Port Side Exhaust Hotter Than Starboard?? |
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Posted: June-29-2008 at 1:38am |
Horkn;
I replaced the thermostat with a 160 degree unit I got from Midwest Correct Craft, and put a new impeller in, and it seems to have solved the problem. Both sides are much more equal in temperature now. While operating the boat on the water, it runs at a constant 160 F as well. Dave |
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horkn
Platinum Member Joined: September-10-2007 Location: Cedarburg, Wi Status: Offline Points: 1511 |
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When my 78 martinique had the same one side hotter than the other problem, it was due to impeller bits stuck in the T stat as well.
I now know it is easier to replace the impellor every 2-3 years than to fish rubber chunks out of coolant passages. |
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78 martinique- refloored, reinforced, stringers re glassed, re engineered interior
GT40P heads Edelbrock Performer intake acme 4 blade http://img.photobucket.com/albums/v64/horkn/fish/nautique.jpg |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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My two bolts have allen wrench holes in them, makes it way easier on the getting them out.
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Tim D
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67ccmustang
Newbie Joined: April-19-2006 Location: Lake James Status: Offline Points: 17 |
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I removed the bottom bolt of the T-stat housing by grinding down a 1/2" wrench short enough to wiggle into the small space behind the timing cover... what a PITA.
The bottom Tee also has a restriction on one side... the smaller opening was oriented toward the circulation pump and the bigger opening toward the RWP. |
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67ccmustang
Newbie Joined: April-19-2006 Location: Lake James Status: Offline Points: 17 |
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THanks Tim.
Is there some trick to take off that thermostat housing? The bottom bolt is really hard to get to behind the water pump. |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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The smaller end goes toward the manifold.
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Tim D
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67ccmustang
Newbie Joined: April-19-2006 Location: Lake James Status: Offline Points: 17 |
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Tim D-
THe setup in your pic looks just like mine (I have a 289 '67 Mustang) I took off the upper tee to replace the hose and now I just realized that one side of the tee has a restriction, but I can't remember if the restriction goes to the exhaust manifold side or the thermostat side. Anyone help? THanks, GLenn N. |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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I was going to suggest the gasket material I got from NAPA one time. Comes in sheets, dark grey and one side has an adhesive. You can cut out intricate shapes with an X-Acto knife.
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Tim D
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Dave, Just to be safe, I would go to the auto supply and get some that is recommended.
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Pete;
Thanks for the advice. I was going to get that area cleaned up with a wire-brush wheel on my drill, and then do as you suggested which was to cut a gasket out of gasket stock. I have some laying around here from a different project. However, I am concerned whether it will be resistant to water. It appears to be a stiff, cardboard-like material. Do you think that material will be okay to use, or should I go buy a special waterproof gasket material? Dave |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Dave, Tim feels I should have stated; diverting lake water "from" and not "to". Ether way, the concept is correct that cool lake water goes to the engine as needed by the operating temp/position of the stat. You can cut gaskets from sheet stock yourself but first I would try to clean up the mating surfaces of the housings. A surface plate,flat steel plate or even a piece of heavy glass with abrasive paper on top will do it. |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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That trap door design is old, my guess original. When I took mine to NAPA, they had never seen one like it. Look on the end, it should have the temp stamped in it. My '66 Mustang had one in it when I bought it. It was rusty too. I didn't like the temp swing I was getting with a new stat, it would go to about 160, then the stat would open and it would drop to about 120. With the weep hole, it stays at 140 all day. Ask for marine, they have it in the great big book on the counter.
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Tim D
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Tim;
Two questions: 1. I noticed the little weep hole on my old t-stat, and then you mentioned it. What does that do for you? By the way, you are correct, mine is the trap door design, and it looked like it wasn't closing all the way. 2. Regarding the temp rating of the t-stat I should get at NAPA, are you saying to ask for a marine grade unit, or ask for one that is ~140 Degree rated? Thanks! Dave |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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Yeah, you need a new t-stat. That looks like the trap door design. The reason for the silicon is you probably can't buy that gasket. When the water in the intake gets hot enough, the back side of the t-stat where the spring is will cause it to open. You can get the marine stat at NAPA. In the pic below, both came from NAPA, the one on the right is the PCM style. I now use the style on the left, I put a 1/8" weep hole near the edge, now I don't have any fluctuation in temp. Both are 142 or 143 degrees, I can't remember which it is.
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Tim D
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Curiosity got the best of me. I went out and pulled that "thing with the four hoses going into it" apart. It was the t-stat housing. Here are some pictures and my theory on what may be going on.
