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time to move up... engine(s) question

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57 minutes ago, Wingnut said:

I/O's allow for trim adjustment which makes a difference in top speed, and if applied correctly better economy in similar hulls. A great side by side was my 30' Sea Ray Sundancer (twin 350 io) and my best friends 300 Weekender (twin 350 V-drives)  I was 7 miles per hour faster at WOT, and the helm was much more responsive at speed. His v-drives maneuvered better at the dock, but at 3,000 RPM I was doing 30 mph and he was doing 25.5. That said he burned 11 GPH at 3,000 and I burned 15.5. Of course the Sundancer was a bit heavier.

Another thing to consider is engine loading. A 28' boat with a single 8.1 is working both the engine and drive line much harder than twin 350's. Twin 8.1's will dent your wallet as they will go through 25 gph at cruise. V-drive shaft seals and/or packing is hard to get to as the stuffing box is under the engine, and alignment is a nightmare as you have to get the engine to transfer case and also case to prop shaft perfected. Straight inboards are much easier, but that does come at the price of more weight forward and compromised storage. The Hurth and Borg Warner velvet drive transmissions are bullet proof, and the shaft struts and cutlass bearings last a good long while.  Pluses and minus to all of them, but if you tend to boat in really skinny water, stick with IO's as you don't get a second chance with inboards.  W

There is a give and take with everything. But, to me you are right on as far as I can tell. I just want to get away from out-drives and get into diesels. 

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6 hours ago, Wingnut said:

Pluses and minus to all of them, but if you tend to boat in really skinny water, stick with IO's as you don't get a second chance with inboards.  W

Amen to that ... I have used my first chance already. Came too close to the rock shelf at low water and nicked the bottom of outdrive bulb pretty badly. The drive went up, the skeg and props survived without damage. Overall, nothing a jar of MarineTex epoxy and four cans of various paints couldn't fix. Got lucky this time.

Having said that, my next boat intended for long term cruising and passage making will have straight shaft or v-drive and two diesels. The i/o is just too complex with too many parts outside the hull that can cause trouble and require a strict and frequent maintenance ... not easy to do when a boat needs a heavy duty lift to accomplish that.

 

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If the boat hull was DESIGNED by a great hull designer ?   He will have      boats  balanced correctly.   

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1 hour ago, Iggy said:

There is a give and take with everything. But, to me you are right on as far as I can tell. I just want to get away from out-drives and get into diesels. 

And a single diesel will work all day long every day and still live longer than most boats it's sitting in. My friend has a 42' Grand Banks with twin Cat V-8's. 11 MPH, at 12 GPH, hour after hour after hour...  W

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thanks for all the comments...like many of you I know there is no perfect boat... and I spend countless hours considering the options. If money was no object I'd have a Hinckley picnic boat.. but now I maybe reconsider my plan mainly because of where I boat.... the dreaming continues... but I feel more educated.  

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On ‎8‎/‎22‎/‎2019 at 11:38 AM, Roady68 said:

I don't know about V-drives pushing engines back.  All outdrives have engines right up against the transom.  On the Sea Ray at our dock that has out drives, there has to be at least 6" more between the transom and engine than on my Sig 300.  Also, V-drives place the transmission towards the center, so should be better weight distribution. Or am I missing something?

So Roady, funny thing happened I thought I would just mention it to you since we were talking about this specific thing that came up last night.  The Garmin guy at the seminar yesterday was taking about mounting radars on boats and a specific boat that they had to drop the front of the radome considerably and even shim the back, and so he asked us if we've ever seen some of the radoms mounted really low in the front and while yes, I've seen it right in my marina and on several other boats -- although rare -- I didn't say anything just to see what the answer is and he said EXACTLY what that lady told me.   He said they mount them that way because they take into consideration 2 main factors, what's the averaging cursing speed the individual will be doing under extreme condition and what engine type does the boat have and because this particular boat he was talking about had V-drives, the radome was tilted down forward a lot more than usual BEACAUSE most of the cruising this owner did was around 10-15knts and he would get a severe bow rise out of it.  I couldn't believe what I was hearing.  Hence in order to get that central beaming as close to operating in maximum range for that most common cruising speed is to position the  radome that way since at that speed, the bow has a severe rise on V-drive boats.  So maybe, just maybe besides there being some truth to what that lady told me at the dock about positioning V-Drive engines way back (and not the fact that what you saw is not withstanding), there might be quite a bit of truth to this now that I think about it.  Not only a lady that has been boating for oh gosh, I would say because of her age (probably in her late 60s-70's maybe 50 - 60 years of experience, she's no slouch I tell ya) and a Garmin rep repeating the same thing, there has to be some truth to this factor.  Perhaps it means the same thing to our engines but the small difference you and I mentioned might be all it takes to cause a big difference in that severe bow rise. 

