45mm to 40mm exhaust hose adapter

[redbeard1]

Hello,


Long story short, I have a vetus waterlift muffler with an output fitting of 45mm. My exhaust hose at this point is 40mm. Is there an adapter that I can buy/make?


Background
Our engine was run without intake water. The exhaust gas melted the old water lift muffler input fitting and part of the hose that connects the engine elbow to the water lift muffler. Instead of trying to measure the ID of the hose (which was deformed from the heat), I measured the OD of the engine elbow fitting and assumed they would be the same. I used the 45mm measurement to order new hose and a new waterlift muffler.


Today, I discovered that all my old exhaust hose is 40mm. My old vetus muffler had 40mm input and output fittings and the previous owner had forced a 40mm hose over the 45mm engine elbow.


So today, my system is 45mm elbow->45mm hose to muffler ->45mm input fitting at muffler ->45mm output fitting at muffler ->40mm hose to transom.


If no adapter exists, I plan to get a 40mm vetus muffler. It appears that the input fitting on vetus mufflers are interchangeable between (40,45, 51).


https://www.imarineusa.com/VETUSUS00...SABEgL52PD_BwE

[HopCar]

This is a Vetus product. Would it work?
https://www.jamestowndistributors.co...t.do?pid=11718

[redbeard1]

Thanks for the reply.



I saw that one yesterday but I need something that connects a male 45mm to female 40mm. I think that is for connecting two hoses.



However, looking at it again, it just occurred to me, that I can attach a 5 inch piece of spare 45mm hose to the muffler and use this device to connect to my 40mm exhaust hose that goes to the transom.


Not elegant, but it is a back-up in case the Vetus 40mm muffler is not compatible with the 45mm input fitting.


edit: mistype exhaust for muffler

[Sailmonkey]

Silicone reducer hose and a fiberglass coupler?

[FPNC]

'Hopcar's' adapter will work both directions. However, 40 mm exhaust is damn small but for a smallest diesel engine. Or an exhaust hose run of any length.

[redbeard1]

In case anyone else has this problem, I can confirm the Vetus waterlock lift muffler has interchangeable input fittings. We got a WLOCKL40R which has a molded 40mm outflow and we are using a 45mm inflow attachment on it.



FPNC - It does seem odd the PO would downsize from 45mm at the engine elbow to 40 after the muffler.



However, our engine is not too powerful (28hp). I've measured water flow at the transom and it is in spec for our raw water pump.

[Sailmonkey]

Originally Posted by redbeard1

However, our engine is not too powerful (28hp). I've measured water flow at the transom and it is in spec for our raw water pump.

It’s not waterflow you need to worry about, it’s exhaust pressure.

Although I suspect your back pressure with 40mm hose will be ok unless the hose is quite long and you make it a habit of running around at full throttle all the time.

[redbeard1]

Thanks Sailmonkey,


I assumed exhaust pressure only mattered with respect to getting the water out of the boat. I guess I'll be reading my Calder this week-end.


Thanks for the warning. However, our engine is rarely run past 2200 (which creates other issues) max, I think, is somewhere in the low 3000.