Overview before disassembly. After the top part of the chamber (which is the t-stat housing) is pulled off. It reveals a very dirty, corroded surface that had enough silicone caulk around it to choke a horse. T-stat pulled out. I think I need a new one. Any suggestions on what temperature t-stat to go with? Now my theory...I am pointing at the hole where the raw water is being fed into the upper chamber and to the exhaust manifolds. As the raw water pump is pumping to the left (towards the starboard side), this may explain why there is cooler water coming out on that side. The force is pushing it all that way and very little to the port side. I am still not sure what the t-stat is doing, or if its even working at this point as it relates to letting all the really hot water out the port side. As mentioned before, once I get a new t-stat in, and get on the water, everything may works itself out. |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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That's so wrong "The thing with the 4 hoses on it is where the thermostat is ether diverting lake water to the engine if the T stat is open or just out to the manifolds if closed." Water comes out of the engine at the t-stat. It enters the engine where the circ pump is.
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Tim D
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Dave, The thing with the 4 hoses on it is where the thermostat is ether diverting lake water to the engine if the T stat is open or just out to the manifolds if closed. Depending on the demand for cooling, the T stat is regulating the amount of fresh water and mixing it.
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Pete....Thanks for the info. If/when I get this thing back together, I will try it on the mighty Fox River and see what happens.
By the way, what is that chamber-like device with the four hoses going into it? Do you suppose water even mixes together in there. The top and bottom may be seperate. I will have to open it up to see what is happening in there. It looks like the raw water flows from the right side, and then down into the engine on the left side. The upper part of the chamber may then receive the heated water from the t-stat, and then divert to the manifolds.....and that may be why I am seeing such a hot and cold difference. Maybe the t-stat is, or isn't opening by only running it in the driveway on the water hose. Just theory, but try to understand why its doing this. |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Dave, The T stat will be on the intake manifold. Change it out but it may not be a problem. In fact, just as the mechanic mentioned, you may not have a problem at all! Check the temp gauge and get it out on the water. Removing the wire on the temp sender and by grounding it on the block it will remove the variable resistance of the sender. The temp gauge should peg max to the right.
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Forgot to mention that while running the boat in the driveway, the temp guage needle stayed buried over to the left at ~100 F. Not sure if that was the real temperature, or if it just never got hot enough to move it. Thought that might be worth mentioning.
Dave |
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Tim;
I just took a picture of the front of the engine to show how the plumbing is set up. The raw water pump is the pulley on the right. It then flows up into a chamber you see in the top center that has the four hoses going into it. Not sure if that chamber holds the t-stat or not. It may actually be in a smaller chamber on the intake manifold. Anyway, thats what the set up looks like. I am thinking that once I get it on the water and really run it the t-stat and everything may come to life and work properly. |
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Tim D
Grand Poobah Joined: August-23-2004 Location: United States Status: Offline Points: 2641 |
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How is the plumbing set up from the RWP to feed constant flow through the manifolds? If the flow crosses the t-stat housing, it is going to push most of the water to that side when the t-stat opens. Look at the pic below of my engine. Number 1 is a T that supplies constant flow to the exhaust. When the t-stat opens, most of the hot water is going to flow to the left.
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Tim D
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Pete;
The original manifolds had an issue. The Port side manifold broke internally and flooded my engine. I just found a pair of PCM's at Midwest Correct Craft (used) and put those on. The volume of water seems equal. I was thinking that it may be a faulty thermostat, or water pump. I can't imagine the port side exhaust gas would be that much hotter. It really seems like somehow hot water is being diverted to one side, and cold/warm water is being diverted to the other side. Oh well, just one more puzzle to figure out. |
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41045 |
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Dave, Weren't you looking for manifolds at one time? I can't remember why! Were you having a problem? When you ran the boat on the hose, could you see any difference in the volume of water from port to starboard? Have you ever broken a pump impeller and couldn't find all the parts?
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davidg
Grand Poobah Joined: January-07-2008 Location: NW Chicagoland Status: Offline Points: 2239 |
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Guys;
I fired the '76 Southwind up the other day in the driveway with the water hose attached to the inlet at the trans cooler. After running it for a few minutes, I noticed that the port side exhaust manifold, and discharge water were quite a bit hotter (very hot) than the starboard side (mildly warm). I talked to one mechanic and he said to just watch it and see what happens when I get it on the lake with more water volume coming through it. Any ideas why this may be occuring? Could it be a bad or stuck thermostat diverting hotter water out one side vs. the other?? Thanks! Dave |
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