I have recently completed a 25 year sanger super jet 460 rebuild, and today took the maiden voyage. 1977 It is a 12jg and had an "A" impeller and would max out at 5200 and ran very, very, well. Years ago I rebuild the motor, I had research the impeller chart and decided to go with a "B" impeller. after all this work and today it did not seem like had the snap or top end. Hey it runs good but I am thinking I went the wrong way. I figure we have 400 - 425hp maybe I should I have stuck with the "A" impeller? "Original 330 hp A impeller"
What is the rule of thumb with 50 - 100 hp? do you go down or up with hp only not increase rpm. should I have stuck with the A?
If a pump came stock with an A impeller and you build the motor for 100 200 Hp 100-300 rpm increase, what would you want do do with the impeller.. what is labor cost for new impeller install.
thanks for your input,
millmnt
It really depends on what the engine was built to to gain the extra power.
Meaning that if it needs to be "freed up" to gain the rpm necessary to muster up the extra power, then cutting the impeller would be the way to do it.
Honestly, I feel an A is about perfect in most cases.
The cost you will incur is the impeller (you can't cut it "up") and of course the labor to swap it out.
Most shops will charge 3-4 hours for this.
It's not difficult to do this yourself with some basic hand tools and the rental of a couple of special tools.
The challenge for you is the lack of a transom adapter. The pump fits in the hull pretty tight and can be a pain in the buttowski.
Post up the particulars of your engine build, something sounds off to me.
Good luck.
GT
