When to rebuild?

[Chris Simenstad]

My 1975 Ericson 32 has been in my possession 11 years now. From what I can tell, the raw water cooled Atomic 4 is original. It has no hour meter, but the engine gets regular use year round. When my kids were small we did a ton of weekending and motoring. One summer I went from the SF Bay down to Southern California and motored back, and most summers I go up the Sacramento/San Joaquin Rivers, which means 25 hours of motoring to make that trip.

This engine has been one of the most reliable things on the boat. It always starts on the first or second try, is quiet, and still has plenty of power.

According to the original water temp gauge (which is flickering and is on my replace list), most of the time it wants to run at 170 degrees, which is a little hotter than it used to run (I did a vinegar flush over the weekend, which didn't help much; I may do another acid flush but I am hesitant given the age of the engine).

Also, I've never had to adjust the oil pressure, but I need to as at cruising speed it is now down from 40psi to a little over 30 psi.

It smokes a bit at startup and also when accelerating after a long idle, but the oil level doesn't go down much, maybe 1/2 a quart between 50 hour changes. The last time I did a compression test, the cylinders were all between 90 and 100 psi.

Other than recommend routine maintenance, I have replaced the exhaust manifold and riser, alternator, raw water pump, coil, rebuilt the carburetor, and changed over to electronic ignition.

When I put the boat away I run 5 gallons of fresh water through the block so when the boat is not in use the engine has fresh water in it. Lastly, I treat every 5 gallons of fuel with both Stabil and MMO.

So here's my question: at what point, barring come sort of catastrophic failure, when do I need to yank the engine for a rebuild? Does the engine lose power, start using a huge amount of oil, etc?

Since this engine has been so reliable, I am hesitant to just do a rebuild, but then again, the engine is obviously aging.

Other than bay and local coastal use, I have no plans for long distance cruising, and if I did, I would pull the engine in November and rebuild it, or put in a swap.

Thanks for reading this long e-mail, and for any insight about engine life.

Best,
Chris

[capnward]

If it ain't broke...

Chris,
Seems to me you can go another 11 years like this. The engine may not be as strong as it once was, but hey, who is? You are obviously taking good care of it. It may even be good for long distances. 170 degrees is fine, but get a temperature alarm if you don't have one. Down half a quart after 50 hours, mine does that too. Just keep feeding the beast. I had mine rebuilt 16 years and 2400 hours ago, have overheated it several times, once badly, with no ill effects. Have never had the manifold, the head, or the valve cover off in all that time. Compression is still good. In hindsight, I may not have needed to do the rebuild, I just wanted to make sure it was ok, and didn't know how to make it run well. I have learned a lot since then. I heartily agree with the use of MMO in the fuel. If you can find non-ethanol fuel, I recommend that. Or you can use 10% ethanol, and replace clogged filters and clean the carb until your tank is clean.
Good Luck!

[joe_db]

I would leave it be. Eventually salt water corrosion will do it in or it could just lose compression and power. Either way you could years or decades away from these issues. A conventional rebuild with the same block would not do anything to fix corroded cooling passages anyway.

[ndutton]

I agree with the good capt and joe, this engine is in good hands and is rewarding your care with many years of reliable performance. I have a few observations though:

• The MMO fuel treatment likely accounts for the exhaust smoke you're seeing. I treat my fuel the same with similar results.
• Have you calculated your ignition system current since changing to electronic ignition? I suspect you have.
• Regarding the slightly elevated temperature, have you inspected the intake thru-hull for internal growth?

I'd like to see you on the forum more. You are exactly the type of owner who can provide excellent advice on how to maintain an Atomic 4. Your results speak volumes.

[joe_db]

BTW - My old RWC A4 ran at 180 and it would start trending towards 200 by fall. High temps plate out salt and minerals. I made a rig to recirculate the same cooling water and filled it with vinegar. A half hour treatment with that and I was back to 180 again It needed doing one or twice a year.

[JOHN COOKSON]

Agree with others. Hold course. I don't think it is time to rebuild yet.

The flickering gauge may be due to loose wiring not the gauge itself. Warm the engine up then shut the engine down then turn the key to the on position. Shake the wiring while a crew member watches the gauge. Careful leaving the key on to long when the engine isn't running. If the EI is closed you can fry the coil.

TRUE GRIT

[Dave Neptune]

When doing a vinegar flush I drain the block and fill it with vinegar. Then I go home and let it sit at least 24 hours and sometimes a few days. Vinegar works slowly and if your patient it does a pretty good job.

Chris, check for a blockage at the exit fitting of the manifold. This is a spot notorious for gathering chunks and restricting flow. May be worth checking.

Dave Neptune

[tenders]

Hmm, my impression has been that vinegar is too dilute to do much of anything, even over time. Not true? Maybe I should be letting that sit around in my engine for the couple of weeks during spring commissioning. It isn't going to dissolve good metal, right?

[joe_db]

I ran my exhaust and water intake into the same bucket so the vinegar was recirculating as the engine ran. I tied a rag over the water intake so all the crap that came out of the exhaust wouldn't get sucked back in. Run until it hits 180, shut down, repeat a few times and you are good

[Chris Simenstad]

Thanks for all the replies. Having just done a re-rig and bought new sails, I don't have the $$ for much of anything right now, and I just want to use the boat. In addition to adjusting the oil pressure, I will add oil and temperature alarms, and will likely do acid and pressure flushes to see if I can get the temp down a bit.

Neil: I have not calculated the ignition system current--I switched to electronic ignition in 2008. What would be the reason too? Not enough current= weak spark?

