My A4 adventures

[Ando]

I found this in my spare parts bin that came with the replacement A4 will it suffice?

[roadnsky]

I found this in my spare parts bin that came with the replacement A4 will it suffice?

IMHO... yes as a temporary solution.
I would urge (when you get the boat buck$) to get a proper strainer though.

Also, definitely replace those plastic hose barbs.

[ndutton]

My suggestion of a raw water strainer was instead of the external strainer. Rather than install the wimpy one you have on hand, maybe make a real project out of it and source a robust, high volume strainer (I like the Groco ARG strainers, mine is pictured) and install it as part of a thru-hull replacement* at the next haul out.

Do it right, cry once.

Your pictured engine intake thru-hull looks factory original to me and if it is, I'd be shocked if it were 3/4" (pipe size). Catalina typically used 1/2" thru-hulls for their A4 engine intakes, mine was and its inside diameter is ridiculously small for a locale with marine growth. Remember, the outside diameter for 1/2" pipe size physically measures 7/8". Also, 1/2" thru-hulls are too small to be able to get bottom paint inside.

Check out this web page for an excellent treatment on what I'm talking about:

https://pbase.com/mainecruising/external_strainers

*My experience is Catalina used engine intake thru-hulls with an integral external grate requiring complete thru-hull replacement to get rid of it. Some builders fitted separate grates over the thru-hull, not Catalina.

[roadnsky]

As Neil points out, my 1979 built Ranger had an original thru hull of 1/2".
When I replaced it I upgraded to 3/4.
Note the difference between the 2 pictures below of the "flow capacity".
That's the cooling difference to your engine.

[Ando]

Whoa?!?

Roadnsky, that’s quite a pic. Thank you. I did shove a rebar down the thru-hull and, though I didn’t leave the valve open for too long, the rate of flow seemed to be really good (if I left it, I could envision the rate of about 17gallons a minute as Ken I think mentioned in another thread).

But I haven’t look down the thru-hull with my own eye and so I will have that pic engrained in my brain until I do...thx again.

[Ando]

My suggestion of a raw water strainer was instead of the external strainer.

I see, ok got it...no internal strainer until the next haul out (at which time the external strainer will be removed and the area under it coated with bottom paint. In the meantime, I’ll ensure my diver shoves a screw driver in there every month.

I’ll also double check that thru-hull diameter.

Check out this web page for an excellent treatment on what I'm talking about:
https://pbase.com/mainecruising/external_strainers

Wow, that website was very informative. Thx.

[edwardc]

...
Check out this web page for an excellent treatment on what I'm talking about:

https://pbase.com/mainecruising/external_strainers

...

Just a quick note:

A few years ago, Maine Sail changed his domain name from https://pbase.com/mainecruising/boat_projects to https://marinehowto.com/. The old domain is still up for now, but I don't think any new material is being added to it.

[ndutton]

Just a quick note:

A few years ago, Maine Sail changed his domain name from https://pbase.com/ to https://marinehowto.com/. The old domain is still up for now, but I don't think any new material is being added to it.

Just this sailor's opinion, much if not most of Maine Sail's articles are outstanding but remember they are his opinions and in some cases are self serving promotion of his business. The discriminating reader should decide for himself what applies to his particular boat and circumstance the same as any other information source.

[romantic comedy]

When I got my boat it had a groco strainer like Neal pictured above. The hose barbs (1/2 inch NPT) were made to accept either 5/8 ID or 1/2 ID hose. The ID of the barb just fits a 1/4 inch drill bit. So for the first 22 years my Atomic Four was cooled thru a 1/4 diameter hole. I had never seen a fitting like this.

Hopefully the barb is pictured below.

[Ando]

Ok quick question: the temp sender is the one in green, correct? If so, it’s not working. That’s why I put the wire on the one in red. Now the temp gauge is reading a steady 150 at 15 min of idle. What is the sender in red for again? Are they interchangeable? Where do I get a replacement sender for the one in green? Do these senders go out after awhile or is there something I can do to have the green one give me readings again (ie salvage it)?

[roadnsky]

It would appear that you actually have TWO different senders from that pic.
The one circled in RED looks like the sender for the EWDS system
(see my first pic) or the Cole-Hersee

My 2nd pic shows a typical gauge sender like the green circled one in your pic.

If you're getting a 150° reading now then you may be fine.
What temp readings were you getting from the other one?
Note that the reading from the "Green" location will likely give you a higher temp than the "Red" location just after the Thermostat. YMMV

[edwardc]

On my A4, the green sender you have circled is where I have an overtemp sensor. It is an NO switch that closes around 200F and sets off an alarm.

[Ando]

It would appear that you actually have TWO different senders from that pic.
The one circled in RED looks like the sender for the EWDS system
(see my first pic) or the Cole-Hersee

My 2nd pic shows a typical gauge sender like the green circled one in your pic.

If you're getting a 150° reading now then you may be fine.
What temp readings were you getting from the other one?
Note that the reading from the "Green" location will likely give you a higher temp than the "Red" location just after the Thermostat. YMMV

Yes, the one in red is set up for EWDS

The temp readings were 160-180, so I went through the entire cooling system to check for any blockages and I think I resolved the overheating but I don’t now know for sure bc now the sending unit isn’t sending any signals to the gauge now for some reason. That’s what made me take the wire from it and placed it on the EWDS sender (as a test to see if the gauge was faulty or the se ding unit).

So is this sending unit repairable? Or should I just buy a new one and, if so, which one should I get please?

[JOHN COOKSON]

I don’t now know for sure bc now the sending unit isn’t sending any signals to the gauge now for some reason.
So is this sending unit repairable? Or should I just buy a new one and, if so, which one should I get please?

The resistance value of the sending unit should change as the engine heats up. The numbers for a Teleflex temp gauge sending unit are 240 -> 33 ohms. I don't know what brand of gauge\sending unit you have. These numbers are only guidelines.

Take a resistance measurement engine cold and another when the engine is fully warmed up and see what the reistance change is, if any. The measurement is between ground and the central post of the sending unit with the wire disconnected.

Usually the sending unit and gauges need to be from the same manufacturer. Some are interchangeable. If you know the brand of the gauge maybe someone will be able to tell you which sending unit to buy.

ex TRUE GRIT

[Ando]

Why is it that this makes me feel like it’s the night before Disneyland when I was a child, or like it’s my bday or Xmas or something?
even set it up next to my bonsai plant for aesthetics