BTW, what you said about all outdrive engines being right up against the transom is not necessarily true.  I looked carefully at mine and there was a bit of space there because f the transom shield for the rear motor mounts and the steering ram below.  Perhaps it is the same concept or close enough that it created the same effect except in our boats, but we have the option to trim considerably, between outdrive and trim tabs?  I would think I Sea Ray like that would also have trim tabs but maybe not and maybe that's why he had such high bow rise.  But if you're going at 10knts without any trim, you'll have pretty decent bowrise.  So when he said  that yesterday, I thought of this right away because it matches what that lady said to me and she also owns a gorgeous, 35ft Sea Ray but she has stern drives and was very adamant about the other Sea Ray I pointed out having V-Drives that are up against the transom.  She also mentioned that in order for him to get to his engines, he had to remove seats and things of that sort while she just had to press a button and the entire top of the stern opened up with a little ladder to get her down in between her engines lol.  Show off! 

I would like to get to that Sea Ray at our marina this weekend and take a pic because now, 2 very experienced people have said the same thing about the (extreme bow rise) to V-drive engines at certain speeds.

This is the  Sea Ray in question, blue one to the right when I was behind it and couldn't believe the amount of bow rise, I should've taken a pic but because of the position, it would've been hard to tell since I was almost directly behind him.   BUT, it was even WORST than this GORGEOUS Cruisers Yachts 45 Cantius Black Diamond Limited Edition that was following us down the Annisquam River and as soon as we exited that dreaded Blyman bridge, this is what it stayed at for quite a while. 

Here's a pic of that Sea Ray in question and you can even see from this angle how forward-tilted that radome is.  Compared to mine or more common ones, it is pitched down at the front unusually more than any of the other ones you would see.

Bywe0En.jpg

Now this Black Diamons Cruisers has pods if I'm not mistaken.  Didn't even look it up and maybe it has sterndrives because it has joysticks everywhere and look at that bow rise.  Although I must admit, most boats in our areas including myself try to cruise with a bit of a high bow simply because it's a much more comfortable ride on ocean chop.  So he might've maintained that bow rise on purpose (which he actually did because we stayed parallel for many miles) and I could see him stay that way for a long time even at high speeds.  I see a lot of CCs do the same exact thing.  I've stopped using my trim tabs and only trim with outdrive to raise the bow since I have absolutely no reason to drop it.  I need it to go up, except for once we're up in the  40mph range of course.  But this is almost exactly the same bow rise as the V-Drive Sea Ray and now that I've heard it from a Garmin specialist, I think there is a lot of truth to it.  Just thought of you when the subject came up and thought I would post about it.  And this boat has an open array beam which has a greater percentage of beam reflection so it's not as necessary and picks up 12 degrees from top and 12 degrees from bottom whereas radomes are only around half of that.

B2jU2o5.jpg

 

 

 

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On ‎8‎/‎22‎/‎2019 at 11:38 AM, Roady68 said:

I don't know about V-drives pushing engines back.  All outdrives have engines right up against the transom.  On the Sea Ray at our dock that has out drives, there has to be at least 6" more between the transom and engine than on my Sig 300.  Also, V-drives place the transmission towards the center, so should be better weight distribution. Or am I missing something?

Went to that boat to take a better shot of the radome on it and look at that angle!

YbswsSy.jpg

ztnC2Cm.jpg

Walking back to my boat I see the wife of the owner of that 2007 Cruisers 350 and I asked her how does he radar work and how happy is she with it and she said it's great from what she knew, said I would have to ask her husband Johny Boy lol since he drives it all the time (no pun intended) and she asked me why?  So I told her the whole story about this Sea Ray and how Christine was talking about it having such a high bowrise because of the V-drives and how most radomes you see are just barely leaning down at the front and then I said "kinda like my boat and yours!" You know what she said?  "We have V-drives too!"  LOLOL!  And her radome was almost perfectly level with the water.  She also said the don't get anything near the bowrise I was describing this Sea Ray was getting.  I told her quietly "that's because John drives that thing like a real captain!" 

She laughed but seriously, I'll never forget the day they came in with that giant boat that looks like it has a 16' beam!  He came into the dock and backed her into the slip like a BOSS!!!  He used his bow thrusters and backed her right in it was amazing.  He's quite the captain.