[Ken Rockwell]

I was thinking a few things. Neither of which is important enough to worry about. Try screwing the main jet in half turns every 30 seconds. Be sure to count them, maybe it got bumped into at some point. Maybe the plugs are bad. Maybe a valve is leaking. A valve could be changed fast, try a compression test. Again, don't worry about it, just monkey around a bit. And I ran muriatic acid through mine. Two caps full in a five gallon bucket. Do not let it set. And do not get it anywhere on yourself or the boat, flush immediately!!!

[ndutton]

Neil: I have not calculated the ignition system current--I switched to electronic ignition in 2008. What would be the reason too? Not enough current= weak spark?

The issue with EI and current is there's a maximum, a not to exceed value of 4 amps. Anything above 4 amps and you risk overheating the coil, damaging the internal windings and repeated engine shut downs. Our recommendation is to build in a 15% margin of safety for a max current of 3.4 amps.

For example let's say you have electronic ignition and a coil that measures 3Ω. You know that the engine operates on a 12 volt system so all seems good (12V÷3Ω=4.0 amps). Not so fast. When the engine is running the alternator determines the voltage, usually around 14.2 volts so in reality your amperage is more like 4.7 amps. Oh-oh, trouble ahead. The example doesn't take into account wiring voltage drop but that's supposed to be less than 3% which affects the result by only 1/10th of 1 amp.

If you're above 4 amps, coil failure doesn't happen instantly. It builds up over time and the internal coil damage is cumulative.

[Chris Simenstad]

Vinegar flush works...

Just a quick follow up about trying to bring the engine temp down:

After sailing several times this spring, and noticing that the temp at cruising speed was 170-175 degrees (about 155-160 at idle after being run for a while), I attempted a second vinegar flush.

The first time I had let the vinegar sit for about 3 hours. This time, after warming up the engine at speed for about 45 minutes, I went back to the slip and ran 5 gallons of household vinegar into the block. Then I let the engine sit for 4 days.

When I started the engine, I expected to see some discolored water come out with the exhaust water. There was a little discoloration, but mostly just the smell of vinegar.

Then I went out for a 40 minute cruise. The temp at causing speed is about 165 degrees--a little improvement--but idling after being run is about 130 degrees, which tells me salts were restricting flow somewhere inside the block.

Looking in my maintenance notes, the first time I did an acid flush was 2008. At that time, the engine was 180 at cruising speed, and when I did that flush I had a big rusty cloud come out in the exhaust water. The temp went down to 155 at cruising/125 at idle after cruising.

My plan from here on out is to do a vinegar flush in the manner every year to so to keep the passages free from excessive salt buildup

I'm also going to change the exit fitting in the exhaust manifold from a 90 to a straight one, and see is that gets me down to under 160 at cruising speed.

[Nanook]

Barnacle Buster is non-acidic, runs about $30 a gallon, and will destroy zincs if used in a heat exchanger on a FWC engine.

I like to follow Don's advice about blasting the 1/8" drain fittings with dock water to loosen the crud up and out before I do anything else.

Either run the engine up to temp and then a bit more; shut down; shift intake and exhaust cooling hoses to a bucket with the BB in it; remove heat exchanger zinc if FWC; (block the exhaust/water fitting with a damp rag to keep fumes out) run until the gallon has circulated through a few times; shut off and let set. You can run again for a few minutes at a time in the bucket closed loop to keep the temp up and Tstat open or normalize the hoses and let normal water blast everything out when you eventually run it hours/days later.

Or...pull impeller and thermostat (RWC)//pull impeller and heat exchanger zinc (FWC). Shift hoses to bucket as above, then flush or even better back flush the BB through the exhaust manifold and engine using a small electric bilge pump for several hours. Normal up the exhaust side, reinstall the thermostat (new gasket would be great but torque is critical) and run the engine to suck most of the now nasty-smelling fluid out of the bucket while leaving the solids in the bottom.

Normal up everything and run up to temp again to verify everything is good while thoroughly flushing everything out with higher RPM bumps.

[romantic comedy]

Barnacle Buster is non-acidic, runs about $30 a gallon, and will destroy zincs if used in a heat exchanger on a FWC engine.

I like to follow Don's advice about blasting the 1/8" drain fittings with dock water to loosen the crud up and out before I do anything else.

Either run the engine up to temp and then a bit more; shut down; shift intake and exhaust cooling hoses to a bucket with the BB in it; remove heat exchanger zinc if FWC; (block the exhaust/water fitting with a damp rag to keep fumes out) run until the gallon has circulated through a few times; shut off and let set. You can run again for a few minutes at a time in the bucket closed loop to keep the temp up and Tstat open or normalize the hoses and let normal water blast everything out when you eventually run it hours/days later.

Or...pull impeller and thermostat (RWC)//pull impeller and heat exchanger zinc (FWC). Shift hoses to bucket as above, then flush or even better back flush the BB through the exhaust manifold and engine using a small electric bilge pump for several hours. Normal up the exhaust side, reinstall the thermostat (new gasket would be great but torque is critical) and run the engine to suck most of the now nasty-smelling fluid out of the bucket while leaving the solids in the bottom.

Normal up everything and run up to temp again to verify everything is good while thoroughly flushing everything out with higher RPM bumps.

I looked up the MSDS on BB and it is 85 percent phosphoric acid:

https://doc.jamestowndistributors.com/userportal/pdfs/MSDS/Trac_Ecological/Trac_Barnacle_Buster_MSDS-1208-M.pdf