January 11, 2016 at 1:55 am #94161
I’m a proud new owner of a 1979 Pearson 424 out of Seattle, WA. I’ve been keeping a close on this forum for information regarding 424’s and have found lots of great write-ups.
I’m looking at potentially repowering in the near future. I’m doing inventory of items that will need replacing and am trying to evaluate if the V-Drive needs replacing.
From what I understand, the copper cooling jacket inside the V-drive eventually plugs up and fails. I opened mine up today and found that there was a moderate amount of salt crud near the seawater entrance and exit. I was able to scrape away most of it within twenty minutes or so.
Based on the attached picture of the cooling jacket, would you consider replacing the V drive? It seems that it has plenty of life left to me.
January 11, 2016 at 6:13 am #94163
DiscoverieParticipantCongratulations on your Pearson 424 purchase. I was unable to see the photo from the email but will check when I’m at a computer. From my experience the choice is to rebuild or replace. In my case I opted for the rebuild as Tor did. As he’s said its about 1/3 the cost, and I expect to get another five to seven years out of it. I’m sticking with my W58 engine so that wasn’t a consideration.A couple of questions I considered:Does it leak?Is raw water flow restricted?Is it noisy?Does it run hot?In my case the answer was no to all off the above. But it looked pretty bad from the outside so I pulled it and sent it to Walter Machine in NJ. Don Chatrnuck gave me the options and I went for the rebuild.Good luck and let us know how it goes. Btw I have the owners manual if you need it.RogerDon’s contact info is below.
January 11, 2016 at 8:54 am #94168
I’ve tried twice this morning to respond to your question by email, but they didn’t get through. Figured I’d do it this way for a change and see if it works.
I admire the 424 owners who keep their boats’ original, now-ancient machinery operating with scrapped & scrounged parts and JB Weld. I’m not nearly skilled (or interested) enough in engine mechanics to do that, yet I rely on my engine and its drive train almost every day. So for me it made sense to start out with good (as in new or newly rebuilt) machinery and then maintain it scrupulously. I gave Silverheels a new engine and a professionally rebuilt transmission right after I bought her. It was another 5 years before I got around to having the V-drive rebuilt by the Walter factory, but now that’s done, as well. For me, the increase in confidence and enjoyment of my boat were well worth the price. For you I guess it depends on your abilities, your budget, and how you plan to use the boat.
Silverheels, P-424 #17
January 11, 2016 at 9:08 am #94169
My boat was the same model year, hull #47. I repowered several years ago. There is no attachment so I can’t see what your v-drive looks like.
Basically, the Walter unit is IMHO poorly designed. The cooling jacket is cast-iron, not copper. It has no provision for fresh-water cooling and therefore is destined to rust out after about 30 years. Eventually, the cooling jacket will rust through near the dipstick, allowing water to seep into the gearbox. Keep an eye on the oil condition. When it fails, the oil will turn to the color of chocolate milk. I’m surprised that your unit hasn’t already rusted out. Perhaps the PO already replaced it once or maybe it was kept in fresh water.
The RV-20 is no longer in production. Cases for this unit are unobtanium. While you could rebuild the gearbox, this seems like a waste of money if you can’t replace the cases. If you decide to replace the unit, you’ll be installing an RV-26. The best time to do this is when you repower since you could then change the gear reduction if you chose. This opens up your selection to more possible engine replacements.
Here are my notes on repowering. There’s a section in there about the V-drive. There is also a spreadsheet attachment that itemizes what this cost me. My suggestion is to nurse what you have and save your pennies. Please feel free to ask questions.
—– Original Message —–
January 11, 2016 at 9:30 am #94170
skipmacParticipantI have read several posts in the past from V-drive owners that just disconnected the raw water cooling to the drive. Supposedly did not run hot at all, even after hours at cruising speed under power and of course solved the corrosion problem.Any consensus or opinions pro or con on doing this?Skip
March 26, 2017 at 6:30 pm #222903
I know this is an old thread, but I’m a recent owner of hull #81 (Papaya) and have been trying to get the v drive sorted out. The cooling passage was mostly clogged up with rust (I think thats what all that black crap is) causing the engine to run hot (Yanmar 75 hp Turbo 4JH3-TE). a yard cleaned it out and restored flow so cooling problem solved. after that I noticed the oil getting emulsified, milky from water contamination. I had been checking the oil regularly before the clean out and it was staying clean. Today I took the cover off the top to get a look at the cooling jacket (to see if the yard poked a hole in it) and it occurred to me that the gasket for the top cover provides another potential route for water to get into the oil. So, my current plan is to marine-tex the inside of the cooling chamber and replace the gasket – maybe that will do it. I also suspect the yard may have let water dribble down the dipstick tube when they took the cover off – maybe. Anyway, in looking over the manual I see that Walter recommends the following:
SAE 30 Heavy Duty Motor Oil
Exxon Spartan EP-68 Gear Oil
APG-80 Gear Oil
They also recommend molybdenum disulphide additive. So, if I end up disconnecting the cooling as others have done, I wonder which of these oils would provide the coolest running temp?? Any thoughts on that?
