Brass Props?

[Beefer]

Are brass props any good? I have a SS 19"p now, but want to try a 17"p (only getting to 4100-4200 rpms with the 19', should be between 4400-4800. It's a Marc 488 w/Alpha I Gen I outdrive. I can get a 17'p brass quicksilver for $40, and was wondering if it's worth the $$$ to see if the improvement would be there, or to have as a spare. Thanks!

 

[Bifflefan]

Re: Brass Props?

should be between 4400-4800.

Are you sure on the max RPM???
I have an 84 470 and its max is 3800-4200. Of which I never go over 3500, but I can if I wanted to. I have an 18p and 20p, both 4 blades and have no trouble with either of them getting to the max rpm i run.
I also have a 16p 4 blade (equivalent to a 17p 3 blade) that I dont run because it can over rev the engine, even with a skier in most cases.

Im wondering if you may be in need of a tune up.

As for the brass, I thought they were only for inboards, so im no help there.

 

[Beefer]

Re: Brass Props?

Yep, says it right on the valve cover - 4400-4800 rpm @ wot. Just gave it a tune up about 2-3 weeks ago, along with a bunch of other things while I was trying to solve a bogging/stalling issue (bad fuel line). What's the HP rating of the 470? Mine is 188hp, 224ci., maybe there is a difference between the 2?

 

[Bifflefan]

Re: Brass Props?

Its the same motor, mine is 170 HP. the only difference I know of is your is a 4 bbl and mine is a 2 bbl.
And evidently, it has a higher RPM than mine.
Like I said mine is on the one in the pics in my signature and I run a 18 and 20p all the time with 3 or 4 adults and 2 or 3 kids either in the boat or on the tube.

470 means 4 cylinder, 170 HP.
488 is 4 cylinder 188 HP.

 

[Frank Acampora]

Re: Brass Props?

First off, It is a BRONZE prop although most refer to it as brass. Brass is an alloy of copper and zinc. It disassociates and corrodes in (salt)water so is never used for props. A lot of guys have their b*lls made of it though. (In stormy weather they clang together and lightning shoots out their *ss)

Sorry, I digress. Bronze is an alloy of tin and copper and in addition to not dissociating, it is stronger. Remember: It was the Bronze Age, not the brass age. Ancient swords were made of bronze. Naval bronze is a specific alloy and stronger yet.

Anyway, Before stainless became widely accepted and relatively cheap to manufacture, bronze props were the premium ones. They are still used in many larger boats and straight drive ski hulls. Are they good? Depends upon your definition of good. They are a better alternative than aluminum and when polished look way classier. Will they damage your engine or outdrive? Same arguments for and against stainless. If you have your eye on a bronze prop for 40 bucks, snap it up. That's a decent price. Even to just hang on the wall.

BTW: I am running a bronze two blade racing prop on the boat in the avatar.