Well, I spent yesterday trying to tighten Paragon oil lines on my starboard engine to stop an annoying leak. Had to get creative to get to some of those fittings! I think I just about stopped the leak, so off for a test drive.....Starboard transmission seems fine, yeah! Temperature on the port engine climbs past its normaly rock steady operating temp past the 195 mark....back to the dock I think it's proabaly a t-stat stuck closed. Water is coming out the exhaust...the impeller on the sea water pump is 1 year old with only 30-40 hours on it.
When I changed the circulation pump on the port side a couple months ago, I had the t-stat housing off and I could not get the t-stat out...it seemed to be pressed into the housing. Are there any tricks to get it out, or just get aggressive??? Also I need a source to buy new one. Are they 140 or 160 degrees? Any help would be great.
Did someone say these boats require a little work most of the time and a lot of work some of the time!!!!!!
There are (at least) two other causes for overheating on a CC motor of this vintage, and the common causes are clogged open pressure regulator valves, and slipping drive belts. The slipping belt will probably be noticed with a squeel at least now and then, and the pressure regulator valves are a problem if they are stuck open while the engine is running at low speed, because the cooling water is being short circuted and not pumped through the motor.
A net impeller on a pump with a bad internal cam profile can also pump less water than it should. Now you're motor is pumping water, presumably the same as the other motor, so the water pump issue seems to be mute.
A thermostat can get stuck just as easily as the pressure regulator valves, and I would think a good soaking with something like CLR would loosen things up. Since thermostats rarely actually go bad, yours probably only needs a cleaning with a wire brush and a decalcification. You can put one in a pan of hot water, raise it to a boil, watch to see what happens; if it opens and closes with the change in temp, it's probably still good. As for the temp, I'd think the 160 is the way to go, since 160 is the preferred operating temp for the raw water (no heat exchanger) setup. The heat exchanger models may even have a different t-stat, and if you find out about that, please post the info here for others. (thanks)
Here is a thread showing two prime sources for the 427 thermostat. These may no longer be available new, and may only be available from those wonderful parts recyclers out there, who help us maintain these vintage boats. http://www.network54.com/Forum/424840/message/1191628881/
Here is another photo of a pressure regulator valve, just to show the kind of crud that can collect on one of these all brass devices. Same thing can happen to the t-stat, and since they slide in a housing that is more controlled than this, it's quite possible it could be stuck or clogged somehow with debris. One way to tell, pop it off and take a look! (A lot easier said than done)
Here is a previous thread on "overheating" that may be of some use to you or someone else with overheating issues.
The 427 t stats are a part of the circulating pump housing, and they are set into a seal assembly. The seal assembly is not unlike a main seal on a crankshaft, and it's sort of strange to see how these are used in a water based cooling system. The thermostat pulls directly out, leaving the seal, which is replacable.
If you're careful, you can pull the t-stat out and reuse the seal. If you mess up the seal, then you'll have to get a new one from a hydraulic equipment supplier, power transmission vendor, or bearing and seal sales dealership such as Allied Bearing. I believe the correct number is 16020 as manufactured by SKF. I'll try to verify that one.
The thermostats may be superseded by a new style (as shown above) and I'm in the process of verifying that too. The old number was Rostra Vernatherm Valve # VD111458B (140-degree, better verify).
In the interim, if anyone has any experience obtaining these from parts recyclers, please let us know. Please also help us verify the thermostat temp range, as I believe the t-stats for a closed cooling (heat exchanger) system is 140 and the raw water system is 160.
Thanks Paul for your comments. I will be going to the boat with tools (again!)in the next couple weeks to remove the housing and inspect the t-stat. I may try soaking the whole assembly (housing and circulation pump) in some CLR, then put the assembly in a pot of water and heat it per your suggestion to see if it operates. If it does, I can put the whole thing back without pulling the t-stat from the housing and risk damage to the t-stat or seal. Next will be the PRV's. BTW, I may not have mentioned, but my motors were originaly FWC, they were converted to RWC in 2004 when they were rebuilt.
I called Vernatherm and the valve was part of their waterstat line, which they have discontinued. The lady was very nice, and recommended I call a company in Columbus, Indiana, called CalTherm.
I looked them up, gave them a call. Less than cooperative, asked if I was a customer, said she could only pass me on to a tech guy if I was a customer (and dumb ole me, here I thought I WAS a customer, ha ha). Oh well, to be fair, everyone seemed to be out to lunch or out for the holiday.
Are you sure your problem is the t-stat? I went throught the same issue a couple months ago. These t-stats are very well made and do not often fail. My problem turned out to be the guage which is wierd too. Are you getting water out of the top of the t-stat housing when she warms up? If so, yout t-stat is opening. If not, I would pull it and clean it up in CLR and test it in a pot of water on the stove. Mine looked brand new.....I am also in the DFW area, email me at trey.andrews@yahoo.com if you want.
