The c4 limps home

Discussion in 'corvette related misc.' started by JakeAl, May 10, 2018.

  1. JakeAl

    JakeAl Member

    Well the car made the 20 mile trip from the shop. My first time driving it but I have to say it sounded bad azz as can be. The exhaust/air bung had to be rewelded since it was poorly welded and leaked air.

    I'll say it turns out it was much much less than the thrill ride I was expecting. I promptly scraped the front and underside while making a U-turn.

    Though I was told the fans were operational, they weren't. By the time I reached the freeway the temp was 240. It cooled down once I got rolling. I couldn't get the self learning icons to come on at the econtroller. The mechanic had been toying with it on a brief test drive and I was locked out of it.

    The e controller wasn't secured and slipped down in the seats. Meanwhile I'm trying to negotiate urban city traffic with rush hour getting underway. Omg... My sister is in front of me as we drive. Suddenly I notice the cowl is not secure and is starting to flop about. It seemed less so when I stayed off the gas.

    I wasn't sure if the efi was doing the self learning thing at this point. I think not. Off the line it seemed like it was ready to haul balls then didn't lol. I pulled off the road to check the cowl and I hoped with a little prayer and tlc it would stay attached. I had no tools so few options.

    We finally made it hope and I promptly shut it down. Again I tried to figure if the fans were working but nope.

    Being quite flustered and stressed, I retired to the air conditioned house took some meds and layed down to think about things. It occurred to me that the mechanic had been trying to tune the EFI by hand and the self learning shut down. After a bit, I drove down the road and noticed the self learning icons were lit. After about 10 minutes performance seemed to improve. I was a little relieved. The directions say to keep driving it to get the computer to bring performance together.

    WHOA .... I gunned it, felt the back slide out slightly and then.... One side of the cowl lifted about 45 degrees....
    I was almost home. I pulled into the backyard and shut it down. I got all but one of the remaining screws off that hold the cowl on. I'll get the last off tomorrow. The original adhesive on the cowl had been long been dried up and useless. I don't know if I'll keep it on or not. I never have liked the appearance. Anyway I'll get it off tomorrow so I can drive it.

    It needs quite a bit of work still... The interior is lame. Tach and speedo not working... Oh well... This is going to be a pita...but maybe I'll learn something, maybe I'll go insane and broke at the same time.

    I'm going to drive this from TX to Mt?!?!??... Ha ha.. God help me lol.
  2. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Oh thats right....
    You Flew out to pick up your C4 Corvette converted Big Block.

    So few have ever been built.
    I knew there was always lots of Pain In The Ass Bugs problems guys never disclosed with Big Chevy swaps.
    Seen plenty of photos here and on Digital Corvette.
    But None ever made a Video or reported the headache problems.
    Plus none ever drag raced them.'
    Just putzed around did nothing.
    Guys were too old.
  3. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    I want to Big Chevy swap my 87 C4 Roadster.
    Time & Money the problem.
    Time required to work out all the bugs problems that come with.
  4. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    I think a Pontiac V8 is good swap into a C4.
    Its less wide.
    Super High Output Engine like a Big Chevy too.
    Grumpy never liked the idea.
    Strictly Attitude likes this.
  5. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    You have to have working electric Fans .
    Big Chevies create allot of heat.
    Hardwire direct to a Toggle switch.
    Let the Fans Run all the time.
    Stays Cool for sure.
    How I did it on my 1963 Pontiac Grand Prix.
    Flex A Lite 398 Fan runs all the the time with ignition key on Via a Relay I use.
  6. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    all the minor issues youve described are rather easily either corrected, or avoided ,
    some rather easily and cheaply,
    others potentially might cost more like the oil pan to pavement issues are easier to change,
    if you have experience and a tig welder.
    but they all take careful inspection, diagnoses and in most cases some experience
    in my opinion, you should start with wiring the cooling fans,
    as you don,t want to damage the engine , if you want a fast & dirty fix,
    you could obviously wire the fans directly from battery to ground with a manual switch.
    next get the self learning EFI functional as that won,t require much actual driving and could be done in a rural no traffic area ,
    or large parking lot, or while driving around a couple local streets.
    next Id check the under the car to pavement clearance it sounds like the less than ideal and too deep for the application oil pan,
    was used, as I've never had one oil pan on a BBC engine swap scrape pavement,
    on a single swap I've done or worked on.
    but all those used an oil pan of 7.5" max depth from the oil pan block rails.
    personally Id remove the hood scoop if its loose until all the other issues are resolved.
    Id also carefully check the exhaust to pavement clearance and verify the drive train shifts correctly,
    and the brakes and signal lights, headlights and steering work and the tires to frame,
    and suspension clearances, and alignment and u-joints are ok.

    related info, don,t get over whelmed, make a list and test adjust correct or replace each problem,
    and check it off the list then move to the next issue,
    its a finite list and theres not a damn thing on it you can,t accomplish,
    with a bit of research, a few questions and this web-sites help
    (a few tools the right attitude and a thick stack of cash would also be useful of course):D:rolleyes:
    Last edited: May 17, 2018
  7. DorianL

    DorianL solid fixture here in the forum Staff Member

    Congrats on getting her home ! Your experience picking up the car seem on par. It seems like every time I purchase an older car, the maiden drive is a near fiasco.

    Enjoy the build !!!!
  8. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    JakeAl , please keep us updated on your progress and as always clear pictures help a great deal
  9. JakeAl

    JakeAl Member

    Just a quick note... i got the fans figured out and the both work and are programmable from the e-tuner.

