steam in exhaust

[goodoldboat]

I am operating a raw water cooled engine without a T stat .. the PO says he removed several seasons ago at the suggestions of a mechanic .

How much steam is too much ? OR is any steam too much ?

I appear to be running at about 180 * and this is my 1st season with the boat so I do not have any prior history .

I did have hot section exhaust system failure on the way to the mooring
on the maiden voyage earlier in the season ,and replaced in its entirety .
I am getting cooling water but again this is my 1st season .

also the engine seems to working harder , i think the prop is foul .

any thoughts on what to coat the prop with in spring ?

I am going to put a clamp on the bypass valve tomorrow after work and clean the prop .

[Ken Rockwell]

What do you mean by prop is foul?

[Hymodyne]

I've used surfboard wax, melted to cover the prop with good success.

James

[goodoldboat]

steam in exhaust

I am operating a raw water cooled engine without a T stat .. the PO says he removed several seasons ago at the suggestions of a mechanic .

How much steam is too much ? OR is any steam too much ?

I appear to be running at about 180 * and this is my 1st season with the boat so I do not have any prior history .

I did have hot section exhaust system failure on the way to the mooring
on the maiden voyage earlier in the season ,and replaced in its entirety .
I am getting cooling water but again this is my 1st season .

also the engine seems to working harder , i think the prop is foul .

any thoughts on what to coat the prop with in spring ?

I am going to put a clamp on the bypass valve tomorrow after work and clean the prop .

[goodoldboat]

steam

the prop is covered with barnacles and sea grass .

Does the surf board wax last all season ?

[Wisakedjack]

My friend and I had good results using Zync based paint. You can get one that Pettit makes, but we use regular paint from Home Depot. Our boats are moored in New Jersey. I've heard good things about using surfboard wax. If I remember correctly its advantage is that it can be applied even under water. But I've never tried it myself. May be I'll give it a try next season. I also tried using lanolin that was applied hot, but I don't think it worked very well.

[Fstued]

how would surf wax work on the bottom to keep growth off I guess you would have to reapply pretty often so it probably wouldn't work. But if the boat isn't moving it might work for those times when no sailing for a month or 2. My boat is wet all year here in SoCal

[Hymodyne]

the prop is covered with barnacles and sea grass .

Does the surf board wax last all season ?

When I've tried it on a two bladed prop, it worked. I used it the last two seasons I had our cape dory. I'll probably put it on the prop of the Triton too.

James

[sastanley]

GOB, A clean prop should help bring the temps down a little bit since the enine won't be working so hard. I have found the A4 very sensitive to prop growth and try to clean it a few times per season. For RWC with no t-stat, 180 is a little warm...I do believe you are on the right track...let's try a clamp (like needle nose vice grips) on the bypass and see how that goes...Moyer sells a nice permanent kit or you might be able to make one with hardware store parts too if the clamp trick works. This was one of the first modifications I made when my A4 was new to me. You might also have some clogged passages or dead marine critters building up in the water jacket too, but we can address that after your first test.

[sastanley]

GOB, A clean prop should help bring the temps down a little bit since the enine won't be working so hard. I have found the A4 very sensitive to prop growth and try to clean it a few times per season. For RWC with no t-stat, 180 is a little warm...I do believe you are on the right track...let's try a clamp (like needle nose vice grips) on the bypass and see how that goes...Moyer sells a nice permanent kit or you might be able to make one with hardware store parts too. You might also have some clogged passages or dead marine critters building up in the water jacket too, but we can address that after your first test. I feel doing too many things at once doesn't always help diagnose which adjustment fixed the original problem, and I was definitely guilty of that early in ownership, but the group here has shown me the error of my ways and helped steer me along back down the straight and narrow!

[Al Schober]

Gosling,
Raw water with no thermostat, you should be running at 120F or so - 180F is a sign of a problem. Yes, close off the bypass - get all the water running through the block. There are numerous places the cooling system can clog and restrict flow - first to check is the outlet elbow from the manifold (an easy one).
Try disconnecting the components from each other and then blow through them - the one with the clog will become evident (your cheeks will puff out).
Hardest clog to correct is the cooling passages in the block by the valves - requires removing the head for access to chisel them open. Hopefully it won't come to that.
Oh yeah, the prop. A dirty prop won't make you run hot, but it will sure slow down the boat and the engine. A bronze (brass) prop gets decent protection from a zinc, but not from fouling. There used to be some TBT sprays that gave decent fouling protection, but they're no longer available. AFAIK, even the US Navy doesn't have an antifouling answer for their props - they just send divers down with 12" hydraulic powered scrubbies. Personally, I use a plastic prop (CDI) and just paint it.

[goodoldboat]

steam in ehaust

I clamped off the by pass hose and still have steam in the exhaust but only when the throttle is open at 2000 to 2100 rpm. With a lower idle I dont see any steam .. However the the water flow is the same with by pass open or clamped ..?can that be ? is that good ? I am very new to this atomic 4 business .

Should the water flow out the exhaust be very forceful or just pouring out like
a garden hose .

But clamped or unclamped the flow appeared the same .

[goodoldboat]

clamped or unclamped it didnt make I difference in the water flow .
and the steam amount was the same ..

although steam was reduced when the RPM was dropped from
2100 to just above an idle ..

[JOHN COOKSON]

clamped or unclamped it didnt make I difference in the water flow .
and the steam amount was the same ...

Did clamping the bypass make the engine run cooler?
If it didn't there is a partial restriction in the cooling system somewhere or inadequate water pump output.
Water out the back of the boat is subjective. How do you know if there even enough water out the back of the boat bypass clamped or unclamped. Did you measure the output or compare the output to some other boat?

TRUE GRIT

[JOHN COOKSON]

A RWC engine will not run hot if there is adequate water going through the engine (NOT around the bypass). Clamping the bypass will force all the cooling water through the engine. If the engine runs hot with the bypass clamped then there is a restriction somewhere or the water pump is not pumping enough water.

TRUE GRIT