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Topic: L-82 Tear down

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L-82 Tear down (1/18)
7/2/12 9:04am

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Peru, IN - USA

Vette(s):
1978 Blue Edition 2001 Torch Red

Joined: 6/2/2010
Posts: 87

Just finished a mild refurb on a 78, 4 speed, I found two years ago at a small garage in another state. Replaced every bushing, brake/fuel lines, dropped tank, most of the wiring, twelve coats of paint, 10 clear. etc,etc.etc ( kept putting it on till I ran out.) Everything works on the car, even has orginal power antenna. Will be able to buff this thing for a millenium without going thru the clear. Had a mid 70's chevelle motor in it orginally that was pretty tired. Came with a L-82 best I can figure, no vin on car anywhere, looked at all three places it may be. Has l-82 tach and correct console label, emblems on hood, all orginal. Took dash out to change to change printed circuit and dash had never been out. Not concerned about matching numbers. I bought a rebuilt L-82 ( CMR) from a guy who builds motors and had all the build sheets. Looked good, dropped it in, and had a ticking noise from the start. Did all the rechecks, took it to good local shop that suspected a tranny noise, took it to tranny shop who "thought" it might be a tang on the pressure plate bent,. Not so after we got into it. Minumum charge at tranny shop. Good guy. I pulled pan off and found right bank rods installed backwards, ( Pistons facing correct) , #1 rod bearings grooved bad, mains okay, #7 cyclinder has unrepairable dip just below ridge line. Cyclinders were bored .30 so no fix there. Pulled heads, turned rods., changed bearings, hone cyclinders. Hoping i could get a summer out of it. Motor has about 50 miles on it. No luck. My question to the experts are: can I use the L-82 guts out of this and drop them in another SMC. Machine shop checked all the rods and pistons, pressure checked heads, etc when I had them out and said there in good shape. I'm thinking of starting from scatch with any good SMC but would like to use the good parts if I can. Just a street machine. Sorry for the long into. Thanks.................

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Re: L-82 Tear down (2/18)
7/2/12 10:55am

manchestershark

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Equinunk, PA - USA

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1972 conv, 4-speed, 350, 200hp, numbers match, rally wheels, war bonnett yellow w/white top. good condition, nice driver.

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Ouch

What a bummer. Let us know what ya find out. I think I would go back to the builder and twist his arm around, and see if he can work with it that way. He MAY want to help you out.

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Re: L-82 Tear down (3/18)
7/2/12 12:08pm

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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I'll post what I end up doing with the replacement engine. I did e-mail the builder and let him know about the problems. I did so to inform him that someone ( builder or machine shop) had a lack of attention or lack of knowledge so it doesn't happen to someone else. I'm not sure who put the block together. I'm not after money, just explanation. I usually build my own. It happens when you buy a pig in the poke. My wife will get a L-82 coffee table for Christmas...

Re: L-82 Tear down (4/18)
7/2/12 12:58pm

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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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The "guts" will fit into another +.030" 350 block with no problems. I would be sure to get a 4 bolt main block, if that's the route you take.
Sux when stuff like this happens. I took some pistons/rods to a machine shop years ago for them to install the pistons on the rods for me, since I dint have a tool for the press to do it at the time. I specifically instructed them to NOT heat the rods to install the pins....but they did anyway...along with putting the pistons on backwards on a couple of them. That's when they told me they dint have the press tool, either.....WHAT?!?!?
Long story short, after fixing the two they had on backwards, the engine lasted about a week before the rods bent and twisted....I was only slightly p Censored

Censored

d...
I also bought my own pin press after that....

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Re: L-82 Tear down (5/18)
7/4/12 6:37am

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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Some machine shops shouldn't be in business. I might just throw in new rods/pistons since I don't what damage was done by the reversed rods. Not looking for high RPM, would these parts fit a SBC two bolt? Thanks for reply..

Re: L-82 Tear down (6/18)
7/4/12 11:27am

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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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Everything will fit the 2 bolt main block fine. The L-82s used a 4 bolt block...supposedly. May not be 100% true, but that's the way they were intended.

You need to check the crank journals where the rods go carefully. Sometimes, if the rod is on backward, it can damage the radius of the crank, depending on how long the engine was run like that, and how hard. Other than that, you should be good to go.

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Re: L-82 Tear down (7/18)
7/5/12 9:23am

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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Thanks Adam. I'll make sure I check that crank. The bad block is a four bolt main. Crank had .020 bearings and I plasti gaged them for my info and they're well within limits. I could drill a two bolt block into a four bolt but then I run into line boring and main caps work, won't need that kind of torque/ RPM. Have access to a 302, old Z-28, 67 I think, DZ I was thinking about building backup. Was going to ask you also if these will also move over to another 350. I'm not sure if they,ve been shaved. These heads passed a pressure check have all new valves. Thanks again

Re: L-82 Tear down (8/18)
7/5/12 10:19am

tonytheroofer
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Rochester, NY - USA

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If you are not looking for 500hp . but a more modest 350 to 400 I would spend the money and get a crate engine from GM performance. My 1980 has the ZZ4 motor and it runs , idles and performs perfectly.