    Well... I'm beat half to death but am on my way home. At motel 6 in Denver now
    It's late. The car... hauls king kong b☆lls!!! Ha ha.. got that thrill i was expecting. Damn loud.. (ask how loud) i put in ear plugs... no instruments except e tuner and using a gps program on my phone. Have the essentials like lights and tires. Doin 70 at about 23k on the tach. I'm stopping in ogden tomorrow to see a long neglected relative. It seems to run good but is a thirsty thunder critter. Hot too. No ac and only drivers window works... I'm hoping for continued (relatively) good sailing. I'll get some pix up later.
  10. DorianL

    DorianL solid fixture here in the forum Staff Member

    Are we having fun yet? I would be !:D:D

    Yes, one thing I did notice is how hot it can get inside the cabin. Something I'll need to address one day.
  11. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Much like every True Race Car.
    Real Man car.
  12. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  13. JakeAl

    JakeAl Member

    Sorry for anyone left hanging on my thrilling story ha ha (thrilling to me anyway)

    I made it back to Montana with no problems. The side trip to Ogden didn't happen as it looks like the opportunity to reconnect with shirt tail relatives has disintegrated. That's a long story now concluded and not to be revisited.

    On the last leg of the trip I ran into a rip roaring downpour of rain. Windshield wipers, which don't work, would have come in handy. I pulled off onto a farm road for about an hour. A working defroster fan would have kept fogged windows clear. Ha ha

    I'll throw a couple pictures on here to give you a visual.
    Screenshot_20180413-072911 (1).png
    Previous carb intake

    Slp claw intake


    Edelbrock xt3 efi
    Topdown view from my motel room in Denver.

    I blew out a exhaust header gasket the second day back. The car is with a friend who helping install a radio. He describes the wiring as a nightmare... We are talking major spaghetti in the mass of wires under the hush panels.

    I was surprised to get complementary comments as gas stations. So the trip was successful overall. I need to figure out how to tune for better economy... taking baby steps is better than taking none at all.
  14. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Its hard to see from my phone.
    Looks like in 1 picture the Windshield Wiper motor is there.
    In the Next it appears missing.

    I told Grumpy Working winshield wipers are a must have.
    You believe me now likewise.
  15. JakeAl

    JakeAl Member

    Yah wiper motor is there. Whoever did the conversion disconnected a whole bunch of stuff. Under the hush panels are several visible disconnections. It shouldn't take to much to get the wipers going. Honestly i didn't even think of wipers at the time.

    I was largely concerned about the overheating... aka no fans. I had a good idea of what needed to be done. My almost brother in law and one of his buds were at the wiring like mad scientists.

    I kept telling them the fans were now controlled by the edelbrock computer... they kept putzing around ignoring me. I told them we needed to see if the pins from the computer box for the fans had wires in them. I was previously told that wiring was paid for and done but i didn't see it. After a day of wire testing and replacing fan relays... fans still didn't come on.

    I think part of the problem was that there was this green plant they lit and puffed on occasionally. It's none of my biz i told myself... been there done that. I kept trying to show them diagrams and reading instructions....

    Finally the next day the light comes on in someones head. There were no wires!! Wires were then purchased and installed and "walla" fans came on.

    Ha ha... somewhat aggravating but i learned something watching their process. They were smart guys and i appreciated their help.
  16. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    well one minor "plus" too this process is that, if your starting from scratch,
    or taking over a partly done and abandoned BIG BLOCK CHEVY ENGINE INSTALL in a C4 corvette,
    by the time youve corrected a bunch of these issues the previous owner ,
    (who obviously was not all that knowledgeable or skilled or even all that concerned with doing the engine conversion correctly,
    is that you can,t help but be guided (almost forced") into learning the how, and why and basic mechanics of how a proper engine swap is accomplished,
    this may not have been the initial expectation, but in the long term, if you stick with it to the end youll have vastly increased your skills ,
    knowledge and significantly increased your appreciation for what is required in a proper performance car build.
    youll also by default have gained the increased skills, tools and intuition, due to the process, to find and rapidly test isolate ind repair most of the sub-systems in the car!.
    in most of those BBC engine swaps,
    its engine & transmission COOLING,
    fuel delivery, proper ignition, advance curve and spark delivery,
    engine lubrication, enhanced suspension, better and larger surface area tires
    and better , larger and more fade resistant brakes,
    a larger and less restrictive exhaust,connecting the sensors and gauges
    and cosmetics like the seating interior and paint,
    that become the areas that need up=grades
    thus by the time your done youll be dragged kicking and screaming into a vast knowledge base based on the c4 corvette plat-form.
  17. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Each thier own..
    I have no Tolerance with people Drinking or Doing Drugs while I am there in person making repairs or building a Race Car.

    My bad habit is nicotine.
    Smoking Cigarettes.
    Like my Caffine Coffeee too.
  18. JakeAl

    JakeAl Member

    Grumpy... heh heh... I really would like to lie and say I knocked this out with my own knowledge... but that would be a big fat lie...

    I studied the overall process, sought advice then organized and financed to get to the drivable stage.

    I think I made a good deal overall and the improvements hopefully increase the value. Yes it is true i am learning but after looking through the service manuels, the complexity of the vehicle is really overwhelming.

    Taking baby steps for sure. Had to get new rear tires. Next will come seeing what is needed to get passenger power window to work. My dog will need to be able to stick his head out. :giggle:
  19. JakeAl

    JakeAl Member

    Here's a link to the etuner for the edelbrock efi

    Etuner link

    You can download it to whatever (phone?) and use it for free. The software program has a "demo" mode. This lets you examine what the etuner does for those interested. If you have the efi setup, after the app is downloaded, you can connect to your phone to the efi system computer wirelessly via Bluetooth to adjust the system.

    Also here is the gps program i used for a speedo. It has several features. YouTube has a couple videos detailing the features.

    GPS Speedometer

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