Cooling Systems Engines and Such Forums

Questions regarding the Farymann R30 and cooling…

Several years ago (about 10 now) I replaced my water pump and believe it was a Jabsco 3nnn series. The only suitable replacement the Jabsco distributor could find in the catalog was a 2620 with a 5.8 GPM flow. It recently gave out and I purchased a 3890-9011 which pumps 11.3 GPM. This required fabricating a new mount and since it wants 3/4″ hose, new hoses all around.

The inlet ports to the water jackets are 3/4″… yet the outlet ports at the thermostats are 1/2″. Is that the way R30s are configured from the factory?

Is there any risk that an 11.3 GPM pump will blow seals?

While hosing the cooling system, I've found what looks to be electrolysis crud under the water jackets. How do I assess how bad this problem might be? Also, what is the best method for ensuring the R30 is properly zinc'd against electrolysis? That is, where to put the strap, what connections to check, how to check the water jackets – they are supposed to isolate sea water from the motor (according to the R30 manual).

Thanks in advance for any help and advice.
John

Update for anyone interested... The 3890-9011 is a good pump for the R30, but on my engine, I had to fabricate a new mount. The pump just barely fits in that it extents aft further than the 2620. In fact, I may have to grind down some of the pedestal edge as it slightly interferes with the oil dip stick.

Whereas a previous owner who replaced a hose here and there without using adapters (just cram the hose on and clamp it down), now, all nicely large hose (3/4" inlet, 1 5/8" exhaust) is in place, no crimps where hoses turn and adapters where needed!

Taking the time to do a job right is well worth it...