Blow By... Front main blown again.

Chevy1925

don't know sh!t about IFS
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I'd get concerned about anything over 25-30%

I wonder if 400 miles just isn't enough to seat the rings? Maybe needs a few hundred miles towing a few thousand pound trailer to help them seat?

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Constant rpm is not the best idea to set rings.

I'm more curious on ptw clearance, ring gap, oil pump he's using, rpm he's turning, compression ratio and injector size.

I have a feeling he has a few things not helping the cylinders seal up
 

LBZ

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Constant rpm is not the best idea to set rings.

I'm more curious on ptw clearance, ring gap, oil pump he's using, rpm he's turning, compression ratio and injector size.

I have a feeling he has a few things not helping the cylinders seal up
Don't recall saying anything about constant rpm. Just increase the load on the engine via pulling a heavy trailer.

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Chevy1925

don't know sh!t about IFS
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Don't recall saying anything about constant rpm. Just increase the load on the engine via pulling a heavy trailer.

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i know, but you also didnt say anything about not staying at a constant RPM. i was just adding to your post. guess it kinda looked like i was trying to tell you about constant RPM :D
 

DMAX497

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Sep 27, 2012
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Truck runs in the upper 3-4K + rpm life... Injector is about 350% over according to flow sheet.

Don't know what oil pump is in it. Nor the ptw or gap. Thought ptw was built into the piston from MAHLE?
 

Chevy1925

don't know sh!t about IFS
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Truck runs in the upper 3-4K + rpm life... Injector is about 350% over according to flow sheet.

Don't know what oil pump is in it. Nor the ptw or gap. Thought ptw was built into the piston from MAHLE?

ptw clearance changes as you hone the cyl walls so while mahle may make the pistons a few thousands smaller, that doesnt mean that the machine shop didnt open the cyl up too much and create too much ptw clearance.

the fact you are not getting any blow by out of one side of the engine leads me to believe thats not so much your issue but something is not fully seated or cant get seated. the LBZ engine i just built has 0 blow by even when first started and ran hard but that is on cast pistons and rings for those pistons, yours is a little different setup.

let that engine get up to temp and put some heat into the system, then go playing with it regardless of the heat soak you are worried about. see if things start sealing up then
 

DMAX497

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The motor doesn't have any odd noises or rattle. Just is smooth and just screams!

What oil should I put in it? Good ole delo? Rotella? Non synthetic...
 

Awenta

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Whatever makes you and your motor happy.

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LBZ

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your choice. the oil debate on here gets retarded.
No kidding!!

Changing from different weights or syn to non-syn may make slight changes in blowby, sound or smoke but not major changes and certainly not fix your issue.

What confuses me is why one side and not the other? It's a common crankcase so I'm not thinking rings now. Beginning to think maybe a valve or injector is leaking past in that head.

Leak down test will definitely help you find the source though.
 

duramaxzak

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Nov 22, 2008
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You should never break in a motor with synthetic oil. I have Mahle forged .020" over Pistons in my pull truck and the PVC hose never even has oil residue in it. I'm guessing your rings have not seated yet.
 

DMAX497

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Had Joe Gibbs break in oil for about 250 miles... Then switched to Redline for the last 100 miles... Going to be putting other oil in.
 

LBZ

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You should never break in a motor with synthetic oil. I have Mahle forged .020" over Pistons in my pull truck and the PVC hose never even has oil residue in it. I'm guessing your rings have not seated yet.
Why? The corvette and other vehicles are broken in and shipped with synthetic in them. As long as you change the oil after a 1000 miles or so in a fresh build there is nothing wrong with synthetic oil.
Amsoil says it's fine also.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
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Why? The corvette and other vehicles are broken in and shipped with synthetic in them. As long as you change the oil after a 1000 miles or so in a fresh build there is nothing wrong with synthetic oil.
Amsoil says it's fine also.

There is nothing wrong with synthetic, just not a good break in oil. Way to slick and will usually not let the rings seat in properly.