Repairing An Intercooler
When Perkins designed this engine, it was a simple tractor and truck engine and it was marinized as the “range Series”. They combined the transmission cooler, oil cooler and intercooler into one stack that is bolted together. I researched it a bit so please don’t quote me, the marinization was done by a third party that went out of business and all the castings were sold for scrap. Several companies make replacements but get you wallet out, Orka Marine was approaching 6k for a replacement. https://catalog.orcamarine.com/item/replacement-marine-heat-exchangers/replacement-marine-heat-exchanger/500940
Are you as disgusted as I was? I cleaned up the tube stack and housing with a pick, CLR and a LOT of patience. This was a known issue and a previous owner used a product like JB-Weld to make a patch which is dangerous. I want you to pay special attention to the color of the copper, this is supposed to be copper-nickel 80/20 and not copper. Electrolysis had leached out the nickel making this rim brittle. This was a ticking timebomb waiting to kill an engine. The aluminum housing damage looks bad but is an easy fix, the tube stack, not so much but I’m going to try.
The tube stack just pushes out however with all the corrosion, I had to use PB blaster and a rubber mallet over a days’ time. I didn’t want to use too much force and bend the tubes so I had to be careful.
I then took the housing and tube stack to a welder for repair. The housing was easy and it was complete in one day and cost around $200. After that, I took it to a machine shop and they put a flat face on both ends and then honed it out for $300 making it like new. This was a mistake though; I didn’t have the tube stack done so they guessed hole size based on an internal measurement. I learned that there is a slight chamfer on the housing and the ends are slightly larger than the internals. This was easily fixed by honing an additional 2-thousandths off and the shop only charged $100.
Pressure Test
The next step was pressure testing, I was not about to reinstall this and not know that it was perfect. A radiator store wanted $75 per section to test and there’s 3 sections (engine oil, trans. oil and intercooler) and each of them have internal and external sections or so I thought. Make sure to be clear when asking the shop for a written quote, I thought it was $75×3, when I got there to test, they wanted $75×6. They wanted to check the water side and the air/oil side separately to guarantee it was not leaking. I passed and went to the hardware store for ideas. I bought the parts from Lowes for around $50 and then got to keep the parts for retesting. Spoiler alert… this was a fantastic decision. While the O-rings held the pressure and all welding repairs were successful, one of the tubes in the tube stack was bad. I had the option to test each tube and weld the bad ones closed but decided to just buy a new tube stack. Fortunately, I found a new-old stock in a beaten-up case on E-bay and he was asking $1200 OBO. $1200 was the same price as a custom one new so I gave a best price offer of $500 plus shipping; much to my surprise they accepted and shipped it out that day.
I installed the new tube stack and pressure tested to 20psi because this was the max pressure of the turbo charger at 2400rpm. I usually run engines at 1800rpm to 2000rpm so I knew 20psi would be more than enough. The new tube stack passed the test and we were back in business
