Reply
 
Thread Tools Display Modes
 
Old 10-08-2010, 11:12 PM   #1
Member
 
City: Milwaukee, WI
Vessel Name: Rooster
Vessel Model: Uniflite 40 - US Navy Tender
Join Date: Aug 2010
Posts: 5
Buying our first trawler

We are sailors moving up to a trawler and have located a great boat but I am concerned about its engines.* It is a 1981 with original Perkins turbocharged ST6.3544M engines that have almost 3000 hours on them.* I'm concerned about a possible future replacement of the turbos in view of the high hours on the engine.* Any thoughts about my concern?* If I need to replace turbos in the future can I convert to a naturally aspirated instead at less cost?**Any other advice would also be appreciated.

Jim
__________________
Advertisement

jtflyn is offline   Reply With Quote
Old 10-09-2010, 05:06 AM   #2
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,524
Buying our first trawler

I have seen at least one conversion where the turbo was scrapped, with no problem.

It was on a 40ish Californian , both were removed (after the failure of one cost an engine its bearings , a crank regrind and some pistons) by a Canadian that would have a heart attack at the fuel flow over displacement speeds.

Moving to a "trawler look" WHY ? ,

have you considered the other options that might work for your Desirements better?

After all a boat with twin turboes was probablt built to plane or semi plane , and is less efficient at displacement speeds as well as running the engines far below their cruise ratings.

What do you plan to DO with the boat , besides own it?

-- Edited by FF on Saturday 9th of October 2010 05:08:48 AM
__________________

FF is offline   Reply With Quote
Old 10-10-2010, 06:07 PM   #3
Senior Member
 
ralphyost's Avatar
 
City: Cape Coral FL
Country: USA
Vessel Name: Say GoodBye
Vessel Model: 21 Mako
Join Date: Oct 2007
Posts: 261
RE: Buying our first trawler

Jim
I suggest you FIRST make a list of what you want in a boat, including first choice of engine then second, third choice of engine. You need to decide what (if any) engine is not acceptable to you.

After you have your list, go shopping and weed out those that are not acceptable enough.

If you dont understand turbos then you dont want to own one.

R.
ralphyost is offline   Reply With Quote
Old 10-10-2010, 06:28 PM   #4
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,168
RE: Buying our first trawler

3000 hrs on a boat that is 29 yrs old, is barely 100 hrs per year. That is average or less than average usage and is at most 1/3 of the expected life of the engines. If you put the same 100 hrs per year on those engines you will be in for a full rebuild in about 70 years. You should live that long!.
Have an engine survey done if you are concerned about them. A far greater concern that the no of hours is the number of cold starts those engines have had to endure. You won't know that, so get an oil analysis, and have somebody (engine survey) who knows what the presence of various metals in the oil really means have a look at it.
Go to Boatdiesel.com. Buy a membership. Ask away and you will get great, knowledgeable advice.
koliver is offline   Reply With Quote
Old 10-11-2010, 04:41 AM   #5
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,524
RE: Buying our first trawler

"3000 hrs on a boat that is 29 yrs old, is barely 100 hrs per year. That is average or less than average usage and is at most 1/3 of the expected life of the engines. If you put the same 100 hrs per year on those engines you will be in for a full rebuild in about 70 years. You should live that long!."

This rather optomistic view requires that the engine was properly serviced each day of its life.

Most TT style boats suffer from a huge lack of maint , usually the boat is walked away from for months (years?)at a time.

For longest engine life the engine mist be "put to bed" in the off season with proper extensive and expensive work.

That so many survive with almost no PM is a tribute to the designers of these old tractor engines , and the fact that 100 hours a year of low load operation will not show up the results of poor PM .

It is also a result of operational ignorance.

