Glastron CVX16 and 150 V6

QBhoy

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Hi all

long shot, I realise, but looking to hear from anyone that has or had, even knows of one well enough, that has similar engine.
keen to hear how she goes.
ive had mine for a while and managed the engine installation at least, but never got a chance to try her out.
I know the current prop is too small a pitch at a guess, being a 21” laser.
the boat isn’t handy where she is stored and looking to get a selection of props ready to try on her early next year.
to save a trip or two, what are we thinning off the top of the head ? 23” for starters ?
obviously well aware of the usual idea of need to know how she goes then go from there with rpm range etc.
the question is more to save me wasted trips to a from her isolated location.
love to hear from anyone who has the same set up. Accounts of performance and props tried etc.

thanks.
 

ahicks

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All due respect, but a V-6 on the back of a 16' boat? Seems like an incredible amount of weight being placed on the transom. Keep us posted though. I'm interested in hearing how it turns out. -Al
 

Chris1956

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Gee, which V6 motor? Merc, Johnnyrude or Yamaha? Merc and Johnnyrude have different gear ratio, which will change the prop pitch.

If Merc, a 23" pitch may be a bit tall, but it is close. If Johnnyrude and a 90's engine, a 23 is likely too tall.
 

QBhoy

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Gee, which V6 motor? Merc, Johnnyrude or Yamaha? Merc and Johnnyrude have different gear ratio, which will change the prop pitch.

If Merc, a 23" pitch may be a bit tall, but it is close. If Johnnyrude and a 90's engine, a 23 is likely too tall.

Apologies Chris. I should have mentioned the type of engine. You’re totally correct.
it’s a black max era 150 merc V6 2.0.
I had previously a ring 18 (U.K. fast racing pedigree hull) with the identical engine and also the 200 merc too (before the oil injection failed). She ran a 23” laser with both engines. Both engines would see over the rpm range on that boat. I’m thinking the cvx will be as quick a hull perhaps and won’t be too far off the mark with a 23” for starters.
thanks for the advice and response.
 

QBhoy

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All due respect, but a V-6 on the back of a 16' boat? Seems like an incredible amount of weight being placed on the transom. Keep us posted though. I'm interested in hearing how it turns out. -Al

Hi Ahicks. Thanks for responding to my post.
I totally get where you are coming from and would normally agree in general...but this wee cvx is quite a special model. It’s a U.K. built (under license from glastron) by Roger Clark marine. The original design was seriously modified by him for bigger motors than the US more common model...they were only rated for 120hp I think. This U.K. one has a strengthening transom and a modified hull to take a larger motor.
that said, she is nearly 40 years old and I have the engine set only a little high on her. Nothing too daring.
there are plenty of even the US versions with V6 motors on them currently and even with jack plates on them. With a 150 on those, they seem to manage around the 70 and just over mark. They usually have cleaver or chopper on them. Not sure I want to go that serious on mine though.
thanks again.
 

roffey

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When I first read your OP I though you had to big a motor so I look around google and nope, I think you can go with even more HP. I love fast boats but yours may be a little to much for me. I can't believe I said that, lol. Let us know you decide and what your MPH are. Not that this is comparing apples to apples but my boat has a 4.3 (TKS, 2bbl carb) with a 24 inch SS prop. I likely have to much prop but I have dreams of installing a 4 barrel carb on it some day.
 

QBhoy

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When I first read your OP I though you had to big a motor so I look around google and nope, I think you can go with even more HP. I love fast boats but yours may be a little to much for me. I can't believe I said that, lol. Let us know you decide and what your MPH are. Not that this is comparing apples to apples but my boat has a 4.3 (TKS, 2bbl carb) with a 24 inch SS prop. I likely have to much prop but I have dreams of installing a 4 barrel carb on it some day.

Thanks Roffey.

yeah she is a proper wee thing.
As said earlier. There are the normal and less sturdy built US versions running with big power on them. Some even with over 200hp and the inboard models with some having big blocks running at over 100 mph.

I think my UK updated one should be ok with the 150. I’ll likely strengthen the transom soon, to be sure. Although she looks ok currently.
a couple of these here came with Yamaha v4 and mercury mariner in-line 6 motors standard. All be it a long time ago. Mine had a Yamaha V4 originally.
 

QBhoy

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Here she is
 

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roffey

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Sharp boat for sure. I'll be waiting to see what the numbers are. Have you checked out a jack plate and what is the max HP rating for that boat?

FYI, I can do 54 on the GPS.
best pic I can do... boat is away for the winter... at dock.JPG
 

Chris1956

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Your motor looks to be early 90's, like mine. I run a 16' Avenger (bass boat style hull) with a '93 Merc 135HP V6. It is 2L like your motor. I can comfortably run a 23" pitch prop. I may be able to run a 25" pitch prop, but have not tried it.
 

QBhoy

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Your motor looks to be early 90's, like mine. I run a 16' Avenger (bass boat style hull) with a '93 Merc 135HP V6. It is 2L like your motor. I can comfortably run a 23" pitch prop. I may be able to run a 25" pitch prop, but have not tried it.

Great info to hear. Really appreciate the insight. Kind of in line with what I’m thinking.
 

QBhoy

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Sharp boat for sure. I'll be waiting to see what the numbers are. Have you checked out a jack plate and what is the max HP rating for that boat?