The cost is well worth it and if I am not mistaken they come with a 3/36 warranty. And although 355 hp may not sound like a huge amount keep in mind the HP at the rear wheels will exceed the total hp your original motor put out at the flywheel.

Just food for thought.. And not for nothing but NEW not rebuilt in my book is a better choice when one considers some of the things you have had to deal with thus far

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1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI

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Re: L-82 Tear down (9/18)
7/5/12 12:41pm

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Duncanville, TX - USA

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#1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas

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The 302 was a 327 block with a large journal 283 crank. The block itself will take the 350 guts, but...IF what you have is indeed a genuine DZ block, I would sell that to one of the Camaro freaks....that would probably give you enough cash to either buy a crate engine, or build whatever you want. Original, genuine DZ Z/28 engines are like gold to the Camaro crowd....

|UPDATED|7/5/2012 9:41:27 AM (AZT)|/UPDATED|

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Re: L-82 Tear down (10/18)
7/5/12 4:57pm

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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I haven't ruled out a crate and 300+ would be plenty. I enjoy building my own and do have the time.

Re: L-82 Tear down (11/18)
7/5/12 5:03pm

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Peru, IN - USA

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Wanted to put the DZ back in a Camaro so probably won't go that way. Appreciate the advice. Any thought on how large an oversize cyclinder would be within limits for the L-82?. .30 is a big as I've ever gone.

Re: L-82 Tear down (12/18)
7/5/12 10:16pm

tonytheroofer
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Rochester, NY - USA

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1980 L- 82 fully restored and upgraded.

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It is fun to set up an engine , nothing wrong with that route !

Here check this

http://www.jegs.com/p/Chevrolet-Performance/Chevrolet-Performance-350ci-355HP-ZZ4-Engine/749876/10002/-1

for 4k , you really get your money's worth and it is new and to me new means a lot more then any rebuild , you have a warranted factory engine, at the cost difference cant be much at all from a good rebuild.

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1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI

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Re: L-82 Tear down (13/18)
7/6/12 8:15am

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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Thanks Tony for website. Not glad L-82 went bad but I enjoy looking at all the options. Never dealt with Jegs but I hear a lot of good about their products. This C3 website is like having a jobber and mechanic living in your garage.

Re: L-82 Tear down (14/18)
7/12/12 8:21am

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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Tony, ordered a GM crate 350, 4 bolt, long block from JEGS Tues and they are delivering it this morning to my front door. $1499.00. No tax , no core, and free shipping. $ 13.00 for handling fee. ( Hope engine is as fast as their shipping) Bought new headers and Edler intake to finish the top. I'm a Quadrajet nut and I have two of them in boxes. Probably run it for the rest of the year and then put a few more horse power in the guts this winter. ( I know it would of been cheaper to order it that way but I enjoy digging into with when its cold and snowing.) Might sleeve the L-82 or move rotating parts to another block. Thanks for eveyone's voice ,,

Re: L-82 Tear down (15/18)
7/12/12 8:40am

tonytheroofer
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Rochester, NY - USA

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1980 L- 82 fully restored and upgraded.

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There ya go .. Cant beat that deal with a stick ..

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1980 , ZZ430 , 3.92 rear , 700R4 2400 stall NEW EZ EFI

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Re: L-82 Tear down (16/18)
7/12/12 12:03pm

danascar
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Germansville, PA - USA

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tttanker said: Wanted to put the DZ back in a Camaro so probably won't go that way. Appreciate the advice. Any thought on how large an oversize cyclinder would be within limits for the L-82?. .30 is a big as I've ever gone.

I'm running .040 over on my 350 in my 74....that would require you to go with .040 pistons. I have flat top pistons and it runs great. Not sure if the L-82 block is any different from other 350's of that era. My engine is not the original that came with the car.

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Re: L-82 Tear down (17/18)
7/13/12 5:05pm

73shark
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Overland Park, KS - USA

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1973 Orange Metallic Coupe (orig owner), L82, 4 spd (WR), PS, (A/C & PW (I installed from wrecked 73)), leather, AM/FM Stereo, ran with '65 FI unit earlier & will again some day.

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AFAIK the L-82 block is the same as the others except it is a four bolt block.

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1973 L-82 4 spd

Re: L-82 Tear down (18/18)
7/26/12 9:10pm

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Peru, IN - USA

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1978 Blue Edition 2001 Torch Red

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Dropped the GM crate motor in and back on the road. Didn't put the headers on yet till I get a couple hundred miles on it. Runs and sounds great. Sure don't miss that annoying ticking noise the L-82 had. ( Cracked piston at wrist pin from rods installed backwards) Appreciate all the input from everyone. Nice people!!

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