i need help from you pros. i am new at the air boat world and have a 14 by 7.5 2.5 deep. set up for 350 chevy. the prop i have is a 12 by 76 stump puller. i was told it is to big to run dd that i need a 2 to 1 prop drive are a 10 by 72 supper snapper. could i get some input. thanks
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wrong prop
- Thread starter clack707
- Start date
kwanjangnihm
Moderator
before spending money on a gearbox and moving your rigging, try a 72" signature series or sensenich Q :thumbleft:
is the motor stock? can you post a photo of your rig?
is the motor stock? can you post a photo of your rig?
my self personally I would go with 70 inch whisper tip Q. I RAN THE 72 AND THE 70 just by changing hubs and could get more rpms out of the 70 inch and a little more pitch which made the difference for me. but a belt drive 1.77 to 1 and 74inch ngq would be the ticket.IMO I came up with enough money to buy this boat and prop with hub and it about cleaned me out. I am 70 and not much coming in. I am rebuilding the motor with what I can scrape up. I just wanted to help the people that get flooded out like when the Red floods up here around Shreveport and the people in the south like Houston. IF anyone has are knows someone who might do some trading maybe I can get this thing together for the next flood. I thank you for your input I have read it all several times and will try to go in that direction. Thanks again
Deano
Well-known member
Unfortunately, my being in Central Florida and using a different brand of props, I'm not able to help you directly.
Were I you, I would call Patty @ Whirlwind and explain to her what you have, and what you are wanting to do. Their
number is (619) 562-3725. She is very knowledgeable and nearly always a big help. Really, all you minimally need is
the correct set of blades to re-use your current hub. She will be able to tell you which blades will fit those parameters,
so you will know what your options are going forward and/or what you are looking for to accomplish that end.
There could be a possibility they have taken a set of blades in on trade that you could use.
That type of possibility may also exist at American Airboats in Orange, Tx. (409) 883-7725 :dontknow:
Selling your current blades may allow you to recoup most of that additional expense. Best of Luck . . .
Were I you, I would call Patty @ Whirlwind and explain to her what you have, and what you are wanting to do. Their
number is (619) 562-3725. She is very knowledgeable and nearly always a big help. Really, all you minimally need is
the correct set of blades to re-use your current hub. She will be able to tell you which blades will fit those parameters,
so you will know what your options are going forward and/or what you are looking for to accomplish that end.
There could be a possibility they have taken a set of blades in on trade that you could use.
That type of possibility may also exist at American Airboats in Orange, Tx. (409) 883-7725 :dontknow:
Selling your current blades may allow you to recoup most of that additional expense. Best of Luck . . .
ercalabria
Well-known member
you, might try getting on facebook and then go to Red River Airboat group, or BRAB (Brazos River Air Airboats), or Southeast Airboat association. Most are members here on Southern Airboat also. The prop you have is a good match for 350 with 2/1 belt drive and should be easy to barter/trade out. I used to run 350 DD and used 72/38 and 72/40 wood prop for years before we could afford composite. Check out the classifieds here on SA also. Have you tried selling your composite prop yet ? How much ?
Deano
Well-known member
Considering the desired end result, there is no question that is the preferred path to take if you have the means. :thumbleft:
Given that course of action, the next biggest consideration to be aware of is that your cam
needs to operate in the same range where your prop is the most productive using the chosen gear.
Based on info in this following thread, it looks like your max prop speed should be 2700 rpm:
https://southernairboat.com/phpBB3/...t=the+older+Stump+Puller+blade+series#p661049
With a 2:1 reduction, that implies you would want your cam to enable you to spin 5400 rpm.
That's not to say that need to spin it that fast, but you will probably want to retain that option.
Does the engine already have an RV cam, or was that just the plan for going with direct drive?
If so, perhaps a 1.77 gear would be a better match if you don't want to change the cam.
In any case, there are improved results to be had by properly matching your engine RPMs with your prop's power band.
Cam choice and/or gear selection are the two primary and fundamental means of attaining that end.
Given that course of action, the next biggest consideration to be aware of is that your cam
needs to operate in the same range where your prop is the most productive using the chosen gear.