So there is something interesting and weird going on here.  Maybe this boat has a certain issue OR, when he was having his Raymarine installed, they asked him what is his average cruising speed and how much bow rise and he told them, so they dropped it down.  Only thing I could think of. 

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On 8/31/2019 at 7:16 AM, Hatem said:

Went to that boat to take a better shot of the radome on it and look at that angle!

YbswsSy.jpg

ztnC2Cm.jpg

Walking back to my boat I see the wife of the owner of that 2007 Cruisers 350 and I asked her how does he radar work and how happy is she with it and she said it's great from what she knew, said I would have to ask her husband Johny Boy lol since he drives it all the time (no pun intended) and she asked me why?  So I told her the whole story about this Sea Ray and how Christine was talking about it having such a high bowrise because of the V-drives and how most radomes you see are just barely leaning down at the front and then I said "kinda like my boat and yours!" You know what she said?  "We have V-drives too!"  LOLOL!  And her radome was almost perfectly level with the water.  She also said the don't get anything near the bowrise I was describing this Sea Ray was getting.  I told her quietly "that's because John drives that thing like a real captain!" 

She laughed but seriously, I'll never forget the day they came in with that giant boat that looks like it has a 16' beam!  He came into the dock and backed her into the slip like a BOSS!!!  He used his bow thrusters and backed her right in it was amazing.  He's quite the captain.

So there is something interesting and weird going on here.  Maybe this boat has a certain issue OR, when he was having his Raymarine installed, they asked him what is his average cruising speed and how much bow rise and he told them, so they dropped it down.  Only thing I could think of. 

So this weekend we were out and I was paying more attention to the express cruisers in the area.  There were several that were cruising along with bow high in the air.  A tilted radome would be necessary on those.  There were a few that seemed to ride level.  Now, here is another part of the observations.  We took a ride from our marina down to city of Buffalo, probably a good 12 mile trip.  My Sig 300 likes to get up on plane and cruise around 3200 rpm to 3800 rpm.  Speed is around 28-30 mph.  I can run down to about 2800 rpm and hang on to plane at 24 mph but I usually will drop trim tabs down to lower bow.  During this range of operation my boat is pretty flat.  Some bow rise, but I can sit in the helm seat and see through windshield and pilot with no problems.  But I noticed that I would come up on other express cruisers pretty fast.  I was always passing them.  We must have passed a half dozen cruisers and a few other smaller boats, all of which seemed to be in a hurry to go somewhere.  So now I am wondering if the drivers of those boats aren't fully up on plane, not using trim of outdrive or trim tabs?  I had no way to stop and ask how they were equipped.  Or maybe I just like speed and I am going fast enough to keep my hull up on the water and making use of the extended V plane design.  Hmmm?

In short, maybe its not the difference between V-drives and outboards, but how the craft is being piloted?

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19 hours ago, Roady68 said:

In short, maybe its not the difference between V-drives and  I/O, but how the craft is being piloted?

FIFY.  Unless you really meant outboards?  But I don't think so since the comparison was strictly between V-drive boats ad I/O like ours.

And that's pretty much what I was saying and if that is the case, which it most likely is, there's still a couple of questions that linger and why is it that the this experienced lady AND especially the Garmin rep said pretty much the same exact thing?  These are not fly-by-nighters so there must be some truth to that.

The other question is why wasn't the guy in the Sea Ray using his trimtabs?  Why have such a severely high bowrise when you can simply push two easy buttons to take care of that?  That thing I swear must've dropped 4ft when he reached the no-wake zone.  Hard to believe it doesn't have trim tabs or didn't come with them and he never installed them? But it's a possibility.  While rare and doubtful with a boat like that, you never know. 

People who have radars installed MOSTLY for fog and incremental weather are not traveling at high rates of speed.  So they take that into consideration when installing them.  I remember being asked this question but I told them mostly for fog, but also nighttime and a lot of overlay so they gave me a very slight, forward angle.  So they pretty much leveled mine.  I had a pic of the 350 Cruisers but can't find it.

dL3CpU9.jpg

 

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Yep, meant I/O.  You can see in my signature photo that mine is only tilted a little.  As I said, I don't have a lot of bow rise on plane.  Maybe 5 to 7 degrees.  I'll have to use the level function next time im out.

 

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On 8/22/2019 at 12:14 PM, Wingnut said:

And a single diesel will work all day long every day and still live longer than most boats it's sitting in. My friend has a 42' Grand Banks with twin Cat V-8's. 11 MPH, at 12 GPH, hour after hour after hour...  W

My next boat will be one that I plan to live aboard and do The great Loop with so diesel will be preferred.  After that it's back to a blow boat and head for the islands mon... 

