Cruising with the Universal M-18

[Bob4203]

Our 1988 Mark II was one of those few hulls that was equipped with the Universal M-18 before the M-25 was an option that soon became standard!

Has anyone done any extensive cruising with the M-18 and had to deal with strong tides? Anyone care to share any opinions on this engine? Not many 30's were equipped with this engine.

I am hopeing this engine might get us around the Great Loop one day.

thanks

Bob
'88 Mark II

 

[DanM]

Bob4203, (that's not your hull number is it?)

I've had my MkI with a M18 for almost 8 years now and find the M18 to be reliable and efficient, but with my 3 blade prop motoring into a few feet of chop into the wind to get to my sailing grounds it certainly seems like having a few more horsepower would be a good deal. This wouldn't be a deal killer for me though if I were shopping for a C30 but if I were going to go long distances I might consider it when I was shopping. I motor at about 2500 RPM and about 5 kts, a few feet of chop and some headwinds and it's pretty easy to be doing 3.5 or 4.0

Mine has the two inch heat exchanger and I find that as long as it is clean (I boil it out every three years or so) it is ok up until the water temperature gets into the high 80's. Around here the water temperature is approaching 90 degrees now and I noticed last week when I was motoring out to my anchorage that the temperature of the engine had crept up to about 170 degrees after two hours of motoring at 2500 rpm (about 5.3 kts btw). With water temperatures below 80 degrees I once motored it for twelve hours and the temperature never budged off of 165ish. The two inch heat exchanger is definately a limiting factor on how hard you can push the engine, and a three inch heat exchanger is a great upgrade. Keep an eye on the zinc in the two inch HE, you don't ever want them to break off in there. I change mine every 90 days or so just to be safe.

Also, the stock alternator is a 35 amp Motorola. I have a fairly large house bank for a coastal boat and if you draw a large bank down enough you can quickly max out the alternator after the engine is started. Can't be too good for the alternator, and the load that it puts on the engine certainly costs a horse power or two and there aren't many to spare with the M18.

All that being said, it's easy to maintain, runs like a champ, new glow plugs from Kubota and rewired the starting circuit and starts are quick and reliable.

I plan on burning about .3 gal/hr and in reality its probably even less than that, so a pretty good range with the 18 gallon fuel tank.

Keep an eye on the bottom curve of the dipstick, it can rust out there and dump all your oil into the bilge. I had to rebuild the raw water pump a few years ago, but the engine had about 1000 hours on it at that point so I wasn't too disappointed with that.

I guess it's all relative really, boats have gotten bigger over the years, engines have gotten bigger and driver bigger accessories, battery banks are bigger so folks think they need big alternators. I'm sure if this boat was built new today the reviews would say that it is underpowered, but I do ok with it fwiw.

Take care,

DanM.

 

[Bob4203]

Thanks Dan.

Nope my hull number is: 5287

The boat has always been in freshwater so I do not experience any corrosion or use up any zincs. I would have opted for the M-25, but hey, this lightly used Mark II came with the M-18, which had to be a stretch from the earlier 11 HP Universal. If we do take the 30 on the Great Loop a great number of miles will be by motor and many in protected and calm waters. No tidal action after leaving the ICW. No doubt the M-18 can be a pain in headwinds and chop, but I expect I will have to deal with that along the way. My plans are to change out the heat exchanger to the larger size and add a heftier alternator and 3-blade prop. With only 500 hours she is like new right now and starts and runs great.

I greatly appreciate the input. If we do this, I expect this litltle jewel will get one hell of a workout; about 5,000 - 6,000 miles worth!

Bob

 

[DanM]

Bob,

I forgot to mention that when I buy parts at the Kubota dealer they sometimes need the serial number of the engine for changes made throughout it's production life. Not really easy to see but it is stamped in the block near the fuel injector pump. The M18 is the Kubota Z600 block. My engine also has a Universal serial number on it, but that doesn't do the tractor parts guys much good.

