no rpm
 

91 42 lightning staggerd #4s on boxes one intch below bottom 900 hp blower motors herring 18-31 18 deg rake can only get 4500 rpm 80 mph also tried some merc 18 -26 5 blade 84 mph @ 5100rpm all trimed out are these hulla that slow ????

Something is wrong, either your drives are too low for the props that you are running or the props are too big for the power that you are making. You are not getting into your rpm range. I would guess that you should be well into the 90’s if you making 900 hp. Someone should pop up that is running #4 drives to help.

Maybe the guys at bblades can help with a prop size : http://bblades.com/

Hey Tommy, Dan is having similar issues with his Flatdeck cig. 17.5x28 5 blades just are too much, even with his 1.58 ratio drives. Cant even get to 5000 with them. I'd like to try those 26's you speak of on it?

Anyhow, about yours. I know its a different animal, being staggard, and a 42, but my 4's are 1.5'' below the bottom. 5 blades slowed me down big time when I tried them, and they were only 16.5 diameter. I know everyone gets excited about 18'' diameter 5 and 6 blades, but, I think you may wanna see what some heavily cupped 4 blades will do on it. I don't think your high enough to truly warrant a 18'' diameter 5 blade wheel. I know ive tried 4 different sets of 4 blades on mine, all similar diameter, and similar pitch. Some wouldn't even plane, some planed like it had TRS mounted 5'' below the bottom. Weird.

Last summer on my non stepped 38 with IV"s, I saw 88 on gps, turning 17x28 4 blades at 5600ish. Engines made around 760HP at that rpm. At 6000RPM they make 800hp.

I have a mint set of 26 spline 17x29p 4 blades. They aren't heavily cupped and don't plane as well as the small shaft 17x28's I am running, but might get you an idea of which route to go once on plane. Dan tried them and had a hard time planning but it did get up. He didn't go WOT, which was what the whole purpose of trying them. We may try those again on his this weekend to see whats up, and where to go. I think those 5 blades he has now are just too much for that setup, esp since he put 2'' spacers in. Its all trial and error. You'll see 90 or better, just think its gonna take some tuning. Cant wait to see the boat. What ratio are your iv's? We thought dan's were 1.5's, but after tearing them down and counting teeth they are 1.58.

To much prop....try 4 blades as MT stated.

joe thanks for your input the drive ratio is 1.50 let me know how dan turns the 29s

Will do. We're gonna give them a whirl and see what happens. Maybe tomorrow depending on my work schedule.

Tommy, I have some vintage magazine articles in front of me.

First boat, was a 1985 12 Meter side by side. With 700HP Turbo engines, and ssm 3 drives, radar was 84mph. Turning 17x28 props at 5500. (prob 3 blades in 1985)

Next boat, 1994 42 Fountain non stepped Staggered 800SC with #6 1.50 wet sump drives. The 800sc's were actually rated at 700HP. Boat ran 84mph on radar, turning 17.5x30P 4 blade cleavers to 5200rpm.

Maybe in the next few weeks, I'll bring mine up to racine, and have dan bring his cig up. Maybe get you and kris out. It can be a weekend of old cigs and old fountains, maybe do some testing and tuning.

joe interesting #s the 42s are a little sluggish sounds like a plan on the testing let me know

I also agree with the 4 blades

I`m hoping the boat wakes up with a set of different props, right now its like I`m towing another boat, from 3500rpm I give it full throttle and its a turd, not much happens.

Im gonna bring some pulleys tomorrow that will make 14psi. You'll see something happen alright when you push those throttles down! It will be a fun 30 seconds. Then we'll play dumb on that and call Kris to help us put some pistons in. lmao

On a more serious note, we'll get here going. You have all the ingredients, just need some fine tuning. Prob same for tommy.

I can tell ya a couple years ago when I first installed the 250 blowers on my engines, initial run on the river I saw 66mph on GPS. I almost puked. By the end of that summer, with some tuning, props, etc, it ran 83mph before I put in away for storage. No bs.

dan I know the feeling its like your on the rev limiters at half throttle I hope the 29s work better for you joe I still have the 17-28-4 blades you tried out dan can use them if he wants to the 26s I tried was a one shot deal they were off ricks nortec

Tommy, are you throwing a rooster tail at speed?

yes, not like a #6 boat I would say 5 feet high 60 feet long

Little birdie told me the big old orange Fountain hit some good speed numbers with some 4 blades.

word travels fast tried some beat down 4 blades 95 @6200 rpm just what the 900s needed im going to try some round ear 4 blade soon keep you posted

Awesome!!!!!! I have those 17x29 4 Blades cleavers you can try also if you want.

Im happy for you man. Thats a number to be proud of! Those round ears just might be the ticket. Carry that nose higher out of the water and get that beak up in the air :)

Godd dammit though. I wanna spend a lot more time in racine next year with you guys, really liked it there. Looks like im gonna have to step up my game to run with you guys though! Know anyone who wants some 468 shortblocks :(

Love that restored fountain
Any updates ?? Did you try the round ear props, yet?

great news!

the round ears got sold on me still looking for some 4 or 5 blades to try out

Tommy I have those 17x29 big shaft 4 blades your welcome to try

joe I should try them out are they 15 deg rake are you coming up any more this year if not ill come see you

Yes tommy they are 15 deg. I had them scanned and one prop measured like 29.5" and other like 29.4" of pitch, so they are about as close to a match as you can get pitch wise. I am looking at a used Lincoln town car up in Milwaukee at a dealer and was thinking of going to check it out soon. I can always bring the props up and meet ya

I have a set of 17.5 x28 5 blades and this weekend I`m picking up a set of 17 3/4 x 27 4 blades... so theres 2 more sets you we`ll have at our disposal.. all I ask is for a ride at WOT:evilb:

I also know of a set of Herring 5 blades 16.5 x 28, 16 degree rake but they want $6K ..

Same here!! I'll bring the Cheetos and cheese puffs in case we go out on Ricks boat

Joe, I know ware you can try a set of 18x27" but they are small shaft 19 if that will help you guys out !!!

Hey Tom ! Those might be worth a try on mine and TNT1's boats. Icedppl has the big shaft 4's.

Yeah, I got a big SHAFT... Mild has a small SHAFT and a paper route but we still love him.

I can go with 19 or 26 spline the 18-27 may also work let me know if your coming up

I think I found the right Prop:


http://33outlaw.zenfolio.com/img/s11...91178751-4.jpg



I may need a bit more boost thou...

wow , impressive BIGGER dose look better..............:whistle:

deadlyhammerhead what do you know about the 18-27 props are they in good condition

They aren't labed and I just took them in and had them checked for true and balance that is all I know......

With the numbers u posted the slip is 9% that isnt bad. Sounds like the motors could be failing or not up to full HP. You also are running to deep for a Fountain.

extemeracing whats the best prop shaft height on this old school flat bottom with ssm #4s have you ever had a chance to run one

deadlyhammerhead have you ever run these props? are they a full 18" tip to tip how much $$$

Yes they are 18" tip to tip 6" hub , no I have not run them I am sorting out my own demons with mine LOL motor issues so I never got to these props..... don't know how much $$ would like some 18x25 4blades for mine , the original owner of my boat said that worked best for him with the same power .....

hammerhead can you send pics [email protected]

Sent you pic. check them out and give me a call..........