Exhaust Elbow Needed!

[Brian K]

I'm looking for a replacement exhaust elbow, part #170-2834 that I believe was made by Onan, for my 1988 E32-200 with the Universal M25XP engine. See the attached pictures. Any idea on sources for this part?

Also, when I took the system apart I found the water injection port to be nearly 100% clogged. And, alarmingly, there was fresh water with no sign of antifreeze in it that came out of the heat exchanger when I removed those hoses. I winterize the engine by running it with the raw water intake hose inserted into a bucket holding 2 gallons of antifreeze. I also have a bucket under the exhaust so I can inspect the discharge to make sure antifreeze has run completely through the system. The bucket under the exhaust outlet did contain antifreeze but yet there is still clear fresh water in some of the lines and heat exchanger that I had winterized. What gives?? I'm completely baffled by this.

 

[mherrcat]

That's a funky looking exhaust riser. I don't think it is original. The exhaust flange looks correct. According to Torresen's site the riser for the 25XP looks like the picture attached. Here is a link to the complete riser kit at Torresen Marine:

http://shop.torresen.com/ships_stor...=EXHAUST+ELBOW+RISER+KIT+1.25&sectionid=10480

 

[Loren Beach]

Strictly in the FWIW observations...
There may have been an overhead clearance issue in fitting the engine in/under the aft cabin interior of the 32-200. Perhaps a different exhaust fitting was needed?

I have the same (M25XP) engine, but also a somewhat larger interior engine compartment for systems stuff like this, too.

Anyone else with one of these models??
Class? Bueller??


Regards,
Loren

 

[Bolo]

That's the one!

I have an E-32 III with a M25XP engine and I replaced the exhaust elbow last year. The replacement looks just like the one pictured in Mark's posting and the one shown in the link even though it says "Westerbeke" on the side.

 

[Tom Metzger]

My '87 E-34 with an M-25XP has the same exhaust riser as Mark's. As Loren suggested, mine has lots of headroom.

 

[clayton]

Exhaust riser

My 32-200 has the same setup as Brian's. It's definitely a space/fit issue, so I assume Ericson came up with it as an alternative.
Clayton

 

[EGregerson]

mystery fresh water

regarding the problem with fresh water appearing instead of coolant, I can only think there might be a water heater involved where fresh water is trapped; or possibly, water trapped in the heat exchanger from the clogged port.

 

[mherrcat]

Found this exhaust elbow at:

http://onanparts.com/index.php?main_page=product_info&cPath=1_113_127&products_id=425

They don't list any size specs, however. If you Google "Onan" you'll find a bunch of sites. Prices vary widely. You might try to find a Cummins dealer/service center in your area that can help.

It's funny that the number stamped on the part in the photo is different from the number they list in the description; and both are different from the number on your part...

 

[mherrcat]

On a hunch I checked on the TDC Equipment site:

http://www.tdcequipment.com/parts.aspx

Click on the Onan logo and you'll get a parts/price list.

If you sort that Excel spreadsheet by the "Part Name" column you'll see that they list a ton of "ELBOW ASSY-EXH", "ELBOW ASSY-EXHAUST" AND "ELBOW-EXHAUST" parts, including:

155-1035
155-1058
155-1059

I stopped by there last week and picked up some parts for my M18 engine. They were very nice. You might want to talk to them. I think their price list is out of date as the prices for my parts were slightly higher than what is on their website list.

 

[Loren Beach]

regarding the problem with fresh water appearing instead of coolant, I can only think there might be a water heater involved where fresh water is trapped; or possibly, water trapped in the heat exchanger from the clogged port.

AFAIK, all the M25XP installations are fresh water cooled, i.e. closed cooling system.
On our boat the hoses to 'n' from the hot water tank are tapped in at the thermostat fitting. No outside "raw" water goes thru the hot water tank heating coil.

