Cruisers Forum

Join CruisersForum Today

Thread Tools Rate Thread Display Modes
Old 18-12-2007, 14:16   #1
Registered User
Bill G's Avatar

Join Date: Sep 2006
Location: Maryland
Boat: Vancouver 32 cutter
Posts: 36
TDC on a Bukh 20 ME

Anyone know how I find TDC on a Bukh 20? I want to adjust the valves, but can't find a reference for TDC - my service manuals give the clearances, but don't indicate where I can find the markings for TDC.


Bill G is offline   Reply With Quote
Old 18-12-2007, 14:56   #2
Registered User

Join Date: Jan 2007
Posts: 497
Images: 1
Don't know specifically for that engine, but in general with any engine we use a dial gauge on a magnetic base with the feeler end extended into the cylinder. Turn it over by hand and find TDC that way. Used the spark plug hole on gas engines, probably an injector hole would work on a diesel unless it has a pre-chamber or something else that obstructs access to the top of the piston.

jdoe71 is offline   Reply With Quote
Old 18-12-2007, 16:19   #3
Registered User

Join Date: Mar 2007
Location: Brisbane
Boat: s/v Sildene
Posts: 91
Bill, I have a Bukh 36 and had read that the flywheel (a real old flywheel, eh, must weigh 30kg on the 3-cyl) had a mark that could be aligned with a protruding metal pointer on the engine block.

In my case though, the flywheel showed no mark, so, as per Jdoe71, I used a dial indicator through an injector hole (the Bukh does not have any pre-chambers or obstructions) to find TDC. And then made my own mark.

sildene is offline   Reply With Quote
Old 18-12-2007, 18:09   #4
Registered User

Join Date: Jan 2006
Location: North Carolina
Boat: 44 footer
Posts: 924
Oooh finally a question I can help with...

Cams are wonderful things, they have what is called a base circle. They hit a point where if you turn in either direction the push rod or rocker doesn't move.

When you are adjusting the valves on an engine so long as the push rod or rocker isn't moving, your on the base circle. The lash is not changing during this period, it is as loose as it will get... exactly where you want it. When is top dead center? The intake valve was the last thing to close, this is top dead center on the compression stroke.

The most marvelous thing ever invented for adjusting valves is the remote starter, hit the button for a split second and bump bump bump. Intake valve is closed, now no movement... wiggle wiggle theres the slack.. its not changing. Set the lash and repeat.

(This is not specific to your engine, and the specs and whether its done hot or cold depend on your engine. This adjustment method works best on flat tappet, solid lifter engines... but it works to find TDC on the compression stroke of any engine.)

Zach is offline   Reply With Quote


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
Oil leak in Bukh Marauder Engines and Propulsion Systems 12 24-01-2008 22:24
Bukh Propellor Marauder Propellers & Drive Systems 22 15-01-2007 20:09
1970-something Bukh 8HP Diesel RichardDiverQld Construction, Maintenance & Refit 1 10-09-2005 10:54

Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:40.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.