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 > Diesel Discussion

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 06-15-2012, 09:48 PM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Prechamber cleaning 617 turbo

Hello, I am in the process of cleaning the prechambers and have used a wire brush to clean the crud off the tips. I have noticed that there is a bit of a burr around the little holes in the tips of the prechambers. I may have pressed a little bit too hard on the wire wheel and flattened out the burrs on some of them little holes.

I thought I read somewhere that the holes can be cleaned with a reamer of some type. I am thinking that I should maybe ream the holes out now that I have probably pushed some metal into the holes oriface by flattening out the burrs. Are those burrs suppossed to be there or would it be better to flatten them all out and ream the holes?

Also wondering if anyone has a trick to getting those old prechamber seal rings off the prechambers...4 out of 5 are stuck on the prechambers and I have tried heat and penetrating oil but that did not help.
Thanks

Reply With Quote
  #2  
Old 06-15-2012, 11:52 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,041
When I pulled mine I assumed the bur was from the wear due to the heat and pressures involved. I am guessing that after years and years of use the holes in the Prechamber Nose get enlarged some.

I have never read of any sort of reamer used to clean the Holes at the Nose of the Prechamber.

I had not read this either but one of our Members on another Forum said that after surfacing the Cylinder Head the Prechambers may need thicker Seals/Spacers. If the Thicker Seals/Spacers are used a Glow Plug Reamer (normally used to ream out the Carbon in the Glow Plug hole) should be used to possibly ream off and metal on the not repositioned Prechamber so the Glow Plugs will fit properly.
But, I had not read that myself.

The Sealing Rings are Aluminum. A Propane Torch ought to have enough heat to expand them; the heat will not hurt the Prechamber.
I don't recall having that problem with mine.
__________________
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
  #3  
Old 06-16-2012, 01:13 AM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Quote:
Originally Posted by Diesel911 View Post
When I pulled mine I assumed the bur was from the wear due to the heat and pressures involved. I am guessing that after years and years of use the holes in the Prechamber Nose get enlarged some.

I have never read of any sort of reamer used to clean the Holes at the Nose of the Prechamber.

I had not read this either but one of our Members on another Forum said that after surfacing the Cylinder Head the Prechambers may need thicker Seals/Spacers. If the Thicker Seals/Spacers are used a Glow Plug Reamer (normally used to ream out the Carbon in the Glow Plug hole) should be used to possibly ream off and metal on the not repositioned Prechamber so the Glow Plugs will fit properly.
But, I had not read that myself.

The Sealing Rings are Aluminum. A Propane Torch ought to have enough heat to expand them; the heat will not hurt the Prechamber.
I don't recall having that problem with mine.

I got the aluminum pretty hot and they would'nt come off....I have them soaking in C.L.R overnight, maybe tomorrow.

I never thought of the glow plug holes not lining up...I did have the head resurfaced by .012 thousands of an inch which I think is about .3 mm which is not very much....and the hole in the side of the prechamber is quite abit bigger than a glow plug tip so I don't think it should be an issue, but we will find out when the seal rings get ordered and everything starts to go back together.

So, what did you do about the burr's around the holes?

I would like to see a cut away of a prechamber or an explanation of how they work. I can see the ball in there but cannot see underneath of it to know what the transition is to the little holes in the tip.
Reply With Quote
  #4  
Old 06-16-2012, 11:33 AM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,041
Quote:
Originally Posted by macdoe View Post
I got the aluminum pretty hot and they would'nt come off....I have them soaking in C.L.R overnight, maybe tomorrow.

I never thought of the glow plug holes not lining up...I did have the head resurfaced by .012 thousands of an inch which I think is about .3 mm which is not very much....and the hole in the side of the prechamber is quite abit bigger than a glow plug tip so I don't think it should be an issue, but we will find out when the seal rings get ordered and everything starts to go back together.

So, what did you do about the burr's around the holes?

I would like to see a cut away of a prechamber or an explanation of how they work. I can see the ball in there but cannot see underneath of it to know what the transition is to the little holes in the tip.
Except for hand brushing the crud off of the exterior of the Prechamber I did nothing to the burrs. I did not feel removing it would serve any prupose.
In fact my reson for pulling out the Prechamber was to test some Tools I had made. I did not remove them to clean them.
I guess it depends how big the burrs are. It is hard to see in the pic but there is a sligntly raised ring around the prechamber hole.

You could try carefully gripping ony the Aluminum Seal Ring with a Channel Locks and see if you can Rotate it. Instlling the Prechamber Puller Tool would allow you something to hold onto.
Attached Thumbnails
Prechamber cleaning 617 turbo-11-use-slide-hammer-pull-out-prechamberx.jpg  
__________________
84 300D, 82 Volvo 244Gl Diesel

Last edited by Diesel911; 06-16-2012 at 11:52 AM.
Reply With Quote
  #5  
Old 06-16-2012, 12:43 PM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Thanks I will try that method with the pre chamber tool attached. I put it in the vise between a couple of slabs of ply wood but was too scared to tighten the vice too much for fear of distorting the prechambers.

