New (spare) prop

[realmasa]

Hi,<br /><br />as i wrote earlier i managed to damage my new Turbo TXP 14x21 and as i have no spare prop i'm going to buy one tomorrow. This is a used one, a ballistic 14x19 with extra cupping so the engine should rev like a 20-21". What do you experts think of this, what can i expect? I had a ballistic 14x21 once and it had good top end but poor acceleration and vented easily, the engine did about 5200-5300 at WOT, with 5500 being max. <br />What will the lower pitch and extra cupping do?<br />Have a look, the prop <br /><br />/Mattias

 

[Texasmark]

Re: New (spare) prop

First of all if you are running a Turbo (hot dog prop) it's already is packed with whoopie. Don't expect anything to outdo it for dia and pitch. (Per Kenny, Grin)<br /><br />The Ballistic is a step child in the experts eyes and I have grown to respect their judgement (So far, I think; at least their decarb works). <br /><br />Running that Ballistic after what you had probably will run you up 3 or 4 hundred rpm's over where you are....(again based upon pitch change and performance degredation based upon Kenny and other's comments).<br /><br />It may get you a faster hole, and may be accompanied by higher rpm's and lower top end (speed).<br /><br />The only way you will know the answer is to run it. All else is just speculation and coffee shop gossip.<br /><br />HTH<br /><br />Mark

 

[walleyehed]

Re: New (spare) prop

It IS speculation...try it...

 

[realmasa]

Re: New (spare) prop

It IS speculation...try it...

Yupp, if everything goes as planned i will try it today, and i will let you know how it performs.

 

[walleyehed]

Re: New (spare) prop

I'm wondering from the pics, where the cup was added....the trailing edges appear stock...that's only one place work can be done of many, but in my testing, it seems that is the trouble area...<br />Hope to hear your report and maybe you can tell us a bit more about your boat and engine set-up.

 

[realmasa]

Re: New (spare) prop

Ok, i took a trip to Sweden this morning and bought a ballistic 14x19 blades are a bit thinned at leading edges and it has extra cupping done on it. I have test run it. Compared to the stock ballistic 14x21, this one has far better acceleration, is very nice and stable at mid and top speed. Did not vent much at all, with very high trim i could hear it sucking in air and speed dropped a bit but did not loose grip completely as the stock ballistic did, this makes me wonder if i should raise the engine one hole. But i have to test the TXP first and see how it performs at this height(can barely wait).<br />It didn't reach the same top speed but that's probably because the engine is a bit underpropped, at max rev 5500 it did 44knots(GPS) while the stock ballistic with higher pitch did about 48knots at 5300(if i remember correctly).<br />Kenny i took some pics of the prop: <br />pic1 <br />pic2 <br />pic3<br />pic4<br /><br />and, my boat yamarin 6110, 6,1m long fitted with a yamaha 200hp hpdi.

 

[realmasa]

Re: New (spare) prop

Both the new ballistic and the txp(i did take a short test run though it was damaged) handles very high trim angles, and when trimmed up the bow gets lift, less drag is produced by engine and hull and speed increases. If i raise the engine so the props handle more moderate trim angles then i won't get as much lift as now, but even less drag is produced by engine and the thrust is pointing more backwards. Which is probably of most benefit in aspect of speed? Is this a case of trial and error as usual? Not that i don't like to test, but..

 

[realmasa]

Re: New (spare) prop

walleyehed , did you ever read my posts?

 

[Texasmark]

Re: New (spare) prop

I don't know (about Kenny) but I am and I have a 17, 21, and 24" XP pitched Ballistic Props.

The XP has a lot more blade area than the others but I was surprised that the cup was almost nonexistant. I do have more blowout than I would like in fast turns with the engine trimmed out where it was prior to making the turn.

Now the blowout is controlled in that I pick up a couple hundred rpm's and that's all; doesn't redline. Once I complete the turn it takes a couple of seconds for the bubbles to clear and the rpm's to drop back to where they belong.

I have 100 more rpm's to spare (to drop to top of the WOT box) so one day I may take it in for some more cupping.

Nice chatting,

Mark

 

[Texasmark]

Re: New (spare) prop

No speakie ze deutch! How do you lift the prop pic off the site home page? I clicked on the verbiage at the center of the blue screen but nothing happened.

Mark

 

[Texasmark]

Re: New (spare) prop

I found them. I was looking at your oridinal post not in your answer to kenny.

I'll agree, someone has tweaked the trailing edge quite a bit.

All the things you mentioned from your test run are to be expected from what you have done so I persoally see any surprises.

So, where do we go from here?

Mark

 

[realmasa]

Re: New (spare) prop

Hi Mark,

I fetched my TXPd from the post office today and it's as good as new. Tomorrow(tuesday), i will test run it if the weather allows, and i will return to this forum with a report. If it's as resilient against ventilation as the extra cupped ballistic i might try raise the engine a bit.

/Mattias

 

[Dhadley]

Re: New (spare) prop

TXP's were designed with very specific hulls and X dimensions in mind. They like boats with a lot of natural lift and very high X dimensions.

 

[realmasa]

Re: New (spare) prop

It is what precision propeller recommended for my boat and engine. Are you saying they are wrong, or is it an excuse in case it doesn't perform as the ballistic. You guys have to be affiliated with precision propeller someway.

 

[Dhadley]

Re: New (spare) prop

The TXP was designed for pad bottom hulls that had a lot of natural bow lift. Allisons, Bullets, Hydrostreams, Strokers etc. The Lightning will have more bow lift and the TXP has overall lift. If Precision recommended the TXP then they must feel that your hull has a lot of natural bow lift built in.

I've never seen a Ballistic out perform a Lightning or a TXP given optimum set ups on all props.

Now, all that being said -- All TXP's and Lightning's are 14 3/4" diameter. And the smallest TXP is 23. They do make a 21 Lightning but not a 14 x 21. So now we have to double check to see what prop we're working with. Are there any numbers on it?

 

[realmasa]

Re: New (spare) prop

Ok, i post two pictures, one from the side of the prop showing the TXP print and one showing the bottom of the hub.
From the side
The hub with numbers
Take a look at this page: http://www.turbo-props.com/TXP.htm you will find this: TXP V-6 14 3/4 X 19-32 X 3
Was i confusing you when i wrote 14x21 instead of 14 3/4x21?


I saw you replied to my other post, you get the part number here.
Thanks,
Mattias

 

[Dhadley]

Re: New (spare) prop

Very interesting. We tried to get smaller ones a couple of months ago. We have a 2006 parts list and it only goes down to 23 and that's what we were told. Is that the Merc hub or the Yamaha hub?

 

[realmasa]

Re: New (spare) prop

Yeah, that's strange. I was recommended the TXP 14.75x21 March the 8th so it has been around for awhile. The hub is for my Yamaha 200 hpdi, any ideas about the problem i wrote about in the "TXP hub" topic?
Btw, TTL 300 is printed on top of the hub.

 

[Dhadley]

Re: New (spare) prop

TTL 300 (Turbo T-Loc) is the correct hub for a Yamaha. Are you using the thrust washer that came with the hub kit?

 

[realmasa]

Re: New (spare) prop

No thrust washer was delivered with the prop. Only the prop with hub installed. You can see the washers I use on this page: http://personal.inet.fi/surf/masa/distanser.jpg
The two on the left side are original thrust washers, only one is used. The nut washer is pretty thick and as i said, without it everything fits perfectly, but you can't really leave out the washer, can you?