A trim tab question (tabmanII a good one for you)

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

I hope this helps on my end.<br />
bellhousing.jpg
<br /><br /> And yes Don I would like to keep this as cheap as possible. I just started my new job this past Monday after being out of work for about 5 weeks. When I mentioned this whole thing last night to the wife she didn't say anything against it but I could see that look in her face. You know that look of "do you have any idea what has been going on lately and now you are talking boat parts in November??" But she would understand if it was a deal I couldn't pass. That is why I love her (for you sweetie if you read this). ;) <br /> By the way Don, thanks for all your help. I see the I/O board was left in good hands. You should have been here a couple years ago. It was like the shoot out at the O.K. coral some days with everyone being hard heads and knowing everything. That last kid that had you and rodbolt got wound up over was everyday thing here but I stuck it out. Only one that got under my skin. If I could find the guy that used to quote USCG regs all the time. "You cant put a 50hp motor on a boat that is rated 45hp. If you get caught you will be liable!!". Drove me nuts. :mad: <br /> Thanks again and rodbolt if you need my email you can get it through my website.
 

Don S

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Re: A trim tab question (tabmanII a good one for you)

We'll see which ujoints rodbolt has on that drive, that will tell the story. You have the course splines there, and I know his are fine. They quit using course well before the DP-A2 drive came out.<br />If you do get the setup, i'll get you a wiring diagram for the trim using a momentary toggle, or even a couple of push buttons. Either way would wire about the same, and no big deal.
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

I know the unit that I am discussing has the fine spline yoke but I cant remember if it uses internal or external ujoints. I know the ujoint kit is avalible to put the older style coarse spline yoke on the late style DPA2 drives as I did two a month or so ago.<br /> however I am almost positive it has the inside keepers on the cross caps.
 

Don S

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Re: A trim tab question (tabmanII a good one for you)

Inside keepes is what I expected. Better get that stuff boxed up, he's probably already out pulling the engine getting ready :D <br />BTW, is that the standard trim pump with 2 relays and plastic reservoir?<br /><br />This one.<br /><br />
Trim%20pump.png
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

yep thats the trim unit.
 

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

While we are on the subject;<br />Why did Volvo come out with the two props on one drive set up? Was it because they fell so far behind Mercruiser (Volvo was making and selling 270's and 280's when Merc had trim, slimmer cases, etc...). I know you could have got trim with the Volvo as a special order but that didn’t happen much at least there isn’t many on the second hand market. Why didn’t the Volvo market demand it or were their buyers at the time not interested in that stuff? Then they jump ahead of Merc in one leap with the two prop thing and trim. <br />Last, not ever having a outdrive like that what are the benefits /draw backs of having the DP set up?
 

Don S

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Re: A trim tab question (tabmanII a good one for you)

Hey Rodbolt, don't sell him that stuff, he has no class at all....... ;) ;) :p :p :D <br /><br />
Why did Volvo come out with the two props on one drive set up?
25% more efficient than a single prop.<br />
Was it because they fell so far behind Mercruiser (Volvo was making and selling 270's and 280's when Merc had trim, slimmer cases, etc...).
Ya gotta be kidding. Volvo has never been behind Mercruiser. The only reason their Alpha drives are so sleek is because they can't hold the horsepower. Especially back when the 270's and 280's were around. All that was out there was the R & MR and even earlier slam-bang shifting dog clutch drives. Gears wouldn't hold any power.<br />Of course Volvo came out with the 40 diesels hooked up to the same old 280 drives that you have and they held up fine.<br /><br />
I know you could have got trim with the Volvo as a special order but that didn’t happen much at least there isn’t many on the second hand market.
Until hulls and speed and performance became a big deal there was no real need for trim.<br /> <br />
Then they jump ahead of Merc in one leap with the two prop thing and trim.
Jump ahead of Merc???? They were never behind. They developed the DP because it worked so much better. Look at the old torpedoes during the war. Dual Props on them. Volvo learned. Others didn't....... and they still haven't figured it out to this day.<br /><br />
Last, not ever having a outdrive like that what are the benefits /draw backs of having the DP set up?
Benefits: Better low speed steering, better out of the hole shots, better mileage, better efficiency.<br />Drawbacks: They cost more than single props. But that seems normal with a more complicated gear setup and 2 not 1 props and prop hardware.<br /><br />Look at it this way. Those people that built your Nova must have known the Volvo was better, or they wouldn't have used it. Right???<br /><br />Just for fun, go to the link below and start at 1960 but specifically check out 1980 and the movies on the DP. Be sure to check out the other overviews and movies also.<br /><br /> http://www.volvo.com/volvopenta/global/en-gb/aboutus/our_history/
 

