Perkins 6.354 Raw Water Flow

I am about to re-install my heat exchanger on my Perkins 6.354 when I noticed that the raw water flow direction didn't seem logical to me.

My raw water flow is from the strainer to the raw water pump to the trans/engine oil cooler to the heat exchanger and out the exhaust.

What makes more sense to me is having the heat exchanger before the trans/engine oil cooler. The heat exchanger has an end cap the can be easily removed allowing removal of any impeller bits or other debris in the system.

Am I missing something?
Is there a good reason to have the trans/engine oil cooler first in the flow?
Does your Perkins 6.354 have the same flow?

That's how mine is setup.

Pack Mule said:

That's how mine is setup.

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Thanks for the feedback.

On my ex turbocharged version of that engine the raw water went thru the aftercooler, then the oil/tranny cooler before the heat exchanger.
On my Lehman it also goes thru the oil cooler first.

My 4.236, same engine without those 2 extra cylinders, is plumbed the same...pump-oil/tranny coolers-HX-exhaust elbow.

It's worked fine for 40 years. I ain't messing with it.

It is probably plumbed that way just to make the hose path easier. I doubt if you would see any difference in performance of the main heat exchanger if you plumbed that first. The oil cooler probably only deals with 5% of the total heat rejected to the cooling system. Measure the raw water in and out temps with an IR gun to see for yourself. I will bet you won't see more than a few degrees temperature rise across the oil cooler.

David

My 6.354's flow from the Pump, twin oil cooler, heat exchanger, then exhaust manifold and then inject into the exhaust at the elbows.

Most likely the flow is determined by the location of the components and simplest routing of the plumbing, as the water is still plenty cold coming out of the heat exchanger.

Thanks for the replies. It appears that the flow through the oil cooler before the heat exchanger is the standard operation.

I found a couple of bits of rubber in the heat exchanger inlet when I cleaned it out. No doubt from a broken impeller at one time. I'm wondering how they got through the oil cooler.

I have not had the oil cooler apart, so I don't know if the tubes in the oil cooler are larger than the ones in the heat exchanger or not. If they are larger or a possibly a single tube, that would explain it.

Anyone had their oil cooler apart so they can see the size of the tube(s)?

Mine is a twin cooler, a Y inlet and outlet with the top for trans fluid and the bottom for engine oil cooling.

jleonard said:

On my ex turbocharged version of that engine the raw water went thru the aftercooler, then the oil/tranny cooler before the heat exchanger.
On my Lehman it also goes thru the oil cooler first.

Click to expand...

Our turbo Volvo's are this way too. Which surprised me. Apparently, the cooling of the air charge is better when the water hasn't already been over hot fresh water and been exposed to exhaust manifold temps

And sorry I couldn't help with the original question. I don't remember the flow of our old Perkins.

Don't remember what original tubing looked like, but by now all our oil coolers have been replaced by aftermarket parts. I've been buying mine from The Manifold Warehouse, Vancouver BC. They are marked with the Seacamp name and ship from Blaine, Wa.
They are double chambered like yours and tubed like the heat exchanger, don't know about tube size. Usually find any broken impeller blades at the inlet to the oil coolers.

Edelweiss said:

Don't remember what original tubing looked like, but by now all our oil coolers have been replaced by aftermarket parts. I've been buying mine from The Manifold Warehouse, Vancouver BC. They are marked with the Seacamp name and ship from Blaine, Wa.
They are double chambered like yours and tubed like the heat exchanger, don't know about tube size. Usually find any broken impeller blades at the inlet to the oil coolers.

Click to expand...

It seems removing broken impeller blades from the heat exchanger with one bolt on the end cap is easier than disconnecting a hose from the oil cooler.

I know from past experience the maintenance side of the equation doesn't always factor into the overall design formula.

I've replaced two impellers on mine and both times I've found the blades in the oil cooler or in the hose between pump and oil cooler. Both times the blades broke off at the base of the impellers , so it's been a big piece that doesn't go far .

I was down to the boat today and noticed one other thing about the raw water flow. The diameter of the pipe/hose from the raw water pump to the oil/trans cooler is 1.5". The diameter of the pipe/hose from the oil/trans cooler is reduced from the 1.5" outlet to a 1" inlet on the heat exchanger.

I don't know if this is the reason the oil/trans cooler comes first in the flow or not.