Prop to pad Explanation

**FUJIMO** · 06-07-2019, 08:01 PM

Originally Posted by donmac

"X" dimension, that's a term I've never associated with outboards! I always thought the "X" dimension was the crankshaft centerline height on an I/0!

that is correct. nothing to do with o/b's.

**FUJIMO** · 06-07-2019, 08:02 PM

**FUJIMO** · 06-07-2019, 08:04 PM

Originally Posted by XstreamVking

I'm thinking that raising the prop shaft to the moon will not help that particular hull. You need some prop in the water to give it bow lift. Raising it for shallow water operation is fine. For speed it will not help imo. Put the prop in the water and run the tempests and trophy.s. Your motor pulling a 24p prop to 5800 should net low to mid 60's. That's IF you can get the bow to lift and eliminate some hull drag. jm2cts.

times two.

**Loxboy1** · 06-08-2019, 11:56 AM

Originally Posted by Dave Strong

You are not going near fast enough to need a coned lower, any positive trim will kill speed.

Dave

well i needed a low water pickup. I spent weeks looking for options and it was eather a bobs or sending it to this guy in FL, his work was much cleaner so i sent it to him. Im not looking fir speed just get the boat running right with the propper rpms

**big tom** · 06-08-2019, 03:08 PM

Not close to the same set up, but I was going to do tempest's on my 31 twin cc then I called BBlades. Raised my motors up 1 notch. Went from offshore series 4 blade 22p @5800 62 mph to 24p BBlade o/b series 5800 69-70 mph 1in dia larger prop. Worth looking at. they are a little pricey..

**donmac** · 06-09-2019, 05:13 AM

Originally Posted by big tom

Not close to the same set up, but I was going to do tempest's on my 31 twin cc then I called BBlades. Raised my motors up 1 notch. Went from offshore series 4 blade 22p @5800 62 mph to 24p BBlade o/b series 5800 69-70 mph 1in dia larger prop. Worth looking at. they are a little pricey..

the BBlades work good! picked up 5mph [73-78] on a Nordic 22 changing from Bravo 1 ,no other changes!

**big tom** · 06-09-2019, 08:49 AM

I also gained big in the mid-range cruise. 4000 rpm 43-45 mph depending on amount of fuel im carrying.

**Radiant** · 06-09-2019, 10:55 AM

What’s the name of the guy who did your cone?

**Loxboy1** · 06-09-2019, 12:06 PM

Update!!

Disclamer:: i was running in a fresh water canal with just me on board and about 20gallons of gas.

24 tempest plus, jack plate raised to 4 with positive engine trim, 5800 rpms 58mph. Blowing a real nice rooster tail, However, steering is extremly tight, i experienced this with the other props i tried last weekend with the jack plate that high as well.
i also didnt get much bow lift that i could tell.

just for compairison i put my 19p mirage plus back on. Boat jumps on plane in seconds. Jack plate up at 2 with slight positive trim 57mph at 5800~5900rpms, i have to be carefull with this prop as i can go past max rpms if im not paying attention. Much better bow lift. No rooster tail at all. And steering is soft as silk.

**XstreamVking** · 06-09-2019, 12:11 PM

That's good for that 2020. They are designed to plane fast and run flat. You have a lot of wetted surface.

**Loxboy1** · 06-09-2019, 01:42 PM

Originally Posted by XstreamVking

That's good for that 2020. They are designed to plane fast and run flat. You have a lot of wetted surface.

Buy why am i getting the mph/rpm from a 24 and a 19? Does this mean my hull likes more prop in the water? Should i be looking into a 4blade??

**Dave Strong** · 06-09-2019, 01:51 PM

Try a Trophy.

Dave

**nitro_rat** · 06-09-2019, 01:52 PM

Originally Posted by Loxboy1

Buy why am i getting the mph/rpm from a 24 and a 19? Does this mean my hull likes more prop in the water? Should i be looking into a 4blade??

prop slip is a factor. this will lower speed/increase rpm's. also not all props run true to pitch number so you 19 could measure 20 or 21 and your 24 could measure 23 or 22. If the props are of unknown provenance they could have been worked to a different pitch in the past and not marked...

slip is probably the main factor in your case.

**Radiant** · 06-09-2019, 02:41 PM

Sounds like you’re running good with the mirage. Maybe try the next pitch up. The tempest with the jackplate higher and trimmed up is probably just slipping. When you drop it in the water to about the same level as the mirage, how fast are you running and at what rpm?