Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-01-2014, 20:20   #31
Registered User

Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
Re: Rebuild or Repower?

As a old time diesel Mech, Ive re-bilt many engines. But theres a BIG difference between a re-bild, and an overhaul !! In almost all cases in an overhaul you have a re-ring and a valve job, new rod bearings, maybe a re-bilt or a new oil pump! Where as a re-bild includes all new bearings includeing the cam bearings, boreing or replaceing the cylinders, new pistons ect ! Theres a big difference !! You can do a overhaul in place most times if theres room, but to do a REAL re-bild the engine must be removed and done from top to bottom !! Bewhere some folks overhauls !! LOL Ive found over the years that poor maintainence is the big problem with most marine engines!! Ive seem a blank look on to many owners faces when ya ask em when they last set the valves !! LOL or even changed the oil and filters ! Ive had a couple of my perkins engines run for over 20,000 hours and stil not burn more then a qt between oil changes !! And not LEAK !! Most folks would be ahead of the game if they took a course in engine maintaince course or geta mechnic to spend an hour or two showing them a few things !! Just my 2 cents. Ive seen to many engines come into the shop for re-bilds that sure did not need them !!!
__________________

__________________
Bob and Connie
bobconnie is offline   Reply With Quote
Old 11-01-2014, 20:31   #32
Moderator
 
sailorchic34's Avatar

Cruisers Forum Supporter

Join Date: Feb 2011
Location: SF Bay Area
Boat: Islander 34
Posts: 4,812
Re: Rebuild or Repower?

Questions. Does the engine start up easy and idle well. Any smoke at start or idle. If it starts easy, within a few seconds of cranking and does not smoke, it's probably just a clogged discharge elbow. If your getting lots of black smoke at high RPM it could be a fowled prop or a bad injector.

Diesel engine rebuilding is not too hard. Seems even poor blonde sailor chics sometime rebuild diesels. Really only need basic tools and a good engine machine shop to do the machining. The hard part is making the special tool needed to pull the inner crankshaft nut off in front of the timing gear.

What worked for me was for every thing that was removed, all the nuts, washers and bolts for each piece went into individual labeled ziplock baggies. It took me a month start to finish to pull the engine, rebuild it in the cockpit and reinstall it after taking it to and from the machine shop. The machine shop takes about a week as does getting the parts shipped from yanmar.

Here's a link to my summer of discontent: I was Bored so Pulled the Head on my Yanmar
__________________

__________________
sailorchic34 is online now   Reply With Quote
Old 11-01-2014, 20:31   #33
Registered User

Join Date: Aug 2012
Location: Charleston, SC
Boat: Tayana 37
Posts: 704
Re: Rebuild or Repower?

Quote:
Originally Posted by bobconnie View Post
As a old time diesel Mech, Ive re-bilt many engines. But theres a BIG difference between a re-bild, and an overhaul !! In almost all cases in an overhaul you have a re-ring and a valve job, new rod bearings, maybe a re-bilt or a new oil pump! Where as a re-bild includes all new bearings includeing the cam bearings, boreing or replaceing the cylinders, new pistons ect ! Theres a big difference !! You can do a overhaul in place most times if theres room, but to do a REAL re-bild the engine must be removed and done from top to bottom !! Bewhere some folks overhauls !! LOL Ive found over the years that poor maintainence is the big problem with most marine engines!! Ive seem a blank look on to many owners faces when ya ask em when they last set the valves !! LOL or even changed the oil and filters ! Ive had a couple of my perkins engines run for over 20,000 hours and stil not burn more then a qt between oil changes !! And not LEAK !! Most folks would be ahead of the game if they took a course in engine maintaince course or geta mechnic to spend an hour or two showing them a few things !! Just my 2 cents. Ive seen to many engines come into the shop for re-bilds that sure did not need them !!!
Maybe I should clarify here. I am budgeting for a rebuild as described here. The kit that I've found includes new pistons, rings, valves, etc. For a job like that, I will probably hire it done as all the yards in Charleston charge an arm and a leg for DIY storage. Usually around 1,000 per month for a boat the size of the TY37. So the cost would quickly add up if I was trying to do it myself.

Sent from my HTC6500LVW using Cruisers Sailing Forum mobile app
__________________
Kevin84 is offline   Reply With Quote
Old 11-01-2014, 20:41   #34
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 1,673
Re: Rebuild or Repower?

It is wise to budget for the worst case, but I really doubt that it will be needed. Right now it is not possible to know what the problem is, but if you do buy then once you get your hands on her it will probably yield quickly to some poking around. It could be fuel starvation from dirty filters or water buildup in water-separating filters or air being drawn into the fuel system, which would be cheap to fix. It could also be that the valves haven't been adjusted (very common) or she could be over-propped, both discussed earlier. These are all far more likely than an engine with fewer than 15 years on it needing a rebuild. Unless there is blue (not black) smoke coming out the back and/or lube oil spraying around in the engine compartment you probably have a serviceable engine. Assume the worst for negotiating - just don't believe it yourself!

Greg
__________________
CarinaPDX is offline   Reply With Quote
Old 12-01-2014, 03:31   #35
Wayfaring Mariner
 
captain58sailin's Avatar

Cruisers Forum Supporter

Join Date: Mar 2009
Location: Homer, AK is my home port
Boat: Skookum 53'
Posts: 4,045
Images: 5
Re: Rebuild or Repower?

The other posters bring up a very good point. It would be a great idea to go through the trouble shooting process very thoroughly, you may not even need a rebuild or overhaul. So take your time and maybe save some money.
__________________
" Wisdom; is your reward for surviving your mistakes"
captain58sailin is offline   Reply With Quote
Old 12-01-2014, 06:13   #36
Registered User

Join Date: Aug 2012
Location: Charleston, SC
Boat: Tayana 37
Posts: 704
Re: Rebuild or Repower?