I found the article about the reaming of the holes....they are also chamfering the burrs off from what I could tell.

If you want to check it out it is on superturbodiesel under the heading.... Prechamber Mod "Flame" Front ....and in particular post #66 by Hercules is what caught my eye.
Be warned though it is very long and technical....took a couple hours to read and in the end there is NO conclusion. What I got from it was that there is a certain "Homeostasis" that is taking place in those prechambers with relationship to the cylinder and the combustion process and the size of holes up to a certain point in horsepower per cylinder. I think enlarging the holes is a BAD idea on a stock engine.

I DO NOT want to make the holes larger but I am thinking that I might chamfer those burrs off and slightly ream the holes to make sure they are clean. I just have a stock engine with no mods to anything except I will probably block and remove the egr stuff when this goes back together.

I have to clean the intake and exhaust manifolds today and am not looking forward to it. Whunter told me to block the egr and the intake won't fill up with junk, which is worth doing considering how much is in there right now.

By the way, I noticed you have some of that white deposit on your prechamber tip too. I had a really hard time getting it off ONE of mine until we soaked them in CLR...then it wiped right off. The wire wheel on the grinder would not even remove it.

I had the white depositit only on the prechamber in the cylinder that had the headgasket leak and subsequent broken valve guide. There was also quite abit of it on the valves in that cylinder. Others were very clean

What is the white deposit from....burning coolant....too rich ....too lean.... I am wondering about the injector in that cylinder?

Thanks

Last edited by macdoe; 06-16-2012 at 01:01 PM.
Reply With Quote
  #6  
Old 06-16-2012, 01:39 PM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
Do not soak your prechambers in CLR.....damn stuff ate the chrome plating off them? They must be made of copper or something that color...2 stayed normal and are really clean but three of them are now a copper or bronze color. I hope they will still work? They look brand new except the color change.
Reply With Quote
  #7  
Old 06-16-2012, 02:09 PM
funola's Avatar
Registered User
 
Join Date: May 2005
Location: NYC
Posts: 8,245
Quote:
Originally Posted by macdoe View Post
Do not soak your prechambers in CLR.....damn stuff ate the chrome plating off them? They must be made of copper or something that color...2 stayed normal and are really clean but three of them are now a copper or bronze color. I hope they will still work? They look brand new except the color change.
CLR's active ingredient is hydrocloric acid, it dissolves metal! Good for cleaning rust. the R in CLR, C is calcium, L is Lime I believe. How long was the pre chambers in the CLR?
__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked
Reply With Quote
  #8  
Old 06-16-2012, 03:05 PM
macdoe
 
Join Date: Sep 2007
Location: Canada
Posts: 759
I left them in overnight. They were in there for approximately 16 hrs...I checked them at 6 hrs and they were clean enough...should have taken them out at 6 hrs. I kind of thought about it being an acid of some type but figured it was mild enough that it would'nt hurt metal. It is used to clean Calcium lime and rust scale from bathroom fixtures such as taps and faucets and I thought that it would be mild to save from eating the plating off of fancy faucets and shower heads...guess not if you leave it there too long....of course I read the instructions after. You can dilute it with water to make it less corrosive. I used full strength.

I kept checking them yesterday and they were probably clean enough when I went to bed but figured they were doing o.k and to leave them in overnight would get rid of anything below the ball in there that I could'nt see. I briefly thought about removing them last night and now I wish I would have. They are soaking in WD-40 now to hopefully neutralize it.

I can see on Diesel 911's picture that some copper is showing on his prechamber so hopefully I can still use them. They are from our 85' wagon so they are the good prechambers. I have another set in the spare 82 300SD motor but really wanted to use these ones cause the holes are bigger and it sounds like the injector is set slightly deeper.


Should have paid more attention in chemistry class I guess. Anyone know what these prechambers are made of? What was the plating on there for? I thought these were just plain old steel but obviously some type of alloy?
Reply With Quote
  #9  
Old 06-16-2012, 07:08 PM
Diesel911's Avatar
Registered User
 
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 51,041
Quote:
Originally Posted by macdoe View Post
Do not soak your prechambers in CLR.....damn stuff ate the chrome plating off them? They must be made of copper or something that color...2 stayed normal and are really clean but three of them are now a copper or bronze color. I hope they will still work? They look brand new except the color change.
The below info is from one of our members:
Prechamber Material, Precombustion Chamber Material
Mercedes uses Nimonic 80A for the prechamber.
That information and figure come from an SAE paper published by Mercedes titled "The Turbocharged Five-Cylinder Diesel Engine for the Mercedes-Benz 300SD".

So the Prechamber is not plated. The acid just discolored them.

Copper Color is not the same thing as it actually being Copper

__________________
84 300D, 82 Volvo 244Gl Diesel
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 10:12 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2024 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page