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15 hours ago, Roady68 said:

Yep, meant I/O.  You can see in my signature photo that mine is only tilted a little.  As I said, I don't have a lot of bow rise on plane.  Maybe 5 to 7 degrees.  I'll have to use the level function next time im out.

Thought of you when I was at the marina yesterday really digging into my new Volvo Interface (man I love that thing) and organizing wires and cleaning the boat and also tying her up like you told me on the Hatem thread because we supposedly had some rain and wind coming last night.  But while taking a break from all that stuff, I walked around to take some pics.

This is that beautiful Cruisers 350 I was telling you about that also has V-Drives that belonged to that girl whom I was talking to about the Sea Ray having a high bowrise supposedly because of having V-drives and how the radome was so tilted and she was the one that said "we have V-drives on out twin Mercs also" remember that?  Well, that's because Johnny Boy (her husband) drives (or planes) that thing nice and straight.  Makes me even more curious about the Sea Ray.  Being the nosy SOB that I am, I kinda know that dude with the SR enough to tell him to open his hatch lemme take a loon at his engines exposed because I'd love to take pics of the V-drive engines and how far back they are and I wouldn't even care about asking why his bow was 4ft in the air the other day also lol.  I'd really like to know why.  Measuring bow rise in degrees is because usually it's within a nominal, "normal" range.  But being a builder, I look at all this stuff in feet and inches and 4ft high, what degree is that? LOL  He did back that thing like a boss, though, which makes it more unusual why he would be driving bow high like that.

But this Cruisers 350 is SPECTACULAR!  All around from the unbelievable beam to the plush interior of the cabin.  So much space oh and I love the tiny grill lol.

mOYeHa6.jpg

Still taking a break and walking around I took this pic and as side by side, interesting to see the difference in the angle.  Both Raymarines so not necessarily a Garmin SOP.

gYFuZ5t.jpg

I figured you would get a kick out of this one LOL!  Seriously, though, WTF is going on here?  Did they not only get a high bowrise but were also interested in seeing things on their radar a lot closer or something?  :D 

uV3k28f.jpg

 

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On ‎9‎/‎3‎/‎2019 at 1:54 PM, Roady68 said:

So this weekend we were out and I was paying more attention to the express cruisers in the area.

Yeah sorry it wasn't you that was asking me about being able to tie my boat with an additional line, it was Tidal Potomac sorry I confused you with him.

And yeah, those Cruisers are really outstanding boats.

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On 9/4/2019 at 3:27 PM, Roady68 said:

Maybe 5 to 7 degrees.  I'll have to use the level function next time im out.

Is that a function on your GPS that will give you that kind of information or something else.  Curious to know how that's achieved.  

I meant to ask you that right after you posted it but forgot.  Do tell, pls.

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19 minutes ago, Hatem said:

Is that a function on your GPS that will give you that kind of information or something else.  Curious to know how that's achieved.  

I meant to ask you that right after you posted it but forgot.  Do tell, pls.

I'll mount my iPhone on the inside of the radar arch or at the helm on the side.  Under the Utilities feature there is a level app.  Works alright.  I'll take a look at various speeds and what the angle of boat is at those speeds.  

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2 hours ago, Roady68 said:

I'll mount my iPhone on the inside of the radar arch or at the helm on the side.  Under the Utilities feature there is a level app.  Works alright.  I'll take a look at various speeds and what the angle of boat is at those speeds.  

Very cool.  Do keep me posted because I love this kinda stuff.  I would ask you to take pics and post them, but most people who are the opposite of me don't like to bother so I won't ask. :D

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On 9/6/2019 at 12:23 PM, Hatem said:

Very cool.  Do keep me posted because I love this kinda stuff.  I would ask you to take pics and post them, but most people who are the opposite of me don't like to bother so I won't ask. :D

OK, so I did a couple of runs and this is what I found.  I forgot to grab the paper I wrote down the numbers on, but I think I remember.    

