Well I can only offer advice based on my limited experience with these
things, torque plate for best results, at your discretion...
Another point to consider may be how close you are holding tolerances. If you
are measuring to thousandths, .0005 is no big deal.
Of course if the engine doesn't see the far side of 5k often, this is not as
critical.
Re the piston coating, it seems to be 5-7 tenths per side so you will pick up
.001-.0015 in diameter (polymer dynamics HoustonTx).
An engine-machinist friend of mine did try coating a set of pistons to make up
clearance, can't remember the number, but it was a huge failure. I honestly
don't know what the limit is.
One of the advantages of having the skirts coated is that you can run less
clearance, but I still shoot for at least .004.
Glen
-----Original Message-----
From: toodamnfunky <toodamnfunky@comcast.net>
To: fubog1 <fubog1@aol.com>
Cc: fot <fot@autox.team.net>; tr4racing <tr4racing@googlemail.com>; johnstydo
<johnstydo@gmail.com>
Sent: Tue, Sep 11, 2012 5:06 pm
Subject: Re: [Fot] Never be beaten by equipment
In the past I've just honed them in the block with an oversized washer on a
head stud to hold em down.
If that's the wrong proceedure I'm still not to old to learn.
On another note, I just spoke to Calico coatings and they say they can put
anti-friction coating on
used pistons and put it on a little thicker to make up clearances. How thick I
don't know but interesting info
anyway.
jimg
From: "fubog1" <fubog1@aol.com>
To: tr4racing@googlemail.com, johnstydo@gmail.com
Cc: fot@autox.team.net
Sent: Tuesday, September 11, 2012 2:57:01 PM
Subject: Re: [Fot] Never be beaten by equipment
87mm (3.425). I usually use BFEs LA Sleeve liners, they are pretty stout
compared to stock liners but still need a torque plate hone IMHO.
Glen
-----Original Message-----
From: tr4racing <tr4racing@googlemail.com>
To: fubog1 <fubog1@aol.com>; johnstydo <johnstydo@gmail.com>
Cc: fot <fot@autox.team.net>
Sent: Tue, Sep 11, 2012 4:46 pm
Subject: AW: Re: [Fot] Never be beaten by equipment
At what bore size?
Gesendet mit BlackBerry von Vodafone
From: fubog1 <fubog1@aol.com>
Date: Tue, 11 Sep 2012 16:45:10 -0400 (EDT)
To: <tr4racing@googlemail.com>; <johnstydo@gmail.com>
Cc: <fot@autox.team.net>
Subject: Re: [Fot] Never be beaten by equipment
Well not to start a controversy, but I have one on the bench right now,
torqued down and ready to go, and the mics don't lie.
The liners tend to waist down around the lower register.
Glen
-----Original Message-----
From: tr4racing <tr4racing@googlemail.com>
To: fubog1 <fubog1@aol.com>; johnstydo <johnstydo@gmail.com>
Cc: fot <fot@autox.team.net>
Sent: Tue, Sep 11, 2012 4:26 pm
Subject: Re: [Fot] Never be beaten by equipment
We did a lot of testing with torque plate and we found NO difference with or
without.
Gesendet mit BlackBerry von Vodafone
-----Original Message-----
From: fubog1 <fubog1@aol.com>
Date: Tue, 11 Sep 2012 16:21:56
To: <johnstydo@gmail.com>
Cc: <mmoore@wave1.net>; <jhhasty@gdhs.com>; <tr4racing@googlemail.com>;
<fot@autox.team.net>
Subject: Re: [Fot] Never be beaten by equipment
The other point that should be mentioned is that these liners should be
honed
using a torque plate.
They get out of shape once they are clamped down in place.
FWIW I use JE pistons and set them at .004, usually with coated skirts as an
added insurance policy against scuffing.
Glen
-----Original Message-----
From: John Styduhar <johnstydo@gmail.com>
To: fubog1 <fubog1@aol.com>
Cc: mmoore <mmoore@wave1.net>; jhhasty <jhhasty@gdhs.com>; tr4racing
<tr4racing@googlemail.com>; fot <fot@autox.team.net>
Sent: Tue, Sep 11, 2012 2:42 pm
Subject: Re: [Fot] Never be beaten by equipment
My math shows that MadMarx is running .005" piston to wall clearance
(.13mm/25.4
mm/inch=.005. Wiseco's suggested clearance for their forged 87mm slugs is
.004,
but others (BFE) have recommended .006, which is what my machinist is honing
to.
On Tue, Sep 11, 2012 at 1:16 PM, fubog1 <fubog1@aol.com> wrote:
I'll try this again, my reply had too much text.
The manufacturers will call out a recommended clearance, but that's all it
is.
The operating speed, temperatures, cooling systems etc all are variables.
Generally the harder it is run, the more clearance it needs.
Also pistons can scuff during warm-up, under certain conditions, so it's a
good thing to get it up to temp before flogging it hard.
Glen
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