While a well operating , well maintained engine might push at cruise speeds at 3GPH and the sad old neglected engine requires 4GPH for the same speed, the burn is so low that saving a GPH or a 100G a season might cost more than proper maint would have.
FF is offline   Reply With Quote
Old 10-11-2010, 10:47 AM   #6
Guru
 
jleonard's Avatar
 
Join Date: Jun 2008
Posts: 2,739
RE: Buying our first trawler

I wouldn't worry so much about the turbochargers. They are easy to rebuild if you are somewhat mechanical and the kit is only about $100.
On a range 4 series Perkins I would be much more concerned with the "manicooler" (exhaust manifold and heat exchanger) and "multi-coolers" *(aftercooler, oil cooler) if so equipped.
Those parts are big bucks and "marine age" does more to them than engine hours.
The base engine is pretty stout but it's the marina add ons that will get you.
Hope this helps.
jleonard is offline   Reply With Quote
Old 10-11-2010, 02:55 PM   #7
TF Site Team
 
Pineapple Girl's Avatar
 
City: San Mateo, CA
Country: USA
Vessel Name: Pineapple Girl II
Vessel Model: PT 35
Join Date: Jun 2010
Posts: 2,165
RE: Buying our first trawler

We bought an '84 trawler ~ five weeks ago with the same engines with just under 2000s hours.* We discussed the engines at length with friends who are boaters and mechanics as well as the mechanic we hired to do the engine survey.* They checked out great and we have maintenance records from the PO, who owned the boat 18 years.* So we really weren't concerned and the boat fit what we were looking for so, we bought it.*

I love my twins.
Attached Thumbnails
Click image for larger version

Name:	engines.jpg
Views:	219
Size:	72.6 KB
ID:	2909  
Pineapple Girl is offline   Reply With Quote
Old 10-11-2010, 03:30 PM   #8
Master and Commander
 
markpierce's Avatar
 
City: Vallejo CA
Country: USA
Vessel Name: Carquinez Coot
Vessel Model: 2011 Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 10,262
RE: Buying our first trawler

I'm "afraid" of turbochargers.* Seems to me they would place extra strains on the engine and shorten its life.* Is the fear rational as far as marine diesels go?
markpierce is offline   Reply With Quote
Old 10-11-2010, 09:38 PM   #9
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,363
Buying our first trawler

IMHO your fear of turbos is*misplaced but not relevant.* As previously mentioned, the HXs present a far greater set of maintenance concerns. With a new build such as you are doing, a Cummins 4B non turbo is a better choice than a revved up Yanmar with a turbo.

-- Edited by sunchaser on Monday 11th of October 2010 09:41:50 PM
sunchaser is offline   Reply With Quote
Old 10-11-2010, 10:14 PM   #10
Member
 
City: Milwaukee, WI
Vessel Name: Rooster
Vessel Model: Uniflite 40 - US Navy Tender
Join Date: Aug 2010
Posts: 5
RE: Buying our first trawler

Thanks everyone for your replies.* I became a member at Boatdiesel.com and I am studying their forum info on perkins engines.* Thanks for all your advise.* I think I'll wait until I can find a boat with a nonturbo engine so that I can run it at displacement speeds without gunking it up.* Thanks again.* I expect to be a regular follower of the Trawler Forum.
jtflyn is offline   Reply With Quote
Old 10-11-2010, 10:15 PM   #11
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,168
RE: Buying our first trawler

This weekend talked to a guy who has 13,000 hrs on his turbo'd 6 cly Volvo 70 series (1980s) diesel. No reason to be aftraid of turbos.
koliver is offline   Reply With Quote
Old 10-12-2010, 06:12 AM   #12
Guru
 
Tom.B's Avatar
 
City: Cary, NC
Country: USA
Vessel Name: Skinny Dippin'
Vessel Model: Navigator 4200 Classic
Join Date: Jul 2009
Posts: 5,153
Buying our first trawler

My only concern after having worked on gassers (in cars and not boats) my whole life is that I see performance additions like turbos and super chargers as burning the candle at both ends. Or better yet... "A light that burns twice as bright, burns half as long." Often, turbos are just added to engines that may not be beefed up in other places for the added strain forced induction systems can put on an engine. Turbo turbine fans spin up at tens of thousands of rpm and get glowing red hot. That causes all sorts of issues with breakdown of metals and bearings.

