steam in exhaust

[edwardc]

Sounds like you have an obstruction further downstream from the block and thermostat. Most likely place is the mixing elbow, as this is where the water encounters the high-temperature exhaust, and salt crystalizes out above 160 degrees.

In a waterlift system, the water should "bloop" out in batches, not flow in a continuous stream.

[goodoldboat]

steam in ehaust

where should I look for the obstruction ...

I just replaced the entire hot section ..

[edwardc]

Check the water injection fitting for salt buildup.

Check the hose from the injection fitting to the waterlift muffler for a delaminated and collapsed inner lining.

Check the hose out of the waterlift for delimination/collapse too.

Also, drain and inspect the inside of the waterlift for rust and salt debris.

[JOHN COOKSON]

GOB
If you want to go to the trouble you can:
Run the engine until it is warmed up* then shut it down. Disconnect the hose at the injection fitting in the hot section and aim it to the cockpit or bilge. Start the engine and briefly** rev it up. You should see a stream like out of a garden hose. I was able to shoot water across the finger pier and into the boat on the other side of the finger pier. I almost wigged out when I saw this happen!
If you are getting this kind of flow with the bypass clamped through the engine the over heating problem is not due to not enough water through the engine.

* I have a thermostat so I wanted to be sure it was fully open when I did this.
**Keep it brief. With out cooling water rubber hoses and plastic mufflers can be ruined.

TRUE GRIT

[goodoldboat]

steam in exhaust

Thanks I will remove the water supply to the the hot end of the water lift
muffler as you recommended in your post

I will do this with the bypass clamped and check water flow ..

But ,should there any steam in the exhaust or is some steam acceptable ...

[goodoldboat]

steam in exhaust

Check the water injection fitting for salt buildup.

Check the hose from the injection fitting to the waterlift muffler for a delaminated and collapsed inner lining.

Check the hose out of the waterlift for delimination/collapse too.

Also, drain and inspect the inside of the waterlift for rust and salt debris.

I just thought of something ..as I was closing the raw water supply seacock on the boat last night , I noticed water around the base of the
water lift muffler.

my question is how does an issue at the muffler end ,make the engine run
hot ?

Should the exhaust have any steam ?

[Van_Isle]

Might be worthwhile if you asked the administrators to merge your two threads.

[Van_Isle]

... I will remove the water supply to the the hot end of the water lift muffler as you recommended in your post. I will do this with the bypass clamped and check water flow ... But ,should there any steam in the exhaust or is some steam acceptable ...

Consider that water boils at 212 degrees F. Consider that your temperature gauge isn't necessarily 100% accurate (and you have had problems with yours ... correct?). Consider that the currently-available grey plastic Vetus type is only rated to 158 degrees continuous. I'm not sure about the older styles. However I think yours is stainless, is it not? ... but there are lots of other bits and pieces in a boat that won't do well at 200+ degree temperatures. Consider that the FWC engine will typically run a 160-degree thermostat while the RWC engine will run a 140-degree thermostat .... the idea being that the RWC engine must run cooler to avoid precipitating salts out into the engine cooling passages. The FWC engine doesn't have this issue, so it can run hotter which improves combustion and reduces plug fouling. But the raw water cooling flow into the hot exhaust must still, for both, keep the temperature within acceptable exhaust operating limits. So .... long story short .... no, steam is NOT acceptable!

Water around the base of the water lift (as you reported in your other thread), I suspect, points to some leakage / failure in the waterlift or connecting hoses. Have you checked the hoses for collapse, as was suggested?

Have you looked at the final elbow (water outlet) at the back end of the exhaust manifold? This is a very common point for crud build-up!

Perhaps we need to step back and think about this in terms of your overall experience with the boat so far ....

1. You've had a complete failure of your hot exhaust riser / mixing elbow. You've replaced that. Good!
2. However, the condition of your hot exhaust could also point to a similar condition in the cooling passages / fittings (elbows) / water jacket / diverter valve and waterlift itself. You may need to muck everything out and do an acid-flush.
3. You say the PO told you there was no thermostat. Have you opened the housing to confirm?
4. It was recommended that if you don't have a thermostat that you install a valve on your bypass hose.
5. Your temperature gauge was pegging at full-scale. In your thread on that subject I don't think you reported on the final resolution on that.

I'm also wondering when was the last time the water pump impeller was replaced?

[goodoldboat]

steam in exhaust

update .

I got to the boat and clamped the By pass hose off completely with a small C clamp .
I ran the engine at 2000 RPM against the mooring in reverse for 30
minutes .. The temp ran at 120 to 130.
I had good water flow and NO steam . I have not checked for the thermostat
the PO was sure it had been removed .
I did not remove the water feed to the water lift muffler it was too hot in the boat to start climbing over the manifold . i will however accomplish this over the weekend as the temps and humidity are expected to drop. Additionally the PO states the Impeller was replaced last year also .