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

***quote: <br /><br />Was it because they fell so far behind Mercruiser (Volvo was making and selling 270's and 280's when Merc had trim, slimmer cases, etc...). <br /><br />Ya gotta be kidding. Volvo has never been behind Mercruiser. The only reason their Alpha drives are so sleek is because they can't hold the horsepower. Especially back when the 270's and 280's were around. All that was out there was the R & MR and even earlier slam-bang shifting dog clutch drives. Gears wouldn't hold any power.<br />Of course Volvo came out with the 40 diesels hooked up to the same old 280 drives that you have and they held up fine.***<br /> <br />---The reason I asked was I have a 1973 Merc 888 and a 1972 Volvo 270. They seem light years apart from each other. I do know the Volvo has a much better reputation for being a tough outdrive. I know I have whacked mine a couple times with only pain scratches to show for it. <br /><br />****quote: <br /><br />Then they jump ahead of Merc in one leap with the two prop thing and trim. <br /><br />Jump ahead of Merc???? They were never behind. They developed the DP because it worked so much better. Look at the old torpedoes during the war. Dual Props on them. Volvo learned. Others didn't....... and they still haven't figured it out to this day.****<br /> <br />----I thought they did that to off set the torque of the prop spinning only one way and to keep it from wondering and on target. (WWII history buff) I can see how it would work. Like the blades on a jet engine. <br /><br />**** Look at it this way. Those people that built your Nova must have known the Volvo was better, or they wouldn't have used it. Right???****<br /><br />---Not a chance. Allmand bought the molds from Nova Marine and then screwed it up so bad they only made about 40 boats when it was all said and done. Wellcraft bought the other boat Nova Marine made and it was the base for every “WellCraft Nova” made. These are the same people who took out a 375HP Chrysler big block and Vee drive and replaced it with a 318 Chrysler with a Volvo drive (with no trim, I say that because these boats cost $10500.00 in 1971). These are the same folks who couldn’t sell these boats even though its cousin, the Donzi were flying off the shelf. So they decided to change the boat a little. See pictures. :mad: :mad: <br /><br />
1f72e900.jpg
<br /><br />
1f61cf80.jpg
<br /><br />A ad from back then. You can see the prop shaft sticking out of it in the middle circle. <br />
18b40ba0.jpg
 

QC

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Re: A trim tab question (tabmanII a good one for you)

I am a big fan uf duo-props, but isn't the real reason that Volvo came out with it is that their current drive was maxed out as far as torque input. Didn't they have to, to keep up with the Bravo?<br /><br />BTW, f_n I test ran my boat yesterday with the trim out half-way and then just used the tabs to control it for hole shot and speed. That worked fairly well . . .
 

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

BTW, f_n I test ran my boat yesterday with the trim out half-way and then just used the tabs to control it for hole shot and speed. That worked fairly well . . .<br /><br />Thanks but I have tried every setting and combo of settings over and over with no luck.<br />I guess I have come to the conclusion that I have peaked out what ever I could get out of my set up. The Volvo 270 has 3 settings for trim. The first is to high. The prop wants to cavitate and will not “hook up” properly . I am sure it has something to do with the prop I run also. But after talking to the designer of the boat and telling him what speed I was getting he said, “it always amazes me what you backyarders get out of these things when we thought the design limitation would only allow for a lot less”. Now he won 1970 Miami- Key Largo offshore race with a stock (extra gas tanks) Nova 19 with a average speed of 52mph. I have had mine to 65+mph with the right set up but it was a tank to drive. <br /> The center trim hole is fine but like I said before the bow does ride lower then it did. With everything moved to the back as far as it can be I have to come up with other options. Tabs will push the bow down (or raise the stern) but tabs will do nothing about bringing the bow up. That is on the drive. I really don’t want to have to put weight in the back of the boat just to balance it. If this deal does not work out I may have to get a different prop (still may hold off because props I like are expensive and the money from the price of one would be a good start toward a new drive) but I very much rather have “trim” so I can have the best of all worlds. <br /> The hole closest to the transom is O.K. also. Just a little blaaa. Maybe it is the angel of the transom but it doesn’t have much effect. The bow rides almost the same as it does on the center setting at speed just maybe a mile or two slower overall. <br /> On any setting I have no problem getting on a plain at a low enough RPM. Also like I said before I have almost never used the tabs and I don’t think I would miss them at all if they were gone. Except for if I ever got caught in another storm and needed to keep the bow down while still going forward below planeing speed. They are good for that and to control bow rise but that is the opposite of what I need. I know the boat is not underpowered and most would be happy with the way the boat handles now but I know it can be better if I just could pick up the bow and get a little more of the hull on top of the water. Put it this way. Driving this boat on flat water is not nearly as fun as if there were a 1 foot chop if that make any sense.
 

