Twins with Twins, Anyone?

Burn Down

Hotrodder
Sep 14, 2008
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Ya had swain tech do em. It's the white TBC.

I haven't checked any others yet, they all look fine at first glance. What's correct way to wipe em down that won't impact the finish so we can inspect?

Second question, how do we safely remove it?

Tks

-K

Cat had us just use brake clean and compressed air, a soft brush can used to gently remove stubborn stuff.
 

2004LB7

Well-known member
Dec 15, 2010
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What about electroplating them with something like nickel? Well it may not reduce heat transfer much it should increase the burn through resistance.

Since the process is quite mature, I would think it would adhere much better than the ceramic/thermo coatings

But I may be way off
 

kidturbo

Piston Tester
Jul 21, 2010
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What about electroplating them with something like nickel? Well it may not reduce heat transfer much it should increase the burn through resistance.

Since the process is quite mature, I would think it would adhere much better than the ceramic/thermo coatings

But I may be way off
Sounds like a question for Fingers. My plan is move onto the monotherm testing, and then this issue is moot for marine application.


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kidturbo

Piston Tester
Jul 21, 2010
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Ok I pulled the studs and spun it over to get a better look at everthing. Some mild scaring on couple cylinder walls, but nothing ya can feel with a fingernail. So that's good.

Here is some as-is pics, and good look at #2 after I wiped top off with alcohol on a smooth rag.

Looks to be mostly in the quench areas, and where nozzle holes was blasting em. Which was my main concern upon assembly. Being it's all sooted over, had me wondering if this all happened on first start up..
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kidturbo

Piston Tester
Jul 21, 2010
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However you can take credit for leaving #2 rocker arm loose if ya want..

Lobe and lifter all good, so calling human error on GM Master Tech Dustin D. Who better get some new feelers off the SnapOn man. LoL...
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2004LB7

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Dec 15, 2010
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However you can take credit for leaving #2 rocker arm loose if ya want..

Lobe and lifter all good, so calling human error on GM Master Tech Dustin D. Who better get some new feelers off the SnapOn man. LoL...
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Looks like maybe a paint stirrer was used as a feeler gauge

What gap where you shooting for? Spec is supposed to be 0.012". The last one I did I set them to 0.011" and it was probably the quietest and smoothest LB7 I've heard
 

kidturbo

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Jul 21, 2010
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Ah crap, we had the . in the wrong place. Thought that read 00.12 spec. :roflmao:

We had full intentions to recheck em after the dyno anyways, so I won't bust on him too bad. NASCAR Tech grad, so they taught em to build loose. But a paint stirrer would probably been tighter..
 

rcr1978

Active member
Apr 1, 2007
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That sucks about the coatings guess I know what I will find in mine now :mad:
I don't know what mine was though it was a dull grey color and Randy's machine did them or had them done :confused:
 

kidturbo

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Jul 21, 2010
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This was a dull grey looking on top also, and somewhat malleable to the touch. I even called Swain Tech and inquired about it before we dropped em in. Said that was normal.

I think TBC is pretty solid tech in gas race engine pistons. However they don't have a 30k psi 7 hole Waterpik head setting half inch away trying to blast the chit off. Nor run the cylinder pressures or heat of these diesels.

And it's not constant pitting on every piston either. #4 piston just has a few specks around the edges. I wanta here more of Jon's input on this before making a final decision on action. Nothing in the surrounding area seem to be effected by it. And I do have two engines to compare..
 

LBZ

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Jul 2, 2007
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Personally if I ever build another engine I’m planning on just polishing the top to as smooth of a finish as possible and that’s it.

I’ve seen some coatings last but I remember most sets over the years never made a race season amongst the folks I know.
 

Stingpuller

The Pusher Man
Jan 11, 2007
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Good ol Duramax

Looks like you might want to open up the ring gap a little. I never liked the coatings on a gas motor or otherwise. Isn't performance motors so fun. lol