Loren

 

[EGregerson]

...and yet

somehow Brian has 'clear fresh' water in the exchanger. Somehow clear fresh (not raw; because the 'raw' has new purple antifreeze in it) water is showing up in the exchanger; this will not bode well when winter sets in. What is warming the bath water in the water heater of the 25xp?; isn't it hot greenie yellow fresh water from the motor? if he flushed the fresh water system (including the heater) and then drained it and added new coolant, is it possible to trap clean fresh water in the heater lines?; then when Brian ran the motor (with winterizer antifreeze (purple)) to fill the raw water system, the motor pumped the clear fresh to the exchanger, which he noticed and became concerned.

I sense the fresh coolant isn't thoroughly mixed; to mix it would require running the motor for a minute (or even less) with all accessory hoses open. (this unfortunately requires putting in new 'raw' water coolant.)

 

[Rocinante33]

Is it possible that the engine wasn't warmed up so the thermostat did not open? Maybe that prevented the antifreeze from circulating through the HE?

 

[Loren Beach]

Brrrrr...

Speaking of closed cooling....
We have an early cold snap forecast for the next few days. So yesterday I did my fall "engine due diligence" and warmed it all the way up, changed the oil and filter, and then pink-anti-freezed the raw water side.
I would note that whether or not the thermostat is open has nothing to do with the raw-water flow thru the heat exchanger. The T-stat is only controlling the flow of coolant thru the h.e. and also the path thru the hot water tank circuit.

I would note that, just like usual, it takes a bit over 3/4 of a gallon before the pink shows at the transom exhaust.


LB

 

[Brian K]

I think I understand the cooling system pretty well. The raw water intake from the through hull goes to the water pump, then through the heat exchanger where it cools the closed loop cooling system, then is discharged into the exhaust system at the elbow and the now warmer water goes out through the exhaust.

There is no interaction between the hot water tank and the raw water cooling system. The hot water tank is heated by the closed loop cooling system, not the raw water system.

So, if I use the winterizing method I described earlier in this thread, and nearly 2 gallons of antifreeze went through the raw water system, how could I possibly get antifreeze to come out the exhaust yet still encounter some pure H2O in the heat exchanger?

There is a small hose attached to the exhaust through hull and I assume it's some kind of anti siphon system but I have not traced that small hose to it's source. When I took the exhaust system (see pictures earlier in this thread) off the engine I could not get water to pass through the input into the elbow - the raw water input into the exhaust system appears to be nearly or completly plugged. Is it possible that my raw water bypassed the heat exchanger somehow, maybe via this small hose that is attached to the exhaust through hull? That would explain how I ended up with antifreeze coming out the exhuast (remember I placed a bucket under the exhaust output when I winterized the engine so I could verify that the antifreeze actually was processed through the system) yet fresh water remained in the heat exchanger.

Loren is exactly correct, the raw water half of the cooling system has nothing to do with the hot water heater, the engine thermostat, or anything else,,,, it's really a pretty simple system.

 

[Loren Beach]

That "small hose"

Brian, I just had a thought! Ouch!
(Yeah, it's gonna be one of those kinda daze.)

On a stock Ericson exhaust fitting I have seen (early 80's model) the metal thru hull fitting had a soldered-in nipple for that syphon break small hose. (This was on the inside of the hull.)

So, when you watch the exhaust gasses-and-water exiting on the outside, you were seeing all the raw water. I.E. what you were watching could be made up of only water from the water-lift muffler can if the syphon fitting in the elbow was clogged, for instance. If the elbow was thoroughly plugged up, the little syphon hose could not carry the volume of water the raw water pump is pushing through. Besides, if plugged verymuch, the engine would likely not run above an idle anyway.

This all occurs to me because on our Olson model the syphon break is a separate fitting on the transom. Reply #5, second picture, in this thread:
http://www.ericsonyachts.org/infoexchange/showthread.php?t=7890&referrerid=28

That fitting emits a steady stream that increases slightly with revs.
I know of another Ericson (a 33RH) that had to have the exhaust hose replaced and due to having to change up the hose size, had to also source a new exit fitting, and then had the syphon hose outlet put in separately like it is on our boat.