Based on info in this following thread, it looks like your max prop speed should be 2700 rpm:
https://southernairboat.com/phpBB3/...t=the+older+Stump+Puller+blade+series#p661049
With a 2:1 reduction, that implies you would want your cam to enable you to spin 5400 rpm.
That's not to say that need to spin it that fast, but you will probably want to retain that option.
Does the engine already have an RV cam, or was that just the plan for going with direct drive?
If so, perhaps a 1.77 gear would be a better match if you don't want to change the cam.
In any case, there are improved results to be had by properly matching your engine RPMs with your prop's power band.
Cam choice and/or gear selection are the two primary and fundamental means of attaining that end.
Deano
Well-known member
I am hesitant to say that was a mistake, but the odds are numerous that it will not be optimal for a 2:1 reduction.
What is the advertised RPM range of the cam you currently have?
If it is ???? -> 4800 RPMs, a 1.77 gear ratio would be a better RPM fit for your prop. However, be aware that a smaller engine
will benefit from all the gear and RPMs you can give it; hence, that gear ratio is typically used with a big block for that reason.
Given that you are looking to buy a used belt drive, I would kind of view worrying about the cam like putting the cart
before the horse. You don't know what gear ratio you will end up with, so the best cam for that gear remains undefined.
If you find a deal on a 2:1 then you would likely be better off with a different cam,
because chances are great that an RV cam is not going to pull all the way to 5400 rpms.
If you find a deal on a 1.77:1, the cam you have may work, depending on it's rpm range. In that case, I would
likely try what you have and confirm that it needed changed before I worried about it . . . hopefully it would not.
What is the advertised RPM range of the cam you currently have?
If it is ???? -> 4800 RPMs, a 1.77 gear ratio would be a better RPM fit for your prop. However, be aware that a smaller engine
will benefit from all the gear and RPMs you can give it; hence, that gear ratio is typically used with a big block for that reason.
Given that you are looking to buy a used belt drive, I would kind of view worrying about the cam like putting the cart
before the horse. You don't know what gear ratio you will end up with, so the best cam for that gear remains undefined.
If you find a deal on a 2:1 then you would likely be better off with a different cam,
because chances are great that an RV cam is not going to pull all the way to 5400 rpms.
If you find a deal on a 1.77:1, the cam you have may work, depending on it's rpm range. In that case, I would
likely try what you have and confirm that it needed changed before I worried about it . . . hopefully it would not.
your sure are a lot of help to me. Don't know what I would do other than make more mistakes with out your advice. thanks again for your help. I will keep trying to come up with a prop drive that will work I hope. If it comes to it I will change the cam. Any one need a new R/V cam HA HA. Thanks again.
One Eyed Gator
Well-known member
I may have missed it above But:
DD = Left-handed rotation
Belt drive = left-hand rotation
Gear drive = right-hand
So what rotation is your super snapper?
Also someone above mention they ran a 72x38 wood prop on a 350 dd he did not say but it was probably a stick prop (narrow blade) I ran a 72 x38 on a DD caddy for a long time it was a wide blade model.Another blade I tried on may caddy was a 74" super snapper, really did not care for it.
While you have gotten some good advice there are a lot on small details to consid
DD = Left-handed rotation
Belt drive = left-hand rotation
Gear drive = right-hand
So what rotation is your super snapper?
Also someone above mention they ran a 72x38 wood prop on a 350 dd he did not say but it was probably a stick prop (narrow blade) I ran a 72 x38 on a DD caddy for a long time it was a wide blade model.Another blade I tried on may caddy was a 74" super snapper, really did not care for it.
While you have gotten some good advice there are a lot on small details to consid
sorry about my like of info. I have a stump puller 3 blade 12 by 76 . It turns counter clockwise standing behind the boat. I been looking for a H 3 belt drive. I was told I need a 2.3 to 1 or maybe a 2.0 to 1. I am sorry about my like of knowledge but I got to learn some way and it is with the help of you pros that keep me in line. Thanks for your help. I really need your input. Sorry about taking so long to answer you but my 93 year old mom is in the nursing home and I have to take care of her needs. Look forward to hearing from you.