Is this an opinion based on scientific discovery? No. Would I avoid a turbo charged engine because of it? I doubt it. Partially because, at least in the case of lots of diesels, they are capable of many thousands of hours of use. Often more than we are capable of using it. Even dividing it in half would still give you an engine that will last longer than the boat it's in. Not to mention that modern engines have largely addressed many of these issues. At least I think so.

In the end, you need to decide if the performance upgrade is worth it. Everything is a compromise.

-- Edited by GonzoF1 on Tuesday 12th of October 2010 06:14:05 AM
Tom.B is offline   Reply With Quote
Old 10-12-2010, 07:34 AM   #13
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,363
RE: Buying our first trawler

In my business, earth moving and mining, turbos are not add ons. They are as essential and common as the starter motor. We are speaking here of tens of thousands of engines per year. It is not uncommon to see some larger engines with 4 turbos. This heavy equipment is not subjected to the same owner abuse as too many marine engines. Plus not having a seawater side pays great dibvidends in these non marine applications. The engines last for tens of thousands of hours and to keep the warranty active must be serviced by the book. The "old" DD 2 cyles set the bar for turbos, 50 + years ago.
sunchaser is offline   Reply With Quote
Old 10-12-2010, 10:21 AM   #14
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,524
RE: Buying our first trawler

The "old" DD 2 cyles set the bar for turbos, 50 + years ago.

The 1936 versions of the 6-71 had a supercharger to help scavenge (push out) the exhaust gas , but it only gave a pound or two of boost at best.

Real turboes came much later.

All the heavy machinery Works for a living , works hard and often.

Pleasure "Trawlers" are run for economy , and lack pro maint.

5-1 service life difference would not be a surprise.
FF is offline   Reply With Quote
Old 10-12-2010, 12:43 PM   #15
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,363
Buying our first trawler

"pleasure trawlers are run for economy"**Huh??

A fully turboed Cummins made in 2010 will get about 20 - 30% better "economy" than a similar HP DD 2 stroke with about 60 -*70% the weight.

-- Edited by sunchaser on Tuesday 12th of October 2010 01:29:06 PM
sunchaser is offline   Reply With Quote
Old 10-12-2010, 05:26 PM   #16
Guru
 
Steve's Avatar
 
City: Thibodaux, Louisiana
Country: USA
Vessel Name: Gumbo
Vessel Model: 2003 Monk 36
Join Date: Oct 2007
Posts: 3,607
RE: Buying our first trawler

These are industrial engines, as sunchaser said many thousands with turbos are built per year for construction, Agriculture and power generation applications. That said, they are additional moving parts which could fail but the benefits outweigh any disadvantage.
Steve W
Steve is offline   Reply With Quote
Old 10-13-2010, 05:06 AM   #17
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,524
RE: Buying our first trawler

A fully turboed Cummins made in 2010 will get about 20 - 30% better "economy" than a similar HP DD 2 stroke with about 60 - 70% the weight.

HMMM 1936 to 2010 , and it gets 20% better fuel burn? WOW!!

That said, they are additional moving parts which could fail but the benefits outweigh any disadvantage.

THe "advantage" is higher output from a smaller motor, where most displacement "trawlers"
suffer from too large engines working not at all hard.

To get a speed boat on a plane , advantage , to get huge power into a boat that uses it to cruise , advantage, to cruise at 3 GPh , its a great advantage if the engine is 75 HP.
FF is offline   Reply With Quote
Old 10-13-2010, 09:46 AM   #18
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,363
RE: Buying our first trawler

FF I never said 1936 - you did.

By the 1990s, the DD 2 strokes were pretty well optimized and at best were about 70 to 80% as fuel effecient as a well designed 4 stroke at that time. In the past 15 years, the 4 strokes have been "dialed in" so they can meet world wide emission regs at virtually any power loading - from idle to max. The DD 2 strokes could not effectively meet emission regs and were discontinued.