There is a M25 mod for a new alternator bracket, and I understand it's not uncommon for the M25 without this mod to crack the timing chain case where the original bracket mounted. When I bought my boat I thought I would do this mod on my M18 but the Universal dealer didn't have any kit to do it and told me that he had worked on hundreds of M18's and had never saw one with a cracked timing case. My point in all of this is that the alternator is larger on the M25 (55a vs. 35a) and one thing I noticed when I installed my larger house bank is that the engine has a noticable load on it when the 35a alternator is operating near it's capacity. I think I might have read in Nigel's book about 1 horse power per 25a, but don't quote me on that one.

The reason perhaps that the M25's crack the timing case and apparently the M18's don't might be because of the lower load of the smaller alternator, I don't know for sure. That is something you might want to look into if you install a larger alternator.

Sounds like you've got a nice freshwater low time boat to work with though, hope you can make your trip happen!

DanM.

 

[Bob4203]

Dan,

We plan on adding a few solar panels and possibly a wind generator for the trip to ad in the battery charge. When she gets pulled we will also R&R the cutlass bearing and check the shaft. Have you upgraded that intake strainer at the thru-hull? It looks so flimsy and weak, but apparently Catalina thought it would do the job. I always felt that a heftier strainer would do better.

Bob

 

[DanM]

Funny you mention that Bob. I just cleaned mine out yesterday and everytime I unscrew the plastic bowl piece off of it I worry about the torque I'm putting on the whole thing. I've never heard of one failing though but I'd agree that it doesn't look very industrial!

 

[Loubert]

Bob,

I also have a 1988 with the M-18 engine (hull #5188). I just bought it last fall and it has always been in Lake Superior. It was in a charter fleet and has over 4400 hours on the engine and it is still running great! The PO had it rebuilt a few years ago when it was experiencing hard starting. I was concerned about the high engine hours, but my surveyor was not. He said they can run a really long time if they are maintained properly. I hope he is right.

 

[Stu Jackson]

M18 Alternator Bracket

There was a recent thread on this board about a fellow with a C30 and an M25 whose old bracket broke. Yikes. Do NOT put replacement off.

There are links in this topic to the alternator bracket story and sources for new ones:

http://c34.org/bbs/index.php/topic,5078.0.html

Many of the rest of the features of the two engines are similar. If you want to start and complete your cruise in safety and fun, do it NOW.

Really, it happened to me.

 

[Bob4203]

Dan,

That in-line strainer is no different than the one you would use for the freshwater line leading to the sink(s)!! I am used to those hefty glass strainers similar to the one I had for my Perkins 4-108.

Bob

 

[Stu Jackson]

Funny you mention that Bob. I just cleaned mine out yesterday and everytime I unscrew the plastic bowl piece off of it I worry about the torque I'm putting on the whole thing. I've never heard of one failing though but I'd agree that it doesn't look very industrial!

The O ring should do the work, not the torque.

 

[Bob4203]

Yeah, but those rubber gaskets do wear out Stu..............

Lets face it, the set up is a bit weak. Its probably best to keep a wooden tapered plug close by in case you snap the darn thing off!!

Bob

 

[Steve Walsh]

My 1986 Newport 28 MKII has the M-18 and it has about 1500 hours on it. I bought it in 1999 with about 900 hours. The engine has been incredibly reliable, with only a raw water pump and injector rebuild at 1,000 hours (ran fine, but seems the manual reccomended it). It also has the 2" heat exchanger and temps max at 170 this time of year in our warm Florida waters at 2,400 rpm. Since the engine operating temp range is rated at 165-195 degrees, I never felt the need to upgrade the heat exchanger. My suggestion is that if you can motor at cruising rpm and stay at 170 degrees, stick with the 2' HX and save the money. Not a big deal to add one later if it does become an issue. Adding the bigger alternator and 3 blade prop may well increase your temps. Have a great trip!