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Discussion Starter #1 (Edited)
History:
I purchased the Corvette in June of 1980 for 3,500 dollars. The Vette was in sad shape as it sat on the lot, barely four years from its St Louis debut. It had already gone through a lot with poor repairs to the passenger front fender, poor repair near the rear fender well behind the passenger seat, and of course, non-matching numbers. It was all the Corvette I could afford.


She went through a mild transformation in the late 80's. GM Poly Brown was stripped from the glass and replaced with a beautiful Mitsubishi, Rio Red; similar to Corvette Torch Red before its introduction. The Buckskin interior was replaced with a more favorable black.


A four bolt main block 350 and a crankshaft from a SB-400 were located, and both were machined to begin the build of a 383. The aged Rochester carburetor was replaced with an 86' TPI. The TH350 and the pumpkin were both rebuilt. And finally, the suspension, steering and brake components were all replaced. In the end, it turned out to be a pretty clean, fun street car.



The Corvette story continues..
Life moves on and priority for maintaining the 76', unfortunately, diminished. She sat for 25 years; some in the weather, mostly in the shop. And during that time, other Corvettes' caught my attention. A black 94 with red over black interior, with excellent air conditioning of course, (a must in central Texas) kept me rolling for a number of years. The 94 was replaced later with my first and only new, fiftieth anniversary year 2003-Z06. This Torch Red/Black beauty kept me rolling in Corvette signature for a few more. All the Corvettes' were unique, fun and special, but the battered 76' remained the keeper.



76' restomod.
I don't want this 76' to look like a pristine 1976' era car. We have new technology, new performance standards and much better creature comforts available today. So the plan is to give the tired, old 76' a new look with a lot of goodies. The C3 body is one of the best for a resto-mod transformation.
The electronic controlled LS is a fantastic engine platform. As I continued to search for a suitable, affordable LS3, I ran across an article regarding the little known L18 - 496. A big block with common generation design as the LS, unfortunately in iron, but more importantly, with old style engine mounts. More research lead to Raylar and suddenly, a vision for a big block with lighter aluminum heads came clear. Combined with a 6L80 six speed and a very streetable pumpkin options, this could be a very sweet ride. I'm SOLD, the 496/6L80 it is!!


More to come...
 

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DC PIT CREW BOSS
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Welcome to DC vetteman. Make sure you keep us updated and post a lot of pics. If you want , you can upload them in the gallery here
 

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Discussion Starter #5
autowiz


Thank you for the nudge...


Actually, thanks to Marks76ray and others here at DC will be the subject of my next post. It is a bit overwhelming to see the awesome work and shared experiences a lot of guys have toiled over to post here. Truly amazing!
 

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Discussion Starter #6
Researching my options for my 76 conversion, I found Raylars site, and a link there to the technical article, swapping the 496 into 69.

As I continued my 8.1L conversion search, I came across Marks76ray build thread here in DC and found it very informative. After pouring through his thread I realized how much time and effort he put into the build, shall I say his continuing build, and the volume of documentation he provided for others.

But the 496 does not make the car. It is the entire package we all seek.

Looking further into DC I found other build threads that interested me as well. The 76project/Brent319 is an excellent thread. My '75 resto mod/gabbett1 is just way, way cool, and Nikki's 69...it begins/69MyWay and My 1968 LSx Restomod Conversion are awesome threads. And many others, too.

I cannot come to this forum today and give thanks to any-one individual. But, I am truly grateful for Marks documentation of his 496 build. Mark, if you are out there, Thank You very much for your pioneering work, time and effort to help other with similar build and interest.

But there is more to say about those willing to contribute. As I have read through a number of build threads I am struck by the resourcefulness, talent, and willingness of these people to help others. I am also thankful the contributors here leave their egos' checked at the front door when they enter. The positive comments and attitudes of those here really make a good forum, a place to be. So, I must say, Thank You to all of you for your great, thoughtful threads. You guys here have really given me better insight where this build will end, and a very positive attitude to get it there.


BillT
 

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Discussion Starter #7
Many threads here in C3 interest me. The 76project/Brent319 is an excellent thread. My '75 resto mod/gabbett1 is just way, way cool, and Nikki's 69...it begins/69MyWay and My 1968 LSx Restomod Conversion are awesome threads. More threads still left to read.

