on a 500efi waterthunder with a 3 blade 80" r with a 2.38 box what is the average pitch mark set at and what is is set at with a 2.68 box with a wot of 5300rpm

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not a single reply i know someone on here has to have a simliar setup or do i need to reword the question to put thrust into aspect instead of hp. what motor do u suggest to swing an 80" 3 blade "R" with a 2.38 box around the 2 mark and what mark will it swing the same prop with a 2.68 box. i am curious as to what motor meets these requirements? and to how much of a change the 2.68 box changes the pitch requirements of the same motor and prop with a preset variable of a 2 pitch mark with a 2.38 box.

I think after all the arguments on a waterthunder question thread yesterday people don't want to get into it again. The simplest answer can be had by picking up the phone and calling Waterthunder. I will say there must be a good reason he pushes 2.68's for his motors so much. My advice is to listen to what the guy building the motor says. Give him a call if you really want to know. 321-508-5316

this questions needs no arguing i am just curious as to how much of a change the 2.38 makes over a 2.68 i am not arguing either box if u want huge low end push a 2.68 box is the way to go if u want overall performance a faster boat but with the sacrifice of low end push a 2.38 would probably be the way to go i am just curious as to how much of a difference each box makes. i dont know the difference in performance as i am not able financially able to try each box i am just curious. would u need to go to a different prop if u had a 80inch r swinging it on 2 with a 2.38 box by switching it to a 2.68 or would the same prop work. what would be he average hp of the motor to swing this setup. i am not trying to defend either box just curious.

I'm an A/C guy but I have two buddies who have 500HP thunder motors with 2.68's that I ride with. I think neither of them will post on here can't say I blame em. The blue Hammant boat called She's a Blowin has one and it's an 80'' R set a tad past 3 and turns 5,400 he is gonna switch to a 4 blade! That boat is big and will haul the mail. I know another guy who has a 500hp with a 80'' R set on 3 turning 5,600. I will say both boats run dam strong loaded with people, just don't tell dave I said that! If I were you I would stay with the 2.38 turn less RPM's and tip speed pushes more then pitch but of coarse I'm sure you already know that!

thank you greenhorn anybody have a 2.38 box willing to say what they turn their's. i dont know of anyone else who builds gen IIIV,IV gm motors, ls or lq series motors othrer than dave, not trying to single u out sorry if it seems that way, u are just the only one talked about on here.

2.37 rotator here with a 600hp 496 and an 80-1/2in 3 blade R set on 3 turning it 5200.....

Stinger 2.38 box with 80" 3 blade R.Set at 2 mark turning 5250.Its not a Water Thunder.Its a Plumbers motor.383 with a bunch of HP.We're not at the boat ramp so I can't dyno the motor here.LOL.I cruise around 3100 to 3200 deep water.Skinny water cruise at 2200.It will tote the mail.I can run anywhere I want.And can do it with 5 adults and cooler.

everyone tells me the diff between a 2.38 and a 2.68 is around 300rpm's at the same pitch. I would believe that because I had somebody tell me Dan at Stinger say's you can't even tell between a 2.55 and a 2.68.

I'am running a 550 Efi Waterthunder with a ch4 2.67 3blade R pitched at 2 running 5900 RPM and this boat runs insane and does it all.

i find it very interesting that nomads boat & gobigred1s boat turn there props at the same rpms, nomad does it at 5250 on the motor with the 2.38, and go bigred1 does it at 5800 with the thunder 550 fi and the 2.68. thats 550 more rpms to do the same thing. nomads prop is turning2205.8 rpms at wot with the 3 blade r 80 in. gobigred1 is spinin his 2164.1 rpms dont know the length of his 3 blade r but there both on the 2 mark, very interesting

Its a 80'' with med hub

hey nomags you want to sell that motor back to me

Seems to me there is something wrong with your motor it should be on the 3 mark or better. I would call Dave and find out what the problem is.


Geoff

Would the difference be caused by him having prop set to run at 5900 rpm rather then the more typical 5200-5600 rpm range. How many rpm's would you estimate the difference would be between a 2 and a 3 setting on the prop. Bud

Good point!

I see your from Ponca City, OK. I'm not to smart about motors but wouldn't being over 1,000ft of altitude loose some power too. wait maybe not he is turning 600 more RPM's out of that prop then most people. It takes me about 125HP shot of nitrous for me to turn 500 more RPM's out of my 80'' sensnich 3 blade R so that sounds about dead on to me. I think some people on here don't realize how hard it is to just turn 300 more RPM's on a big prop. I now when I put a 50HP shot I thought I would turn 500 more RPM's I don't think I even turned 200 more I had to go aup to 125HP just to pick up 500RPM's.

I do, I had one. I think if he chokes it down to 5400rpm he would probably would be on the 3 mark.

Geoff

well dont underestimate nomags little motor it does have10.5 comp all eagle stuff world heads and 6 more cubes im not a engine builder but i have assembled a couple in my day, i was gonna put it on my fox boat and sneak up on some thunder ride boats but i sold it, i put it in a car for a week till i realized roscoe was gonna kill himself, i wanted to see it in a boat so i sold it to nomad for less than the parts in it , he let me drive it at the first howl bitch will put the left front corner under if you dont lift ,if nomad ever ran it wot it would probaly be scary hell nomads got every thing known to man in that boat some where hes even got heated seats, and 500 lbs of electonics he stacked fire wood to the gunrails and ran the bus when it was bad sticky like it wasent nothing and thats when it had the stump pullers on it, i bet the r blades are the bomb on it, its badder than i thougt it would be

Ya. Nomad told me how cheap he got that motor from you. That definitely was a great deal!

We are still playing with it when we first set it at 1 it spun the prop crazy rpm so we put it at 3 and it ran about 5600rpm but choked it down and had vibration, set it at 2 and it seems to run its best. Keep in mind this thing runs dry like its in the water and top speed is 70mph at 5900rpm, its a freaking monster and Dave still has to tune it.

im just happy hes happy , i would go crazy if i built motors for airboats and had a crap load of them out there, i gave nomad no warranty, he had a stock oil filter colapse right off the bat , and then a year later he heated it up pretty bad, water pump malfunction and the thing is livin good i coulnt sleep if i had 100 of em out there, cause i know airboaters there kinda like your babys theres so many things that can happen to a hipo motor specialy on a airboat. my hats of to people like thunder and felber, that do it every day, and buy the way carmotors suck

So froms y'all experience I have never dynoed my motor and I turn my 80" r set at 2 5400 on the trailor with a 2.38 stinger soft drive what would u estimate the horsepower to be in comparison to yalls know powers

dont know what your runnin but its strong 5hun plus would be my round about guess what you got

gobigred heres a question for ya i see you had a ww Sirius on you set up how did it do, i had that prop on a boat with a 230 belt and i loved it 2nd question how do the r and the Sirius compare just curios