Reply
 
Thread Tools Search this Thread Display Modes
 
Old 10-28-2018, 09:41 PM   #1
Member
 
City: Toledo
Country: United States
Vessel Name: Nevermore
Vessel Model: Marine Trader Tradewinds 38
Join Date: Oct 2018
Posts: 6
Mainship Nantucket 40 with Detroit 8.2 L Diesels

Anyone out there have a 40 with two Detroit Diesel 8.2 L engines. What is the expected fuel usage and cruising speed for these engines?
__________________
Advertisement

cantal is offline   Reply With Quote
Old 10-28-2018, 09:55 PM   #2
Guru
 
Ken E.'s Avatar
 
City: Bellingham WA
Country: United States
Vessel Name: Hatt Trick
Vessel Model: 45' Hatteras Convertible
Join Date: Nov 2016
Posts: 705
Suggest you visit boatdiesel.com and inquire on these engines. You will get varying viewpoints.
__________________

Ken E. is online now   Reply With Quote
Old 10-29-2018, 05:47 AM   #3
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23- outboard
Join Date: Aug 2012
Posts: 4,329
I have done the boatdiesel research and what I found is there is a problem with the coolant system air locking at high power levels which results in overheating, head warping, etc. It apparently is easily fixed (before it overheats!) by installing a bypass from the back of the head to vent the air lock.


I used one for a week on a friend's MS34 and it was a smooth and solid engine. We were running at about 7 kts so no stress at about 1,500 rpms.


David
djmarchand is online now   Reply With Quote
Old 10-29-2018, 07:39 AM   #4
Guru
 
City: Fort Myers
Country: USA
Join Date: Jul 2013
Posts: 1,054
This is a four cycle diesel, which I find if you look at fuel usage/load charts they are all somewhat comparable.

This series had a limited lifetime in the marine world, might want to also check around on parts availability as well.
Marlinmike is offline   Reply With Quote
Old 10-29-2018, 09:52 AM   #5
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 4,908
Run easy like on a trawler, they can live long. Run hard (near their rated output), they are prone to cracked exhaust manifolds and head gasket trouble.

Second that about checking on parts availability. Especially exhaust manifolds and turbos specific to the marine application. Base engine part should be available.

Also has an annoying "road load" or speed limiting governor. Not a big deal, just different from most marine engines.
Ski in NC is offline   Reply With Quote
Old 10-29-2018, 11:14 AM   #6
Guru
 
djmarchand's Avatar
 
City: Litchfield, Ct/Punta Gorda, Fl
Country: USA
Vessel Model: Atlas Pompano 23- outboard
Join Date: Aug 2012
Posts: 4,329
Like I said above I captained a boat with an 8.2 Detroit for a week and never noticed the different governor. Maybe if I knew in advance I would have picked up on the differences, but they are subtle and no reason to not consider this engine.


I believe that the manifold cracking that Ski mentions is due to the air pocket issue I noted above and I understand that the vent hose solves this problem. But I agree I wouldn't want to run this engine much over 100 hp in any case.



David
djmarchand is online now   Reply With Quote
Old 10-29-2018, 11:49 AM   #7
Guru
 
City: Between Oregon and Alaska
Country: US
Vessel Name: Charlie Harper
Vessel Model: Wheeler Shipyard 83'
Join Date: Jun 2016
Posts: 1,307
There are a number of companies that make replacement manifolds for Detroit Diesels and other makes. Surplusman : Home Page sells used marine diesels and parts.
Attached Thumbnails
Click image for larger version

Name:	Barr.JPG
Views:	22
Size:	78.5 KB
ID:	82349   Click image for larger version

Name:	marine exhaust.jpg
Views:	23
Size:	98.0 KB
ID:	82350  
Lepke is offline   Reply With Quote
Old 10-29-2018, 11:54 AM   #8
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 4,908
None of those ads cover manifolds for the 8.2.
Ski in NC is offline   Reply With Quote
Old 10-30-2018, 06:05 AM   #9
Veteran Member
 
KneeDeep's Avatar
 
City: San Antonio
Country: USA
Vessel Name: Betsy Lee
Vessel Model: 37 Atlantic Double Cabin
Join Date: Jan 2014
Posts: 96
We have a pair of 8.2's in our Atlantic and they run great. 1650rpm / 5.5pgh / 7kts all day long. No problems replacing HE, exhaust elbows, etc so far, but i can see some potential long term concerns with limited service availability (our local DD dealer won't work on them) We want to keep the boat for another 10+ years and do some longer cruising (loop, bahamas, etc.) so could be an issue down the road. Boatdiesel is a great resource.
__________________

KneeDeep is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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





All times are GMT -5. The time now is 06:06 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012