Autowiz is correct. Much thanks go out to Marks76ray for the time and the effort he spent to document his build here in DC. Marks thread provides valuable insight as I move forward with mine. Thank You Mark!!

But the 496 does not make the car. It is the entire package we all seek.

Thanks to the other builders that contribute with their hours of labor, resourcefulness, talent, and willingness to share with others, their successes and sometime their failures. 69MyWay, gabbett1, Brent319; great contributors, thanks go to them as well.


Finally, I must say, Thank You also to those here that leave their egos' checked at the front door when they enter. The positive comments and attitudes of those here really make a good forum, a good place to be.



BillT
 

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Discussion Starter #8
Many threads here in C3 interest me. The 76project/Brent319 is an excellent thread. My '75 resto mod/gabbett1 is just way, way cool, and Nikki's 69...it begins/69MyWay and My 1968 LSx Restomod Conversion are awesome threads. More threads still left to read.

Autowiz is correct. Much thanks go out to Marks76ray for the time and the effort he spent to document his build here in DC. Marks thread provides valuable insight as I move forward with mine. Thank You Mark!!

But the 496 does not make the car. It is the entire package we all seek.

Thanks to the other builders that contribute with their hours of labor, resourcefulness, talent, and willingness to share with others their successes and sometime their failures. 69MyWay, gabbett1, Brent319; great contributors, thanks go to them as well.

Finally, I must say, Thank You to those here that leave their egos' checked at the front door when they enter. The positive comments and attitudes of those here really make a good forum, a good place to be.


BillT
 

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Discussion Starter #9
496 disassembly

So it begins. The disassembly of the 496...


A few weeks ago I took the intake and the heads off to begin the initial tear down. I was glad to see the cylinders, even with the pistons still in the bores in good shape. I checked the rod clearances recommended by GMC. All rod clearances were within allowable specification. I also checked the breakaway torque from the nose of the crank with torque wrench. It consistently took 30/lbs ft to get the assembly rolling. Breakaway torque is normal too.


Today I decided to pop the pistons out.


No surprise to find the rod bearings shot. However, I'm a little surprised to find the #3 rod bearing wearing to one side. Hmmm, not quite sure what to make of this yet. Number 4 was wearing to one side as well, but not as severe as number 3. The other pairs of rod bearings showed normal wear, but shot!! What would one expect from a 140K plus engine.


After pulling the pistons, the cylinder bores still look good. You can see the factory cross hatch from the top all the way to the bottom on all cylinders. Cylinders 7 and 8 have a very small amount of oxidation from radiator fluid that sat on the rings after engine removal. Even with the cylinder clean and very clean fingers, I cannot feel any imperfections in the area of the stain.


With the pistons and rods out, I can easily turn the crankshaft by hand using the front pulley. By grabbing the pulley with an open hand and rolling my wrist quickly, the crankshaft rolls one and a half turns before stopping. The crankshaft turns very freely and smoothly in its bores.


I got my fingers crossed we're not looking at a couple of bent rods, #3 and #4. We'll see what happens when we get it all to the machine shop.
 

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Discussion Starter #10
496 teardown

So it begins. The disassembly of the 496...

A few weeks ago I took the intake and the heads off to begin the initial tear down. I was glad to see the cylinders, even with the pistons still in the bores in good shape. I checked the rod clearances recommended by GMC. All rod clearances were within allowable specification. I also checked the breakaway torque from the nose of the crank with torque wrench. It consistently took 30/lbs ft to get the assembly rolling. Breakaway torque is normal too.

Today I decided to pop the pistons out.
No surprise to find the rod bearings shot. However, I'm a little surprised to find the #3 rod bearing wearing to one side. Hmmm, not quite sure what to make of this yet. Number 4 was wearing to one side as well, but not as severe as number 3. The other pairs of rod bearings showed normal wear, but shot!! What would one expect from a 140K plus engine.

After pulling the pistons, the cylinder bores still look good. You can see the factory cross hatch from the top all the way to the bottom on all cylinders. Cylinders 7 and 8 have a very small amount of oxidation from radiator fluid that sat on the rings after engine removal. Even with the cylinder clean and very clean fingers, I cannot feel any imperfections in the area of the stain.

