Author Topic: GT 160 prop suggestions  (Read 11678 times)

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Offline 63g3

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GT 160 prop suggestions
« on: January 17, 2017, 09:34:16 AM »
Hi guys,
Just looking for suggested prop sizes. I'd like to look around for props this winter,I have not run it so, I have no baseline. I just finished the boat, it's a 1975 and it has a fresh 76 1150 Merc so, that's the flywheel rating lower power 1150. Motor has PT. I would like it to spin in the 5400 to 5600 range, me alone in the boat, the in lines are better off spinning higher than lower.
I'm thinking 19 to 21 pitch range for a simple cupped three blade or possibly something with bow lift so maybe a Laser? Those would be in 20 to 22 range. Not sure if torque steer gets bad with the lasers or any prop with rake as the motor is on the transom top, not raised. I kept the boat original so it has the single push pull bolted to the motor well, it's 100% good but not sure I'd want to load that arrangement up with lots of torque steer. It also seems these boats get chine walking once you try to get much bow lift by over trimming so that may mean you can't really take advantage of a prop that lifts the bow. I drive fast v pad bottoms so I can handle chine walk but, concerned that would start working the steering a lot. I want to keep the boat original so I wouldn't upgrade to a dual cable or hydraulic.
Anyways, I figure this boat motor should be high 40's maybe low 50's with right prop so looking for some input, comparisons, experience. I'm not looking to get the last mph, got other boats for that, just a good balance and not much torque steer. The boat is too cool just the way it is.
Thanks,
Randy

Offline David CVX-16

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Re: GT 160 prop suggestions
« Reply #1 on: January 17, 2017, 10:03:42 AM »
Chris had a boat and motor just like yours, and tried a Laser II, 2-blade bronze 21", and a Ballistic stainless steel 3 blade 21" pitch. He had the best performance from the Ballistic, which has mild bow lift. I believe his speed was about 53 MPH. That Ballistic should not be hard to find used on e-bay. This prop with the universal hub has a difference part number.

I tried these same props on my Glastron V-153 and the Ballistic performed well. The Laser II had lots of steering torque and the Ballistic not so much.


Let me know if you need exact part numbers for a search. 
David
87' CVX-16, 85' 115 HP Johnson, 58.8 MPH GPS w/ 23" SRX Prop

Offline Hyperacme

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Re: GT 160 prop suggestions
« Reply #2 on: January 17, 2017, 01:16:12 PM »
Welcome to the forum Randy !

Gil and Dave also had / have GT160's.
I'll do some searching and see what they were / are using.

You really never know how a prop will perform until ya try it.
Buy them cheap on Craigslist & eBay, try them, sell them if they don't work for you ...

Try a NFB steering system.
 http://www.seastarsolutions.com/

Offline Scott in nh

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Re: GT 160 prop suggestions
« Reply #3 on: January 17, 2017, 01:29:10 PM »
I have a GT160 1150 that I have used almost every year since 1990.
For a simple 3 bladed cupped prop on the 21" is too much, use the 19" with some rake for bow lift.
I would also suggest placing a 3/4" aluminum bar on top of the transom to raise the motor.
I would also add a NFB steering rack to it and making sure the splashwell mount is in good condition.

Scott

Offline Hyperacme

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Re: GT 160 prop suggestions
« Reply #4 on: January 17, 2017, 01:37:21 PM »
Looks like Gil had a 1987 Merc (prop rated 115 HP) and was using a 21P ballistic @ 54 MPH / GPS.

Offline Scott in nh

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Re: GT 160 prop suggestions
« Reply #5 on: January 17, 2017, 03:09:01 PM »
Looks like Gil had a 1987 Merc (prop rated 115 HP) and was using a 21P ballistic @ 54 MPH / GPS.

I have a friend with a GT160 1150 that could never stay with my boat until he upgraded to a newer prop shaft rated 1150 and went to a high performance 21p (I do not recall brand, type or specs).
He now is able to go upper 50's no problem.

With the flywheel rated engines (more like 90 hp at the prop) you can go with a big prop with all the mods and have a single purpose boat that still isn't that fast and won't pull a skier or turn well or you can put a good 19p on it and have a nice well rounded runabout that will go upper 40's all day, pull skiers, and do whatever else a runabout is good for.

Offline 63g3

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Re: GT 160 prop suggestions
« Reply #6 on: January 17, 2017, 11:57:39 PM »
Great input exactly what I was hoping for, thank you to everyone.  Sounds like a 19 plain Jane with a cup is a good place to start so I'll start sniffing around for one. I'll keep an eye open for a low pitch ballistic or a laser once I get a baseline on the 19......now just gotta wait for spring!
Randy

Offline 63g3

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Re: GT 160 prop suggestions
« Reply #7 on: January 18, 2017, 07:55:39 AM »
I scored a 19 ballistic on eBay in the original case for 150 and looked through my props and came up with a standard stainless three blade 19. Based on what has been tried and recommended one of these should work out or at least be close.
Thanks again...just in time to catch that ballistic auction.
Randy

Offline Oldfishguy

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Re: GT 160 prop suggestions
« Reply #8 on: January 18, 2017, 08:17:09 AM »
I'm glad you got that settled, and now we need a few pictures of the rig!  😀
1972 1/2 Glastron CV 16
1973 Chrysler 120

Offline Hyperacme

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Re: GT 160 prop suggestions
« Reply #9 on: January 18, 2017, 09:38:53 AM »
Dave is correct ...
We need pictures !