Best,
Loren

 

[Brian K]

So Loren, are you saying that the siphon break hose runs from the muffler? As I said, I have not followed that hose back to the source. I also have yet to find the muffler. I think it's under the starboard lazarette flooring. Next time up to the boat I'll focus on finding that for a couple of reasons: 1) to check the condition of the muffler and connnections there, 2) to see if the sipon break originates at that point.

One of my original problems with this system this year was the decreased flow of water through the system. I limped along through the 2nd half of the season by not pushing the engine much. The water flow was not nearly as much as I thought it should be.

I also need to follow the hose from the water pump to the heat exchanger. It seems to me that it goes into a "T' fitting if I remember correctly. If that is the case, maybe somehow fresh water can bypass the heat exchanger route to the elbow.

WOW, it would be so much easier to understand all this if we had a schematic of the complete exhaust system as installed by Ericson.

 

[mherrcat]

I believe the siphon break hose should run from the raw water outlet on the heat exchanger to the siphon break fitting above the water line to the exhaust elbow on the manifold. The small "breather" line, for lack of a better word (until someone corrects me!), runs from the siphon break fitting to its own transom through hull fitting or to the exhaust hose through hull fitting. Whether the small line goes to the transom or the exhaust through hull makes no difference, it accomplishes the same thing.

There is a System Plan for the E30+ in the Documents and Downloads section that shows the exhaust system; it's a little hard to see and it doesn't include the heat exchanger but it basically shows the water and coolant lines.

 

[Stu Jackson]

Mark's right. While a schematic of how Ericson installed their systems would be helpful, every book about below the waterline diesel engines shows exactly what Mark just described. Some vented loops do not connect from the top and go to an outside fitting. Mine doesn't. Still works. Our C34 engine and owner's manuals show it quite well, perhaps yours do, too.

 

[lindaloo]

Brian, your original post mentioned the water inlet at the elbow was almost 100% blocked. The flow of antifreeze mix from the bucket may not have been fast enough to effectively flush the water out of the HE when you winterized.
When I recently fired up a newly installed engine, on the hard, I stuck the raw water intake into a full 5 gal pail (in the galley), with a hose going full blast INTO the pail. The hose couldn't keep up, the pail was empty in minutes. Long story short, your Oberdorfer should inhale that 2 gal of antifreeze away pretty darn quick. Did it ?
Maybe change the hoses from the Oberdorfer to the HE, and the loop to the new elbow. And I can't imagine any possible need for a tee that you mention at the HE inlet.
Restored full flow should "sweep" the HE more efficiently so no fresh water remains.
Rewinterize, as if there was fresh water in HE it will also be in the muffler, and it gets cold on Lake Ontario.

Rob L
E34, Vancouver

 

[Brian K]

Stu, I'll try to track down that vented loop line maybe next weekend. But don't get me started on the owners manual issue!!! I've been trying to find a manual for my specific boat (E-32-200) since I bought it 3 1/2 years ago but so far, no luck. I have come to the conclusion none exists. UGH!! I do have a E32 manual but most systems are not the same.

Rob, yes your suggestion about the lack of water volume may be the answer to fresh water in the HE. My volume was no where near what you described. It looks like I'll have to install a completely new exhaust riser system since I don't think I can get this one apart. At least it came off the boat easily.

I'm not too concerned about the water that may be left in the system because I am going to remove the HE and have it flushed and cleaned this winter and I have already removed the impeller. All the other raw water lines are fully drained, but the muffler concerns me a little. I'm going to track that down and inspect the condition of it next weekend. Hopefully I can pull a hose and determine if the muffler does have any antifreeze in it. If not, maybe i can pour some in through the muffler output hose nipple once I get that off. I may take the muffler completely out if it's not too difficult.

Yes, it does get cold on Lake Ontario in the winter!!!

Thanks for the feedback gentlemen.