Yanmar 3GM30F HP one-hour rating (??) - Page 2 - SailNet Community
 3Likes
Reply
 
LinkBack Thread Tools
post #11 of 25 Old 01-26-2013 Thread Starter
Senior Member
 
gamayun's Avatar
 
Join Date: Aug 2009
Location: San Francisco
Posts: 562
Thanks: 17
Thanked 28 Times in 28 Posts
Rep Power: 7
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Great info everyone. Thanks. The boat is a Freedom 36/38. The 38 refers to the "sugar scoop" transom but that probably won't affect LOA that much in relation to power through the water. It is a pretty flat bottom. On the sea trial with new bottom paint, we got it up to speed and it was close to 7 knots but that was without wind, current or swell working against it. I am hoping it is going to be OK, but it's a "sail" boat, yah? Big, diesel guzzling engines are the reason I got out of power boating....

Here's the funny part. The Yanmar contact I made told me that the 3GM30F is a 27HP, 3600 RPM engine, but the plaque on the engine itself says 24HP, 3200 RPM. I remain confused!

Anyway, I do plan to take a diesel engine course but the one recommended by aa3jy is only on the East Coast so I'll have to find something in California. In the meantime, I'm just going to plow right in. It looks like much of the maintenance I can (and should) do myself. The internet is a great thing, too, if I should get stuck ;-)

Cheers!
gamayun is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #12 of 25 Old 01-26-2013 Thread Starter
Senior Member
 
gamayun's Avatar
 
Join Date: Aug 2009
Location: San Francisco
Posts: 562
Thanks: 17
Thanked 28 Times in 28 Posts
Rep Power: 7
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Oh, on haul out, it weighed 20,000 lbs, which is pretty close to the specs.
gamayun is offline  
Quote Quick Reply Share with Facebook
post #13 of 25 Old 01-26-2013
Senior Member
 
Join Date: Jul 2006
Posts: 1,270
Thanks: 1
Thanked 40 Times in 39 Posts
Rep Power: 10
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Quote:
Originally Posted by gamayun View Post
Oh, on haul out, it weighed 20,000 lbs, which is pretty close to the specs.
Actually your 38's design spec is more like...

FREEDOM 38 sailboat specifications and details on sailboatdata.com

..well within the capability of the Yanmar 3GM30F

Here are some details from the workshop manual:

Model 3GM30
Type: Vertical 4-cycle water cooled engine
Combustion Chamber: swirl pre combustion chamber
No cylinders: 3
Bore x stroke mm(in): 75 x 72 (2.95 x 2.83)
Displacement litre (in³): 0.954 (58.21)

Continuous rating output (DIN6270A)
Output crankshaft speed Hp/rpm (kW/rpm): 24/3400 (17.9/3400)
Brake mean effective pressure kg/cm² (lb/in²): 6.66 (94.71)
Piston speed m/sec (ft/sec): 8.16 (26.77)

One hour rating output (DIN6270B)
Output crankshaft speed Hp/rpm (kW/rpm): 27/3600 (20.1/3600)
Brake mean effective pressure kg/cm² (lb/in²): 7.07 (100.54)
Piston speed m/sec (ft/sec): 8.64 (28.35)

Compression ratio: 23.0
Fuel injection timing degree: b.TDC18±1°
Main power take off: At flywheel side
Front power take off: At crank shaft V pulley side
Direction of rotation - Crankshaft - Counter clockwise viewed from stern
- Propeller shaft (ahead) - Clockwise viewed from stern
Lubrication system: Complete enclosed forced lubrication.
Starting system: Electric and manual

Lubricating oil capacity (rake angle 8°)
Total litre (in³): 2.6 (158.65)
Effective litre (in³): 1.6 (97.63)

Engine weight with clutch (dry) Kg (lb) : 130 (287) Raw water
Engine weight with clutch (dry) Kg (lb) : 138 (304) fresh water

Gearbox
Model: KM3A
Constant mesh gear with servo cone clutch (wet type)
Lub oil: SAE# 10W-30, CC class
Lub oil cap: 0.3 ltr
Dry weight: 11.0kg (24.3 lbs)

Last edited by aa3jy; 01-26-2013 at 03:52 PM.
aa3jy is offline  
Quote Quick Reply Share with Facebook
post #14 of 25 Old 01-27-2013 Thread Starter
Senior Member
 
gamayun's Avatar
 
Join Date: Aug 2009
Location: San Francisco
Posts: 562
Thanks: 17
Thanked 28 Times in 28 Posts
Rep Power: 7
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Those specs are close but mine is not a shallow draft. This is more like it: FREEDOM 36 sailboat specifications and details on sailboatdata.com, which doesn't actually specify the HP rating.

Sooo, maybe I am missing something obvious to everyone here but me, but why would the engine plaque say it's a 24 HP when the Yanmar Company and Freedom say it's a 27 HP? I can only assume that the one-hour max rating dictates its upper threshold. Are other Yanmars like this? Anyway, it's somewhat immaterial. I bought the boat. And now lots to learn!
gamayun is offline  
Quote Quick Reply Share with Facebook
post #15 of 25 Old 01-27-2013
Senior Member
 
bjung's Avatar
 
Join Date: Apr 2009
Location: Blue Ridge
Posts: 473
Thanks: 5
Thanked 0 Times in 0 Posts
Rep Power: 7
 
Re: Yanmar 3GM30F HP one-hour rating (??)

