LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

383 dead/dying, need opinions on what went wrong.. :-(

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Old 06-20-2008, 09:32 AM
  #16  
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Originally Posted by WS6T3RROR
Good grief, what is with people and wanting tiny *** ring gaps. The area exposed for leaking is almost nill when the rings get hot anyway because the gap closes up. I always gap my stuff on the loose side for recommended street with the 2nd ring gapped wider than the top. Too wide a gap is a minimal loss in power maybe and a fractional percent increase in blowby, too tight is busted ring lands and fractured rings and bad wear. You tell me which is more desirable .

The melted ground strap could just be the plug was too hot for nitrous and you needed to take it a step or two colder for the dope. Did you have a wideband on it at any point during the tuning to make sure it wasnt lean? Some of your issues could probably be fixed by tuning stuff up and swapping parts, but your oil consuption is horrific at least you dont have to worry about bugs in your driveway from all the smoke.

When you pull the bearings the top of the rod bearings will be fubar'ed and nasty if you had bad detonation. It will probably be discolored along the parting line as well. If it was doing it and bad enough the bearing will sometimes flake and transfer material to the journal too.
I agree with this guy on the gaps. I have big gaps and minimal blowby. Small gaps will kill the engine when Nitrous heats up the rings like in all the extra power you made on the dyno -

If you have an extended reach plug that is also not good for Nitrous, you need a recessed tip one, and yeah it may have been too hot.

If you have a couple cylinders out, I would be surprised if oil wasn't getting in there (but you say the compression is good?)
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Old 06-20-2008, 06:51 PM
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Burning oil is a fast way to cause major detonation which does a lot of damage in a hurry.

I would also not call 180psi all that good.

I had a stock 180K b-body LT1 crank 200 and the heads/cam motor cranks just about 230psi.
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Old 06-23-2008, 12:56 AM
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WS6T3RROR-yes the wideband was on during the dyno tuning and the tuner said everything looked almost perfect. Starting to wonder though since he seemed impressed that i made 383hp on motor with my mods while my friend makes 426hp on stock ported heads and small cam like mine.

I was at the girlfriends this weekend but i dont work tomorrow so i hope to do a compression test on the rest of the cylinders tomorrow.
My compression ratio is supposed to be 11:3:1, dunno what that translates to in PSI???

Ill post back asap with results!
Thanks guys, keep the replies comin :-)
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Old 06-23-2008, 09:21 PM
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alright quick update.

Got to do compression check on cylinders 1, 2, 3, 5, 7 the lowest showing 181psi and the rest showing anywhere from 200psi up to 221psi.
The pieces of metal and stuff on the spark plugs was good enough reason to not bother with the rest of the cylinders since its such a major PITA to do.
Started pulling it apart tonight. got the intake ready to come off except i gotta go to the parts store tomorrow and get the plastic fuel line popper-off thingys.
That said, the lifter valley and stuff looks spotless from what i can see so far

Will post pics once i get more of it apart. Gonna try to get the heads off tomorrow if i have time after work.
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Old 06-24-2008, 01:06 AM
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I've heard that there is only supposed to be 10% differance between cylinders. Not sure if thats true but if it is you motor has to much variation between cylinders.
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Old 06-24-2008, 05:48 PM
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Metal on the plugs is a good indicator of problems!
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Old 06-24-2008, 08:35 PM
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hey all quick update.
Got the intake off and driver side valve cover off now. The intake tract on the number 6 cylinder as well as the number 2 cylinder is completly brown/oil soaked. Intake gaskets look good though, didnt see any rips or anything?

Will check more tomorrow if the dentist doesnt torture me too much during the day
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Old 06-24-2008, 11:13 PM
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did you put thread sealer on the rocker studs? maybe its sucking in oil past the studs? could have been the begining of your problems. oil in the combustion chambers isnt good for power either. but your blowby is cause to believe the rings and/or pistons are fubared. my 383 is gapped at .023/.023 for use with alot of nitrous. I seemed to consume bout a quart every 1000 miles or so? but I also had a valve cover leak too. never found any evidence of burning oil. no smoke out the back, no burning oil smell, no chared oil remains on the plugs. so I assumed most of my oil consumption was only from my bad valvecovers that wouldnt seal up. (cheap chrome junk covers that I made worse by gutting them). hurry up and get those heads off damnit. very curious what this will turn out to be. but my official guess will be rings/cyl. wall no good.
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Old 06-25-2008, 11:00 PM
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I wasnt around when the heads were put on and iam doubting they used threat sealer.
As far as the heads coming off, i just got off the phone with a guy who does or used to work for Draime, which is regarded as one of the best engine builders for late model/ dirt and asphalt racing engines.
Basicaly, he said he'd be happy to take it as is (half apart) and completly tear down and fix everything and double and tripple check stuff, do whatever was needed.
I'd trust him to do it as opposed to me since ive never had to completly tear down anything worth this much $$$ before and i dont really want a $14k learning experience, get my drift? Also, most of my tools seemed to have disappeared and iam working in a new garage thats not even finished yet so i would have to be constantly parking the car outside when stuff was being done in the garage.
So long story short, iam considering taking it to him and having him take it all apart, fix or rebuild it, check the heads, basicaly make it all right.

