Lly rebuild

DDiesell

DDiesell

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Oct 24, 2014
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Hey guys. We have an 08 with an lly engine. Owner wrecked his built lly and bought the lmm and swapped engines.

Carrillos
Girdle
Cam
Delipped lb7 pistons
100s
Dual pumps
Danville 66/s480 compounds

Pretty sure it just cracked #7 piston. It will be getting fingers oval bowls.

Question is about the crank. What are our options here? I would hate to put this together and break a crank.
 
DDiesell

DDiesell

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It has a cam. I am not sure what it is. We will know when we get it apart.

But i have seen guys on here saying cranks still break with af cams.
 
P

pizza pig

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Feb 13, 2012
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Even if, the comparison between the failures are on opposite ends of the spectrum. Plus, there has been no real proof of cranks breaking with AF cams, simply hearsay. :thumb:
 
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schulte

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Jul 31, 2010
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Just because someone breaks a crank with an AF cam doesn't mean the AF cam won't solve the widespread issue of breaking cranks, likely due to harmonics. People have broken Carillos; that doesn't mean that Carillos don't fix the issue of breaking rods.
 
DDiesell

DDiesell

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Thanks for the input guys. The truck works great. The truck dynod 768 with a slipping trans and shitty tunes. Now has a new trans and tunes from rob. Pulls harder than it ever has. Last night after a hard run it had a rough idle and serious oil leak. Blew dipstick out. Ccv hoses blew off. Looks like it blew the rear main out. Cylinder 7 glowplug was covered with oil and that cylinder has no compression.
 
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schulte

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Jul 31, 2010
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AF cam seems to be the only solution there is any consensus on for breaking cranks. Some still say that you should start with an LB7 crank instead of anything newer.

A good used crank that doesn't need to be polished or a factory new crank to the tune of $900, plus an AF cam, seems to be the best setup.
 
rgullett83

rgullett83

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Oct 27, 2008
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Either through tuning, or changing injector pins at the ecm. I know Kory and fleece can change the firing order through tuning
 
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dirtymax36

dirtymax36

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Apr 11, 2013
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get a new oil cooler and key a new oil pump. As for cranks, my build looks very similar except for pistons, I just went with a lb7 crank with 70k miles and had it all polished up and magnafluxed. I guess we'll see how long it lasts. Definitely an AF cam. The 3388 cams are suppose to be very good on the street and good with vgt's.
 
DDiesell

DDiesell

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dirtymax36 said:
get a new oil cooler and key a new oil pump. As for cranks, my build looks very similar except for pistons, I just went with a lb7 crank with 70k miles and had it all polished up and magnafluxed. I guess we'll see how long it lasts. Definitely an AF cam. The 3388 cams are suppose to be very good on the street and good with vgt's.
Click to expand...
Just read your thread. I would get pistons if I were you. I am pretty sure ours just cracked a delipped lb7 piston. It would suck to have to do it again.
 
NJ_LLY

NJ_LLY

Back in action
Nov 4, 2008
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Why do some stock trucks break the crank in the same spot as 1k hp trucks? GM built millions of these trucks that never break the crank. I believe it's a casting issue. Can't make millions of cranks without a few bad ones.
 
dirtymax36

dirtymax36

2nd place is last
Apr 11, 2013
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DDiesel, I actually used coated race casts .20 over instead of de lipped. I chickened out. I traded dual cp3s for them. Easier to swap out single/dual cp3s versus pistons.

Like Mike said, go cast not forged if its a street truck and you wont have to worry about re-ringing and blow by when its cold and such.
 
J

jkholder09

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Jan 8, 2012
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I have access to street pistons that go 100k. they are armorplated in the top ring which prevents the piston groove from spreading.
The stainless rings will last 100k plus easy.
The pistons are priced very close to the oval pistons.

I am not saying oval bowls are a poor choice.

In my opinion a cast piston is on borrowed time above 800 rwhp.
 
mike diesel

mike diesel

I'm alright.
Sep 6, 2012
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jkholder09 said:
I have access to street pistons that go 100k. they are armorplated in the top ring which prevents the piston groove from spreading.
The stainless rings will last 100k plus easy.
The pistons are priced very close to the oval pistons.

I am not saying oval bowls are a poor choice.

In my opinion a cast piston is on borrowed time above 800 rwhp.
Click to expand...

Have you not research oval bowls? 1300+hp on cast pistons all day long.
 
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