Sensenich JN72 v/s JM70

[lewisdj1971]

I am looking to upgrade my prop. I have an 0360 AV and currently I am running a 67” Sensenich JM. I built a new hull and now I have room to spin a longer prop. My question is which prop would give me the best overall push? The 70JM is 10” wide blades and the 72JN has 8.5” wide blades. So which would give more overall thrust the 8.5” 72” long blade or the 10” 70” long blade? I’ve heard it both ways some people say wider is more push and some people say blade length is king. I may be splitting hairs but just trying to get some input. Thanks!

 

[lewisdj1971]

I am looking to upgrade my prop. I have an 0360 AV and currently I am running a 67” Sensenich JM. I built a new hull and now I have room to spin a longer prop. My question is which prop would give me the best overall push? The 70JM is 10” wide blades and the 72JN has 8.5” wide blades. So which would give more overall thrust the 8.5” 72” long blade or the 10” 70” long blade? I’ve heard it both ways some people say wider is more push and some people say blade length is king. I may be splitting hairs but just trying to get some input. Thanks!

I need to add that what I’m looking to achieve is to be able to run dry ground good and I’m not concerned about top end speed. I want the most push I can get for a hunt boat.

 

[lariat]

I personally think more length is better for running dry.

 

[Gary S]

I think your asking a lot out of a 0360 to spin a 72 inch blade.

 

[kwanjangnihm]

more length is better

that's what she said

 

[lewisdj1971]

I think your asking a lot out of a 0360 to spin a 72 inch blade.

I was thinking that too. The guy I spoke to at Sensenich seemed to think I could turn the narrow 8.5” 72. I’ve always heard 70” max on an 0360. So you think I’ll gain anything by going to the 70JM? My current prop is a 70JM cut down to 67”.

 

[kwanjangnihm]

where is your 67JM set now and what is your WOT?

 

[lewisdj1971]

where is your 67JM set now and what is your WOT?

I’m at the 13-14 mark turning 2850

 

[Slidin Gator]

A buddy of mine runs the 72" Whirlwind WT on a O360. I think it's a 10-1/2" blade, regardless the exact same blade my son runs on a O540. It pushes well enough, but we have come to the conclusion that it is just a bit too much prop and talked about downsizing it to 70.

I may be splitting hairs but just trying to get some input. Thanks!

I think you are splitting hairs, the engine will turn the 72" narrow just fine, but the 70" wider blade will probably prove best all-around (a bit more snap) and give better clearance on the rigging. Moving from a 67 to a 72 inch prop, you will miss the snap.

 

[lewisdj1971]

A buddy of mine runs the 72" Whirlwind WT on a O360. I think it's a 10-1/2" blade, regardless the exact same blade my son runs on a O540. It pushes well enough, but we have come to the conclusion that it is just a bit too much prop and talked about downsizing it to 70.



I think you are splitting hairs, the engine will turn the 72" narrow just fine, but the 70" wider blade will probably prove best all-around (a bit more snap) and give better clearance on the rigging. Moving from a 67 to a 72 inch prop, you will miss the snap.

Should I see a noticeable difference between the 67” and 70” JM? Trying to justify the cost of 2 more blades.