LT1-LT4 Modifications 1993-97 Gen II Small Block V8

Replacing connecting rods on LT1 by myself

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Old 10-06-2007, 02:49 AM
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Default Replacing connecting rods on LT1 by myself

So I have experience in replacing motors, but only on an import (93 240sx). I've also replaced clutches and transmissions. I've recently found out I need a new connecting rod, because the one in the motor now is bouncing around making a loud knock. I think this was caused by not having oil in the motor, because somehow it all burnt up, maybe from a piston ring going out I was told.

I haven't driven it since it started, and only drove it for 2 miles after it started making the knocking noise. But I have started it up once for about 20 seconds to show a guy that work's with LT1's what it sounded like so he could diagnose it.

I ordered a haynes manual so I could pull the motor through the hood in a friends garage, and then have someone with the right tools replace the connecting rods themselves in a shop. Or maybe I can do it myself? I'm borrowing a cherry picker and other tools from a friend to do remove the motor. The price I was quoted for the work if they did EVERYTHING was over $3,000, and I have about 200 in my pocket right now. So I have to do as much as I can on my own.

My question is, what exactly should I expect on my 93 Z28? Like I said, I've replaced a motor before, and it was probably more complex considering I had to frankenstein it from a OBD II to OBD I and it had about 99999 sensors. I've heard of guys doing this on the concrete, so I shouldn't have a problem in a garage with some good tools. I had oil up to it's level about a month prior to it all disappearing, is there anything I should replace in the motor while I have it out? Someone said this site is the best when it comes to fbodies,so I hope I can figure this out and get some good pointers. Thanks everyone.
Old 10-06-2007, 01:07 PM
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I believe your problem is a rod bearing not a rod.

If you ran it w/o oil, at the minimum you should check all of the bearings (rods and mains) and your cylinder bores too.

Rebuilding the LT1 is the same as rebuilding any SBC, its going to be the OH buy the ways and might as wells that will blow your budget.

Good luck.

Mike
Old 10-06-2007, 05:39 PM
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Ok so check the bores, bearings not rods, and try not to spend cash on things I don't need. Got it. Thanks.

Anyone else?
Old 10-06-2007, 06:35 PM
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Man, i ran a dodge 318 with no bearing(it spun and chewed it up) and was bouncing off the rev limiter not caring. After tear down for rebuild i had to replace the crank, but...the ******* rod was still good!! I only had to resize it! It is not hard to do though, if it just started nocking i bet you are in good shape, prolly just replace the bearings, have the rods checked, have the crank turned, hone the cylinders, throw he back together with some port work on the heads and a little cam, you will be happier than ever. Good luck!
Old 10-06-2007, 10:00 PM
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Drop the motor out of the bottom, much easier, only took me five hours with two friends and a lift, we could have done it just as fast with a cherry picker..


Old 10-07-2007, 10:11 AM
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If knocking there is a good chnce the crank needs at least a polish.
The rods are pressed to the piston pins so no way you can seperate them safely at home.

If you think dropping a OBD2 motor into a 93 required "frankenseining" then this is going to go badly as VERY minimal changes should have been required to put a 96-7 motor in so if you thought it rquired any creativity you did something wrong.
Old 10-07-2007, 10:15 AM
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pull the motor. dont go through all that just to find a chewed up crankshaft and need to pull the motor anyways.
Old 10-07-2007, 01:27 PM
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Originally Posted by mr_wizard
I ordered a haynes manual
You would be much better off ordering a helms service manual for your year.
Old 10-07-2007, 03:45 PM
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Originally Posted by Sgt. Spuds
Drop the motor out of the bottom, much easier, only took me five hours with two friends and a lift, we could have done it just as fast with a cherry picker..
I'm sure it's easier if you have a lift. But I don't have a lift much less a garage, which I'll have to find one for this project. It will most likely be just myself doing this too. Thanks for the info though.

Originally Posted by 96capricemgr
If knocking there is a good chnce the crank needs at least a polish.
The rods are pressed to the piston pins so no way you can seperate them safely at home.

If you think dropping a OBD2 motor into a 93 required "frankenseining" then this is going to go badly as VERY minimal changes should have been required to put a 96-7 motor in so if you thought it rquired any creativity you did something wrong.
Ok guess this is definitely going to the shop after it's pulled. As far as my previous motor swap goes, there wasn't a set way of swapping out the type of motor I did for an OBD II so I had to mix and match the correct sensors for the motor and tune it without any help or guide. Took me a few weeks of working on it every other day for a couple hours, so unless I'm retarded but can throw sentences together and spell correctly, I think it required some creativity.

Originally Posted by vtec
pull the motor. dont go through all that just to find a chewed up crankshaft and need to pull the motor anyways.
So your saying I don't need to pull the motor if it's just the bearings, but I do if it's a chewed up crankshaft?

Originally Posted by infinitebird
You would be much better off ordering a helms service manual for your year.
As far as I know from what people have been telling me and doing my own research, the Haynes manual is the only one explaining how to pull the LT1 through the hood. Why is the Helms Manual better?

Thanks for the input everyone.



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