Repowering our 30 ft Sundowner

[Eris Turner]

Our 34 year old Pathfinder engine died yesterday. We are beginning the process of figuring out what engine to replace it with. The one we have is a 70 hp. We would like to go to a 90 or 100 hp. Any suggestions? Yanmar, Kabota, Cumming....? Any idea of the price? Appreciate any suggestions.

 

[Sailor of Fortune]

I don't think you can get a Cummins in that small of HP. My vote would be Kabota.

 

[Eris Turner]

I have heard good things about Kabota, what do you think of Perkins or Lehman?

 

[Donsan]

Might want to consider Beta Marine. Believe they use the Kabota block and have 85 and 100hp units.

 

[Eris Turner]

Thanks for the Beta marine suggestion. How does Yanmar compare to Kabota? The reality of what just happened is just now sinking in! We were meant to be cruising in the Gulf of Mexico around the barrier islands this werkend, instead I'm in my living room trying to decide on how to spend thousands of $$$! Aaah, the joy of boat ownership!

 

[Nomad Willy]

Eris,
If you cruise above 7 knots frequently you may want to look at the Yanmars. They are lighter and if you keep your boat light too more speed should be in the bag. A light engine w a turbo should provide.

 

[DavidM]

I think that the 75-100 hp Betas arebased on the Isuzu block, but still a fine engine and Beta is a quality marinizer.

The 100 hp Yanmar is a smaller block and uses an after cooler which means more maintenance.

So my vote is for the Beta. But also look at the John Deeres.

David

 

[sunchaser]

Go to the engines section of boat diesel. Research each and every engine in the size range you’re considering. I’m not aware of any other on line source that compares with this data source. There are more choices than you can imagine, with your nearby dealer support playing an obvious role.

Dimensions, weight, drawings, specs etc are all available. Don’t forget gears are part of the equation. Take your time. This gives you the opportunity to clean up the ER and redo the hidden things that will appear once you’ve begun.

 

[bgillroy]

John deer

 

[healhustler]

If you’re doing a new engine, Beta. If used, there are plenty of JH series Yanmars out there. For ultimate simplicity, Kabota 85. I’m also a Deere fan, but they tend to be tall and heavy.

 

[MurrayM]

Many moons ago, Tad Roberts (naval architect who frequents this site) recommended Beta Marine if we ever wanted to repower our 30' Sundowner Tug.

The PO of our boat put in a 100hp Yanmar 4JH2-UTE and I believe it's too big. We usually run it at 2700rpm which is not much past half throttle, and the turbo doesn't really wind up till just below 1/2 throttle. This gives us 7 to eight knots depending on currents, etc, and uses about 1.3 gph. Adding throttle past that point does add speed but the arse end squats badly, the bow starts plowing a huge wake, and I imagine fuel consumption would increase quickly. It is maybe two/three inches from the forward bulkhead in the engine room.

If we ever repower it would probably be the Beta Marine naturally aspirated 75hp or the 85hp turbo...would have to research a bit.

I'm a letter carrier and can recognize the sweet, smooth running sound of a Kubota diesel engine in a backhoe doing work in someones yard from a street away

 

[hfoster]

Mate,

I would have a look at Caterpillar's C-7s or C-7.1s.

Best of luck.

Cheers.

H.

 

[Woodland Hills]

Mate,

I would have a look at Caterpillar's C-7s or C-7.1s.

Best of luck.

Cheers.

H.

400hp might be a bit much considering it is a full displacement hull with a 30’ lwl and was built with 70hp.... 7 liters is a bit of overkill.

 

[Pack Mule]

I would look at Beta Marine / Kabota as well . Great little engine and good support from Beta Marine.

 

[Nomad Willy]

Beta is great ...
But pricy and getting parts may still be problematic.
I have a back hoe engine too and it’s been great for about 12yrs.
Far less money than ... you name it ... but no bright colored paint job.

