If I had just remembered this stuff before I'd have had another ten
pages
for my book. I used chrome rings in my TR-4 engines and found that lapping
them in first saved a lot of breaking time on the dyno and always gave a
higher power number and a lot less blowby and early loss of pressure. My
system is not fun to do but here is how I did it successfully for lots of
years & engines:
With the pistons you are going to use fit all the rings making sure to
already have the end gap checked. Fit the correct rod.
Then lay out four pans that will hold about a quart of your favorite
cleaning fluid.
( I used lacquer thinner cause it was there and no one was lighting
fires
in the shop)
Mount the sleeve in a fixture to hold it .
(such as easy gripping in the vise)
Make up a thin paste of kerosene and Bon-Ami ( yup, the old time
cleaning powder) The paste should be about the consistency of cold 50
weight
motor oil.
Apply a lite coating to the rings of the piston that matches the sleeve
in
the vise, and a lite smear to the bore of the sleeve
Fit your ring compressor to the rings just as normal.
Fit the piston into the sleeve and give it ten strokes , one up and two
down and so on.
Remove the assembly from the sleeve, carefully remove the compressor and
ABOVE ALL, DO NOT TAKE ANY OF THE RINGS OFF THE PISTON. DO NOT DISTURB
THE RINGS.
In the first pan of cleaner use a small paint brush to start cleaning
the paste off the piston and the rings. After the worst is removed go to
the
second pan, DO NOT TRY TO MOVE THE RINGS. Work with a brush again to clear
the paste residue.
Now go to the third pan and very carefully by gripping the ring away
from
the ends move it slightly and a little more and a little with the head of
the piston submerged in the liquid more until the ring is free to turn
easily. Do one ring at a time, this is not the time to be lazy.
On the the last pan of fresh cleaner. Move the rings as above several
rotations on the pistons making sure there is no gritty feeling.
Now that the pain part is over, wash in hot soapy water and blow dry and
immediately coat with WD-40 or similar type oil. Do not try to remove or
bend
the rings or pull on the ends.
You will see a fine grey line on the top edge of the rings showing that
they indeed are lapped into the bore. Not only that the rings are ROUND.
(keeping them round after the lapping is why you don't want to carelessly
try to move them too soon while cleaning.)
Wash the sleeve in the same manner, you can eliminate a couple of the
cleaning steps as there is no finesse involved,. Finish though with soapy
water and blow dry and coat with lite oil. Both the piston assembly and
the
sleeve should be immediately put into a plastic bag or sack to keep clean
and
dust free until time of assembly. Remember each piston has it's own sleeve
and should not be changed out to another part.
Clean the ring compressor some before starting on the second piston
assembly.
When fitting to the engine just a lite oil on the rings and bore, finish
up and stand on the gas after about four or five minutes.
Done in this manner my rings lasted longer than any other method and
gave
the best perforce all round.
I did make up a torquing plate for the dry blocks and did everything in
much the same manner. My torquing plate was made of 1" thick mild steel.
----- Original Message -----
From: "Bill Babcock" <BillB@bnj.com>
To: "Joe Curry" <spitlist@cox.net>; <N197TR4@cs.com>;
<fot@autox.team.net>
Sent: Monday, February 09, 2004 3:47 PM
Subject: RE: 86 MM Chromium Rings-Help
> They can be great if you install and break them in correctly. This is
all
> bike experience, but it should be proper for wet sleeve engines. You
need a
> really good hone job with the cylinder under normal clamping pressure.
This
> means an adapter top and bottom to distort the cylinder as it will be
under
> torque. You might get away without this since the beam strength of a
triumph
> head and the block might be high enough for the four bolt clamping
zones
to
> not distort the cylinder, but I doubt it.
>
> Once it's honed, while it's still clamped at torque, you use a dummy
piston
> and rouge to lap the rings in. Takes about ten minutes of lapping per
> cylinder. You're looking for a continuous dull line with no bright
gaps.
> Once they are lapped you absolutely don't want to confuse either the
> cylinder you lapped them in to or their order on the piston.
>
> Then break them in by slamming them against the cylinder. You do this
in
a
> relatively low gear so you're not bogging the engine, quickly
accelerate
to
> near redline and abruptly shut the throttle, coast to about 2-3000
RPM.
Do
> that a couple of times and Bob's your uncle.
>
> Works perfectly on a bike engine. In fact it's the only way to build a
> racing engine for a motorcycle since it's going to live at redline for
it's
> entire life brief life. I can't think of a bike engine that doesn't
use
> chrome rings.
>
> -----Original Message-----
> From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On
Behalf
> Of N197TR4@cs.com
> Sent: Monday, February 09, 2004 2:49 PM
> To: fot@autox.team.net
> Subject: 86 MM Chromium Rings-Help
>
> FoT,
>
> What is your input on Chrome Piston Rings?
>
> Application: Street Use Only.
>
> I have a set of 86MM Liners and AE chromium rings.
>
> What is your feedback on Chromium vs. Cast Iron.
>
> What is the best break in procedure?
>
> TIA
>
> Joe (A)
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