With the pistons and rods out, I can easily turn the crankshaft by hand using the front pulley. By grabbing the pulley with an open hand and rolling my wrist quickly, the crankshaft rolls one and a half turns before stopping. The crankshaft turns very freely and smoothly in its bores.

I got my fingers crossed we're not looking at a couple of bent rods, #3 and #4. We'll see what happens when we get it all to the machine shop.
 

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Welcome aboard! Nice to see another '76 project. Mark is still around and I am sure he will be stopping in to welcome you also.
Looking forward to seeing your progress.:thumbsup:
 

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Glad to see someone one else taking on the 496. I'am still here just haven't worked on my vette in some time. If you read my entire thread you have seen all the things that have to be done to install this BBC. One of the things I did not post was the fact that I had to modify my left side side pipe headers. If I knew what the real problem was I would not have done the modification. For some reason the engine is twisted just enough that the headers touch the frame on the drivers side. I suspect it's the engine because my frame was put on a alignment machine and all dimensions were checked and adjusted. If I had it to do over I would have cut the motor mount and re welded it, problem solved. It cost me $500 to have the header modified. Raylar is the go to people for making this BBC scream, just costs big bucks. I do believe the Edelbrock elbow and Dart intake will be a good combination. Anything I can help you with just let me know.


:cheers: Mark
 

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Discussion Starter #15 (Edited)
Thanks Mark for your insight.


As I said a couple of days ago I, pulled the pistons out of the 496. I was a little surprised the see that #3and #4 rod bearings have uneven wear. I showed it to a machinist at a local high performance machine shop and he said he sees that kind of wear on high mileage motors often, and not to worry. There is a bit of a back log in the shop, so it will take about a month to get it back. In the interim, I'll be building a body dolly and gutting everything I can to prepare the body for removal.



A photo of #3 rod bearing
 

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Discussion Starter #16
Better Understanding with the 6L80

As I said earlier in this thread, the 6L80 will be my transmission behind the 496. Getting there however, may take a little finesse.

Grayflame posted photos of his 6L80 resting in a C3, and I have seen other C3 builds done as well. So, I know the install can be done without much trouble. But getting the 6L80 to work electronically will take more time, understanding, and perhaps drive a little deeper into the budget.

The 6L80 is a computer controlled transmission. There are no provisions for it to run in a standalone mode. Two way communication between the engine controller and the transmission controller must always be maintained, otherwise, the transmission is nothing more than a 225lb box of rocks.

AND, the 6L80 can only communicate with a Gen IV or GEN V engine controllers. If you have one of these controllers, don't get comfortable, there's more. Most all documentation says the controllers, both ECU and TCM must match, specifically by year.

None of this is a problem if you buy the engine controller and the transmission from the same donor vehicle. Otherwise, try to obtain transmission and ECM from the same year and model donor.

This, unfortunately, I Did Not Do!!!

The L18-496 is the only Big Block in LS clothing that GM built. The L18 only received Gen III controllers, therefore, my controller is not compatible with my 6L80 transmission. It will never work.

The problem is the early Gen III controllers used a 24X reluctor wheel, and the Gen IV and V controller used the 58X reluctor.

So, the problems I have to solve now are, 1) replace my 24X reluctor with 58X reluctor and Sensor on the existing 496 crank, 2) purchase a ECM controller to match my existing 6L80 transmission. Hopefully, this should put me back on track..

I'll add documentation later this evening or tomorrow to help make this a little more clear.



BillT
 

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Also be aware the transmission tunnel on a manual car is smaller than a tunnel on a automatic car. I found this out when several people said my 4L80E would not fit so I researched it and found this information. I only had to dimple the pan around the yoke area to make it fit because mine was a automatic car.

:cheers:
Mark
 

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http://www.novak-adapt.com/knowledge/transmissions/automatic/6l80

It requires a CAN Bus Communication Network line.
Torque input capacity is just 440 ft/lbs stock.
Got better with the 6L90E.

The 496 built can put out 700ft/lbs Race ready.
Street tame it will be 550-600 ft/lbs.

I know a Turbo 400 is a no go on this project.
It can handle 800 ft/lbs stock rebuild with near zero internal upgrades.

4L80E is so much more flexible for driving needs.
Much better support.
 
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