sprink58

In converting my 255 Formula to Bravo I am engineering the set up/location of the raw water pump. Since I will have the raw water pump set up is there any real need for the original circulating pump on the engines? Seems redundant to me to have both. I see some rigs with it ...and some with a crossover that eliminates the pump. What is the determining factor in doing away with the circulating pump?

sprink58

WOW...I know I'm not the only one to think of this....anybody?

US1 Fountain

iTrader: (1)

Been discussed 100's of times, that many just don't respond anymore. A search will keep you busy for the rest of the yr.

Griff

On a basically stock engine, I'd use a circ pump. It will maintain more consistent temps. A crossover can create all kinds of issues with water pressure and oil temps.

brian41

iTrader: (1)

We run circulating pumps when ever we can to eliminate hot spots in the engine.

joe27baja

I use the crossovers and No issues what so ever plus the it cleans up the engine area....

Uncle Dave

The absolute determining factor is the need to run closed loop cooling.

I prefer the cleaner more functional crossover, and also gain a few (up to 15 HP) on the recirc pump.

I see no need to carry around a secondary but not actually redundant water pump in a fresh water application.

Uncle Dave

brian41

iTrader: (1)

We have found that the rear of the engine while running without a circulating pump is 50+ degrees hotter than the front. Take a temp gun out next time you run and check. If we run without the pump we run hoses from the rear of the intake to the front to help with the problem.

Rookie

iTrader: (4)

+1
I removed my circulating pumps and went with crossovers. At the same time I changed to Merlin steel heads. I never got more than 3 minutes after getting on plane and I would seize #8 exhaust valve right into the piston. This happened 3 times before I figured it out. Good thing I used Ferrea inconel valves I never took out a piston. I was not getting flow to the back of my engine. On the hose I use to see 240F+ on the back side of cylinder #8 and 160-170F on all other corners. I drilled extra holes in the heads to promote flow. The only thing that fixed it was drilling out the back water ports on the intake manifold and dumping into my exhaust. I had constant flow through the back of my engine.

I have my problems corrected and has been great for a few years now. I am not saying not to put a crossover on but know there is some issues that might occur.

Esal

iTrader: (2)

I always had a hard time getting the motor, on my old boat, to catch prime I would have to rev the p*ss out of it to get it primed. Not good for a cold motor. Once it was primed it was good for the day.