Stuck #4 Exhaust Valve: A special Tartan 30 problem?

[jellisfeingold]

I have chronic stuck #4 exhaust valve issues in my '76 Tartan 30.

At Don's advice, I've been running MM oil in the tank, and last year, at his advice, I reamed the exhaust valve guides 0.317" to increase clearance a bit. But the problem persists. Don and I corresponded recently, and he suggested that I post the matter here and see what we learn.

Don's theory is that the Tartan 30's port side thru-hull exhaust exit somehow lets moisture back into the exhaust manifold which, in turn, accelerates rusting of the exhaust valves, the stems of which are, of course, are open to the exhaust manifold. Since the manifold exhaust flange is at the rear of the engine, the #4 exhaust valve gets the moisture.

Does this ring true to other Tartan 30 (or Tartan 34)owners, or other boat owners with side-exiting exhausts?

FYI - the exhaust exits the manifold via the rear of the engine, which points toward the bow, runs through a 12"-15" 1 1/2" exhaust pipe to the waterlift muffler, then through a vented loop and out through a thru-hull on the port side, just at the waterline.

What fixes are there? Any suggestions?

Thanks,
John Feingold
Tarte Tatin
Tartan 30 #430

[RISAIL]

Tartan 30 Problems

I have a 1979 Tartan 30 (#572). I replaced the original A-4 in Spring 2005. I also installed a new (port-side) fuel tank this Spring. Despite the remanufactured engine, I continue to have problems with the engine. I am getting water into the combustion chamber. I've had the carburetor taken apart and cleaned twice in the past three weeks. The new Fuel-Water Separator and inline fuel filter show no signs of water. However, it clearly had water in it the other day and refused to start. I have been fouling plugs in this engine since it was installed last Spring. The mechanic who got me up and running this week indicated that the compression was the least in the aftermost cylinder. It also had the most moisture.
The general consensus right now is that my problems are related to ethanol. I am in the northeast where 10% ethanol has been on the market for some time. My sense is that ethanol is going to become the Weapons of Mass Destruction of gas engine failures. Like the WMD theories, I think this is BS. I've had a problem with my Atomic Four from the beginning and am about to cut my losses and rid myself of this vessel. Perhaps the port side exhaust of the Tartan 30 is a design flaw. However, they have been around for over 30 years, so who knows.
I wish I could offer some better advice, Mr. Feingold. However, I have had two consecutive summer vacations interrupted by Atomic Four issues. My frustration level is a bit high right now.

Joe Walkden
RISAIL@aol.com
October Moon

[Don Moyer]

Joe,

I wish I had better advice also, but I do not believe your problem has anything to do with Ethanol, convenient though that cause factor would be.

I'm attaching a recent Q & A that we prepared on the subject of water intrusion into combustion chambers for you to consider, which includes methods of checking the three major water jackets for leaks.

In most cases, water intrusion into the engine does result from design flaws and/or failures in exhaust systems which are usually quite easy to pinpoint. However, each year we seem to be dealing with one or two "mystery" water episodes that defy all usual remedies.

If you'll allow me to report from my memory and not necessarily from data that I could easily document, here are a few of those cases:

1) In one case, a small amount of water fed back into the exhaust manifold from a hot water heater that was mounted just a bit higher than the engine.

This episode was particularly difficult to resolve, since the number one cylinder was the one being affected, which is the "uphill" cylinder, and not the fourth cylinder (the "downhill" cylinder). The explanation ended up being that the engine was a "V" drive with a front exiting exhaust, and the amount of water feeding back from the hot water heater was just enough to fill the first of four gullies in the bottom of the exhaust manifold (a gully exists below each exhaust port), plus a couple tablespoons to flow into the number 1 cylinder and cause its intake valve to stick.

2) In another case, so much moisture formed within the engine compartment that condensation would form and drip off most of the engine and related components anytime the boat was left unattended for any length of time. Valves would continue to stick until the owner installed a light in the engine compartment to remediate most of the moisture problem.

3) And (sorry about this) we've had a couple reports over the 15 years or so that we've been messing around with the Atomic 4, from folks with side exiting exhausts who have had to stuff a rag into the end of the exhaust when the boat was left unattended for any length of time to prevent stick valves, and I'm quite sure I recall one gentlemen who installed a big ball valve in the hot section of his exhaust so he could close it off more easily whenever he left the boat unattended.

With respect to side exiting exhausts, there is no one that has more respect for the Tartan fleet than I, and a couple episodes of sticky valves from moisture feeding back through their side exiting exhaust systems hardly rises to the level of a serious design flaw. Moreover, these systems have a really wonderful design feature, which is that if you over do overcrank a hard starting engine, water will eventually flow out of the exhaust system and fall harmlessly overboard instead of back into the manifold.

I'm hoping that others will weigh in with their own "mystery water episodes" to add to this small list.

Don

[Warren Trafton]

Tartan 30 Exhaust

I have chronic stuck #4 exhaust valve issues in my '76 Tartan 30.

At Don's advice, I've been running MM oil in the tank, and last year, at his advice, I reamed the exhaust valve guides 0.317" to increase clearance a bit. But the problem persists. Don and I corresponded recently, and he suggested that I post the matter here and see what we learn.

Don's theory is that the Tartan 30's port side thru-hull exhaust exit somehow lets moisture back into the exhaust manifold which, in turn, accelerates rusting of the exhaust valves, the stems of which are, of course, are open to the exhaust manifold. Since the manifold exhaust flange is at the rear of the engine, the #4 exhaust valve gets the moisture.

Does this ring true to other Tartan 30 (or Tartan 34)owners, or other boat owners with side-exiting exhausts?

