forged 346 going to heaven & i'm in hell
Thread Starter
Teching In
Joined: Mar 2005
Posts: 24
Likes: 0
From: ohio
forged 346 going to heaven & i'm in hell i started building my short block early spring with new forged internals-the machine work was done by a local machine shop - it was the only one i could find in the area that i thought i could trust-what a bad idea-he did the align honing,boring,polishing crank,ect.- i put my short block together in the shop where i work- to try to save some money-everything went so smooth that i could hardly believe it-i used prc 2 1/2 heads with ms3 cam- the car ran fine -great up to 800 miles- after that i lost oil pressure -for no reason-i was still breaking in my engine not going over 3000 rpm-i took the oil pan down at home & i found out that number 4 cam bearing backed out-i called the machine shop-he said he did not believe me that he even put lock tight on.-pulled the engine took the short block to him & sure enough no lock tight on the bearings- he said he would stand behind his work-installed new bearings,bought new gaskets and he assemble my long block-everything was fine after 300 miles i blew my dip stick tube out-i have a very high blow by=machine shop said thats normal & will disapear after a 1000 miles= 1300 miles i dyno'd 441 horse & 406 torque with a steady 12.6 a-f -i was very pleased with the power but i have so much blow by now oil is spraying out from the dip stick tube -when i removed the oil cap smoke came out and i could feel the pressure coming out from the crank case -i did a leak down test #7 84% the rest 30% -i want to know if any knows what is happening ?s there anyway to check out the short block work? any suggestions?
I'd take the car to his shop and show him what is happening. Obviouslly the ring in #7 looks shot and 30% on the others is horrible. Leak downs should be under 10% to pass. This is why I only trust people who build these motors everyday to do short block work.
Originally Posted by Beast96Z
I'd take the car to his shop and show him what is happening. Obviouslly the ring in #7 looks shot and 30% on the others is horrible. Leak downs should be under 10% to pass. This is why I only trust people who build these motors everyday to do short block work.
Joined: Nov 2001
Posts: 3,043
Likes: 0
From: Texas and Qatar
84% is a ton of leakdown and 30% is not any better! I overheard you on the phone the other day asking for tech help from Brian. Sadly I think you need to tear it down and document how you find everything (cylinder wear pattern, ring gaps and locations). Probably needs new rings, I don't think it would have hurt the pistons, but won't know until you see them.
fyi, you dont break in these engines, if it is built with precision like a ls1 should be the best way to seat the rings with todays fine cylinder hones is to beat the crap out of it shortly after running the car, bearings should not need to wear in if the motor is assembled correctly. some people agree with this some dont, most of the people around here that know crap about ls1's will tell you the same thing. ive seen proven tests to support this. 
however this wont help you till you get the machine work properly in the first place
good luck
however this wont help you till you get the machine work properly in the first place
good luck Trending Topics
TECH Junkie
Joined: Aug 2002
Posts: 3,726
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From: Fort Collins, CO
Originally Posted by SMOKIN01TA
fyi, you dont break in these engines, if it is built with precision like a ls1 should be the best way to seat the rings with todays fine cylinder hones is to beat the crap out of it shortly after running the car, bearings should not need to wear in if the motor is assembled correctly. some people agree with this some dont, most of the people around here that know crap about ls1's will tell you the same thing. ive seen proven tests to support this.
however this wont help you till you get the machine work properly in the first place good luck
however this wont help you till you get the machine work properly in the first place
good luckLS1 Tech Stories
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Originally Posted by KingCrapBox
Unless you have a STF valvetrain, the break-in time on all engines is pretty small. Most engine builders generally recommend you keep the RPM low for a few minutes, and then when nothing has blown up, hammer away.
I beat the **** out of my motors right off and they have held up great. Exact machine work is a necessity on lsx motors. I wouldn't let that guy tear it apart. People never admit fault on their own work from my experience. Pull it apart yourself and document everything with pictures.
Daves Engine Machining in Newark,CA. did my block (align-deck-crank-balance), the works. I assembled it. They did tell me "Do not break it in with synthectic oil because the rings will not seat properly". These people build race LS1's everyday. In house engine dyno. Could be just my rings (Mahle) and the hone I dont know.
Thread Starter
Teching In
Joined: Mar 2005
Posts: 24
Likes: 0
From: ohio
here is my update -i dropped my engine last weekend,took the heads off and made a horrible discovery -my cylinder head looked like a bomb full of bolts had gone off -my piston doesn't look much better. 
the ring land is broken-why i had know idea at first-i am a mechanic not an engine builder -i really wanted to get a professional to check out my engine block -so i drove to Kentucky to see Brad at ForceFed -Sunday afternoon i met Brad at his shop- the general diagnois -looks bad- Tuesday he called me with the bad news- my engine is trash-on top of the cylinder being messed up -my ls1 block was not machine correctly -if i understand it right the top and bottom were tighter than the center -which caused the rings to flutter -massive blow by- and i wanted a little bit over 11 to 1 compression -my machine shop called Texas Speed for the milling specs 30ths -Brad told me that head was milled 50ths -my machine shop totally screwed up-i have only 2000 miles on the forged engine 
NOW I HAVE NOTHING -i called the machine shop -he is a hard headed guy-he told me he machine everything correctly & that i blew it up -that i detinated -if this is true it would be because he milled the heads incorrectly which would take me over 12 to 1 compression-i don't know what to do now - any suggestions????? here are some photos...[img=http://img6.imageshack.us/img6/8641/p10101769vy.jpg]
[img=http://img6.imageshack.us/img6/5011/p10101818tm.jpg]
the ring land is broken-why i had know idea at first-i am a mechanic not an engine builder -i really wanted to get a professional to check out my engine block -so i drove to Kentucky to see Brad at ForceFed -Sunday afternoon i met Brad at his shop- the general diagnois -looks bad- Tuesday he called me with the bad news- my engine is trash-on top of the cylinder being messed up -my ls1 block was not machine correctly -if i understand it right the top and bottom were tighter than the center -which caused the rings to flutter -massive blow by- and i wanted a little bit over 11 to 1 compression -my machine shop called Texas Speed for the milling specs 30ths -Brad told me that head was milled 50ths -my machine shop totally screwed up-i have only 2000 miles on the forged engine NOW I HAVE NOTHING -i called the machine shop -he is a hard headed guy-he told me he machine everything correctly & that i blew it up -that i detinated -if this is true it would be because he milled the heads incorrectly which would take me over 12 to 1 compression-i don't know what to do now - any suggestions????? here are some photos...[img=http://img6.imageshack.us/img6/8641/p10101769vy.jpg][img=http://img6.imageshack.us/img6/5011/p10101818tm.jpg] 
I can understand and would agree inaccurate machining.... but you couldn't HEAR that happening? Were you not monitering your dyno pulls w/some type of software to show you what you weren't hearing?
Not trying to be a dick, but damn it man.
That sucks hard. I'd be having a documented secondary shop's oppinion/diagnosis w/a certified letter of demand hand delivered/signed for to the shop that built that abortion.
If he isn't readily willing to nut up..... get an attorney..... yesterday.
Good luck bud-
Not trying to be a dick, but damn it man.
That sucks hard. I'd be having a documented secondary shop's oppinion/diagnosis w/a certified letter of demand hand delivered/signed for to the shop that built that abortion.
If he isn't readily willing to nut up..... get an attorney..... yesterday.
Good luck bud-