QC

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Re: A trim tab question (tabmanII a good one for you)

Originally posted by f_inscreenname:<br /> Driving this boat on flat water is not nearly as fun as if there were a 1 foot chop if that make any sense.
I had a fixed trim I/O too once. I completely understand. Arneson manufacturer's a tab setup that they claim can increase bow lift. I have no idead if they work, here's a link. They look like they would be more $ than the new drive . . . :rolleyes: <br /><br /> http://arneson-industries.com/Arneson Rocker Plates.htm <br /><br />I still don't think that the tabs are keeping the bow down now in your boat (In fact they are a little weight on the stern too). It still sounds a lot like balance to me.
 

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

**I still don't think that the tabs are keeping the bow down now in your boat (In fact they are a little weight on the stern too). It still sounds a lot like balance to me.**<br /> I totally agree. I never thought taking off the old exhaust manifolds and replacing them with much lighter manifolds would screw up the balance like it did. It wouldn't be the first unique problem for this boat. Most boat have to much lift with the bow. Go figure.<br /><br />***Arneson manufacturer's a tab setup that they claim can increase bow lift. I have no idea if they work, here's a link. They look like they would be more $ than the new drive . . .***<br />Yes they do. With just a few parts off of them I could make trim for my 270. They are super nice and built hardcore but I guess you need them to be with a boat like that. I still don't see how they work. They do have a side piece on them but I think that would be for side slip. Is it because they are mounted different? Or the shape of the plate?? Sure would like to know how it is done. <br />
RkrPlts38.jpg
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

while thats a killer pic of a plane its also on a bravo type drive with power trim, by itself with no power trim the trim tab cannot by itself create bow lift as it lifts the stern. <br /> trim tabs are good at what they are designed for but wont help a no power trim or poor hull design other than the ability to bring the bow down,decrease squat on plane as well as bow rise on plane and hull balance.<br /> can also give a better ride in a head on sea by forcing the bow down.
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

not very smart,I just bang my head on them a lot :) :) .<br /> bang your head on them enough and something will stick.
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

yep<br /> Joes says he should have a price worked up tomorrow. if not Ill call the owner and try to ask directly. if not this stuff will clutter up this small 3 bay shop forever.<br /> already have to much junk and the 3rd bay is unusable.
 

rodbolt

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Re: A trim tab question (tabmanII a good one for you)

if joe dont move ill ask the customer if he would wish to deal direct with ya.<br /> does not matter to me as far as money, I am out of the loop on that. I just replace and fix them.<br /> I suspect the upper seal in the gearbox is leaking as a bit of oil was in the bellows. but thats a minor thing.<br /> but itsw a thing I will bring up to reduce the price.<br /> but if the price is right I will pressure test it and take some pics with the shop digital cam.<br /> but if you honestly getting over 300 HP out of that motor the DP with power trim will wake it up.<br /> I wish volvo would make a commercial with their drive dyno. ya outta see the abuse they use to test the drives. I watched a bit of a test where they applied 400HP for 3000 hours with routine stops to change the drive oil with no failures. the same test with an alpha netted just over 350 hours. but I can rebuild 5 alphas for the cost of one DP.
 

f_inscreenname

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Re: A trim tab question (tabmanII a good one for you)

I have had both Merc and Volvo over the years and I know from personal experience that Volvo is much tougher overall. My 270 on the boat now is almost 35 years old and besides some gaskets it has not been worked on at all. Just wish it had a few things like trim to start..
 
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