 

[Al]

Our 34 year old Pathfinder engine died yesterday. We are beginning the process of figuring out what engine to replace it with. The one we have is a 70 hp. We would like to go to a 90 or 100 hp. Any suggestions? Yanmar, Kabota, Cumming....? Any idea of the price? Appreciate any suggestions.

Hello Eris,

Thought over considering a "Running Take Out" or other reason for being on the market? Asked as when faced with the cost of a new replacement engine in a boat that is valued say, around $25-30 Thousand, our attitude changed and we made a serious charge to locate a replacement engine. We were successful in obtaining a Perkins 4-236 to replace our Perkins 4-154, a 85 hp upgrade from the 58 hp that was. We acquired ours off Craigslist but there are so many other outlets that one has to ask. I'd ask around the waterfront mechanical shops or even dealers who have made engine change outs knowing of a good 'running take out". This while you price and determine a new engine if that is the determination.

I agree, you had better have dealer coverage for what ever new engine you purchase. By the way, who is going to do the change out? DIY? asked again as installers other than dealers, would perhaps have knowledge of existing used engines.

To for stall the naysayers on used engines, we all are not so wealthy as to buy off the shelf, yet we to enjoy boating, this post is offered as a alternative, not the final solution. Thank you.

Al-Ketchikan

 

[markpierce]

The EPA has caused marine engines to be turboed, often resulting in overpowering boats. I'm nearly the last USA recipient (2010) of a naturally-aspirated diesel at 80 hp. No?

 

[Nomad Willy]

Mark NO that does not caues overpowering.
Even easier to put in a smaller turbo’d engine.
They need to get the hp right.

 

[Nomad Willy]

Murray wrote;
“If we ever repower it would probably be the Beta Marine naturally aspirated 75hp or the 85hp turbo...would have to research a bit.”

Turbo w/o the aftercooler would be OK but 65hp would probably make you just as happy. You seem to have a JH series Yanmar and the basic JH is a natural 55hp. That would probably work very well too.

You could find a take out as Al was talk’in about.

 

[Rocky Champagne]

Rocky

My 30 Sundowner was repowered from the 54 hp VW to a 80 hp Cat 3034T (Perkins M85T) 2,400 hours ago. It runs easily at 7kt at 2,000 rpms, burning 1.6 gph. It will go up to 2,600 rpms and 8.1 kt but the fuel burn is probably 3X and the bow tries to climb out of the water. You will see posts claiming “cruises at 8-10 kts” in ads but it is a lie. Set your sights on the 80-85 hp range and be happy. Anything bigger is a waste of time, money and space.

Rocky Champagne, “Agnes Jean”, 1982, 30 Sundowner, hull #3

 

[AusCan]

Lots of things to consider besides brand of engine.

When you narrow down your engine choice to 2 or 3, get the dimensions and footprint of each and compare to what you have. A bit of thought and measuring is required to see how your engine mounts and alignment will work out.

With a larger engine, you'll need to ensure you still have decent access to all components needed for servicing. You may need a larger diameter exhaust system and/or raw water intake, and/or prop shaft.
If you are re-using your gearbox, check to make sure that is possible with your chosen engine. If changing, ensure your down angle will be correct for shaft alignment. Check to see the gear ratio will allow you to re-use your existing prop.

Also consider using the time when your engine is out to perform other maintenance. This is the time to access fuel tanks, paint the bilge, improve the soundproofing, install engine lighting etc.

 

[High Wire]

The Perkins 84 hp 4.236 non-turbo is still around. Call Trans Atlantic Diesel www.tadiesel.com

 

[O C Diver]

The Cummins 4BT 150 HP is still available as a factory rebuilt which means at least one used part.

The other option is to find a used Cummins 4B 80 HP (non turbo) and have it rebuilt. While the 4B doesn't have cylinder liners, it's quite common to have the block bored and press in sleeves for essentially new cylinders.

I like my JD 4045. As previously mentioned, probably to heavy and tall for your application.

Ted

 

[Sailor of Fortune]

The Cummins 4 is known as a shaker.... Good engine but vibration issues.

