Finally warming it up after 28 years of 100 degrees

[bigoledave]

Here I am again.....now it has been 31 years(!) running raw water with no thermostat.....
.........but here I am again needing a whole new exhaust standpipe!

The last time it corroded and failed was 2012.....THIS time the elbow
area just below the steel standpipe is swiss cheese black crappola.

Now I see this Tartan ten SS Moyer standpipe....and it arrives today. It will
take some fiddling but I think it will fit my Columbia 29 Mark I 1965.

I finally gave in and bought the Indigo bronze raw water thermostat 140 degree
"kit" and will FINALLY run this beast a little warm......

(All below is from my original post of 2017...)

Crazy I know...but my A4 early model, mounted in my Columbia 29 1965,
has always been running with NO thermostat and NO manual valves since 1989 when I bought the boat. I have cruised this boat from Seattle up to Desolation Sound.. and all over the place with little cooling " issues".
I can reach through a 4 inch hole in the cockpit and touch the vertical
standpipe water muffler i built...and warm my fingers but never burn them.
My temp gauge, nice one..never gets off the needle. The engine runs great.

But now, seeing my plugs after a five hour motor trip being pretty black.. I may finally give in and and am ready to run it at 140 or so.

So.....after reading waaaay too much on the subject I see three alternatives:

1) Go cheap..go simple....install a stainless 90 degree ball valve in the
cockpit to divert water and control the temp to whatever i want.
Install some manual "stops " so I can repeatedly position it for the temp
I want.

2) Go "old school" original. Buy the original design thermostat housing sold
by moyer which mounts on the top of the manifold..then buy an 85 dollar
Dole and a bunch of misc. fittings.

3) Pay Indigo $150 for their SS thermostat housing and mount it on a
bulkhead. Then I guess I still need a pricey thermostat..

I am a nut for absolute simplicity on a boat and am also a cheapskate.
So..number one looks intriguing but maybe it is a bit silly. Comments appreciated. Cheers!

[Dave Neptune]

Dave, I'd take a look at a few other things before blaming engine temps. First I would check the timing and if all is well there take a look at the carb and fuel mixture.

I ran for over 30 years without a t'stat at around 125 and never saw a sooty or even a "dark colored" spark plug. Mine were always tan to grey and lasted for at least 3 seasons. And I run/ran the stock Champion plugs at .040 with an electronic ignition so I would pretty much never need to mess with the ignition side of things.

Dave Neptune

[bigoledave]

Thanks for the reply Dave,

I have rebuild my old Zenith card about 20 x and I think the fuel/air mix is ok..

BUT!!..I just read this below from the moyer catalog.......and on my last cruise one cyl dropped off once in a while..weirdly, it then it ran BETTER on 3 than on four..


"....Normal back pressure for the Atomic 4 is only 1 to 1 1/2 psi. Even subtle increases over 2 psi tend to result in symptoms starting with sooty spark plugs, and as back pressure builds through 5 psi, symptoms incrementally worsen until intake valve stems coat over with a very think caramelized goo (which will eventually cause them to stick). Rather abrupt increases in exhaust back pressure over 5 psi will usually result in one cylinder dropping out, since the reduced flow of exhaust gas is only able to support a "three-cylinder Atomic 4". You can easily test for this condition by removing any one spark plug lead. If the engine seems to run smoother with one plug wire removed, you definitely have seriously elevated exhaust back pressure...."

I have a gauge and and am going to do some drill-tap-measure stuff next weekend..should be interesting

thx again...

dave

[Marian Claire]

You may have read my rants/comments on how I feel about the re-circulation loop. If that is what you are thinking about in your #1 idea I am all for it. From what I understand this is the original set up. The Dole T-stat came after this. Very simple as long as you can access the valve.
The sudden change in your plugs gives credence to what Dave is saying.
Dan S/V Marian Claire

[bigoledave]

YEP....K.I.S.S.

I am leaning heavily towards doing a nice cosmetic install of a 90 degree ss ball
valve mounted on the backside of the cockpit front wall. Then install a "nice looking" handle/knob that protrudes next to my wide sweep Stewart Warner gauge. If it is a disaster...then plan b and c are still possibilities..

Thx for the feedback,

dave

[Dave Neptune]

dave, how old is the exhaust? The reason I ask is it can also cause a rich (dark~sooty) plug color. However the exhaust beginning to plug up is usually associated with a drop in performance too.

Dave Neptune

[bigoledave]

dave..

it is a welded steel diy design re-built 4 years ago....yes, i have had severe performance issues with it clogging up years ago with steel/rust chips . i then
cut it open, cleaned it all out and welded it up...

now, the engine is running very well so i am not sure there is an issue...but i am
going to measure the back pressure and go from there...i am also getting some hotter ngk plugs.. btw ..compression is 105-90-90-85 front to back..

thx again

[Al Schober]

I'm also in the 'no thermostat' school. What plugs are you running now? I'm running RJ12s with no thermostat, and they're fine. Have you tried the adjustable main jet in the carb?