January 11, 2016 at 10:10 am #94173
Yes, and I also recall some saying the beast runs quieter if you use a really heavy gear oil in it. (Like, 90W? I don’t remember exactly.) Wouldn’t hurt to call the Walter factory and ask them about both options. Everyone else is guessing.
Silverheels, P-424 #17
January 11, 2016 at 10:29 am #94175
john stevensonParticipantI also went the replacement route in 2011.Â I should have done that when I repowered in 2008, since I used a yard for the repower.Â I probably could have negotiated a better overall price for both jobs by doing is at one time.Â If you are doing the job yourself, that wouldn't apply and there is no logistical reason to do both jobs at once.Â One problem I encountered with the replacement of the RV-20 with the RV-26 is that the 26 has a slightly larger case.Â With me repower the jackshaft to the RV-20 was shortened to its minimum length, and then was too long for the RV-26 without having to move the V-drive mounts.Â I purchased a new shorter jackshaft from Walter.Â Walter clearly understands that the V-drive case is made out of iron, but they must think their jackshafts are made of titanium.Â I think I paid around $1,200 for the shaft.My decision to replace rather than rebuild was based on several factors.
Here's a link to my experience with the RV-26 installation:Â http://www.svsarah.com/Sarah/ewSarahVDrive.html ÂÂ Â
- I had the unit re-built by Walter in the first year I owned Sarah, and I was not sure how much value I would get out of another rebuild.
- I was aware of the problems with corrosion of the case, and as Rich points out, no replacement of the case was available.Â I did not open the case to determine how serious the problem was with my unit, but Sarah is hull #2 so it was the second oldest unit in the fleet.
- I was planning to resume long distance cruising (maybe the SoPac) within the next year or two, so like Tor, I wanted to be as confident as possible in the drive train.Â We cruising sailors don't like to admit it, but even on ocean crossings we use the engine a lot.
- And the real reason: I just got off a 2-month delivery job and I had 3 or 4 boat units burning a hole in my checking account.
January 11, 2016 at 10:43 am #94176
I tool a look at your installation and noticed that you appear to have no provision to make athwart-ship alignment adjustments on your unit. How did you align the thing?
January 11, 2016 at 11:09 am #94178
John, I freely admit my ignorance of most things mechanical, but isn’t that jack shaft just a short shaft? Mine sure looks like it. The machine shop at Green Cove Springs Marina bangs out new prop shafts on his lathe for, like, a few hundred bucks; keyed, tapered, drilled & tapped or whatever it takes to duplicate the old one. Seems like he could knock off that jack shaft for half that much.
What am I missing here? Why buy one from Walter?
Silverheels, P-424 #17
January 11, 2016 at 11:34 am #94182
DiscoverieParticipantWalter recommends non detergent oil. Exactly why that is, go figure.
January 11, 2016 at 11:44 am #94183
Thanks again for all of the information!
John and Richard — I’ve been reading your repower write up over the past few weeks religiously. I’m looking towards the Yanmar 4JH4-TE (if I can find one as they no sell them from the factory) or a 4JH80.
The VDrive doesn’t have any leakage or temperature issues. The only thing I noticed was a restriction on the inlet/outlet ports of about half to 1/3rd of normal. I was able to remove most of the debris blocking this.
The quote for a new RV-26 is a big investment when considering all of the other items in the repower project. I contacted Walter and they indicated my RV-20 unit was manufactured at the same time as the boat. I’m assuming that it’s the original that came with the boat. They’re suggesting a rebuild if the jacket is still in good shape. For those who rebuilt instead of replacing — have you had any problems? I’m curious if I can hold off upgrading to the RV-26 for four or five more years.
Tor — I’m going to be running into a similar issue. The shaft from the engine to the V-Drive is fairly corroded due to water from the shaft seal splashing up there over the years. I’d think that a machine shop could make a similar quality shaft — I wonder what you get from Walter by paying the premium for their shaft?
January 11, 2016 at 11:53 am #94185
Hi Skip et al.
