Caddilac Reductions

[mickey5978]

Please post info about those boats running caddy reductions. Engine vs. prop RPM's, prop size etc. Built a 479 (472.035 over) Has about the same HP as a 502/502 with about 150 more lbs torque. If it were yours, what ratio would you run. I keep reading about everyone's MORE RATIO=better. I just don't want to run the higher rpms. Want the motor to last a LOT longer! Caddy's aren't the best at running high rpms for a sustained period of time (running dry for extended periods of time if you had to). I have the whirlwind prop PSR 80 prop max rpm is 2200. I think I want a 2:1 So max rpm engine is 4400 and prop is 2200. Convince me I am right or I am crazy before I send my life's saving to Faron. (just kidding thre, Faron)

 

[jdotson]

I'm running a 2:1 with a 78" 3 blade "wide" Sensenich. I've pitched it numerous times with various results but I'm happiest with it pitched to run 4200 WOT. At that setting it cruises at about 2200 and moves on ground around 2900 - 3000 rpms.

 

[Waterthunder]

There ya go that kinda proves my point you just stated your favorite spot is turning 4200 with a 2.12 that comes too 2,000RPM at the prop. Everybody and their uncle, boat manufacturers and prop manufactures will all say that’s to slow. This is how I set my stuff up. I bet your boat is a great cruiser and planes out at fairly low RPM. So if you were to run a 2.38 with the same exact prop speed your motor would turn 4,600RPM then I would just a little more pitch to choke it down 200 more RPM then go out and pull up some stumps and cruise at a very low RPM. Like I always say use the gearbox as a torque multiplier not an RPM enabler. I run a 2.68 and set my pitch so my motor only turns 5,800RPM I NEVER EVER turn it that high unless I’m racing because I have soooooo much push because of how much pitch I’m swinging I only tap the throttle to run the hill. My buddy that refused to believe this theory went with a 2.38 to one and cruises at 300 more RPM and can’t run dry as good as I do. I feel the hull you are running dictates what gear box you should run just as much as the motor does.

 

[John C]

I am running a 500 caddy on a 15 x 8 ft apache hull. mods to the motor are about the same as jdotson. I was turning it up to 5200 rpms With a 3 blade Falcon, 80 in. After getting alot of good advice here. I maxed the pitch out. Now I am turning it up to 4600 rpms. All I have to say is WOW. big differance. I would like to get her down to 4200rpms but I am all ready 1/4 in. past the start mark. Wish I had a little more prop. I am running a 2.12:1 rotator gearbox. Now I know why most of the caddy guys run between 4200-4400 rpms. What thunder said about more pitch, lower gear ratio makes sense to me. I think she would run even better with a 2.37:1 and more prop.

 

[bondsman]

i have the psr blades on my caddy the usefull range is from 2200 to a max of 3000 prop rpm.they push real nice.i have a caddy 1.9 -1 gearbox
60degrees of pitch max engine rpm almost 4200 rpm. i have it pitched deep i wanted less prop sound is why.

 

[mickey5978]

bondsman, can you run dry? how well if so. I just want to be able to run up 0on the bank to park my boat and NOT have to worry about getting stuck. Not looking to cruise the roads or anything. Just enough to use if I need it.

 

[bondsman]

i can go just about anywhere i want. jdotson has a video of how well his caddy performs on the video link its called reducted caddy pounding ground.we are set up similar.