| Author |
Message |
    
William J. Foster
New member
Username: bill_foster
Post Number: 3
Registered: 01-2008
| | Posted on Friday, August 26, 2016 - 01:08 pm: | 
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I see with the pw27 that I am trying to bring back to life has the raw water cooling loop through the cylinder jacket, which I intend to pump coolant through and use a closed loop keel cooling system for.
The concern I do have, and please correct me if I am wrong here, but the engine has a standard impeller pump coupled to engine rpm that pumps water through the jacket. There is no thermostat and bypass, so how does one ensure the engine is being a) cooled sufficiently and b) is not being cooled too much?
Was it just accepted at the time with this type of engine that it might be over or under cooled and the consequences were acceptable?
Has anyone installed a thermostat with bypass to and promote longer engine life and running at a regulated temperature?
Bill |
Howard Argales Sinclair Jr.
Member
Username: vahowdy
Post Number: 12
Registered: 01-2015
| | Posted on Friday, August 26, 2016 - 07:33 pm: |
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My PW27 runs just fine the way it was enginered. Why try to change things when it works so well the way the factory made it. KISS. Keep it simple and it will run. What you need to do is be sure the jug is not full of sediment and that the head has good flow. The only part I can not touch when running is the exhaust just before the water is injected. Put in a new impeller and seal.
The temp. regulates itself. The faster it runs the more water it uses. |
William J. Foster
Member
Username: bill_foster
Post Number: 4
Registered: 01-2008
| | Posted on Friday, September 02, 2016 - 10:23 am: |
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Howard,
So I finally have the engine running thanks to Ernie's help re: magneto drive coupling.
I flushed out the jacket and now have fresh water pumping through. Some rust came out but it seems to have excellent water flow through, quite a steady stream at idle and a vigorous stream throttled up.
It seems to be pumping clean now, still a little off color as the jacket has had green coolant in it for decades. No known leaks or cracks in the block thus far.
I�m still trying to get the carburetor tuned out properly.
Have you run the pw27 on a pair of wood runners on a shop floor before? If you throttle up is the engine pretty lively walking across the shop? Mine is and I figure its normal for a single cylinder but I just want to be sure.
Also, I�ve been noticing a little rattle or grinding sound out of the back of the engine. It�s not the reversing gear (I think) as that has its own whine if the brake band for reverse is gripping. It�s more of a loose washer under a bolt sort of sound, intermittent every 2-3 seconds at idle and seems to be coming from the back right side of the block around where the water pump is mounted. Any thoughts on this? I�m not sure if the gear has a damper plate or if maybe I have a loose valve guide. I can't reason why I hear this sound only after throttling up and settling back to an idle and why its every 2-3 seconds given the rpm of about 400 at idle.
Bill |
Howard Argales Sinclair Jr.
Member
Username: vahowdy
Post Number: 13
Registered: 01-2015
| | Posted on Friday, September 02, 2016 - 06:55 pm: |
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My carb will flood from time to time. I think the fuel pump is pumping past the float valve. That said, I was surprised to see how far I had to open my carb needle valves. 4 or 5 turns.
I don't have a clue about the sound. Get a mechanic's stethoscope and hunt around. Things are much easer to fix, if it doesn't break.
Howdy |
William J. Foster
Member
Username: bill_foster
Post Number: 5
Registered: 01-2008
| | Posted on Monday, September 05, 2016 - 08:41 am: |
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Howard,
The engine seems to be running reasonably well now with some carburetor tuning done and a good idle. I have finally been able to run it up in the rpm range and as I'm sure you know, she's a noisy one. I wanted to ask you, if you have any issue with engine backfire when throttling down from higher rpm? I think its pretty acceptable in this instance when you start to close the throttle and the engine is momentarily running rich with excess fuel/air ending up in the exhaust system, some more puffs and smoke in the exhaust system at this time?
Also, given the age of the engine I was wondering what if any additives people are using in the fuel system? I am using regular low octane fuel with some startron additives for fuel storage... the usual stuff.
Bill |
Howard Argales Sinclair Jr.
Member
Username: vahowdy
Post Number: 14
Registered: 01-2015
| | Posted on Monday, September 05, 2016 - 03:00 pm: |
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Bill,
I never ran my PW27 out of the boat. It has no muffler but the exhaust is water cooled with about 8 ft of 1.25 hose. It's not that loud pushing the water past a 360 loop and then out. I started to put a homemade muffler on it but the guys at the marina like it so i'll leave it.
I have never heard a back fire. (meaning the gasses are ignighting in the exhaust - not a pre-ignition and spitting out the carb.) My exhaust is cooled down in the first 4 inches of the manifold. I'll try and get some pictures of the PW27 this week when I go down to install the new Gen/Starter.
I am using straight gas/and 10w 40w synthetic oil |
