Another LT5 build wohoo!!

[oricale]

So,... I had an engine that was offered to me, & I didn't initially want to take it on because I have a spare built engine already,... However you can never have too many LT5's available ....anyway got home last night at around 6:30...and had to see what was inside....OMG....it was a goddam nightmare!!..I have found #8 piston cup/rod.mount destroyed and a few bolts (which was the start point of the damage) pics coming; )

[Dynomite]

Originally Posted by oricale

So,... I had an engine that was offered to me, & I didn't initially want to take it on because I have a spare build engine already,... However you can never have too many LT5's available ....anyway got home last. Igh at around 6:30...and had to see what was inside....OMG....it was a goddam nightmare!!..I have found #8 piston cup/rod.mount destroyed and a few bolts (which was the start point of the damage) pics coming; )

Not sure I want to see the pictures
I do know what you are talking about however

Kind of like the Registry web site issues at the moment......frustrating.

[oricale]

Here's a few pics:

[oricale]

So after tearing the engine down to the block itself, I've came to the conclusion on the past rebuild of this engine that: #1: no gaskets are used, different types of sealant were used in place of required gaskets) #2: no thread lock was used.. ( there are various points in this engine that thread lock is mandatory, one of them being the oil pan baffle bolts(which happen to be the three bolts bouncing around in the engine cavity- lodging one of them into number 8 piston under / rod mount shattering it.. however, it is not all bad news, even though there is enough metal shavings and pieces sloshing around inside the engine-to build another engine, the liners one through seven are good, and no damage to heads or anything else, although I will have to clean up and machine the cavity of the block due to the popcorn effect of 100's of little prices of metal and aluminum bouncing around the cavity of the engine.

I just remembered I will find another little treasure trove of metal in the oil filter!!

[oricale]

I have been asked if I'm going to build this engine for myself or to sell,... At this point I'm building for myself, however if someone needs an engine..and has the money to buy it I can build and powder coated for them. Currently my plan is to build this stock - ported, powder coated a bright crinkle red with black writing. And do some other little details as well like eliminating secondaries eliminating water through the throttle body or the plenum. solid NO- weak link strong engine.

[oricale]

A few more pics:

[efnfast]

What a mess. Somebody needed Jerry's phone number.

[vilant]

I know where that came from Was curious how was bad it was, and it's worse than I thought. That was a "professional" mechanic's shop that did the rebuild too, if I'm not mistaken.
That's awesome that you're going to do bring it back right. Would love to see pics of it when you're done. Hope the rest goes smoothly for you

[WARP TEN]

Originally Posted by vilant

I know where that came from Was curious how was bad it was, and it's worse than I thought. That was a "professional" mechanic's shop that did the rebuild too, if I'm not mistaken.
That's awesome that you're going to do bring it back right. Would love to see pics of it when you're done. Hope the rest goes smoothly for you

Oricale since you have no axe to grind with the original rebuild shop, I wonder if you planned to share your findings with whomever the owner of that shop is? Might help him if he ever gets another to rebuild, and therefore save a potential Z buyer from disaster. I do love the picture with the bolt stuck in the valve. Priceless. Just a thought--Bob..

[oricale]

When it comes to other shops...I ONLY state what I found during the tear down investigation....obvious things are clearly an issue. Small.things like thread lock in this is situation almost destroyed this engine. When I tore down Yun's engine and documented what I found. I did my normal procedure of pics and documentation and go.from.there. his build issue was a popped plug, head clearence issue and possible torque values. IMHO : follow tech data and don't bend corners...not with an LT5.. using wrong sealant. No Gaskets. Bolts in wrong locations, and lack of thread lock in required locations Can lead to major issues...

Bob. As for the findings. It was simple things that led to.major issues...some were active some didn't effect.

Sealant in place of gaskets:... aside from the obvious issues with using sealant as opposed to gaskets many of the bolts that held water sleeves and IH's or corroded due to insufficient sealing .

Incorrect bolts in locations throughout the engine, and torque specs not followed in major locations: in certain locations within the motor different bolts were put in wrong locations, while this had no bearing on the failure of the engine it is to be noted as part of the attention to detail.

Minimal use of thread lock throughout build:with the rebuild of this engine was done with only 4-5 bolts thread locked, the first thing I noticed upon dropping the pan was three bolts missing, I initially thought is just another oversight then looked inside of the cavity and saw all the damage and immediately assumed bolt head became loose. ( during tear down I found numerous bolts in the lower end of the assembly, the remaining baffle bolts were finger tight only)

Bolt in the exhaust valve, and plastic coupling in the secondary: I do not feel this was done during the rebuild I think this was done during the removal process of the engine, however the plastic coupling in the secondaries was covered in fuel and seemed as it was in place for a while there by keeping the secondaries open at all times, not a source of failure in this engine.

Major findings from this tear down,... The personnel who rebuilt his engine while a good mechanic, may not have utilize the correct technical data or torque values required to build these engines correctly, everything that has to do with standard engine building - (bearing /crank/cams ect) - seem to be inherently correct,failure to use thread lock in all of the correct locations was the biggest contributor.

(As far as telling the shop)...I'm sure if he reads this, he will see the small errors and will fix it next time, no need for me to speak to them..im.sure they are good what they do...these things happen.