4-154 thermostat housing

[Paul Barbour]

Seeking solutions

The 4-154 North American version thermostat housing is such a pain.  Some of you know what I mean.  It’s close proximity to the heat exchanger (on my engine 3/4” space between the two) makes it impossible to put it on the stud and at the same time put on the hose connection to the heat exchanger – or so it is for me.

The problem is the stud.  However, removing the stud does not appear to be an option.  There is not enough clearance to use a bolt.

I started looking for replacements / options so that I don’t have to take the heat exchanger off to maintenance the thermostat.

The Japanese version uses a straight up housing and a hose that turns 90 degrees and is 1.5 on the housing side and 1.875 on the heat exchanger side or so I think.  I bought the housing being very excited at such an easy solution but sadly found the hose is not available.

So what are other owners doing?  Your going to laugh I know, but this has been a part time project going on 4 months now just because I got stubborn about taking the heat exchanger off.  So I would really like to put this to bed and hope someone has the magic answer.  Also, the North American thermostat housing is not in real good shape anymore.  I tried to buy one but I was told it was $400.00…… This made me even more stubborn.

Paul

[Peter Roach]

From a frustrated brother - I can feel your pain. I have thought about having another housing made that has a slot cut in the side of the stud hole on the housing so you can slide it under the stud once it is in place. You could then tighten down the bolt. I have not done this but have thought about it. Let us know what you come up with.

[Paul Barbour]

Yep, gave the slot idea some thought as well.  I thought it would work but Rick at Gulf Coast Machine was not confident it would work once heat and other issues with being attached to an engine began to effect it.  He thought it might leak or worse crack and leak.  He is good at what he does, has not been wrong yet, so I gave up the idea.

If I come up with something...... I will get back to ya.... gotta do it soon, I don't like having the engine apart during this time of year.....

Paul

[Dave McCampbell]

Hi Paul,

Hope all is well and this is the least of your boat problems.

As you probably know, I too have a Perkins 4154 NA version and have had the problem you mention.  No matter what you do, it is a tight fit to leave the SW heat exchanger in place, bolt on the thermostat housing and then fit the hose between the two.

However, if you use the new blue silicone engine hose and notch it where it fits over the inboard thermostat housing stud/nut it will slide on considerably easier than if you are using black heater hose.  Slide the hose on the heat exchanger first, then bend it to slide over the thermostat housing with the notch in the hose over the stud and then install the two hose clamps. 

It helps if both the heat exchanger and thermostat housing nipples are clean and smooth and if you apply some Red Silicone Gasket Maker to both.  With the right Perkins thermostat and the blue silicone hose it will be years before you have to do this job again.

Dave

[Jules Shockley]

Paul,
I must have a Japanese housing as the connector comes straight up out of the thermostat housing. I,too, had a frustating time trying to get a short 90 degree hose with slightly different diameters at each end. A piss poor design. I found a copper plumbing 90 of a middle diameter (1 1/4 or so) and was able to fit short straight pieces of hose to  each side. With 4 hose clamps, it looks a bit Rube Goldberg , but it holds well and has been on for 3 yrs and 600+ hours. I can send a picture if this is not clear. By the way, I use propylene glycol as an antifreeze as it is less corrosive to the aluminum heat exchanger. Now I din't notice any tell-tale white residue.
Man is this fun or what?
Jules