Perkins 4.108 OR Yanmar 3HM30F?? Tayana 37

[Doldrumdayz]

to all the owners of 4.108s or these yanmars !

In my Tayana 37 i have a Yanmar 3hm30F with rated horsepower of 27, and 2.14:1 tranny.
It runs fine, a little vibration when at high rpm.
i got the boat with this engine and a maxprop (18"?) fitted.
she was sitting for years before i bought her and grew a city of barnacles,,,
when i brought her to the boatyard i did ~4.2 knots at the max my throttle would let me. with the current, flat water

i thought for sure the boat was underpowered. (or the mass of barnacles and a possible wrong pitch of maxprop)

upon researching i noticed that the perkins 4.108 was almost a standard install to these t37s.
with a higher hp rating, they seemed more suited to handle the weight and provided the power when needed

so i have aquired a used 4108 with 2.57:1 velvet drive tranny and got her running (another engine that sat for ? years)
she smokes slightly at high rpm steady and leaks oil of course..

my question is,, to all owners with 4108s.. what is the prop size / pitch you use? speed? are you happy?

OR

should i just keep this yanmar? i got a new 16"x 9, 3 blade prop ready to go on.

i would save a ton of work not swapping engines,, but to me the more power when needed is worth it. anyone else have this type of engine?

looking forward to hearing back any bit of direction! cheers and thanks in advance

[GordMay]

Greetings and welcome aboard the CF, Doldrumdayz.

Different engines have been used in the Tayana 37: the Yanmar 3QM30, the Perkins 4-108, and the Volvo MD17C. The latest change, in 2011, was to the Yanmar 4JHE (55 HP)as standard propulsion.
2011 Spec Sheet ➥ http://www.tayanaworld.com/upload/Fi...3015548--1.pdf

➥ http://www.practical-sailor.com/issu...w_11848-1.html

[gjordan]

If you havent motored the boat with a fresh bottom, then you havent given the present motor a chance. You could very well be going to all of the trouble of a swap and not need it. If the boat sat for years, I suspect that you will have enough real issues to fix before you start on one that may not be a problem at all. Just my 2 cents worth. ____Grant.

[Lepke]

It's a lot of trouble to change engine types. I would wait for a clean bottom and explore your prop options before I changed engines. You're never going to go much more than 7kts.
The 4108 should be overhauled before being installed if it burns any oil at all. Out of the boat is easy. The leaks are easy to fix. Rear main almost always leaks. It's not a bad engine. I have one on a generator. An engine kit (sleeves, rings, pistons, bearings and gaskets) is about $800. The head should be done, too.

[rbk]

How many hours on the Yanmar? If its above 2K you're probably approaching a rebuild anyways especially if the engine maintenance was as good as the hull cleaning. If you're planning to keep this boat for any real amount of time or off cruising the world; I'd do a rebuild on the Perkins while its out then swap when you're ready. this will allow you to clean the bilge, service the beds and mounts (probably due from the sound of it), re-place hoses to holding tank, sound proof engine compartment and a host of other items. A fully mechanised re-sleeved rebuilt 4108 with new leakless rear seal is about as good as it gets IMO.

[Doldrumdayz]

thank you all for your honest in depth replies------
GordMay
long time reader, figured it was time to join.
the new yanmars installed are rated at 55 hp! i almost had my chance at one of those too..
gjordan
youre right, i havent seen what she can do without a river buffet underneath
. yes many projects have arose
Lepke
it would seem a lot of trouble, but currently it doesnt seem like a hassle in my situation,, im agreeing with rebuilding it before it would go in,, seems silly replacing used engine for another used
rbk
they both are at over 2k hrs from hour meters
thats good advice

so for now im leaning towards putting new prop on (16x9) and seeing what performance i get with current engine..
original plan was to sell the boat when finished spiffying up,, after a couple trips,
but if i splash and dont like the performance, ill have the perkins sitting to rebuild at my leisure

my last boat was underpowered and it was hell powering thru in a squall or fast current! couple of emergencies because of it,
this is why im debating this deeply

[CHRIS V CLEMENT]

I have a 1973 Perkins 4-108 with the 2:1 velvet drive reduction gear. It has a 1" diameter shaft and an Eliptec 2 blade folding prop LH18D x 16P-3. I believe that this is an 18" diameter propeller. With a clean bottom, my Gulfstar 41 gets 6 knots at 2000 rpm with smooth seas and no current. I can run all day at 1 gallon per hour with no smoke and no engine leaks. She has about 3,000 hours on her. The only repair was the rebuild of the injector pump, due to a very slow fuel leak at the throttle linkage. Rebuilding that pump clearly gave her new life.