We’ve been running our v-drive with no cooling for 2 years now.Â
We’ve run in excess of twelve hours straight at 6.5 knots and never
seen the v-drive case temp above 95F.Â Granted we are in Lake
Superior so I can’t comment on warmer climes, but it works for us.
Dave and Pat
January 13, 2016 at 12:46 pm #94263
Hi Skip et al.
Weâ€™ve been running our v-drive with no cooling for 2 years now.
Weâ€™ve run in excess of twelve hours straight at 6.5 knots and never
seen the v-drive case temp above 95F. Granted we are in Lake
Superior so I canâ€™t comment on warmer climes, but it works for us.
Dave and Pat
Never posted before so no laughing or general mocking!!
Like Dave and Pat above, I have run my Vdrive (after repowering with a Beta) without any cooling at all and found it never gets hot. I take its temp. religiously and its seems to have survived nicely. The former owner took it from Victoria to Australia and back without incident.
January 13, 2016 at 12:58 pm #94264
My RV-26 gets warm even with cold Atlantic seawater running through the cooling system.Ã‚Â Without cooling, I think it would run hot.Ã‚Â I typically cruise a bit faster than what you report, about 7 or 7.3 kts.
January 13, 2016 at 1:20 pm #94267
rduggerParticipantI have been operating our V-Drive without water cooling for 8+ years, including all day motoring runs in summer heat. There is another 424 in our marina, in the southern Chesapeake, that has also operated without water cooling for a similar period of time. No discernible issues.Ã‚ÂRickEclipseÃ‚Â
January 13, 2016 at 1:35 pm #94269
I agree with the idea to run heavy oil in the Walter but I have been using the regular engine oil Rotella with Lucas Oil additive, 25%. I started using Lucas in my old P323 volvo diesel when I noticed that many the shrimp boats in my north Gulf Coast area used it with success to keep their old engines running. I have used it in my W-60 for the 5 years I have had this boat and I swear that it runs better now after 1200 hours than it ever has. This was a great lakes boat when I bought it, and it only has about 3200 total hours on the original engine now. I have NO oil leaks (finally) and my bilge is now clean. Now after having said that, it will probably blow up on my next gulf crossing. As you know, they don’t break close to home-port. I have had to replace just about everything else that is attached to the engine, however, which includes belts, alternator, tranny, water pumps, hoses, injector pump, fuel pump, even the dip-stick. Just wonder if any other old engine boats use the Lucas or other additive. Some people love it, others hate the idea of it.
January 13, 2016 at 1:41 pm #94270
What is the easiest way to disconnect the RV-20 and remove it from the shafts? I have an exploded parts diagram, but that doesn’t help much.
As y’all may know, I’m kissing the old W58 goodby and going electric. I’ve had several requests for parts, and I’ll be responding soon.
S/V Jolly Lama #135
Keehi Lagoon O’ahu
January 26, 2016 at 7:13 am #97631
Thanks for that picture Rob, it clears up a little mystery for me. My V-Drive top cover has a bunch of goop that the PO applied but never cleaned, it’s never leaked so I’ve left it alone but was curious. My PO put a 3/8″ pencil zinc in that space, it’s in the plug at the lower right of your picture. I check it regularly and as I remember the first few months aboard it seemed to do it’s job, (corrode) rather slowly. I think it was about a year maybe a little more before I replaced it. Since then the zinc comes out almost looking “rusted” and with no corrosion that I can tell. Not sure what’s happening there. Does anyone have any ideas? I might re-bed the cover and take a good look to see if any excessive corrosion is taking place. Yours doesn’t look that bad to me but I’d might take a semi sharp object and poke a little, gently, where the others have mentioned it breaking through.
Taking what comes as I get it, using it all as much as I can and trying hard to leave all the shit behind.
January 26, 2016 at 9:10 am #97632
I’d be hesitant about putting a zinc in there. Any chips that fall off will find their way into the heat exchanger. They will plug up some of the water channels. Walter didn’t put one in there. If they thought it should have one it would.
The two plugs in the cooling jacket are for an oil cooler. Some models have a coil that runs through there to provide extra cooling for the gearbox oil. With only about 50 HP, the W60 didn’t need an oil cooler.
On my old RV-20, the plugs rusted through and started leaking. Once the head rusts, its a bear to remove them. You have to drill them out and retap. I suggest replacing them every 10 years or so. You need a tap for a pipe thread. I think this has the right size.
