Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Tech Help

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 02-16-2006, 05:15 PM
Registered User
 
Join Date: Jul 2003
Posts: 528
m116 valve lapping?

Are you supposed to lap the valves on this v8, I read that the block is a special metal process that you don't wont to start honing etc,
what about the head? valve seats are they alloy and lappable?
Thanks.
__________________
Thanks, Juan
Reply With Quote
  #2  
Old 02-16-2006, 07:53 PM
t walgamuth's Avatar
dieselarchitect
 
Join Date: Apr 2005
Location: Lafayette Indiana
Posts: 34,604
the valve seats

will be hard steel. so normal grinding proceedures will apply.

tom w
__________________
[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.
Reply With Quote
  #3  
Old 02-16-2006, 08:31 PM
Registered User
 
Join Date: Jul 2003
Posts: 528
great, thanks
__________________
Thanks, Juan
Reply With Quote
  #4  
Old 02-16-2006, 08:47 PM
MS Fowler's Avatar
Registered User
 
Join Date: Jan 2003
Location: Littlestown PA ( 6 miles south of Gettysburg)
Posts: 2,208
AFAIK lapping is OLD technology. Three angle valve/seat grinding is the way to go.
Reply With Quote
  #5  
Old 02-19-2006, 12:24 AM
Registered User
 
Join Date: Jul 2000
Posts: 638
valve seating

If you are replacing the valves, or resurfacing them - do it right. A competent machine shop (one that really knows how to do Mercedes heads) has the tools.

You want a '3 angle grind' on both the valves and seats, with a 1 degree interference angle so the valve will seat at the top first. This ensures a better seal and helps prevent any leaking and overheating. The valve seats are 'stellite'--a special very hard material. The fit of each valve and seat should be checked with 'prussian blue' twice--first to ensure a spot on the valve face contacts the seat all the way around--ensures the seat is ground perfectly square to the valve guide; secondly to ensure a spot on the seat will contact the valve head all the way around--ensures the valve head is ground perfectly square to the stem- and the position of the seating surface (the pretty purple/blue streak all around the seat) on both the seat and valve face. You do not want the sealing surface too close to the edge of the valve or too far down from the head. Similar for the seat sealing surface- should be right in the middle of the 45 degree surface. Only if all these checks are made and passed will the valve job hold up.

Be sure and have them check the valve stems for wear and the guides as well. Each valve stem diameter should be measured at several points to determine any wear. With a new valve, any play in the valve head -side-to side-when the valve is at maximum opening, should be measured with a dial indicator to ascertain any guide wear. Then the fit of the particular valve with the guide must also be checked to ensure the side play is well within specifications. Otherwise, the new valve stem seals will quickly fail and your valve will leak from the get-go. It is easy to drop in a new set of valve guides with the head off.
Reply With Quote
Reply

Bookmarks

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On




All times are GMT -4. The time now is 12:22 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page