[peter57]

Originally Posted by CHRIS V CLEMENT

I have a 1973 Perkins 4-108 with the 2:1 velvet drive reduction gear. It has a 1" diameter shaft and an Eliptec 2 blade folding prop LH18D x 16P-3. I believe that this is an 18" diameter propeller. With a clean bottom, my Gulfstar 41 gets 6 knots at 2000 rpm with smooth seas and no current. I can run all day at 1 gallon per hour with no smoke and no engine leaks. She has about 3,000 hours on her. The only repair was the rebuild of the injector pump, due to a very slow fuel leak at the throttle linkage. Rebuilding that pump clearly gave her new life.

One gallon of fuel per hour produces less than twenty horsepower, something to note for the OP to work out that he is pushing a smaller boat than yours and therefore less horsepower might be necessary. I don't know the continuous rating of his Yanmar, could be around 24Hp. I would agree with other posters to give the Yanmar more of a try. 2000 hours is just another service schedule, not a rebuild unless there is something awry.

[UNCIVILIZED]

Now that the bottom's clean, I'd be inclined to stick with the Max Prop for now. Since you can tinker with it's pitch without having to pull it off, or haul the boat out. And they do help a lot when handling a boat in close quarters. Not to mention aiding your speed when under sail.

BTW, Nigel Calder briefly touches on what's involved in an engine swap in this article. Meaning the pre-installation prep, as well as the fiscal realities -> A Refit Reality Check | Cruising World

[gjordan]

You say you are going to sell the boat. The best way to lose money on a flipper is to start spending on things that dont need to be done. If you say the engine runs fine then clean it and touch up the paint and get the Max prop checked while the boat is out. You have bought a prop without knowing if it is even close to correct pitch. The Max prop can be adjusted (even when in the water) to give you the correct rated RPM. Even though I personally think a Perkins is a better engine, I dont think most of the buying public would agree with me. Clean and fix what needs to be fixed and dont fix what is not broken. That is my 2 cents worth of advice. Worth what you pay for it. _____Grant.

[Cheechako]

Originally Posted by Doldrumdayz

to all the owners of 4.108s or these yanmars !

In my Tayana 37 i have a Yanmar 3hm30F with rated horsepower of 27, and 2.14:1 tranny.
It runs fine, a little vibration when at high rpm.
i got the boat with this engine and a maxprop (18"?) fitted.
she was sitting for years before i bought her and grew a city of barnacles,,,
when i brought her to the boatyard i did ~4.2 knots at the max my throttle would let me. with the current, flat water

i thought for sure the boat was underpowered. (or the mass of barnacles and a possible wrong pitch of maxprop)

upon researching i noticed that the perkins 4.108 was almost a standard install to these t37s.
with a higher hp rating, they seemed more suited to handle the weight and provided the power when needed

so i have aquired a used 4108 with 2.57:1 velvet drive tranny and got her running (another engine that sat for ? years)
she smokes slightly at high rpm steady and leaks oil of course..

my question is,, to all owners with 4108s.. what is the prop size / pitch you use? speed? are you happy?

OR

should i just keep this yanmar? i got a new 16"x 9, 3 blade prop ready to go on.

i would save a ton of work not swapping engines,, but to me the more power when needed is worth it. anyone else have this type of engine?

looking forward to hearing back any bit of direction! cheers and thanks in advance

By all means go to the Perkins.... if you are up to the task of changing anyway!. 2000 hours is nothing on a Perkins. The engines really aren't comparable HP wise alone. The 4-108 in my 44 footer did nearly 8.5 knots in flat water.... at 2800 rpm. 17" Max Prop. I had no leaks ... ever. Go figure! I had the older Yanmar 30 in my HC38, heavy boat like yours. It definitely wasnt enough HP. The boat would just wallow in a heavy wind chop.
Consider resealing the pan and main seals prior to installing the 4-108.

[Cadence]

Originally Posted by gjordan

If you havent motored the boat with a fresh bottom, then you havent given the present motor a chance. You could very well be going to all of the trouble of a swap and not need it. If the boat sat for years, I suspect that you will have enough real issues to fix before you start on one that may not be a problem at all. Just my 2 cents worth. ____Grant.

[FionaJC]

I have just re-engined from a Peugeot XD2 to a Perkins 4107 the non sleeved version, its less thirsty, lower power so it doesn't dig the stern in and quieter. I think its a better engine. The engine change? Two more years of therapy and I might be over it. Just my 'tuppenny worth.

[Cadence]

Originally Posted by FionaJC

I have just re-engined from a Peugeot XD2 to a Perkins 4107 the non sleeved version, its less thirsty, lower power so it doesn't dig the stern in and quieter. I think its a better engine. The engine change? Two more years of therapy and I might be over it. Just my 'tuppenny worth.

I had a Long tractor with a 32HP Peugeot for power, it was a strong reliable engine. The Perkins is a good engine but hope you didn't trade out a good engine.

[Doldrumdayz]

Hey all, thanks again for the time spent replying.
I sold the max prop a long time ago so thats out of the question. Im fairly sure this new props alright.
My main question is now about the transmission. With a 2.57:1 velvet drive i feel i may not get the rotations needed? Does this high ratio give me more torque so i could essentially put a bigger prop on? Or should i prefer a 2:1?