If you pull them both out, mark the one in the motor that appears to be a problem, put them in a pan and start to boil the water. Watch the good one. If the so-called "bad one" opens the same as the good one, it is for sure NOT a thermostat problem. The raw water motors and the antifreeze coolant motors take a different thermostat, they are NOT the same. I believe the running temp for the raw water version (called the "standard version" by Chris Craft) is a 160-degree device, and the anti-freeze heat exchanger version is hotter.
Paul,
My entire Sunday was spent as a contortionist between the starboard motor and hull side, on top of the battery bank, in the fetal position trying to tighten up a trans hose to stop an irritating leak. The connection to the reverse gear cooler had a slight leak and of course was damn near unaccessible to anyone over 3' tall with double jointed arms but I was able to get a wrench on the swivel nut to get the 1/16" turn then spin the wrench for another 1/16" turn and so on and on. Once the fittings were off I realized the hose was wedged between the motor mount and trans cooler body which made it impossible to pull the hose with the fittings thru the pinch point. Whoever did this should be shot! Several futile attempts to saw thru the high pressure braided hose with a hack saw (blade only due to space limitations) failed and hours later I was able to muscle the hose out of the pinch point. Note to all, when installing ANYTHING please keep in mind it may have to be replaced again so take a little extra time to make things accessible for the next guy!
Now back to the Motrin bottle and back therapy......
Steve
Ohh boy, do I EVER relate to what you just described.
Being the week-end DIY warrior I am, I have gotten myself into one jam after another, and this has gone on for years, with one issue after another. The last similar event was the header pipe on my 740 GLE 16V, which decided to split and fail, and sound like a open exhaust European ice racer, ha ha.
I (finally) found the right header for that low production motor, got it for about half what the dealer was asking, and proceeded to twist off the end of the stud on the cast iron header itself. So then I had to remove the header. I took it sheepishly into my favorite mechanics shop, and they tapped it out and installed a new one, with the special locking buts, all for $57. Ouch. I paid it and said "thank you".
Finally got everything bolted back up, the new header pipe, mated to the catalytic converter, had to literally lay on the motor and then under the motor to get the wrench to do the job, and finally got the car back on the road. Had I taken it to the dealer, they would have charged me the better part of $400 for the part, and probably $200 for the labor. As it turned out, I got the parts for around $160, had to pay the additional $57, learned a couple of new Swedish cuss words, gave a little blood for the cause, and learned what the underside of a Volvo looks like with your face pressed up against a frame.
With boats, memories of pulling the hub off my Dad's 31 last year still make me want to reach for the Motrin, ahhhh, that was a battle. And then there was the time.................
(and so it goes)
Some of us are just blessed with being in the midst of problems that need to be solved
regards,
Paul
PS: Sometimes there is a better solution than Motrin, ha.
Man you guys are complaining about that come on that's nothing. Deb and I left for Kelleys Island Friday night and at a little less than half way there I saw the oil pressure gauge bounce. We found we still had an oil leak on the port motor. I decided to turn around and go back to home port and was determined that this was going to get fixed once and for all. Remembering a post I saw on this forum not too long ago I woke up saturday morning and gave my buddy Bruce a call at Lakeland Auto and Marine in Port Clinton Ohio. Well Bruce was busy and couldn't come to the phone so I told the wife let's take a drive. Arriving at the shop I got a moment to talk to Bruce and asked about the Chris Craft Q motor oil pan seal Bruce's reply oh that custom seal only Chris used. Hmmmmmm ok Bruce get me the whoole shootin match for a 350 Q oil pan. After about 20 minutes he came back he handed me a seal and I tell you that thing was at least 5/16" thicker then a std oil pan seal. Ok after a trip to Wally world to make the wife happy we headed back to the marina. I began the process of assembling the swing set to yank the motor at 1 pm at 9:30 pm that night the motor was back in its cradle in the mounts and waiting for me to wire and hook up coolant lines etc on Sunday. Even the wife pitched in to hand me the cast iron oil pan down on my chest to get it back into position on the bottom of the motor. Ever try lifting a cast iron oil pan with 7 qt capacity into position and starting the bolts all by yourself? And you want motrin? bah grow up and suck it up be a man!
ROFLMAO right now.
Oh and yes I did do this this weekend the notor fired at 2pm Sunday. with a minor transmission line leak which was promptly corrected.
I think it's proabaly a t-stat stuck closed. Water is coming out the exhaust...the impeller on the sea water pump is 1 year old with only 30-40 hours on it.
