Perkins 4.108 low-line

[Richard Z]

Is anybody familiar with the low-line model of the 4.108?
I've been having some problems with mine, mostly overhearing and hat exchanger problems. In my search for a similar heat exchanger, I found out that there are two types, the standard and the low-line. I have the latter, where the heat exchanger is separate from the header tank unlike the standard where it is inside the header tank. Also another difference is the obvious location of the thermostat on the standard, but a mysterious location on the low-line,( I am yet to find it)
If anybody with a little knowledge about the location of the thermostat cab throw in some ideas, that will be greatly appreciated. Also if anybody knows what does the low line mean for that model.
Thanks

[model 10]

If we are on the same channel, the thermostat is under the header tank.

[beebopbogo]

My Perkins 4-108 was overheating and it turned out to be the heat exchanger. I also replaced the thermostat just in case. Easy and cheap, and yeah: under the coolant tank. The coolant hoses had some scaling which reduced the throughput a bit, so replaced those. The heat exchanger had the worst clogged holes though and a quick muriatic acid soak cured that up. See http://adamrbecker.com/engine-overha...-water-system/ for details.

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[DeepFrz]

beebopbogo, I read your blog and like it but have a couple of nits. First, you don't mention cleaning and inspecting the water injection elbow. This item can be a big problem in engine overheating situations. Also about not lubing the new impeller. IMO, that is a big mistake. Some dish liquid and water on the impeller will keep it from overheating in those first seconds before the cooling water reaches it. Also, the hose and anti siphon valve between the heat exchanger and injection elbow should be checked and cleaned.

[Richard Z]

Thanks.
I have already cleaned all the water tubing abd pipes including the injection elbow and the water heater hoses.
The copy of the shop manual says that these model(low line), the thermostat is located under the water outlet casting and it's on the cylinder head. There is a lot to take off to reach that area, and my concern is that I don't want to take anything off that is not broken. I hate to take stuff off and maybe break a few parts only to find out that the thermostat is good. The old saying about disks( if it ain't broke, don't fix it).
I ordered a new heat exchanger, so I well install it as soon as I receive it abd test for over heating.if none, then problem solved, if not I'll start tearing stuff up to find the thermostat.

Any body has an idea what does the designation low-line stand fur?

Thanks

[Richard Z]

Correction.the old saying about diesels nit disks

[beebopbogo]

DeepFrz: Thanks for the additional content. I'm always learning and that site is definitely a work in progress. It just gets more detailed and more accurate with time thanks to good quality criticism

Richard Z: My Perkins has just a couple easy disconnects and a few bolts to remove the coolant tank. I was worried I'd be digging myself into a new project by removing it, but I was pleasantly surprised at how easy it was.

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[Richard Z]

Beebopbogo,
Thanks, I was worried, but I did it, and there it was under the header tank. I appreciate it. That manual threw me off and I did not want to think about all the parts that I would have had to remove to get to where it said the thermostat will be. Thanks again....
I could not find a similar thermostat (open at 155 and fully open at 188) so I bought one that starts opening at 160, so hopefully that well be a good choice.
Still waiting for the new exchanger to put in and try it.

[Richard Z]

Guy,
Thanks also. Y you were right. That's again

[Chasing Summer]

DeepFrz ... you know you could sail south to warmer waters, say, the South Pacific. You'd have to change your name, of course.

You mentioned checking the water injection elbow. I've read a lot of your posts. You have a lot of diesel knowledge. I have a quesiton for you. As you know I rebuilt my 4-107. This does not, however, make me a diesel mechanic or installer. The engine I bought for some accessory parts that I didn't have came with a Westerbeke exhaust riser. Which do you prefer and why? injection elbow and water box or exhaust riser and would use a water box with the riser?
I was planning to using 2-45degree elbows to lower the exhaust riser about 4 inches below the manifold before going to the overboard exhaust, which is pointed down just above the waterline. Would it be good to put a high loop with a vent between the riser and the overboard?
I can post a picture of where the engine is in the boat if you need me to.

[Chasing Summer]

I've been reading about marine exhaust systems. Hmmm ... guess my aluminum wet riser is way old fashioned and a big NO NO ... especially way I was going to install it.
Just one of the articles I've been reading: Designing a Marine Exhaust System
I'm don't even have the engine bolted down yet, but I'm always planning projected projects. I know that water and engines only mix when done right. Also, 1000 miles out to sea is not the time to discover you should have done it differently.