't mention trying a thermostat after the new headers. Put one in and try it. If it doesn't do the job..one way or the other, take it out and put it in a pan of water on the stove with a cooking (candy) thermometer and see when it opens.. Running the engine COLD is not good..short of an idle. John

I figured as much. I maybe know enough to keep myself out of mechanical AND the following financial ruin, but maybe not quite enough to fix the situation! Not too proud to ask for advice and help either, obviously! Thanks John. :yes:

I am in freshwater, well for most parts of the year, but boat will be seeing saltwater. Good part is that I always come back home to freshwater for a good flushing!

[gcarter]

I don't remember what drive you have, would you mind reminding us?

[HOWARD O]

I don't remember what drive you have, would you mind reminding us?

George, it's Cuda Joe's old 22, TRS 454/330.

[VetteLT193]

Stainless Marine told my brother to put in a T-Stat with 3 holes drilled in it.

Hopefully my brother chimes in with the size to drill. (3/16 comes to mind) ***edit, just read above at blown's post, so it is 3/16ths! ***

The idea is to let the air out through the holes in the t-stat when the water enters the block, this lets water into the engine, then when it warms up the stat opens and life runs as normal. Without the holes the air can't escape so the water never goes into the block, it just gets bypassed to the exhaust. This makes the engine almost instantly overheat.

[HOWARD O]

Stainless Marine told my brother to put in a T-Stat with 3 holes drilled in it.

Hopefully my brother chimes in with the size to drill. (3/16 comes to mind) ***edit, just read above at blown's post, so it is 3/16ths! ***

The idea is to let the air out through the holes in the t-stat when the water enters the block, this lets water into the engine, then when it warms up the stat opens and life runs as normal. Without the holes the air can't escape so the water never goes into the block, it just gets bypassed to the exhaust. This makes the engine almost instantly overheat.

Thanks Vette, that was extremely helpful! I have a direction now....much appreciated! :yes:

[HOWARD O]

I am going to try the drilled thermostat tomorrow, however not only is there a brass plug in the intake next to the t-stat housing, there is also one facing forward directly UNDER the thermostat housing......I have arrows pointing to each in the attached photo.

I have a concern with the drilled thermostat only. That it won't flow enough water and it might be excessive water pressure. If so, I am thinking I can utilize these 2 plugged holes and run hoses to from either one and tee it to the exhaust or use both of them and run one to each. I think this is easily doable and if that's too much flow that the motor never gets to 160, then I can constrict that flow somehow. Sound good? :confused:

[VetteLT193]

I am going to try the drilled thermostat tomorrow, however not only is there a brass plug in the intake next to the t-stat housing, there is also one facing forward directly UNDER the thermostat housing......I have arrows pointing to each in the attached photo.
I have a concern with the drilled thermostat only. That it won't flow enough water and it might be excessive water pressure. If so, I am thinking I can utilize these 2 plugged holes and run hoses to from either one and tee it to the exhaust or use both of them and run one to each. I think this is easily doable and if that's too much flow that the motor never gets to 160, then I can constrict that flow somehow. Sound good? :confused:

I might have missed the answer on this but I don't see it... do you have the hose that runs between the lower part and upper T-Stat housing?

Assuming you do you will be fine with the holes drilled out.

[HOWARD O]

I might have missed the answer on this but I don't see it... do you have the hose that runs between the lower part and upper T-Stat housing?
Assuming you do you will be fine with the holes drilled out.

You just lost me......and I'm sure it's me, not you. Can you be more specific?

Nevermind......are you referring to the plugged hole on the side of the t-stat housing itself? I do NOT have that hose...........maybe I'm just a wee bit confused on how this all works!

[VetteLT193]

http://www.donzi.net/forums/attachment.php?attachmentid=31858&d=1190818239

I tried to find a pic of my engine since I just got the new hoses routed but couldn't. the one above is my brother's old engine.

There are 2 kinds of crossovers. ones that are designed to be use with T-Stats and ones that are not. My brother's is designed for use with a T-Stat. it has the hose that connects the lower X-over and the T-stat housing. it's mostly blue in this pic, and only a few inches long running vertically.

With the holes drilled in the t-stat the water flows into the block first, the air purges out the 3 holes in the t-stat. it goes into the block first because the hose between the X-over and the stat housing is smaller than the block, so the water takes the path of least resistance. once the block fills up the stat is closed because it's cold. the holes in the stat are so small that the water routes through the line between the X-over and the T-stat housing then straight out to the exhaust.

When the T-Stat opens, water flows into the block again because it's easy for it to travel there.

If you don't have that hose between the X-over and the stat housing you might want to re-think things.

[HOWARD O]

ahhh, a picture is worth a thousand words, thanks. I'll study on that a bit.... :yes:

[VetteLT193]

The kind of X-over that does not work with a T-stat is this kind:

http://www.stainlessmarine.com/images/fs882790632.jpg

the water in this scenario must always be flowing through the block because that is the only route it can take.

I have heard of some guys putting in a restrictor plate instead of a T-stat to just slow the flow down. no idea what that will do in your area though, if you have this kind of setup.

[HOWARD O]

Yep, I see how that works now.....but I don't believe my lower x-over has provides for a hose to be attached to the upper x-over. For that matter, the plugged hole on my t-stat housing I believe is probably for a sending unit anyway. The setup on the engine in your photo is very clean and simple.

I have looked at stainless marine and think I'll just get one of their "kits" and be done with it. I think this is the cleanest way to go.

Thanks for that photo Vette, sure helped! :kingme:

[HOWARD O]

The kind of X-over that does not work with a T-stat is this kind:
http://www.stainlessmarine.com/images/fs882790632.jpg
the water in this scenario must always be flowing through the block because that is the only route it can take.
I have heard of some guys putting in a restrictor plate instead of a T-stat to just slow the flow down. no idea what that will do in your area though, if you have this kind of setup.

I have read about restrictors on another site this morning. I follow your diagram and see the difference. I agree, it'd be okay w/out a t-stat in warmer waters......but I plan on using the boat year round, so must go t-stat.

[VetteLT193]

slow work day today, did some searching. good news is Cuda documents well with pictures.

http://www.donzi.net/forums/showthread.php?t=47346&highlight=crossover&page=3