AQ271C Raw water intake hose inner diameter for flush valve

[screamingbuick]

What size of flush valve do i need, its a 1988 350ci with the impeller on the harmonic balancer.

 

[alldodge]

Assuming the flush valve is for rpm's from idle to 1200 rpm, a 3/4 feed would be good enough to keep the impeller from damage.

 

[Scott Danforth]

the hose from the power steering cooler to the inlet of the raw water pump is 1-1/4" however i suggest a set of muffs and a cork vs the flush valve.

 

[screamingbuick]

Thanks, but muffs don't work on this lower unit because the finned openings are on the front edge of the lower unit. Not on the sides per say. I'll pull a hose and measure it this weekend.

 

[alldodge]

Thanks, but muffs don't work on this lower unit because the finned openings are on the front edge of the lower unit. Not on the sides per say. I'll pull a hose and measure it this weekend.

You mentioned a valve which lead me to believe the plan was the typical valve to shut off water intake from the drive, and have it come in from another source. This is how VP, Merc, Indmar do it

if this is the case then while the intake hose from the drive should be 1 1/4 in ID, and a valve is closed, another opened and it can be flushed with 3/4 in city water supply, same as if done if muffs could be used.

Now another way without using a valve, is get a bucket/tub to drop the drive in, keep the water filled in the bucket while the motor is running

 

[Scott Danforth]

Thanks, but muffs don't work on this lower unit because the finned openings are on the front edge of the lower unit. Not on the sides per say. I'll pull a hose and measure it this weekend.

You have to use the muffs for Volvo AQ drives. And you have to put a cork in the lower pickup.

Been using it for years, works better tgan the standard muffs on a mercruiser

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