Learning About 525's
 

Does anyone know about the old Merc "blower" 525's? Are they 454's or 502's? Are they 500 hp? Is this an inexpensive long block to replace if you have trouble? Can the power be increased by changing blower pullies?

Re: Learning About 525's
 

They are 454's. I'm guessing the HP is 500. Cant help on the rest.

Re: Learning About 525's
 

I have a set of 525 SC hawk's (454 cu. in.)

They say its a stock MerCruiser 420 hp. with a B&M 174 baby blower.3-4 lbs. of boost'

They run great, idle at 700, never load up.

You can change the boost by changing the pulleys.

I'm very happy with this set up.


L.S.

Re: Learning About 525's
 

They are bullet proof 454's with a wieand 177 blower. Blower is about maxed out as it is for this usage. Better off with a 250 or beter yet an 8-71.

Engine was built to be a blower motor with 7.5:1 compression, blower pistons, different cam and a few other things. It wasn't built on the cheap by merc and was 490hp at the prop and 525 at the crank.

Do search and you can find a lot of info here

Re: Learning About 525's
 

I heard the mercruiser labeled blowers were good, that you could reoil them. is that correct?

Re: Learning About 525's
 

I have a pair of 525's that I just freshened , due to smaller pullies. The rings and the heads were shot. I had the heads redone , new file fit rings, rod bearings, main bearings, All new gaskets and seals, rebuilt the carbs, and changed the oil in the blowers, I put the boost back to stock 35deg timing, and the motors run great. Merc did a nice job on these motors. I had a pair in a 29 fountain that I had built 5years ago, they are still running strong today and have never been apart. And they have had the ---- run out of them. " If you don't let off , They can't catch ya "