old boat/stock prop

[tileguy]

Hi all, first post here and new boat owner. Just bought my first boat, an older 1979 Glastron SSV 176 with a Merc 115 outboard. Is it worth while to get a new prop vs. the stock prop to get more speed, pulling power? I will be using it for skiing, tubing and my daughter wants to wake.
I know nothing about the size/pitch and will be relying on you guys for advice...
Thanks, T.G.

 

[steelespike]

Re: old boat/stock prop

Prop size should be on the barrel something like -- X --. ex. 13" X 19"
diameter by pitch. We can't help much without your prop size and your
max rpm and speed with one aboard. Let us know if prop is stainless or aluminum.Aluminum is usually painted.
depending on your results a prop may improve things.

 

[tileguy]

Re: old boat/stock prop

Thanks I do know its a 3 blade painted black prop, I will have to check on the rest. I should be taking her out Tues. eve and will check the rpm's and the barrel #'s and get back to you with that info.....
Thanks again, T.G.

 

[steelespike]

Re: old boat/stock prop

don't forget we need rpm and speed.By gps is best.

 

[tileguy]

Re: old boat/stock prop

Ok, here is what I have so far.....
Prop # 4877344A4 17P
RPM 5200
Speed about 41

It is the old painted alum. prop.
Thanks, T.G.

 

[walleyehed]

Re: old boat/stock prop

17P has always been ball-park on the SSV-176 with a 115.
If the engine is bolted clear down "ON" the transom, I would highly recommend you lift the engine to the third set of holes.
A real good prop on that rig is the Stiletto in SS.
We ran about 43mph with the Johnson V-4's and 17P's.
If you like aluminum, take a look at the Solas Rubex props here at iboats....I'm flat-out impressed with them and I run a ton of props.
You might want to see closer to 5500rpm at max with a normal load. If the engine is healthy and if you can get it up a hole or 2, you should see that figure pretty easy.

 

[tileguy]

Re: old boat/stock prop

Thanks walleyehed, but what size and pitch with those 2 props?
T.G.

 

[tileguy]

Re: old boat/stock prop

The engine is also set on the second to last set of holes, I will try moving it to the third.......
T.G.

 

[walleyehed]

Re: old boat/stock prop

17P would be my choice in any design/brand....I'd adjust engine height to get the right rpm.
Let us know what you get lifting the eng. 1 hole.

 

[tileguy]

Re: old boat/stock prop

Ok just got back from the lake, raised the engine uo to the 3rd hole, seemed to run smoother, gained about 1 mph. and maybe a bit on the RPM. Still flirting with 5100 at WOT, maybe this is as good as she gets? Or you think the extra money with a 17p. Stilletto would give me a little more?
Thanks for all you help guys......
T.G.

 

[walleyehed]

Re: old boat/stock prop

Do we know for sure that this engine is good and healthy???
I still service a couple of SSV-176's because we used to sell Glastron....both run 115's and in the third hole both run about 5600-5700 with std 17P aluminums.
3 or 4 people and some gear and it drops to around 5400, which I don't like...I'd like to see the 5700 with a load but they seem to have gotten by since 1978 with both of these rigs.
Now, I must add, we are operating at 3200 to 3600ft above sea-level..AT sea-level, a 19P should be ball-park if set up right.

 

[tileguy]

Re: old boat/stock prop

So your thinking I should go with a 19p? Is the 19p more or less pitch then a 17? Sorry to sound like I dont know much but I dont.
As far as a healthy eng.? I dont know, sounds and feels good, I will do a comp. test this week.
Thanks again walleyhed.
T.G.

 

[walleyehed]

Re: old boat/stock prop

If we're only getting 5100 with the 17 we need to find out why.
It should be doing a bit better than that....it could be a tach issue and may be an inaccurate reading.
Yes, the 19 would not be a good thing right now...it would likely drop the rpm to around 4700-4800...we need to go the other way.