76" NGQ RPM

Aircraft powered airboat discussion.
Post Reply
carte89
Southern Airboat Member
Posts: 42
Joined: Tue Jan 29, 2019 10:19 am

76" NGQ RPM

Post by carte89 »

I currently turn the prop 2600 wide open on the water. I like the cruise rpm and seem to be able to do everything I need, but was curious on wether or not the extra 100-150 rpm would give any more push. Thanks for the input
14' x 7.6 Robicheaux Lycoming 0540 up-stack pacemaker 76" NGQ

User avatar
smokster
Southern Airboat Member
Posts: 156
Joined: Sat Jul 28, 2007 8:38 pm
Location: Interlachen FL.

Re: 76" NGQ RPM

Post by smokster »

mine likes about 2800 but its a 72"

SWAMPHUNTER45
Site Supporter - III
Site Supporter - III
Posts: 3034
Joined: Thu Nov 21, 2013 11:38 am
Location: Naturecoast, Florida

Re: 76" NGQ RPM

Post by SWAMPHUNTER45 »

It is hard to say if going up in rpm and down in your pitch will yield a gain in push. I would strive to put it at 2750 if it was me. I ran a 76 NGQ on a Branch 514 with Nitrous. We would choke it down around 2600 so when on the power adder we were under 2900 rpm. That prop liked pitch. If you set it at 2750 I think you will get good push and a faster spooling which may be snappier. It is an easy test to perform so experiment and find what is best for your engine.

One Eyed Gator
Southern Airboat Member
Posts: 1340
Joined: Wed May 30, 2007 11:33 am
Location: Ocala,Fl

Re: 76" NGQ RPM

Post by One Eyed Gator »

My 2 cents take a maker and mark current pitch then i would be to change the pitch and take it fro a ride. Take your tools with you and changed the pitch a few times and see what works best for your set-up. To me you have to find the sweet spot between snap and push/ cruise rpm.

Also remember that wot on the water is about 50-100 rpm more than static on the trailer.

carte89
Southern Airboat Member
Posts: 42
Joined: Tue Jan 29, 2019 10:19 am

Re: 76" NGQ RPM

Post by carte89 »

I double checked my rpm, according to my pacemaker read out I'm at 2650 wide open on the trailer. Coincidentally my mechanical tach went out between the original post and now so it may have been off. I have a replacement on the way.
14' x 7.6 Robicheaux Lycoming 0540 up-stack pacemaker 76" NGQ

User avatar
kwanjangnihm
Site Supporter - IV
Site Supporter - IV
Posts: 2131
Joined: Sat Mar 30, 2013 8:23 pm
Location: Bartow FL

Re: 76" NGQ RPM

Post by kwanjangnihm »

At 2650 WOT where is the pitch mark? Are you over or under 2 right now?
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

carte89
Southern Airboat Member
Posts: 42
Joined: Tue Jan 29, 2019 10:19 am

Re: 76" NGQ RPM

Post by carte89 »

I would have to double check but I am 90 percent yes it is under 2
14' x 7.6 Robicheaux Lycoming 0540 up-stack pacemaker 76" NGQ

carte89
Southern Airboat Member
Posts: 42
Joined: Tue Jan 29, 2019 10:19 am

Re: 76" NGQ RPM

Post by carte89 »

IMG_1724.PNG
IMG_1724.PNG (72.83 KiB) Viewed 1884 times
14' x 7.6 Robicheaux Lycoming 0540 up-stack pacemaker 76" NGQ

terrible ted
Southern Airboat Member
Posts: 2878
Joined: Tue Aug 12, 2008 8:07 pm
Location: orlando

Re: 76" NGQ RPM

Post by terrible ted »

It will depend on you motor HP at rpm. My motors rating at315 hp @ 3200 and 3400 is for like 5 minuets overrev. I run a 74 inch prop @ 3000 slightly more push than at 2700. But fuel economy better at 2700

carte89
Southern Airboat Member
Posts: 42
Joined: Tue Jan 29, 2019 10:19 am

Re: 76" NGQ RPM

Post by carte89 »

I like where it is at as far as cruise rpm and normal usage. Just was curious if the extra 100 or so rpm would make that much difference. Mines a 300 hp upstack. I believe it was a tio engine but is now a carbed setup with n/a
14' x 7.6 Robicheaux Lycoming 0540 up-stack pacemaker 76" NGQ

flcracker9
Site Supporter - III
Site Supporter - III
Posts: 538
Joined: Mon Aug 11, 2014 10:05 pm
Location: Loxahatchee

Re: 76" NGQ RPM

Post by flcracker9 »

As a general rule, like mentioned previously the NGQ props like RPMs. The way I look at it, why not try it and see? It's easy enough to adjust and if you don't like the results, move it back down. I run a 72" NGQ, it's at the 2-1/2 mark, and it runs 2850 on the trailer, that's where it seems to run best on my boat
12' Open Palm Beach, IO-0470-L 260hp, 72" NGQ

SWAMPHUNTER45
Site Supporter - III
Site Supporter - III
Posts: 3034
Joined: Thu Nov 21, 2013 11:38 am
Location: Naturecoast, Florida

Re: 76" NGQ RPM

Post by SWAMPHUNTER45 »

You don't spin a 76 NGQ with winglets like you do some other shorter slick blade prop.

Set it at 2750 on the trailer if you want to try a different setting and that should have you at 2850 on the water apx.

We found the prop liked pitch and taking pitch out only favored a weak engine or an engine with to much duration in the cam.

When that 76 inch NGQ gets above 2850 - 2900 all I remember was the deafening noise it made not an increase in push.

The maximum safe rpm for the NGQ is 2850

When in doubt call Darrin at Sensenich

User avatar
Slidin Gator
Site Supporter - IV
Site Supporter - IV
Posts: 995
Joined: Sat Feb 03, 2018 11:33 pm
Location: Jupiter Farms, Florida

Re: 76" NGQ RPM

Post by Slidin Gator »

I run a 74" NGQ with the winglets cut off, making it 72", on a ~250 Hp engine. According to Darrin the performance with or without the winglets is supposed to be similar with the same size hub. The prop is quiet below 2,000 RPM but it beats me in the chest at 2,850 RPM. I change the pitch depending on the need.

For summer time frogging etc., I set it to 2,600. At that setting it runs quiet as I can cruise and run most ground below 2,000. I think it is a bit better on fuel, but it lacks balls when needed.

For winter time hunting season with lots of dry, I back the pitch off to max it out at 2,850 RPM, the performance difference is significant, but it is gonna roar.
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.

Post Reply

Return to “Aircraft Power Only”