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Old Dec 12, 2011, 09:38 PM
Cox Engine Hoarder
Jason_WI's Avatar
Neenah, Wisconsin, United States
Joined Jun 2004
570 Posts
Question
HB 61 PDP Blitz ring installation

Any tips for installing the wafer thin PDP 61 Blitz ring with out breaking it? I already broke one as I was fitting it around the the piston.
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Old Dec 12, 2011, 10:03 PM
"Unnecessary Necessity"
coriolan's Avatar
Canada, QC, Quebec City
Joined Sep 2006
5,917 Posts
Mecoa has that nice "how to":
http://www.mecoa.com/faq/rings/install/install.htm
for this and many other things:
http://www.mecoa.com/faq/index.htm
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Old Dec 13, 2011, 11:01 AM
-insert witty saying here-
Hemikiller's Avatar
United States, CT, Killingworth
Joined Dec 2005
1,920 Posts
The method on the MECOA site is what I have always used. Interestingly, I recently found a copy of the Saito 4-stroke book by RCM and the author, Graham Rice warns against it. He says it will twist the ring and cause sealing problems. His method is to use your thumbnails and stretch the ring out around the piston, similar to what an automotive piston ring tool will do.

http://www.sears.com/shc/s/p_10153_1...u=SPM214233129
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Old Dec 14, 2011, 01:26 AM
Cox Engine Hoarder
Jason_WI's Avatar
Neenah, Wisconsin, United States
Joined Jun 2004
570 Posts
I got the ring on with out breaking it this time. I think it may have been damaged before I even tried to install it as it was in a sealed plastic bag without any cardboard backer to support it.

Now the question should I removed the glaze on the cylinder liner? I believe this is chromed as it is the Blitz version of the engine. Usually one doesnt want to touch a chromed liner with any type of abrasive.

Jason
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Old Dec 14, 2011, 02:22 AM
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Sweden
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I don't think there is any formation of glaze on a chromed cylinder bore. A glazed surface is something that appears on steel surfaces after long running.
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Old Dec 16, 2011, 02:06 AM
TigreJohn
United States, CA, Corona
Joined Aug 2008
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Glazing is basically the elimination of all machining and honing scratches in the liner (mirror finish). The original scratches (supposedly controlled) are there initially to help a new ring match the walls of the liner faster (breaking the motor in) And they are impossible to avoid in the machining process. The ring while it still has pressure eventually polishes out the scratches (glazing). If you put a new ring into a "glazed" liner, it will take forever and a day to "break-in".

Chrome does wear and will polish (glaze), albeit slower than steel, but it is softer than carbide or diamond. Best practice on a ring replacement is to prepare the liner with 600 grit (or finer) to scratch (and remove any varnish from castor oil containing fuels) from the cylinder. Do not scratch up & down, do it radially. Have fun.
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Old Dec 16, 2011, 10:19 AM
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Sweden
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To me the word "glazing", when used in connection with steels, is describing the hardening of the surface that can occur to iron and steels (intentionally or unintentionally). It is this hard surface that one should scratch or score a little before installing a new ring.

This hardening will not happen to a chromed surface, and I cannot see any reason to scratch the already thin chrome layer.
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Old Dec 17, 2011, 01:41 AM
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Belgium
Joined Aug 2004
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Here are some honing devices that I do use. They do come in different sizes.
As you can see the first type consists of tiny balls like a wine grape. Also one can choose the grit size. The second version consists of two or tree spring loaded grit stones, these in fact made for honing brakes. Both types are held in a drill or mill and one does move the cylinder up-down-up-down etcetera and adding oil from time to time.
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Old Dec 17, 2011, 03:49 AM
TigreJohn
United States, CA, Corona
Joined Aug 2008
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Quote:
"This hardening will not happen to a chromed surface, and I cannot see any reason to scratch the already thin chrome layer."

Irrelevant. I have yet to see a current expanding ring engine, small or large, that uses a plated (with whatever) cylinder/liner. Typically, plated liner engines are the lapped piston type. No need to scratch a plated liner, you buy a liner and piston as a set.
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Old Dec 17, 2011, 02:33 PM
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Sweden
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Quote:
Originally Posted by jjkupinski View Post
Irrelevant. I have yet to see a current expanding ring engine, small or large, that uses a plated (with whatever) cylinder/liner.
Then perhaps you should read the earlier parts of this thread:

"Now the question should I removed the glaze on the cylinder liner? I believe this is chromed as it is the Blitz version of the engine."

That is the text that I first replied too.
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