New Props for .12 Engines

[Eric Perez]

Got back from the pond yesterday tested a bunch of props on my .12 Nitro Trident Rigger...

Well, I finally got to test the V937/3 and all I can say is wow this thing is fast! The engine was not even on the pipe due to the glass smooth water plus other factors. Launching was a little nerve racking, it went something like this...

Throw the boat in and the prop cavitates like crazy as the rear end sinks in -the engine is spinning hard. You think it's over, but then the boat develops a little forward motion and before you know it the prop bites! Out like a rocket!

No hopping and the rigger makes great right and left turns. It's funny I tried the V937/3 on my other rigger without the rear shoes and it would not stop hopping -no matter what I did to the strut I was never able to get the rear end stabilized.

I also got my hands on the new Octura Y536 (.187) prop. It has a smaller blade area than a prather S215 but with more pitch. It actually looks alot like a modified S215. I think this will be the best all arround prop for small-block boaters.

I will try to get some test time with the Y536 this weekend.

 

[Don Templeton]

Eruc:

What engine are you running in the Nitro Trident?

 

[Eric Perez]

Totally Stock Picco XP with the side exhaust running 30% Nitro with Macs pipe.

The engine was put on the RCCA dyno I think it came out at just a little under 1HP.

These new 1.2-1.4HP engines that are in the market should have no problem turning a V937/3.

 

[Saugling]

I also tested a V937 on my .12 rigger....with great success....nearly no cavitation and no hopping! Greatest prop so far for my rigger!

 

[DJT]

Eric

You stated that the Y536 had more pitch than the 215, according to my Octura chart the Y536 has 2.200" of pitch and my Prather chart says the 215 has 2.5" of pitch. Both of the charts are the ones supplied by the manufacturer, is one of them wrong? Just wondering. Also has anyone tried the 1938 or 2137/3 from Octura?

 

[Eric Perez]

By the time you are done back cutting and rounding a 215 it's smaller than the original that affects the pitch diameter ratio. I can't measure the pitch on props but I know the prather props have 1.4 pitch, while the Y536 is 1.5 pitch. On anti-cavitating props the trailing edge has the most pitch, when you backcut you loose some pitch.

Saugling: Funny that you mention it, my boat reminded me so much of your boat video that I did a double take, looks and rides the same on the water, with a low roostertail.

 

[Don Templeton]

I've been running a 1640 cupped on my boat and it really works very well. I just received two new props from shoboat. A 1640 with more cup and a V940 with cup and cut, I think. The V940 should be interesting if nothing else! However, I was at the Hydro Masters a week ago and ran the boat during open water. Got stupid and decided to run in lane one after about three laps. The end result after a couple more laps was lost an arm on #2. Worse than that, it was the left sponson!

Oh well it's fixable but it will take a little time.

Don :blink:

 

[Ron Olson]

Eric, I've got one those old Trinity/Picco .12's. I love that motor! I broke the crank on it but found another complete motor for $40.00 . Right now I'm trying to find an aluminum spacer right now for the new one, the other one got tossed when the crank broke.

 

[ClayGlover]

Hey Don,

Keep us posted on those props. I know mine could swing more pitch on the v937, so the v940 could be a h00t for straightlines. I'd really like to hear about the 1640's as well. Thanks for the real world feedback guys.

 

[ClayGlover]

Hey, I just realized I had never heard of a v940

Is that a new size prop? I assume it's 3 blades? I can't find it on any octura charts I have. :huh:

 

[Ron Olson]

It's pretty new. Gary Preusse had one on his .12 'rigger at the Record Trials earlier in the year. Octura is coming out with a lot more props this year, I just picked up a M435/3, why, I don't know.

Yes, it's a 3-blade.

 

[jayt]

The v937/3 has been the most record-setting SAW prop in fast electrics. It started setting records in the early 1990s and continues today. One of it's greatest features is the tapered blade, which allows the hub to rise well out of the water for reduced blade drag - but the pitch is still there.

These props were designed for stock 3.5 outboards but didn't do so well there - they have come into their own in the FE and small nitro hydros. Limited lift, good efficiency, good plane-off, what isn't to like? Well, they are not strong enough for speeds over about 75 mph without hardening. Unhardened v937s will "flower" the tips, changing their appearance and pitch. This is confirmation that at these speeds the prop is running with the hub well out of the water.

 

[Preston_Hall]

Well, they are not strong enough for speeds over about 75 mph without hardening. Unhardened v937s will "flower" the tips, changing their appearance and pitch.

Not that yours don't "flower" but I have never seen this.

 

[Precision Boats]

Hey Guys,

I have a Firefighter .12 with a O.S. .12 TR motor. I raced it last weekend at Jackson TN and took 1st in the B Hydro class. Only three boats where there?? But I raced with a Prather 215 and was running a consistant 46.8-47 mph all weekend. I also tried a Ocutra X637 and was only able to hit 42 mph with that prop. These where the only props that I had that where small enough to run on the boat. What props do you recommend I try for my rigger?

Thanks for the help.

Josh

 

[TomMoorehouse]

That's cool Josh!

for top speed try the v937 i dont think the tr will spin up the v940 on a firefighter...... mine did not like it at least. i cant remember if the 1938 worked right or not.

 

[Precision Boats]

Tom,

Can I still get the Sponsons for that boat? I hit a bouy and have fixed it but I was just curious if I can get a replacement set. PM me on the cost of them.

Thanks

Josh

P.S. I will post a picture of it when I get the sponsons put back on.

 

[Eric Perez]

Well, as part of my weekly on going testing with my .12 rigger here are (6) small-block pipes that I'm going to be trying out with the V937/3 prop.

I would like to point out the last pipe of the bunch which is the MACS T-Maxx 2.5 pipe. It has a wider belly and is shorter than the very popular MACS 2.5 pipe that a lot of small block boaters use.

I will post some results after the test session. Never got a chance to test the Y536 last weekend (my radio box sprung a leak). It's fixed now so I hope to have time to post some results for that prop as well.

 

[TomMoorehouse]

I would email Peter at climate to see if he can set you up with just sponson parts. Nobody has asked me for just sponsons before...... guess we will have to figure that one out huh?

 

[TimD]

Nobody has asked me for just sponsons before......

Hey Tom,

Forgotten something?

Tim.

 

[TomMoorehouse]

ummmm uhhhh duhhhh wait.....

ya know a buddy of mine once said I have mind like a gnats ass :blink:

uhhhh i meant to say sponsons for a .12 before...... yea thats it.....