FYI, I can do 54 on the GPS.
best pic I can do... boat is away for the winter...

That’s mega quick for a 4.3 2 barrel.
I nearly put a jack on it, but want to keep it as original as I can really.
 

Chris1956

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My gear ratio is 2::1, probably like yours, however, I do hear of some Merc V6's with a 1:87::1. Not sure which motors those are.
 

QBhoy

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Your motor looks to be early 90's, like mine. I run a 16' Avenger (bass boat style hull) with a '93 Merc 135HP V6. It is 2L like your motor. I can comfortably run a 23" pitch prop. I may be able to run a 25" pitch prop, but have not tried it.

Chris what rpm and speed are you pulling with your set up ?
 

Chris1956

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Unfortunately, it is hard to give accurate RPM and speed at max throttle. To be safe requires one hand on wheel and one on throttle.

My max RPM is 5600+, and will rise higher than that, however, I do not have enough calm water to see how high she will go. Calm water is a must for that kind of speed, and it is in short supply in the bay.

I cannot advise on speed as I do not have a built in GPS, and cannot group around for a handheld at that speed. I would estimate high 50s MPH.

I can cruise quite comfortably at about 45MPH, with moderate trim, in reasonably calm bay water. Faster than that requires more trim to lift bow, and calmer water.
 

QBhoy

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Unfortunately, it is hard to give accurate RPM and speed at max throttle. To be safe requires one hand on wheel and one on throttle.

My max RPM is 5600+, and will rise higher than that, however, I do not have enough calm water to see how high she will go. Calm water is a must for that kind of speed, and it is in short supply in the bay.

I cannot advise on speed as I do not have a built in GPS, and cannot group around for a handheld at that speed. I would estimate high 50s MPH.

I can cruise quite comfortably at about 45MPH, with moderate trim, in reasonably calm bay water. Faster than that requires more trim to lift bow, and calmer water.

Thanks. Appreciated.

im aware of guys with the us hull of this touching 70 by all accounts with this motor and a jack perhaps
 

Old Ironmaker

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Mate what are you trying to do? Get to France in 15 minutes or less? There was a time in my life I could never forfill my need for speed, on my Harley (slow as molasses but fast enough to kill me) my 76' Vette, or my19' StarCraft, almost as slow as molasses. I now leave my need for speed to the airline Pilot now. You must like going ridiculously fast. A 5 way harness may be a suggestion for you. Enjoy and good luck.

p.s. Had a 30 day contract in Southern England a few years back in June. I wasn't looking forward to the dark, wet and damp English weather. It rained maybe twice. England is now my second favorite country in the World and I've been to more than a few. Palm trees in Bournemouth, who knew?
 

QBhoy

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Mate what are you trying to do? Get to France in 15 minutes or less? There was a time in my life I could never forfill my need for speed, on my Harley (slow as molasses but fast enough to kill me) my 76' Vette, or my19' StarCraft, almost as slow as molasses. I now leave my need for speed to the airline Pilot now. You must like going ridiculously fast. A 5 way harness may be a suggestion for you. Enjoy and good luck.

p.s. Had a 30 day contract in Southern England a few years back in June. I wasn't looking forward to the dark, wet and damp English weather. It rained maybe twice. England is now my second favorite country in the World and I've been to more than a few. Palm trees in Bournemouth, who knew?

Haha. Thanks for the concern. Think you are one of the few I’ve known who doesn’t like a fast classic. These are designed to go fast from new. I’m not adding much to what they are originally.

with regards to England...I’m on the north side of the border. Scotland gets more rain. But when the sun does shine...it’s gods country. England has nothing close to it.
cheers.
 

Old Ironmaker

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Haha. Thanks for the concern. Think you are one of the few I’ve known who doesn’t like a fast classic. These are designed to go fast from new. I’m not adding much to what they are originally.

with regards to England...I’m on the north side of the border. Scotland gets more rain. But when the sun does shine...it’s gods country. England has nothing close to it.
cheers.

I have seen the "white light" as in " Go towards the light" twice in my life and don't want to see it again until it's my time. I don't want to go towards the light doing 120 MPH on the water.

I love the classic go fast boats, I just don't want to die in one. I forgot you are north of L'Engla Terre. Been once to Scotland, Troon, the hometown of my former wife's family for a big Family Wedding in the 80's. It rained so much that week we couldn't golf not even once. Kinda' like a randy teen invited to The Playboy Mansion and made to stand outside the front door. If I even smell Scotch today I get deathly ill. I think they served the new stuff.
 

QBhoy

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I have seen the "white light" as in " Go towards the light" twice in my life and don't want to see it again until it's my time. I don't want to go towards the light doing 120 MPH on the water.

I love the classic go fast boats, I just don't want to die in one. I forgot you are north of L'Engla Terre. Been once to Scotland, Troon, the hometown of my former wife's family for a big Family Wedding in the 80's. It rained so much that week we couldn't golf not even once. Kinda' like a randy teen invited to The Playboy Mansion and made to stand outside the front door. If I even smell Scotch today I get deathly ill. I think they served the new stuff.

Excellent. You have a way with words. Typical west coast weather you describe too. Slightly
further to the north, still on west is where the beauty spots begin.
 
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