Quote:
Originally Posted by captain58sailin View Post
The other posters bring up a very good point. It would be a great idea to go through the trouble shooting process very thoroughly, you may not even need a rebuild or overhaul. So take your time and maybe save some money.
That's what I'm hoping for. If I can get the engine running strong for a few hundred verses a few thousand, I'll be a happy man.

Sent from my HTC6500LVW using Cruisers Sailing Forum mobile app
__________________
Kevin84 is offline   Reply With Quote
Old 12-01-2014, 15:57   #37
Registered User

Join Date: Aug 2012
Location: Charleston, SC
Boat: Tayana 37
Posts: 704
Re: Rebuild or Repower?

Ok, found out a little more about what's going on with this engine. She apparently starts and runs fine. Until you hit higher RPMs. Then, though it still runs ok, it starts pumping out black smoke. So doesn't "sound" like it needs to be replaced.

Sent from my HTC6500LVW using Cruisers Sailing Forum mobile app
__________________
Kevin84 is offline   Reply With Quote
Old 12-01-2014, 16:01   #38
Senior Cruiser
 
Sailmonkey's Avatar

Cruisers Forum Supporter

Join Date: Sep 2009
Location: Houston
Boat: '76 Allied Seawind II, 32'
Posts: 5,770
Quote:
Originally Posted by Kevin84 View Post
Ok, found out a little more about what's going on with this engine. She apparently starts and runs fine. Until you hit higher RPMs. Then, though it still runs ok, it starts pumping out black smoke. So doesn't "sound" like it needs to be replaced. Sent from my HTC6500LVW using Cruisers Sailing Forum mobile app
That sounds over propped to me
__________________
Sailmonkey is offline   Reply With Quote
Old 12-01-2014, 16:02   #39
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,039
Re: Rebuild or Repower?

Black smoke is usually excess fuel or not enough air, still doesn't guarantee its not shot though, but if it has good oil pressure at idle when hot, and doesn't have any blue to the exhaust, it may be just a clogged exhaust elbow, or maybe fuel injectors, maybe
__________________
a64pilot is online now   Reply With Quote
Old 12-01-2014, 16:03   #40
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,039
Re: Rebuild or Repower?

Or yes, overpropped
__________________
a64pilot is online now   Reply With Quote
Old 12-01-2014, 16:09   #41
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 19,355
Re: Rebuild or Repower?

I think your boat is underpowered, so I would upgrade in HP if possible. Motorsailing into heavy chop, my guess is you dont move much....?
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is online now   Reply With Quote
Old 12-01-2014, 16:13   #42
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 17,039
Re: Rebuild or Repower?

You know he started the thread by saying it was underpowered at 30 hp for 24,000 lbs.
But I thought 1 HP per thousand was acceptable, if it isn't what is?
__________________
a64pilot is online now   Reply With Quote
Old 12-01-2014, 16:25   #43
Registered User
 
CarinaPDX's Avatar

Join Date: Jan 2010
Location: Portland, Oregon, USA
Boat: 31' Cape George Cutter
Posts: 1,673
Re: Rebuild or Repower?

Badly adjusted valves can also cause black smoke and lack of power. Adjusting the valves should be high on the list of tasks once the boat is purchased.

Underpowered? The context matters. It is definitely not underpowered for a traditional auxiliary. It is a little underpowered by modern motorsailor standards. Yes, there will be times where having an extra 10-20 hp would help when pounding to weather to get somewhere, but this should be relatively seldom and will if anything make the trip more miserable if shorter.

If the engine is fundamentally sound then unless the OP likes throwing around $20k it is not worth worrying about.

Greg
__________________
CarinaPDX is offline   Reply With Quote
Old 12-01-2014, 17:36   #44
Registered User
 
Celestialsailor's Avatar

Join Date: Nov 2006
Location: In Mexico, working on the boat
Boat: Hallberg Rassy 35. and 14ft.Whitehall pulling skiff.
Posts: 8,013
Images: 5
Re: Rebuild or Repower?

I've seen poor injectors do that. They can easily be rebuilt. 1hp per 1000lbs. is minimum. Against current and wind, 3hp per 1000lbs. is nice. I weigh 17,000 fully loaded and have a 46hp. Max power is at 2800 rpm. With current and wind, I run 1400 rpm. and hit 5kts. against wind(15kts) and a 2 kt. current, I run 1800 rpm and do 5 kts. so I do have good reserve power. I burn about 3/8 of a gallon an hour. If I had to really work the engine, say 2200 rpm. I would imagine consumption would be well over .5 of a gallon an hour. It's always a balance of power, speed and consumption.
__________________
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well-preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming: Wow - what a ride!"

http://wwwjolielle.blogspot.com/
Celestialsailor is offline   Reply With Quote
Old 12-01-2014, 17:41   #45
Registered User
 
cwyckham's Avatar

Join Date: Apr 2011
Location: Vancouver, BC
Boat: Niagara 35
Posts: 1,870
Re: Rebuild or Repower?

Quote:
Originally Posted by Kevin84 View Post
Ok, found out a little more about what's going on with this engine. She apparently starts and runs fine. Until you hit higher RPMs. Then, though it still runs ok, it starts pumping out black smoke. So doesn't "sound" like it needs to be replaced.

Sent from my HTC6500LVW using Cruisers Sailing Forum mobile app
Is this in gear or out of gear? If it's still smoking out of gear at high revs, then it isn't the prop, obviously.
__________________

__________________
cwyckham is offline   Reply With Quote
Reply

Tags
rebuild, repower

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not 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 Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 10:10.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.