Offline GIL_CV21

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Re: GT 160 prop suggestions
« Reply #10 on: January 18, 2017, 04:44:22 PM »
Its pretty trust me . May be he'll throw a few pictures of his pristine Hydrostream .

Offline 63g3

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Re: GT 160 prop suggestions
« Reply #11 on: January 19, 2017, 08:32:17 AM »
Gil has me blushing now as you know how good his work is. Years ago I was hunting for either a Hydrostream Vector or a GT160. At that time I got close to popping on a GT but found a Stream that got the nod for sentimental reasons. The balsa core in the Streams make for hideous work to correct so, although I've done other boats since it diminished my enthusiasm for basket case restos.
    I have been keeping  one eye out for a Glastron jet, (Gil's project got me cranked up about that) in case the right one drifted by, then I spotted this  GT end of the summer. It was listed in the VT craigslist but, it was in Canada. A 1975 not wet since 81 and always in a garage, original now very elderly owner. The only downer was it had an line 4 Merc 850 rather than an inline 6 but that was a easy problem to remedy, I've got tons of that stuff. It was within a days drive for round trip pick-up, crossing boarder proved to be a non issue. I guess it was gonna be another outboard rather than a jet.
This was an easy resto as  compared to what I've done before, every once in a while you get lucky.
I'm completing the 76  1150 powerhead this winter that's the last of the heavy lifting on this project.
 I just ran out of time so,  the push was to get the boat done before the weather shut me down.
I won't bore you here but  I posted the work on fiberglassics under members projects topic is "what to do on a minty barn find". Surprising how much was needed to straighten out the typical Glastron weaknesses but, that said I was impressed with the way most things were done compared to other boats I've restored from that era. Overall a nice rig at the time and this being so original I tried to keep it so while making the improvements. I do have the Glastron wheel but where I had this wheel with the ride guide cap I thought it OK to keep the dash all year correct quicksilver components. I also don't risk the original wheel which is just plastic, I'll swap out for shows. 
Anyways, here are some not so good photos of the boat pretty much done prior to shrink wrap for winter..... also, where Gil suggested 🤗 I'll do another reply with a pic of my Stream.
   
« Last Edit: January 19, 2017, 09:14:37 AM by 63g3 »

Offline David CVX-16

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Re: GT 160 prop suggestions
« Reply #12 on: January 19, 2017, 08:47:33 AM »
Absolutely gorgeous. What a showpiece. 
David
87' CVX-16, 85' 115 HP Johnson, 58.8 MPH GPS w/ 23" SRX Prop

Offline 63g3

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Re: GT 160 prop suggestions
« Reply #13 on: January 19, 2017, 09:04:25 AM »
OK and here is my Vector all 1974, this has a 1500 done with XS parts but using a 20 inch mid, a good day gets a tick over 70 with a 24 laser.  Boat in motion picture was taken at a Scream and Fly event a few years ago wow did they get that right. The other one is where I would take the cover off of it when working on the GT as inspiration, obviously Hydrostream stole a few styling cues from Glastron!
Randy

Offline Hyperacme

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Re: GT 160 prop suggestions
« Reply #14 on: January 19, 2017, 09:37:44 AM »
WOW !
Don't see many Glastron's in that shape ...
Even less in blue with the front seats intact.

Your "Stream" looks pretty sweet also !

Offline 75starflight

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Re: GT 160 prop suggestions
« Reply #15 on: January 19, 2017, 10:22:51 AM »
Very beautiful Boats!
1975 v-179 starflite

Offline Jason

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  • 1974 CV16SS, 1986 CV23
Re: GT 160 prop suggestions
« Reply #16 on: January 19, 2017, 12:18:30 PM »
Very nice!
Jason S.
1974 Glastron Carlson CV16SS 140 I/O
1986 Glastron Carlson CV23 260 I/O

Offline Rosscoe

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Re: GT 160 prop suggestions
« Reply #17 on: January 21, 2017, 10:06:54 AM »
Extremely nice 160. I like the Riv on the background as well! 68-69?
Ross
61 Surflite 1964 90HP Johnson project
67 V163 Bayflite Super Sport  1989 100HP Merc
67 V164 Bayflite 120HP
67 V174 Crestflite Rat Rod
71 V175 Crestflite 350ci -Jet
73 GT 160
84 CVX 17  83 115 Merc
88 CVX-23 350 Mag

Offline V153

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Re: GT 160 prop suggestions
« Reply #18 on: January 21, 2017, 02:02:48 PM »
I'm surprised no one recommended a Raker. Give you better performance than a Ballistic or Laser.
'81 C500_given away, bought back_75.1 mph
'81 Baja 15SS_140 Frankenrude_66.7 mph
'70 something SpeedCraft_(Allison 16R Clone)_69.0 mph
'79 CVZ19_given away
'71 V153_54.8 mph_wrecked


WALK TALL AND CARRY A BIG BILGE PUMP

Offline 63g3

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Re: GT 160 prop suggestions
« Reply #19 on: January 21, 2017, 04:24:17 PM »
Ha,
You guys are Good! Now I need to look for a Raker to try also.  Keep in mind it's torque steer I want to stay away from I'll trade less torque steer for less speed on this particular ride...I can hear the booo's and hisses now! Any opinions on the torque steer scale for a raker?
Geeez nothing escapes keen eyes, its a 67 Riv, I suspose you also noticed my lawn is a mess🙂 I just rebuilt the motor and dropped it in  between sessions with the GT Resto work, a busy fall for sure.