Sitting in the slip, lets call this the reference, the radar dome is about level.  Maybe, 1 degree down.  Maybe.  Hard to get super accurate as I was standing on the transom seat back and reaching up.  Placing level on the ledge at the base of the gauge cluster, I had a reading of -5 degrees.  That is, there was a slope of the shelf I set the phone on such that it dropped down 5 degrees towards the bow.  At slightly above idle, say 1000 rpm, my speed is about 5 mph.  No change in level at the helm.  At 2400, I am doing about 18 to 20 mph.  Level is reading plus 2 degrees.  So what that is saying, is the bow rise is about 7 degrees.  Note that at this speed, I am not on plane.  I can lower trim tabs all the way and drop bow about 1- 2 degrees so that the level is reading about 0 degrees.  Getting the rpms up to 3200 to 3400 rpm gets me up on plane and bow drops back down such that the level reads about -4 degrees.  Speed is about 26-28 mph.  I can drop revs back a few hundred rpm and hull will stay up on plane.  That means that the bow is riding about 1 degree up.  Based on my reading of the radar dome, I would say having it set at the angle it is set at is pretty much perfect.  Increasing speed to 32 mph doesn't effect the attitude of the hull.  Again, dropping trim tabs all the  way down will lower bow about 2 degrees.  So I can pretty much get same attitude of the hull at speed as it is when sitting still.  But, I notice that dropping the tabs all the way did add more load to the engines and speed drops.

I've run with full throttle.  Engine revs got up into mid to high 4000s.  Speed got up to 42., again no real change in attitude of the boat, so still runs pretty level.   I ended up with an alarm after a few minutes which cut the full throttle test short.  I shut it down  and restarted and alarm went away.  A friend hooked up scanner and found out it was knock sensor.  I guess I need to look up the causes and potential corrections.  Next season.  Boat will be out of the water in two weeks for winter storage.

 

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10 hours ago, Roady68 said:

Sitting in the slip, lets call this the reference, the radar dome is about level.  Maybe, 1 degree down.

Sorry, I'm laughing so hard ATM and DEFINITELY not at you, but at someone else who jumped all over my case when I was telling @Benda23 that they would probably end up installing his dome at almost level or thereabouts, and it got ugly as #$^% and here we are.  It does feel good, I must admit.  Sorry I just had to throw that in there.

I actually have a bevel level, lol, I know that sounds funny but it does exactly what you did but is shaped as a level and folds and you can open it up to any angle to determine what it is and it has a digital read-out.  We use it a lot to cut rafters when building houses and additions or even stair runs or anything.  Would work well on this application now that I think of it. 

10 hours ago, Roady68 said:

Sitting in the slip, lets call this the reference, the radar dome is about level.  Maybe, 1 degree down.  Maybe.  Hard to get super accurate as I was standing on the transom seat back and reaching up.  Placing level on the ledge at the base of the gauge cluster, I had a reading of -5 degrees.  That is, there was a slope of the shelf I set the phone on such that it dropped down 5 degrees towards the bow.  At slightly above idle, say 1000 rpm, my speed is about 5 mph.  No change in level at the helm.  At 2400, I am doing about 18 to 20 mph.  Level is reading plus 2 degrees.  So what that is saying, is the bow rise is about 7 degrees.  Note that at this speed, I am not on plane.  I can lower trim tabs all the way and drop bow about 1- 2 degrees so that the level is reading about 0 degrees.  Getting the rpms up to 3200 to 3400 rpm gets me up on plane and bow drops back down such that the level reads about -4 degrees.  Speed is about 26-28 mph.  I can drop revs back a few hundred rpm and hull will stay up on plane.  That means that the bow is riding about 1 degree up.  Based on my reading of the radar dome, I would say having it set at the angle it is set at is pretty much perfect.  Increasing speed to 32 mph doesn't effect the attitude of the hull.  Again, dropping trim tabs all the  way down will lower bow about 2 degrees.  So I can pretty much get same attitude of the hull at speed as it is when sitting still.  But, I notice that dropping the tabs all the way did add more load to the engines and speed drops.

Tremendous stuff!  Really enjoyed reading that and I'm sure that doing this test, gave you, yourself, more knowledge about your own boat and it's attitude at these different speeds.  This part here is fascinating to me and tells me that the radar dome was installed perfectly on your boat.

10 hours ago, Roady68 said:

Getting the rpms up to 3200 to 3400 rpm gets me up on plane and bow drops back down such that the level reads about -4 degrees.  Speed is about 26-28 mph.  I can drop revs back a few hundred rpm and hull will stay up on plane.  That means that the bow is riding about 1 degree up. 

Outstanding.  Sounds like your radar is working perfectly, and I'm actually surprised you don't get that much bow rise for a twin 330.  Seems like that boat is so well-balanced.  Thank you for doing this experiment and sorry it ended in the knock sensor alarm going off, but at least you know about it and have plenty of time to take care of it.

Our marina has October 15th as the deadline for hauling boats out, but they let people milk it to the end of the month but it won't matter in our case since we're hauling it out next week and getting ready to trailer it to south Cape Cod to go great white shark "visual" hunting.  Thanks again, Roady.  Good luck with everything.

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