 

[O C Diver]

The Cummins 4 is known as a shaker.... Good engine but vibration issues.

The earlier units varied in the amount of vibration with some being quite significant. The more recent ones are much better as Cummins made changes that made them much more civilized. It should be noted that 4 cylinder diesels will never be as smooth as 6 cylinder diesels do to the dynamics of the cylinders in relationship to each other.

Ted

 

[ktdtx]

Have you considered two brackets and a pair of outboards as an out of the box possibility?

 

[Nomad Willy]

Ted,
6cyl smoother than a 4 is a given but ....
All other things must be equal and they never are.
I had a 3cyl motorcyle and rode it about 10miles at speed on the hwy in Yyoming and then noticed (by the light in the speedometer) that I was not in top gear. This engine’s crankshaft rotated in the opposite direction of the flywheel. Plus it had counterweights. Very smooth. Smoother than run-of-mill 6cyl engines.

 

[Nomad Willy]

Have you considered two brackets and a pair of outboards as an out of the box possibility?

That would upset the CG and balance of the boat. You read a previous poster remark that above 7 knots the boat assumed a very high angle of attack. That would only be amplified by hanging heavy outboards aft of the boat. Bad idea. As are most extended outboards. Just my opinion though. But it should be obvious. Big changes in an as designed boat rarely (if ever) work well.

 

[psneeld]

Just passing along what has been passed to me so all can stay informed...

"Tad Roberts (naval architect who frequents this site)"

By someone who researched some claims by several TF members.....so "advice taker beware'....of any and all unless verified or satisfied with credentials.

"He is not and never has been a naval architect. That fraud was debunked a few years ago and he was threatened with legal action by the professional licensing board of British Columbia for making that claim."

 

[Al]

My 30 Sundowner was repowered from the 54 hp VW to a 80 hp Cat 3034T (Perkins M85T) 2,400 hours ago. It runs easily at 7kt at 2,000 rpms, burning 1.6 gph. It will go up to 2,600 rpms and 8.1 kt but the fuel burn is probably 3X and the bow tries to climb out of the water. You will see posts claiming “cruises at 8-10 kts” in ads but it is a lie. Set your sights on the 80-85 hp range and be happy. Anything bigger is a waste of time, money and space.

Rocky Champagne, “Agnes Jean”, 1982, 30 Sundowner, hull #3

[Quote:]
The Perkins 84 hp 4.236 non-turbo is still around. Call Trans Atlantic Diesel www.tadiesel.com
__________________
Archie
1984 Monk 36 Hull #46
Englewood, FL and Cape May, NJ


The Perkins 4-236 is a engine found in the Sundowner. There are two here in SE Alaska I know of with this engine, as it is the replacement engine in our Marben I spoke of.. I agree, TAD is a known supplier with a solid reputation. While a bit high in price, you do have assurances with their rebuilds. The engine itself is a engine that will go on forever, one will far outlast your boating hours. Simple engine to work on, nothing fancy, it is a tractor engine meant to be dependable with as few fancy add ons as possible. No computer, not tier "what ever". Air/fuel/and go.

By the way, our complete running takeout engine was later discovered by serial number to be a 2009 year, There was noting missing or having to be replaced. it has then and now, 60#oil pressure, runs like a top. Purchased from a fellow in Everett, Washington who had no knowledge or history of the engine,other than it was sold to him by a party he trusted.

He delivered to our Alaska Barge line for the full price of $1,000.00.Yep, a thousand bucks!!

We in turn sold our running takeout to a party in North Carolina!! Who paid $1200.00 in freight to ship from Ketchikan. We sold our engine to them for $600.00 and clearly advised that there needed to be a main seal replacement as it leaked. (A common issue with the 4-154.107 and 108 model of Perkins) All of this via craigslist which is preempted with a "BUYER BEWARE" warning. You have to do your due diligence to the best of available ability and sources when dealing at a distance.

Al-Ketchikan