Using GM's EOS after breakin?
Thread Starter
Race Director
Joined: Sep 2002
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From: San Diego - Deep Within The State of CONFUSION!
Using GM's EOS after breakin?
I've built lots of motors and often used EOS for cam breakin. The blueprinted stroker in my Vette now is actually, the very first motor that I've PAID somebody to build for me. It's an all forged Eagle bottom end with H-Beam rods, file-cut rings and 10:1 pistons ... yada yada yada.
The reason I used a local hot rod shop for the engine build was because I wanted a stroker and had never built one myself - and at the time, I had the $$ which helped.
Now four years and 20K miles later, I'm tempted to put EOS in it, with this week's oil change. Not for any reason other than summer heat and that it tends to ping when I run the a/c ... and no other time. I know the supplement wont change AC ping (nothing else has, so far) but I figure that it sure can't hurt. Is this stuff _JUST_ a 'breakin lube,' or is it really a good oil supplement too?
This is also my first stroker motor so I'm still not used to the bottom end noise when it's cold and I'm wondering if EOS may help that?
The reason I used a local hot rod shop for the engine build was because I wanted a stroker and had never built one myself - and at the time, I had the $$ which helped.
Now four years and 20K miles later, I'm tempted to put EOS in it, with this week's oil change. Not for any reason other than summer heat and that it tends to ping when I run the a/c ... and no other time. I know the supplement wont change AC ping (nothing else has, so far) but I figure that it sure can't hurt. Is this stuff _JUST_ a 'breakin lube,' or is it really a good oil supplement too?
This is also my first stroker motor so I'm still not used to the bottom end noise when it's cold and I'm wondering if EOS may help that?
Race Director
Joined: Nov 2000
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From: Waterloo ontario Canada
Funny you use EOS for breaking in the cam and yet my new Eagle rotating assembly instructions warn not to use EOS or anything else for proper piston breakin??? So if I want to save the cam I am to use EOS and yet to save the pistons and allow proper breakin I am NOT to use EOS??
Very confusing.
As for using it later how can it hurt???
I would also use the shell rotella diesel oil with it's added Zinc and phosphate protection.
Very confusing.
As for using it later how can it hurt???
I would also use the shell rotella diesel oil with it's added Zinc and phosphate protection.
Le Mans Master
Joined: Jul 2005
Posts: 5,752
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From: Austin Texas
EOS is not recommended for use after break-in. I switched to a oil with higher Zinc content (Rotella) after the rash of cam lobe failures earlier this year. The noise you hear when the engine is cold is probably the forged pistons knocking a little in the bores, a harmless sound which usually quiets down when warm.
Thread Starter
Race Director
Joined: Sep 2002
Posts: 10,362
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From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by norvalwilhelm
Funny you use EOS for breaking in the cam and yet my new Eagle rotating assembly instructions warn not to use EOS or anything else for proper piston breakin??? So if I want to save the cam I am to use EOS and yet to save the pistons and allow proper breakin I am NOT to use EOS??
Very confusing.
As for using it later how can it hurt???
I would also use the shell rotella diesel oil with it's added Zinc and phosphate protection.
Very confusing.
As for using it later how can it hurt???
I would also use the shell rotella diesel oil with it's added Zinc and phosphate protection.
Yes it is confusing. AS for oil, I use the same as I've been using since I was a kid in the Phoenix Desert: Valvoline Racing Oil 20w-50
Valvoline's VRG has high zinc content also and in decades of hot rodding I've never had a failure yet. Admittedly most of those years we still had zinc in our oil.
But Valvoline Racing Oil has never let me down yet and I'm not about to change now!
Thread Starter
Race Director
Joined: Sep 2002
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From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by big_G
EOS is not recommended for use after break-in. I switched to a oil with higher Zinc content (Rotella) after the rash of cam lobe failures earlier this year. The noise you hear when the engine is cold is probably the forged pistons knocking a little in the bores, a harmless sound which usually quiets down when warm.
I wonder if that Rotella is cheaper than my Valvoline Racing Oil - it's sold by the gallon, right?
I'd still have a hard time changing from Valvoline though. Wow I have been using it for a looooong time.
And the hot rod shop here in town that built the motor, said to use it too. So that was a good enough reason for me to continue.
Thread Starter
Race Director
Joined: Sep 2002
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From: San Diego - Deep Within The State of CONFUSION!
Originally Posted by stingr69
I suspect that EOS is hard on catalytic converters over time so if you are still using a cat, you might not want to use more EOS than nessesary.
-Mark.
-Mark.
Le Mans Master
Joined: Sep 2001
Posts: 7,739
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From: Unreconstructed, South Carolina
Originally Posted by SanDiegoPaul
I wonder if that Rotella is cheaper than my Valvoline Racing Oil - it's sold by the gallon, right?
Last edited by jackson; Aug 8, 2006 at 10:50 PM.
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