Five years ago when boat shopping I had the opportunity purchase a refit vessel with the last 6-71s 485 (?) hp*made and with less than 100 hours. They were found on a dealers* storage floor in crates and had been there for about 3 years. They ran well, looked wonderful, were heavy, sounded great - and slobbered oil like all good 6-71s.

The notion that a new turbo diesel "block" will not last as long as*an older NA version is pure bunk. On blocks, the warranties are even better today that 30 years ago. As always, it comes down to owner maintenance though. go by the book.

Last but not least, if you are looking for something economical, knit.
sunchaser is offline   Reply With Quote
Old 10-13-2010, 10:26 AM   #19
TF Site Team
 
Baker's Avatar
 
City: League City, Tx
Country: Texas
Vessel Model: Carver 356
Join Date: Oct 2007
Posts: 5,630
RE: Buying our first trawler

Quote:
GonzoF1 wrote:

My only concern after having worked on gassers (in cars and not boats) my whole life is that I see performance additions like turbos and super chargers as burning the candle at both ends. Or better yet... "A light that burns twice as bright, burns half as long." Often, turbos are just added to engines that may not be beefed up in other places for the added strain forced induction systems can put on an engine. Turbo turbine fans spin up at tens of thousands of rpm and get glowing red hot. That causes all sorts of issues with breakdown of metals and bearings.

Is this an opinion based on scientific discovery? No. Would I avoid a turbo charged engine because of it? I doubt it. Partially because, at least in the case of lots of diesels, they are capable of many thousands of hours of use. Often more than we are capable of using it. Even dividing it in half would still give you an engine that will last longer than the boat it's in. Not to mention that modern engines have largely addressed many of these issues. At least I think so.

In the end, you need to decide if the performance upgrade is worth it. Everything is a compromise.

-- Edited by GonzoF1 on Tuesday 12th of October 2010 06:14:05 AM
Gonzo, gassers and diesels are a bit different in the diesels, by design, lend themselves to turbocharging. *In a gas engine, there are 2 main challenges with forced induction. *The strength of the rotating assemble and the ability to force air into the combustion chamber without "pre-ignition"(detonation). *The rotating assemble of a diesel engine is already very stoutly built. *ANd ignition of the fuel/air mixture is basically the same thing your are trying to avoid on a gasser....detonation...or compression ignition. *I am not saying that you should just bolt a turbo onto a diesel and every thing will be dandy. *It should still be part of the overall engine design. *But it is not as big of a challenge or strain as it is on a gas engine.

*
Baker is offline   Reply With Quote
Old 10-14-2010, 05:06 AM   #20
FF
Guru
 
FF's Avatar
 
Join Date: Oct 2007
Posts: 16,524
RE: Buying our first trawler

They ran well, looked wonderful, were heavy, sounded great - and slobbered oil like all good 6-71s.

In my experience the DD did not slobber oil when new , only after a local "mechanic" was used to service the engine.

Our "lobster boat" the 50 ft USN Utility has a "new" DD , it was stored in the can sometime in the 1950's and finally sold as surplus in the 90's .

With under 1200 hours it has only had tune one tune up (to depower with smaller injectors) and leaks not a drop.

Interesting is the unit has a "color filter" a by pass filter , but no full flow oil filter .

That's how it was done then, amazing to any DD owner is the oil stays car like clean , not dark black till about 50 hours , where it starts to get darker till the 125 change out.

"last 6-71s 485 (?) hp" when used in fish killers at speed get about 1000 hrs to rebuild.
__________________

FF is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
buying a trawler edbulmer General Discussion 51 06-01-2015 10:33 AM
Buying a Pacific Trawler Jay N Pacific Trawler 17 12-10-2014 11:37 PM
Buying a used trawler Dimview Power Systems 14 09-13-2010 04:39 PM
Top Five Trawler Buying Mistakes N4061 General Discussion 4 03-25-2010 08:21 PM
Buying your trawler - documentation marinetrader General Discussion 33 10-30-2007 07:46 PM




All times are GMT -5. The time now is 04:45 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012