FYI - the exhaust exits the manifold via the rear of the engine, which points toward the bow, runs through a 12"-15" 1 1/2" exhaust pipe to the waterlift muffler, then through a vented loop and out through a thru-hull on the port side, just at the waterline.

What fixes are there? Any suggestions?

Thanks,
John Feingold
Tarte Tatin
Tartan 30 #430

Hello John,
I bought Tartan 30 #163 in 1986. Four round trips, New England to Bahamas. That is 365 ten hour days at 6.3 knots.

Seven years ago, I decided hat the waterlift muffler and the vented loop were robbing the Atomic 4 of power and keeping the Manifold and firing chambers in a damp environment. So, I removed both.

In small boats the waterlift cannister is not mounted low enough and doesn't serve any useful purpose that I can determine and it increases back pressure. The vented loop will stop water from siphoning back if you turn off the engine while sailing and healing to port in the T-30. However, it restricts the water flow and makes the engine work harder pumping. I start the engine with the water intake valve closed.So, there is no chance of water backing up into the manifold if the engine does not start right away. When it starts, I open the valve. On shut down the process is reversed. First shut the water intake valve and then turn off the engine. This will leave the manifold and exhaust dry. Obviously, this is not for everyone but once you get used to the routine it is automatic. Make sure you carefully instruct others who may operate the boat.

For seven years, this has worked well for me. The sound is a little bit different but no one has noticed.

There are real advantages to the engine location in the T-30:1) The prop is just aft of the keel where it will not snag lines etc underway.2) Excellent engine access for maintenance and repair.3) Improved sailing performance with the 200 lb engine amidships.4) You can drive larger yachts crazy when you appear to sail past them with no transom exhaust to indicate that the engine is running. However, the side exhaust does leave less room than the aft exhaust on most installations.

Remember that the T-30 was originally set up with a stand pipe exhaust in the head. I'm sure that all of these have now been replaced.

WARREN TRAFTON
SailingYachts 1Rhode Island
CERTIFIED PROFESSIONAL YACHT BROKER
97 LAFAYETTE ROAD
NK, RI 02852

https://www.SailingYachtsRI.com

office 401 268 3850
cell 401 374 7978
fax 401 295 9766

[Don Moyer]

Warren,

The only editorial comment I would make is that our recommendation for reaming valve guides is to .314", not .317".

Don

[jellisfeingold]

Warren, let me understand you correctly. You run a straight, unmuffled pipe from your Atomic 4 straight out the side of your Tartan 30? Interesting. It really must sound like the African Queen. But seriously, do you run a hot pipe from your manifold, inject your cooling water (how far from the manifold?), and run a rubber hose in a loop and then out? A description would be appreciated.

Also, Don, you are correct -- 0.314. The 0.317 was my typo.

I have continued to ponder my valve issue, and have concluded that my exhaust system probably feeds steam back into the manifold. Based on all the input I've gotten (I've even consulted Foy Brown, of Brown's Boatyard on North Haven, ME), my plan involves the folowing:

-- replace #4 exhaust valve (current one might be bent from hammering it down so many times, which would, in fact, contribute to its sticking;
-- replace all valve springs (Moyer's are stronger than stock);
-- rebuild exhaust system to place water injection point closer to muffler and more distant from manifold.

Warren's advice is sage: start engine before opening raw water intake and close intake immediately prior to shutting off. Pending better understanding of Warren's exhaust system, maybe I'll scrap my muffler, as well.

Regards and thanks,

John Feingold
Tarte Tatin
T30 #430

[Warren Trafton]

Tartan 30 Exhaust

Warren, let me understand you correctly. You run a straight, unmuffled pipe from your Atomic 4 straight out the side of your Tartan 30? Interesting. It really must sound like the African Queen. But seriously, do you run a hot pipe from your manifold, inject your cooling water (how far from the manifold?), and run a rubber hose in a loop and then out? A description would be appreciated.

Also, Don, you are correct -- 0.314. The 0.317 was my typo.

I have continued to ponder my valve issue, and have concluded that my exhaust system probably feeds steam back into the manifold. Based on all the input I've gotten (I've even consulted Foy Brown, of Brown's Boatyard on North Haven, ME), my plan involves the folowing:

-- replace #4 exhaust valve (current one might be bent from hammering it down so many times, which would, in fact, contribute to its sticking;
-- replace all valve springs (Moyer's are stronger than stock);
-- rebuild exhaust system to place water injection point closer to muffler and more distant from manifold.

Warren's advice is sage: start engine before opening raw water intake and close intake immediately prior to shutting off. Pending better understanding of Warren's exhaust system, maybe I'll scrap my muffler, as well.

Regards and thanks,

John Feingold
Tarte Tatin
T30 #430

John,
When I gave up on the old stand pipe exhaust that was original from Tartan, I installed a Yanmar exhaust elbow in 1992 that allows the raw water to enter the elbow with in a few inches of hose from the manifold. This has worked very well. Then seven years ago I removed the water lift muffler and vented loop. The sound level of the exhaust is only slightly different and not louder. Not a single person has noticed the change. I run the exhaust hose as high as possible in front of the fly wheel, and then looped down to the exhaust through hull in th boot stripe under the sink in the head.
Good luck.

Warren Trafton
SPARTAN
T30 # 163

[deckhanddave]

I'm currently in the begining of an A4 rebuild in a T30 and have been wondering about the placement of the air intake for the A4. From what I can see, my vent goes from the rear of the cockpit, down to the bilge, up into the seats on the side of the engine compartment and into the compartment. Is it just me or is this a bit odd? Why not just have it come down the bulk head of the head straight from the cabin top? This would eliminate something like 15' of hose... I'm posting this here because I'd like to know more about that straight pipe alteration as well. Any ideas?