So if i am going to run W/O a Thermostat I must install the bypass valve ?
when I do install the by pass valve , when do I adjust it ? or is it always left
closed ?

[tenders]

To reiterate, you should have ZERO steam, ever.

My raw-water engine has been run without a thermostat since 1993 and runs below 120 degrees in Long Island Sound. I put a couple of ounces of Marvel Mystery Oil into the fuel every time I add fuel; this helps lubricate the valves at these lower temperatures. (I also enjoy the wintergreen smell and cheerful red color.) The occasional sticky valve is the only side effect I've noticed from running like this, and the MMO fixes it entirely.

My bypass hose doesn't have a valve on it, and it isn't adjustable; it just has a short stainless bolt stuffed into it, headfirst, so it's easy to pull out by the threads when you take off the hose (which only needs to be done when you're replacing the hose every 5-8 years). This bolts acts like a plug, preventing almost any water from going through the bypass and forcing it all through the block and head. The friction of the bolt head in the hose stops the bolt from going anywhere in that short section. Barbaric, yes, but effective.

There are several benefits to this arrangement. One is that winterizing the engine does not require "warming it up" to get the thermostat open so antifreeze gets in the engine instead of running through the bypass. I run a gallon or two of freshwater through a cold engine, followed by a gallon of antifreeze as I spray fogging oil into the mouth of the carb, and that's it. Another is that the thermostat housing and the associated engine studs never need to be removed to check, I haven't had mine off in more than a decade. Most importantly, if the engine temperature ever gets high, I know there's something wrong with water flow, and there are only two things that can cause it: an intake clog or an impeller problem. Replace the impeller every few years and there's actually only one thing left likely to ever cause a temperature problem.

It sounds like the issue with your setup is that the previous owner didn't have a restriction in place, so water was going through the bypass instead of through the block.

Here's what I would worry about now: running seawater through an engine above 170 degrees makes salts precipitate out of the seawater and into the engine. This reduces the flow of water through the engine AND acts as insulation between the water and the engine, further reducing the cooling effect. The "acid flush" procedure described in the Moyer manual and discussed at length here on the forum is designed to dissolve those precipitates and get your engine back to Coolville. If you're running above 120 and below 140 this season, you can probably wait to do this before you winterize in the fall.

[JOHN COOKSON]

Answers To Questions

So if i am going to run W/O a Thermostat I must install the bypass valve ?
when I do install the by pass valve , when do I adjust it ? or is it always left
closed ?

Must install the bypass? No, you can do whatever you want.
When do I install the bypass valve? When ever you want to.
Now, in a more serious vein:
A valve on the bypass will allow you to balance the water flow through and around the engine. As you noticed restricting the bypass forces more water through the engine which results in cooler running.
Every engine is a bit different. The cooling passages in some are severely restricted. Other engines not so bad. Your particular engine? Who knows. This is why it is good to have a valve on the bypass so the water flow can be fine tuned. On my RWC engine with the bypass valve fully I run ~150 degrees. Apparently the valve fully open provides just the right amount of restriction for my A4.
I would do two things:
An acid flush as previously recommended.
Put valve on the bypass.
Betcha a quart of MMO your cooling issues will be solved.

TRUE GRIT

If the muffler is leaking it won't get better by itself - but you're on that.

[goodoldboat]

steam in exhaust

Tenders thanks for advice on your by pass "bolt " I would love to see a picture of it , if available .
I see that you keep your boat at Harlem YC , for years we kept a J-24
at City Island YC. We probably sailed passed each other many times , nice to meet you in this forum .

John ,should the quart of MMO go in the crankcase ? or in the fuel ? I have been adding MMO to the fuel as recommended .New question .. what is the optimal operating temperature ? Is there a temp that is too cold like below 120 ?

Also I am the third owner of a 40 year old boat , P/O owned for the last 12 years and states he never did an acid flush , he does however state that he
would run fresh water through the the system 2 or 3 times a season ? but without a bypass valve and thermostat I don't know how much if any made it to the block

Prior to his ownership I have no service records or history .

[JOHN COOKSON]

.New question .. what is the optimal operating temperature ? Is there a temp that is too cold like below 120 ?
.

I have the original A4 owners manual. It came with the boat. It recommends running between 140 and 160 degrees. It also says if the engine is run cooler condensation can form in the valve chamber which can lead to sticky valves.
That said some members run below 140 and are perfectly happy (Tenders post #25)

TRUE GRIT

[goodoldboat]

steam in exhaust

thanks John ...

you said put about a quart of MMO and it will help , did you mean in the
fuel or crank case .

I reviewed the original owner manual and i found it help full ..

My question is if the by pass is closed off completely , how does the water
get to the manifold ? through the engine directly ?

thanks for your help ..

[roadnsky]

My question is if the by pass is closed off completely , how does the water
get to the manifold ? through the engine directly ?

Yes, but thru the thermostat housing.
All cooling water flow makes it's way thru the manifold.
See the diagram attached...