Where to find a 7/8" barbed hose adapter

[Jetexas]

A litte backstory, I have a 1982 O'day 34 with a Universal 5424 diesel. It had the original 2" diameter heat exchanger, which was undersized. I was limited to about 1900 RPM before overheating.

I finally ordered a 3" heat exchanger meant as a replacement for Universal Diesels through Catalina Direct. However, I didn't pay attention to the line sizes in and out of it.

Adapting the 3/4" fresh water lines to 1-1/8" was easy enough. However, the 1/2" raw water line out of the Oberdorfer now needs to be 7/8". I cannot find a 7/8" barbed brass/bronze/stainless adapter anywhere.

I tried to get a 3/4" hose to fit onto the 7/8" inlet on the heat exchanger, but that was a no-go.

Any ideas on where to find a 7/8" adapter or how to get a 7/8" hose to seal onto a 3/4" barb?

[savoir]

I have never seen any marine plumbing fitting in 7/8". They are always 3/4" or 1". Never seen any form of hose in 7/8" either.

Time for a custom fabrication.

[Scott Berg]

I'd think you could upsize it to 1", available everywhere

[Jetexas]

Here is the heat exchanger I'm using.

Catalina Direct: Heat Exchanger M-25XPB, M-35B 3" Diameter

The 7/8" raw water inlet seems to be standard on all of these Universal heat exchangers. West Marine had the 7/8" hose in stock. I'm just at a loss trying to find the adapter to make it fit the 1/2" outlet of my oberdorfer.

[Terra Nova]

You should be able to get the 7/8" hose to seal on a 3/4" hose barb fitting (which actually measure much larger than 3/4").

[Mikado]

Originally Posted by Jetexas

A litte backstory, I have a 1982 O'day 34 with a Universal 5424 diesel. It had the original 2" diameter heat exchanger, which was undersized. I was limited to about 1900 RPM before overheating.

I finally ordered a 3" heat exchanger meant as a replacement for Universal Diesels through Catalina Direct. However, I didn't pay attention to the line sizes in and out of it.

Adapting the 3/4" fresh water lines to 1-1/8" was easy enough. However, the 1/2" raw water line out of the Oberdorfer now needs to be 7/8". I cannot find a 7/8" barbed brass/bronze/stainless adapter anywhere.

I tried to get a 3/4" hose to fit onto the 7/8" inlet on the heat exchanger, but that was a no-go.

Any ideas on where to find a 7/8" adapter or how to get a 7/8" hose to seal onto a 3/4" barb?

Check with your local Parker Store in Houston. They should be able to help you out.

Good luck.

Jeff

[Terra Nova]

Also you could use a 1/2" pipe nipple, which is nearly 7/8" outside diameter.

[mcgann454]

Check with a local Hydraulic Hose supply company. They usually have any size you need and can adapt anything.

[yachtgemini]

I have a few odd sized joiners on board and frankly, don't trust mixing various adapters with different metals or metal/plastic and thread mismatches to 'manufacture' a solution. These lash up jobs are too often a disaster waiting to happen.

I keep a little 2" and 1" bronze stock on board and when I need an adapter made simply get a local machine shop to slice a bit off and make me 2 of what I need. Why two ? Because the cost is usually in setting up for the job and subsequent units cost cents.

I also have a stock of bits cut off old prop shafts that are 316ss but the machine shops often prefer to make fittings in the softer easy to work bronze. Bronze purchased from a non-ferrous metal wholesaler is often surprisingly well priced.

The same approach can probably be applied to Delrin and other plastics.

I have used the same logic on consumable parts on my Westerbeke generator such as the water pump shaft and have saved money over buying original parts.


Ross

[Xthewater]

Originally Posted by Jetexas

A litte backstory, I have a 1982 O'day 34 with a Universal 5424 diesel. It had the original 2" diameter heat exchanger, which was undersized. I was limited to about 1900 RPM before overheating.

I finally ordered a 3" heat exchanger meant as a replacement for Universal Diesels through Catalina Direct. However, I didn't pay attention to the line sizes in and out of it.

Adapting the 3/4" fresh water lines to 1-1/8" was easy enough. However, the 1/2" raw water line out of the Oberdorfer now needs to be 7/8". I cannot find a 7/8" barbed brass/bronze/stainless adapter anywhere.

I tried to get a 3/4" hose to fit onto the 7/8" inlet on the heat exchanger, but that was a no-go.


Any ideas on where to find a 7/8" adapter or how to get a 7/8" hose to seal onto a 3/4" barb?

In Portland Oregon Superior Rubber carries them.

[sailah]

How about this? One of the parts we make for a radiator steam trap. I could chuck it up and machine the end more like a beaded hose barb for you. Internally it has a hex broached to allow it to be installed with an allen but this would probably not be wanted as it would restrict flow. Would recommend drilling it out so the inside flow is clean.

Yours for postage if you have no other options. Parker is the world leader in hose barbs, I checked they don't make one and all the usual sources come up blank

[Defeverboat]

Call Palmer Power. 7136446410. Blackburns marine 2813345474

[Larry Florida]

I went thru a similar saga.

You can try try using this 7/8 x 3/4 adaptor to get you to a more common size. 3/4 x 1/2 is very common.

https://www.pegasusautoracing.com/pr...sp?RecID=11142

[Jetexas]

Thanks for all the input. Right now I have the 7/8" hose triple clamped onto a 3/4" barbed fitting, and it's not leaking, but I just ordered that 7/8" to 3/4" straight hose reducer.

[savoir]

The whole 7/8" business is quite strange. Through the past 2 years I have totally replumbed my boat (almost finished) and scoured several catalogs in the process. There are plenty of 3/4" and plenty of 1" but not a single item in 7/8". Oh well. I can only suggest that the original 7/8" part was built for the auto industry.

For anyone doing plumbing work, these guys are very good for connector and adapter parts.

MarineEast [www.marineeast.com]