You can clean and coat the cooling jacket with epoxy such as marine-tex. I did this to my old RV-20. Scraping away the rust is a terrible job. If you do any scraping, be sure to flush any chips out of the cooling jacket so they don’t travel through to the heat exchanger.
—– Original Message —–
March 19, 2016 at 12:16 am #220370
Mark OppeParticipantHi JohnThe new V-26 has fitted in easily. I moved the raw water strainer to starboard side as it was close to the V-26 and it is a better run there as my raw water pump is also starboard side of the engine as is the inlet seacock.I am also not thinking of repowering and replacing the original W58. How have you got on with the Yanmar and which model did you fit ? I also have a velvet drive on the W58. I’m back in the UK this summer and will also look at the Beta set up.Thanks for your article and help.Kind regardsMarkSv Mary MurrayPearson 424 ketch #164Sent from my iPad
March 24, 2016 at 4:51 pm #220428
Mark, we installed a 4JH57 in a Hunter this past week. It is the new common rail version of the long running 4JH series. I was really impressed with how quiet the thing is. Really quiet.
Regardless of what you get you’ll have to come up with a solution to get the exhaust output around the engine to the water lift. You’ll be upsizing the exhaust to 2.5 inches minimum depending on your selection. I chose to run mine around to the stbd side as things were really tight on the port side with the alternator being there. I went to 3 inches based on the manufactures recommendation. 2.5 probably would have been adequate.
I replaced my RV20 due to case failure long before I repowered.
The costliest part of a 424 repower is getting rid of the bottomless bathtub that Pearson put in there for a mounting surface. It was the original engine sump for the 422 (or a center cockpit version?) I’m pretty certain, look closely the next time you are in the bilge under the galley and you can see where the thing was to reside. They cut the bottom out and turned it around backwards and installed it . It was a really poor solution as everything dripping from the engine ends up in the bilge and it makes for a terrible support structure. I will say it was tenaciously affixed to the hull.
If I can find some photos of the engine beds I created I’ll post them. I created a tub that contains engine fluids. Hoses running through the sump (under the engine) aft to front allow pass through for bilge pump hoses and a drain that allows any loose water behind the engine to make its way to the bilge without touching the sump contents.
March 25, 2016 at 11:32 am #220437
Thanks for the great discussion –
I just pulled the Velvet Drive transmission for a rebuild and to get adapter plates fitted for the new Yanmar 4JH80 I purchased. Unfortunately, the transmission shop said the reverse pinions are worn out due to a damper plate issue. I believe the previous owner replaced the damper plate with a new one but it must have been too late. I’ll be upgrading to the ‘German style’ plate that contains rubber bushings in a remanufactured Velvet Drive.
I’m still looking into the options with the V-Drive. With the new engine turning at 3,200RPM, I’ll need to regear. I’m hearing there are 2.56:1 and 3:1 options for the RV-20. With the cost of the gears and a rebuild, it’s coming close to the price of an RV-26 so I may go that way shortly.
Where did everyone purchase their RV-26? Was it directly through Walter?
For those who have done this exercise before – did you consider upgrading the prop size? What’s the maximum that can fit on our Pearson’s?
March 26, 2016 at 8:15 am #220439
Rob, the faster turning engine will require less prop. The engine should be able to obtain its max rated rpms under way if the prop is set up correctly. All your changes made to the propulsion system, gearing etc. will determine what the prop pitch ends up being. A larger diameter blade would be a bigger more expensive prop with less pitch than a properly sized blade with nominal pitch.
You can do all the math and come up with what you think you’ll need or finish the install put the old one on, determine what it turns and adjust from there.
Photo tach should be used, don’t rely on the tachometer.
March 26, 2016 at 8:37 am #220440
quentParticipantChuckReduction gearing in transmission is also a factor re prop shaft speed.Quent
March 26, 2016 at 10:23 am #220444
Quent, you are correct. The engine however doesn’t have any concern how fast the prop shaft is turning. The number being displayed on the tachometer is the crankshaft rotations and is not directly modified by gearing changes. Overload the engine by whatever means (poor gear selection, wrapping a crab pot around the shaft, etc) and you can slow down the engine but your simply binding it up with resistance.
The engine wants to turn in the rpm range in which is was designed to operate. The engine at wide open throttle should be able to turn at its max rated rpm (in this cases 3200 rpm) and reach a nominal speed, on the 424 around 8 knots. If its running slower than that then it is probably under propped.
What you don’t want to do is set it up so that its running at 8 knots at 2200 rpms. This will overload the engine (using said resistance) and ensure a premature demise.