Another thing, hes a friend of my dad and I and the $$ involved wouldnt be all that great. Probably just parts or mostly parts.

What do you all think i should do?

Last edited by coolraptor; 06-25-2008 at 11:03 PM.
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Old 07-21-2008, 06:02 AM
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Lightbulb

Update?

Im in Marietta too, btw. Dont think Ive seen you around, though. (dont know if you know my cousin... Ash Carr(?) Hes got the red 97 SS clone... 383 w/a Vortech YSi trim...)

Later man

Keith
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Old 12-16-2008, 03:40 AM
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Sorry for late post. Almost ready to go back together now ill make a new post with details and whatnot.
I cant even remember everything that was wrong at the moment but it is 4:30am and iam half asleep but here is what i remember:
Almost all bearings toast (dirt during assembly looks like)
Cylinders bored a hair too small some how
Pushrods waaaay too long
Gasket covering quite a bit of the intake port on heads (wtf, i know lol)
Rotating assy out of balance (just barely though, wasnt noticeable at all while running)

Theres a bunch of other things i cant remember but its almost ready to go now.
Upgrades this time around are:

Splayed 4bolt conversion
Milodin oil pan/high volume/pressure oil pump
Complete MSD Opti setup
Ported intake
Some misc work on heads

Ill post back once she's running.

Oh by the way, you know me Bishop, I had the black Camaro a few years back, you took me for a ride accross the interstate bridge in your mustang one night and i saw you this summer sometime if i remember right ha.
And yes i know Ash, got some parts/advice from him before and have hungout with him at 'the lot' on the weekend sometimes.
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Old 12-16-2008, 03:59 AM
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Originally Posted by coolraptor
Almost all bearings toast (dirt during assembly looks like)
Cylinders bored a hair too small some how
Pushrods waaaay too long
Gasket covering quite a bit of the intake port on heads (wtf, i know lol)
Rotating assy out of balance (just barely though, wasnt noticeable at all while running)

Theres a bunch of other things i cant remember but its almost ready to go now.
Who built your engine dude?

Originally Posted by LOW-LIFE
Now i dont know much bout nitrous but i do know that when you are doin the piston rings you want them tight as possible...
Also to whoever claims nitrous needs tight ring gaps, that is false and could not be more wrong. They need gap so they have room to grow, what happens when they run out of room because its to tight.

Last edited by bombebomb; 12-16-2008 at 04:06 AM.
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Old 12-16-2008, 08:33 AM
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Originally Posted by bombebomb
Who built your engine dude?


Also to whoever claims nitrous needs tight ring gaps, that is false and could not be more wrong. They need gap so they have room to grow, what happens when they run out of room because its to tight.
+1 who built your engine, as we need to get the word out to avoid them like the plague. FYI - with that many problems you outta document your issues during the tear down and take them to small claims and sue em' as that is wayyy out of line for the money paid/work received. God I can't believe a halfway competent builder even let that motor leave the shop with that much shotty work.
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Old 12-16-2008, 09:39 PM
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The guy who built my engine is someone i used to work with at a garage. He doesnt build them for anyone else now he just ''used to work at a shop that did nothing but build engines'' and the boss man gave him the OK to assemble mine since i worked there.

I agreed that after the car left the lot it was my baby no warrenties of any kind etc etc besides it was a few years ago now and i dont have any interest in getting into legal junk with them.

His reasoning for my engine problems are that i "over revved it and used nitrous" which he ''set it up for nitrous'' because he 'used to build nitrous engines'' too.

i think in total i had $1500 in labor plus parts and misc stuff naturally. Small chunk of the insane amount i have in it now

Once its all done ill have a detailed list of what went wrong. I cant remember all the little things at the moment.
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Old 12-16-2008, 11:29 PM
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Originally Posted by coolraptor
The guy who built my engine is someone i used to work with at a garage. He doesnt build them for anyone else now he just ''used to work at a shop that did nothing but build engines'' and the boss man gave him the OK to assemble mine since i worked there.

I agreed that after the car left the lot it was my baby no warrenties of any kind etc etc besides it was a few years ago now and i dont have any interest in getting into legal junk with them.

His reasoning for my engine problems are that i "over revved it and used nitrous" which he ''set it up for nitrous'' because he 'used to build nitrous engines'' too.

i think in total i had $1500 in labor plus parts and misc stuff naturally. Small chunk of the insane amount i have in it now

Once its all done ill have a detailed list of what went wrong. I cant remember all the little things at the moment.
Yeah, if you use nitrous it makes your pushrods the wrong lenght, makes your bores smaller, and blows oil out the dipstick.
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