[bigoledave]

Thanks Al,

Yes, I have fiddled with the main jet...nothing scientific..but i think it is
adjusted ok..maybe too rich??

i do notice this..the front plug looks pretty good...the others are definitely
dry blackish on the perimeter of the plug..and the electrode area is more brownish than tan.

all the chatter about getting sticky valves and fouled plugs if you run cold make me think i need to get it running in the 140 range..

dave

[capnward]

I have FWC, and am happy with my Indigo thermostat. I got a bronze one; now your choice is aluminum, for FWC, or SS for RWC. I'm pretty sure you can use the stainless one for FWC if you want. I like being able to mount it away from the engine a bit; mine is mounted right on the Moyer heat exchanger. I might not do that with an aluminum one. Most are mounted on a fitting on the exhaust manifold. They cost $130 for aluminum and $150 for stainless, including the thermostat. If you want a different thermostat for different (160 or 180) operating temperatures, you can get one from NAPA for maybe $10. Not very pricey. A ball valve in the cockpit might be fun but is really not necessary; just use a thermostat, that is what they're made for.
Many people prefer to run coolly, and do so with no ill effects, because these engines are such anvils. I ran for years with no t-stat; the guys who rebuilt the engine in 2001 left it out and recommended I not use one, but I have read on this forum many times that 160 for RWC or 180 for FWC is optimum for these engines. With no t-stat I could barely make it to 140. I also ran for a while with a re-circulation loop and manual valves, but I had to watch it closely and tinker with it. It took too long to get up to temperature, and then not as high as I would like. With the Indigo I just forget it's there. That's my idea of simplicity.
20 years ago I met the man who owned my boat from 1952 to 1977, whose dad's company built 9 boats like this, and around 2000 boats total from WWI to the 50's. (All made out of wood, of course. Fiberglass mass production put them out of business.) Norman C. Blanchard, a great guy. He warned me that engines like the A-4 like to get warm, to cook the condensation out of them. Since we have sailboats, and often only use the engines to get in and out of the marina, we don't get them hot enough, for long enough. A thermostat that gets the temperature up quickly is better for the engine, in my opinion. I ran for 5 hours yesterday at 170, at 5.5 knots, on what I think is a 160 thermostat. Could have gone faster and warmer. The little A4 ran like my mother's sewing machine. It was Mother's Day, after all.
Your sooty plugs could be there for a different reason than low temperature, like running too rich. The adjustable main jet turned out too far can do that. (1 + 1/2 turns from the seat is about right.) So can having the distributor turned too far counter-clockwise. Too much back pressure caused by exhaust restrictions can also soot up the plugs. If you are adding Marvel oil to the gas, 2 oz. per 5 gal, your valves will not stick anyway. IMHO.

[tenders]

I'm a no-thermostatter too and your initial post made me recoil in horror. What fever has beset you to decide to fix what ain't broke and that seems to have served you well for all this time? Surely something else on your boat warrants more attention than this.

[capnward]

Tenders is right. Life is too short. Don't worry about running it too cool, just run it. They like to run.

[bigoledave]

Thanks to all who posted....

i am concurring with the "if it ain't broke don't fix it" thoughts....

Yep...3 out of four plugs are a little dry-sooty on the perimeter of the plug.

YEP..Engine runs great most of the time

Yes..I could fiddle more with my main adjustable jet

Yes..I have not checked the timing in years

Yes..i have no idea if i have any back pressure issue in the exhaust system..but
am planning to measure it. I did have the experience mentioned in the Moyer
exhaust catalog of having the engine recently start missing...and then when i pulled off the #1 plug wire while it was running for it to run SMOOTHER for a bit. crazy...

SOOO...WHY CHANGE MY COOLING SYSTEM WHEN IT HAS NOT CAUSED ANY SERIOUS PROBLEMS (that i know of) IN THE 28 YEARS I HAVE HAD IT!

thx again everybody..
dave

[JOHN COOKSON]

A bit of reserve cooling capacity is a good thing IMO.
If it has been awhile since the last one try an acid flush. The hotter running running may be due to crud in the cooling system.
An acid flush is a maintenance procedure for a RWC engine.

TRUE GRIT

[Dave Neptune]

Dave, the plug color is the color on the ceramic around the electrode not the plug body. It is normal for the trans end to look richer and this is mostly caused at idle as the manifold is not level and usually tilted so the heavier fuel at lower velocities such as idle tend to "drop" to the lower end.

The heat of the engine or the operating temp have nothing to do with plug color. Plug color is determined by your air/fuel mix. Plug fouling is not caused by engine temp!

Do you have the adjustable main jet? The idle mix adjusting screw only controls the idle and nothing else. Also note it adjusts the air and not the fuel so out is leaner and in is richer.

Dave Neptune