The engines are 565 ci. alum. heads, stought hyd. roller cam, water crossover & no tstats, 5600max.mostly 42 to 4400rpm cruise, # 3's on fat ole 38 cig.Question is, will the Johnson pump part #10-24232-1 flow enough to cool them?Also is the additional bracket even needed? Some o.e.m. do not use a bracket the 2- 11/4" hoses appear to be rigid enough to keep the pump from rotating.

WTF did I do Something wrong? I realize this pump has been discussed b4. but I thot some of you experiened engine guys like Dave @ Wesco And others would Have tried this.

Don't know anything about um, but give it time. Probably not that many people have used them and those that do know about them have not checked the board since you posted.

I had one on a SB 350 and it worked OK. The pump has to be perfectly centered on the crank or it shakes like a b*tch. Use a bracket for sure.

Have had these on my ski boats and they have worked very well and are easy to service. As far as flow, I can't imagine it wouldn't serve up as much as the stock merc. Eric

I use one on my Donzi and love it.

If I'm not mistaken, they are also used on all Volvo big blocks, as well as GM's 8.1L 525 race motor. I think they provide plenty of flow, and changing impellers is a BREEZE!

MOPOWER from this site did the conversion, maybe he'll chime in...

Jim

I have a crank mounted pump on a SBC Volvo. I dunno if it is a Johnson or not, I imagine it is, as I don't think too many people are making pumps these days. Anyhow, it is stock and works fine. I have heard they sometime make a lot of water pressure and impeller wear is somewhat accelerated because the pump obviously spins at crank speed. I never looked at a pulley driven setup close enough to see what a normal reduction is in that style setup. I also agree on most boats impeller changes are easy. (my boat has a fiberglass wall just in front of pump that makes you hang upside down like a monkey to change., I would rather do 5 drive pumps for one of my "easy" ones)

Night,
I have a pair of Johnsons on my NA 540s with circulating pumps , t-stats , oil coolers and ps cooler and temperature has never been a problem , nor has water pressure. I've spun them as high as 5600/5800 and had 10 lbs of pressure .

AND you have two less belts to worry about.I changed mine because in my application it took over an hour per pump to change impellers with the Merc setup . These are 10 minutes hanging over the back seat .
I do use the bracket to hold them but you are probably right about the hoses holding them by themselves. If I remember correctly the bracket was about $10 and I figured it might relieve any stress on the hoses and clamps. Another thought is you can't easily change belts with the pump and hose attached to the crank. That' s why you see a belt in place and tied back in the one picture. It's already over the hose and pump...just swing it around into position and tighten the belt.Starboard pump had to be removed to get engine out of boat.

BTW 10-24232-1 are the pumps I'm running and I did have the same concerns as you before my conversion
I even went as far as to check the pump specs (both Merc and Johnson). This turned out to worsen my delemma since the Johnson gph is about 1/2 that of Merc. All I can say is , you see it and it works for me.