Set up correctly she should make around 6.5 knots at roughly 2500 rpms which is 80% of max and is where the power plant is designed to run.
Rob’s 80 is turbo charged and it’s especially important that it be run at load.
The death of these engines is being run to lightly and run too seldom.
Hope this helps.
March 26, 2016 at 10:44 am #220445
quentParticipantI agree. My only point was that the W58 BW trans is direct drive, the Yanmar or whatever might have a reduction. Ergo, shaft speed into v-drive might not be that different.Q
March 26, 2016 at 12:40 pm #220449
You want to keep the tip speed on your propeller below where it will start to cavitate. If you repower with a faster turning engine, you may need to change to a smaller prop to keep the tip speed down. This requires changing to more pitch to counter the loss of blade size. There are efficiency issues with too much pitch however.
You probably need to change gear reduction to keep tip speed down. With about a 19â prop, you should adjust gearing to keep the shaft turning no more than about 1200 RPM. Since your engine turns 3200 RPM. A 2.5:1 gear reduction would give you this. You should contact a prop manufacturer and discuss your options before spending a bunch of money on this. Give them the specs on your engine and boat. Figure about 25000 lbs for boat weight.
My yanmar develops 75HP at 3800 RPM. Yours develops 80HP at 3200 RPM. My prop is 18.5×12. I think itâs just a bit under sized but close to correct. I would guess that a 19×13 would work very well for you. My original prop is 20×13. Yours is probably the same and could probably be cut this down to 19â. If you try to stick with a 2:1 gear reduction you may end up cavitating at high throttle settings. Youâll experience vibration at high speed and raising the throttle will increase engine speed but not make the boat go faster.
I donât think you can get an RV-20 anymore. Maybe you can find a used one in good condition. Switching to the RV-26 is expensive and a bit of work. It wonât drop-in without work.
My notes are below if you havenât already read them. Thereâs a model linked for selecting prop size.
March 26, 2017 at 10:03 pm #222904
JodyandStephenParticipantHi Ben,We had a gearbox mechanic service the V Drive when we installed the new motor last year. It was confirmed that water was able to enter the body from the top jacket and after it was cleaned professionally, so we decided to disconnect the water, plugging the ends and run a monitoring method through installing an oil temp guage. In now 140 hours of running in Australian summer conditions, i.e. hot, the temp has remained quite low on the guage. As for oil; we run SAE 30 oil, with 30 – 50% Lucas oil. additive.Hope this helps.Stephen ParryS.V. Blue Pelican
March 27, 2017 at 10:51 am #222906
Hey Ben + thread,
My RV-20 V-Drive blew up within a year of this thread.
I snagged a crabpot over the summer and it bent the shaft ever so slightly. The yard thinks this contributed to the failure of the bearings inside the V-Drive. I was motoring down from the San Juan Islands two months after the crabpot strike and started to get a terrible vibration. Something internal to the V-drive had failed.
When we took it to a transmission shop, they pulled it apart and noted a dime sized hole of rust inside the case. I wasn’t able to get pictures of the hole. As you can see in the original picture I submitted, there weren’t any obvious signs that something was wrong.
I’d be overly cautious about simply removing the cooling to solve the problem as there may be more damage and wear that’s not apparent. Who knows how long a dribble of salt water was in the oil getting into the gears and bearings…
I replaced the unit with an RV-26. They’re about $3,000 just for the unit and require some modification+alignment to replace the RV-20. Like Rich, I cruise a little bit faster and find that the unit is very warm to the touch.
March 27, 2017 at 11:31 am #222907
If you decide to replace the V-drive, consider changing the gear ratio so that you can better use the power your engine puts out. I think I sent you a link to my repower notes. I have the same engine. Changing to a 2.5:1 gear ratio seems just about right for the Yanmar 4JH3-TE. If I had it to do over again, I might go with just a bit more pitch on my prop but Iâm happy with what I have.
March 27, 2017 at 4:24 pm #222909
10 years and well over 1000 NMI with no cooling, including a year in the tropics. I put a temp alarm on it at 210 degrees F, and it has never reached that temp. Measuring by hand, my guess is that the peak temp is about 140 F. The air temp that day felt like 140. Motor oil handles much higher temps. My old 911 used to hit 310 F oil temps on hot days, it was running great when I sold it with 200k mi on it
Remember, they put that same unit on powerboats making 4 to 5x the power. With 250 hp going through them, they prob need cooling.
March 27, 2017 at 5:17 pm #222910
Ben FrothinghamParticipantGreat information. Thanks. Ben
Ben FrothinghamCell 508-742-7049
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