One point of caution about RPM gauges. Most of them will give you a faulty reading, either because they are off, or calibrated incorrectly. I checked the RPM gauge on our boat with a meter at the crankshaft pulley and it turned out to be reading 380 RPM too low. So running at max RPM would be a short lived experience, followed by an engine rebuild.
In 30 years of working with diesel engines, I haven't found an accurate gauge yet. They are all off, some more than others. Beware.....
gamayun likes this.

Last edited by bjung; 01-27-2013 at 06:30 AM.
bjung is offline  
Quote Quick Reply Share with Facebook
post #16 of 25 Old 01-27-2013
Senior Member
 
redline's Avatar
 
Join Date: Feb 2010
Posts: 189
Thanks: 1
Thanked 9 Times in 8 Posts
Rep Power: 6
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Quote:
Originally Posted by gamayun View Post
why would the engine plaque say it's a 24 HP when the Yanmar Company and Freedom say it's a 27 HP? I can only assume that the one-hour max rating dictates its upper threshold. Are other Yanmars like this?
It's not inconsistent - there's limited space on the rating plate, and the 'continuous' figure is correct, and safe. The manual has more space to expand on that with the 1-hour rating. From experience with marketing departments, they will naturally insist on showing the "best" number, caveats aside. marketing wrote the spec sheet, but the engineers designed the plate that went on the motor.

My previous 2GM20F and current 4JH2TE both had/have continuous and 1-hr ratings. And I've never needed to run either above, and seldom at, the continuous rating. (Until I re-pitched my Maxprop last spring, I could not even get the 4JH to reach its continuous RPM rating, but that's a different discussion). Consider the one-hour limits a nice cushion for really bad conditions.

Norman
s/y "Redline"
1998 Jeanneau SO45.2
redline is offline  
Quote Quick Reply Share with Facebook
post #17 of 25 Old 01-28-2013
Senior Member
 
Join Date: Sep 2010
Location: Boston area
Posts: 110
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 5
 
Re: Yanmar 3GM30F HP one-hour rating (??)

One simplified explanation of the 24/27 hp ratings is that the HP output of an engine is directly related to the RPM. HP rises with RPM up to a max, then tails off at the very end of usable RPM range or redline (usually). At 3400, your engine is producing 24 hp, and if you push the RPM's to 3600, it is putting out 27 hp. The problem is that Yanmar does not want that engine to be run at 3600 for any long periods. Therefore, it gives it a max rating of the HP produced at 3600, but also gives the max generally usable output as 24 HP at 3400 which can be run all day. Technically it can produce 27, but you can only expect to use 24 for regular use. If you are cruising at, say, 2000 RPM,. the engine will be producing a much lower HP (perhaps 16-18) and you can look at an output graph for that engine and see just what the output is at each RPM level.

Mike sullivan
1985 Marshall 22 catboat
mbsl98 is offline  
Quote Quick Reply Share with Facebook
post #18 of 25 Old 01-28-2013
Senior Member
 
Join Date: Aug 2007
Location: NY
Posts: 2,247
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 9
 
Re: Yanmar 3GM30F HP one-hour rating (??)

I have a 3gm30 on my Caliber 33 and would never run at 3400 rpm "all day". I tend to run at around 2800 but that is well above the "max distance gained per gallon of fuel burned" rpm's - That is somewhere around 2000 rpm's.
sck5 is offline  
Quote Quick Reply Share with Facebook
post #19 of 25 Old 01-28-2013
Senior Member
 
Join Date: Aug 2007
Location: NY
Posts: 2,247
Thanks: 1
Thanked 1 Time in 1 Post
Rep Power: 9
 
Re: Yanmar 3GM30F HP one-hour rating (??)

oh and another vote for mack boring's diesel course. They ask what engine you have in your boat and then provide you with THAT SAME EXACT ENGINE to work on for the 3 day course. You will never again get such a good view of the back side of your engine
sck5 is offline  
Quote Quick Reply Share with Facebook
post #20 of 25 Old 01-29-2013
Senior Member
 
Join Date: Jul 2006
Posts: 1,270
Thanks: 1
Thanked 40 Times in 39 Posts
Rep Power: 10
 
Re: Yanmar 3GM30F HP one-hour rating (??)

Quote:
Originally Posted by sck5 View Post
I have a 3gm30 on my Caliber 33 and would never run at 3400 rpm "all day". I tend to run at around 2800 but that is well above the "max distance gained per gallon of fuel burned" rpm's - That is somewhere around 2000 rpm's.
Around 2450 +/-
aa3jy is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Bleeding a Yanmar 3GM30F jlmarra Gear & Maintenance 6 07-12-2015 09:38 AM
yanmar 3gm30f 1 cylinder bad condition yjchun Diesel 15 09-05-2011 10:59 PM
Yanmar 3GM30F aa3jy Diesel 7 11-23-2009 08:45 AM
Yanmar 3GM30F Bill Mc Gear & Maintenance 30 11-28-2007 07:51 PM
Prop for Morgan OI w/ Yanmar 3GM30F cwarwick Gear & Maintenance 1 11-16-2004 01:17 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome