Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 14-11-2015, 10:04   #1
Registered User

Join Date: Oct 2013
Location: Kingston, Ontario, Canada
Boat: Columbia, 8.3 and 8.7 (1977)
Posts: 153
Volvo Md7a

I'm in the process of rebuilding my Md7a and the question I have is which cylinder in #1. I have the emanual but it doesn't tell me. Thanks
__________________

__________________
weephee is offline   Reply With Quote
Old 15-11-2015, 15:58   #2
Registered User

Join Date: Oct 2013
Location: Kingston, Ontario, Canada
Boat: Columbia, 8.3 and 8.7 (1977)
Posts: 153
Re: Volvo Md7a

I'll try again. Does anyone know which cylinder is #1 on a Volvo md7a. Thanks
__________________

__________________
weephee is offline   Reply With Quote
Old 15-11-2015, 16:58   #3
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Volvo Md7a

I'll bet they are on the engine or head casting somewhere. Then I'd bet #1 is in the front too.
__________________
Guy is offline   Reply With Quote
Old 17-11-2015, 07:00   #4
Registered User

Join Date: Oct 2013
Location: Kingston, Ontario, Canada
Boat: Columbia, 8.3 and 8.7 (1977)
Posts: 153
Re: Volvo Md7a

Thanks for your reply. I assumed #1 Cylinder would be at the flywheel but wasn't sure.
__________________
weephee is offline   Reply With Quote
Old 17-11-2015, 08:06   #5
Senior Cruiser
 
hpeer's Avatar

Cruisers Forum Supporter

Join Date: Dec 2008
Location: Philadelphia
Boat: Murray 33-Chouette & Pape Steelmaid-44-Safara-both steel cutters
Posts: 3,900
Re: Volvo Md7a

I've had the head off and didn't see any marker.

Why is it important to know?
__________________
hpeer is offline   Reply With Quote
Old 17-11-2015, 08:25   #6
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Volvo Md7a

Quote:
Originally Posted by weephee View Post
Thanks for your reply. I assumed #1 Cylinder would be at the flywheel but wasn't sure.
Funny, one of us is probably right.
__________________
Guy is offline   Reply With Quote
Old 17-11-2015, 08:31   #7
Registered User

Join Date: Oct 2013
Location: Kingston, Ontario, Canada
Boat: Columbia, 8.3 and 8.7 (1977)
Posts: 153
Re: Volvo Md7a

It is important to know because the manual calls for piston #1 to be TDC when adjusting the injection pump.
__________________
weephee is offline   Reply With Quote
Old 17-11-2015, 09:03   #8
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Volvo Md7a

Quote:
Originally Posted by weephee View Post
It is important to know because the manual calls for piston #1 to be TDC when adjusting the injection pump.
You can figure it out logically. Note the direction of rotation. Turn the engine until the front piston is tdc. Check to see if the both valves would be closed. Look for the timing mark on the fuel pump drive gear. If that did not work check the rear one . If you are still puzzled, figure out the firing order from rotating the engine and watching the cam. #1 will not be one of the middle cylinders.
__________________
Guy is offline   Reply With Quote
Old 18-11-2015, 16:19   #9
Registered User

Join Date: Jan 2010
Location: Ma
Boat: Sabre 28
Posts: 190
Re: Volvo Md7a

"It is important to know because the manual calls for piston #1 to be TDC when adjusting the injection pump."

#1 is the flywheel side of the engine. Are you removing the injector pump? If so make sure you remove the access cover (where the water pump is) and spin the engine until the timing mark on the injector pump gear AND on the drive gear line up. If you have lousy access to the rear of the engine (my Sabre's is tough) get a $99 bore scope from Home Depot. It makes this dramatically easier to see. There is a 2:1 ratio between the pulleys so you might need to spin it over twice to get the marks to line up.

Removing the exhaust riser (and manifold) really helped give more access to this area. On my MD7A I had a couple of corroded bolts due to a leaking water pump. I had to drill them and that was not fun.

I initially tried to duplicate the injector timing based on where the old pump was. However, I found adjusting the timing based on the actual running of the engine seemed to work better. I would adjust it slightly, start engine and see how easily it started and how much smoke it had. I adjusted timing for the least amount of smoke and the engine has run great after that. Small movements make pretty big difference in the amount of gray smoke you get and also in how easily the engine starts. If the timing is off too much the engine won't start at all.

Shawn
__________________
Shawn67 is offline   Reply With Quote
Old 19-11-2015, 08:03   #10
Registered User

Join Date: Oct 2013
Location: Kingston, Ontario, Canada
Boat: Columbia, 8.3 and 8.7 (1977)
Posts: 153
Re: Volvo Md7a

Thanks guys, I really appreciate your responses. The engine is out of the boat so I will try your suggestion Shawn and see how that goes. I intend to start it before installation so I should be able to adjust accordingly. I also have a yanmar 2qm15 so I'm not sure yet which engine I'm going to install in my 8.7 columbia. The MD7A will be in good shape so I will sell it if I install the Yanmar. Thanks again
__________________

__________________
weephee is offline   Reply With Quote
Reply

Tags
volvo

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Volvo MD7A thermostat housing Axell Engines and Propulsion Systems 4 22-07-2014 11:48
For Sale: Volvo MD7A ketchman Classifieds Archive 0 10-01-2013 10:06
Alternator for Volvo MD7A 13hp hpeer Electrical: Batteries, Generators & Solar 2 08-05-2012 15:25
volvo MD7A jouet 820 Engines and Propulsion Systems 19 22-12-2008 01:03
volvo md7a, low power ian stratton Engines and Propulsion Systems 5 14-11-2008 16:20



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 00:12.


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.