8V71TI zincs

[llldks]

Ok, PO painted everything white. So where are the zincs and how many on a 1972 8V71 TI?

Water pump and heat exchanger, and where on each?

Larry
Seadation

[MikeP]

Two on the heat exchanger, one on each side. They will have a large bolt head - maybe around 1" or larger, I can't recall. One MIGHT be on the water pump but many people don't use one there since erosion causes a lot of zinc particles to end up in the intercoolers. There does not appear to be any issue with not having them in the pump. There have not been any in my 1980 54MY's water pumps since at least as far back as 1992 and the pumps are original.

[rsmith]

Two on the heat exchanger, one on each side. They will have a large bolt head - maybe around 1" or larger, I can't recall. One MIGHT be on the water pump but many people don't use one there since erosion causes a lot of zinc particles to end up in the intercoolers. There does not appear to be any issue with not having them in the pump. There have not been any in my 1980 54MY's water pumps since at least as far back as 1992 and the pumps are original.

I was told when we bought the boat not to put two zinks in the heat exchangers because they cause a battery effect with the exchanger in the middle(i dont know how to verify that but ive been doing it for 34 years). Ive always put one in the h2o pump because ive got it bonded to the fuel cooler.If you let them go too long its a pita getting them out of the cap

[MikeP]

Actually, I omitted the HE zinc that is first in the RW stream to avoid the erosion and zinc particles that end up in the HE. I did this for years. Last year I noticed some green corrosion around the HE connections and I thought it was possible that this was due to insufficient zincs so I put the "forward" zinc back in. However, I have since discovered that, as suggested by folks here, that the green is never caused by galvanic corrosion and was due to a very slight seepage from the RW gasket at the HE. So I have removed the forward zinc again. So the only zinc in my engines is the one on the exhaust end of the HE.

[rsmith]

Ive had a lot of trouble over the years with the 1/8 pipe plugs that drain the neat exc turning to mush usualy they look fine until u try to put a wrench on them. I had one blow out at sea and ruined the alternator. I never use teflon tape because it insulates the fittings. I always use permatex #2 on the threads and have only had a problem with these little plugs.their brass

[Nonchalant1]

8V71TIs have zinc holes on both of the heat exchanger flanges. the flange can be placed so there is a zinc coming out the front side or the back side. Check both sides of both heat exchanger flanges for zinc caps. Original DD zinc caps have a square brass head. Newer universal replacement zinc caps have a brass hex head. These two types take different zincs because the threads on the original DD zincs were smaller.

The water pump zinc is on the upper half of the raw water pump. It is a shorter zinc than the heat exchanger zincs. I keep zincs in the raw water pump and the heat exchanger outlet side. No matter where you put them, they can slough zinc shards into something, raw water pump into intercoolers, heat exchanger inlet into heat exchanger and heat exchanger outlet into the shower heads (raw water inlet to the exhaust), so I put them where they were originally designed to go.

Doug