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"How To' notes on cylinder boring machine work

Started by SUPERTUNE, November 06, 2019, 12:00:31 AM

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SUPERTUNE

There were a lot of posts lost out on this subject with the passing of the old forum.
Here is a post of a recent discussion.

http://www.2strokeworld.net/forum/index.php?topic=1112.0 
RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

SUPERTUNE

#1
What prompted this was a Daytona Special rebuild that had some issues with not getting the carb jetting correct, head work, ignition timing, etc, ect, and suffering detonation of the pistons from not being setup correctly.

Bore work was done by a local shop. It can be a hit or miss for a lot of customers.

This cylinder was poorly done as they started boring it .002 in. too big and then stopped, reset the cutting bit and then bored all the way through, still boring it too big for cast pistons also...









So it can be a hit or miss for local machine work being done on these 2 stroke cylinders.

Very specialized equipment should be used and someone familiar with using this equipment.

In these next pic's I'll show some close up of the machine work that was poorly done.
Note how you can see the tooling cutting marks in the cylinder...a simple low pressure 40 psi glass beading of the walls will reveal the work under the poor honing that was almost nonexistent.



RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

SUPERTUNE

#2
I might have been able to slightly hone it for some of the scratching of the walls, but the job is bored too big, so no room to be able to save this .75mm over bore.
So in my Rottler Boring bar it goes... to bore up another size, all the while I'm very nervous if it was even bored straight to begin with. (Another problem I always encounter from poor boring equipment and/or lack of skills.)






Video of me running the Rottler Boring Bar on these Daytona Special 2V0 cylinders.


https://imageevent.com/supertune/rd400enginebuildpics?p=75&n=1&m=-1&c=3&l=0&w=4&s=0&z=3

https://imageevent.com/supertune/rd400enginebuildpics?p=76&n=1&m=-1&c=3&l=0&w=4&s=0&z=3

Here is a few pics of the finish that the Rottler gives me...it's very good and I do bore about .003 to .0035 undersized to have honing room to get the proper finish and piston to wall clearances with my Sunnen special honing stones and .0005 tenths dial bore gauge.





In this last pics of the 2 sets of cylinders (1 set RD350's and the Daytona 2V0's) I bored today you can see exactly how close on tolerance I can do with this Rottler by looking at how they are all perfect in size with the pistons are sitting in the bores before honing.  :righteous:

Chuck
RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

Hawaii-Mike


RustyRD

Hey.  Those look familiar.  At least they have my name on them :whoop: :whoop:

SUPERTUNE

Quote from: RustyRD on November 06, 2019, 08:12:28 PM
Hey.  Those look familiar.  At least they have my name on them :whoop: :whoop:
You have a perfect name that was like these cylinders were... RustyRD!  :wave:
Speak to you soon Russ.
C
RD machine work, boring, porting, cranks and engine building.


Chuck 'SUPERTUNE' Quenzler III
Team Scream Racing LLC
1920 Sherwood St. STE A
Clearwater, FL. 33765
cqsupertune@tampabay.rr.com

RustyRD

 :umm: I will take that as a compliment :whistle: I am looking forward to the end product. I am sure the cylinders will run great.