New BBC swap, with some new Ideas!

Discussion in 'MISC. mods and equip.' started by MarauderPrime, Jan 4, 2019.

  1. MarauderPrime

    MarauderPrime Member

    Hey All, my name is Blake, and I have been a long time lurker, and have had some complications in my corvette owning experience,
    but I own a dark red metallic 1986 corvette base, that I originally purchased for a song,
    and intended to flip, as it had a flattened cam lobe.
    I picked the wrong shop, and suffice it to say, I drove it off the trailer into their shop 3 years ago,
    needing only a cam change, and that was 3 years ago. Since then,
    I got laid off, started my own business, and am in the process of finalizing a home purchase, so since they hadn't completed the work
    , and they cant charge storage until the job is done, and they have been storing it inside, I haven't made any effort to get the car out of storage.

    Now that things are starting to settle down, I am going to go in there with a trailer and just tell them they can either give me back the car,
    or I will have paid book time for half of a camshaft swap into a court registry by the end of the day, have the complaint for conversion,
    I prepared filed by the end of the day, and return with the Sheriffs to recover the car.

    It has a set of Skip white NKB heads, Ram's horn manifolds, and a gm flat tappet 327 300 hp cam in it.
    They got the cam in, then called me to tell me the pushrod holes in the head were in the wrong place
    (even though they are clearly not, and the car actually ran in that configuration.
    Next they told me I needed to put stock c4 manifolds back on it because the sparkplugs didn't clear the rams horn manifolds,
    (which we already know they did, because the car ran in that configuration.
    That was the only 2 complaints I heard in the last 3 years,
    and it continues to sit, while I am sure the tires flat spot,
    the Battery loses its charge, and every seal in the car goes bad.

    My original plan was just to flip it. With C4 corvette prices all over the board,
    I am no longer positive I would even be able to make any money off of it,
    so I sold my other 2 project cars in the anticipation of getting the car back to put a turbo on.

    Now I am very serious about putting a Gen Vi BBC in it with EFI,
    and seeing if I can get it to clear the stock hood and parts with the right combination of swap parts.

    I have soaked up everything on this amazing site, and when I get moving
    (hopefully by march of this year)
    I aim to keep a detailed log with lots of updates to share.
    I think a BBC can be put in here,
    without having to move the steering rack,
    or notching anything with the right combination of parts.
    I believe my toughest issue will be getting everything to fit under the stock hood.
    I don't suppose anyone knows if the stock L29 vortec manifold would fit under the stock hood?

    Otherwise, I was thinking about getting an Edelbrock Victor Jr. Efi Oval port manifold, shaving down the carb bad as much as possible,
    and then running an Accufab low profile 4150 throttlebody on it with a drop base air cleaner.
    I believe I could get that to work under the stock hood,
    although If I could get the L29 manifold to work, it would save a boatload of money!

    I am also interested in doing this with as many factory GM parts as possible.
    Lofty goals, but I have had some fairly successful projects in the past.

    Happy to be here, and look forward to our future discussions!
    Last edited by a moderator: Jan 4, 2019
  2. Indycars

    Indycars Administrator Staff Member

    Welcome the forum Blake!

    Looking forward to reading your detailed log about your Vette!!!
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    welcome to the web site, and yeah, pictures of the corvette would be great here!
    yes I also think its potentially possible, to get a bbc installed and retain the stock hood,
    but the issue with the potential steering rack to damper clearance may still be an issue,\
    if you do the C4 BBC engine install/ swap,
    please take and post lots of clear detailed pictures from lots of angles

    related threads, Im sure youve looked through
  4. MarauderPrime

    MarauderPrime Member

    I have them bookmarked and read through them often haha. So far all of the swaps and articles I have seen were based around a bbc long water pump. Edelbrock now makes a 5.750 inch short reverse rotation water pump, that is actually slightly shorter than the factory c4 sbc water pump. I called kwik performance, and found out that their sbc to bbc bracket adapters will work with the stock corvette accessories and crank pulley on a big block, so I’m going to end up with all of the factory c4 accessories and brackets in the stock location. Based on the measurements I’ve taken, the crank pulley will be 2” further from it’s stock location.

    I am purchasing a ZR1 evaporator cover (thanks Grumpy), and the gentleman I am buying it from informed me, then showed me pictures as proof that you can move the stock c4 k-member forward .55” which is not enough to drastically affect the handling, and then dirty dingo sells bbc mount sliders which would allow me to then slide the engine back a full inch, think there isn’t that much firewall clearance, but there is enough that I think I can get the crank pulley to a spot where it is only an inch forward.

    Attached Files:

  5. chasracer

    chasracer Member

    Why not forgo all that craziness and put an LS engine in it? OR build a HUGE 23 degree small block with your turbo deal? While moving crossmembers, etc will not affect handling that much, an extra 200 plus pounds on the front certainly will. This will be interesting to watch - best of luck with it.
  6. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Bring it home and do it yourself.
    What this website is for.
  7. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    where did you find a ZR1 evaporator cover for sale,
    what did it cost?
    and do you think they may have another one or several more for sale?
  8. MarauderPrime

    MarauderPrime Member

    there are a number of reasons I want a big block. I’ve already had a turbo ls g-body, and it was great. 3400 lbs 5.3 s366 t56. I liked it, it felt similar to my 2011 gt500, but lighter, and didn’t sound quite as good. Unfortunately as g-body’s do, it rusted out from under me quicker than I could fix it.

    I could do a turbo small block, and have 90 percent of the parts to do it, and still flip flop about it back and forth all the time, but I imagine it would be pretty similar to what I just had. More displacement, less head flow, same turbo, a little less weight.

    Honestly, I was planning on consolidating all of my vehicles, the Monte (already sold it to a nice guy who is turning the body work into a father son project). My 2002 crown Victoria sport which is for sale that runs low 13s on the motor and mid 12s on the bottle. And dump my current toy a 2018 392 charger, and get a gen 2 or 3 viper.

    Then I stumbled upon this website. I read and read and read. I have had a supercharged car, and 2 turbocharged cars, and what I realized is that I really enjoy the feeling of driving a car with just a really big engine. I actually prefer my charger to my old Shelby as far as drivetrain wise.

    I’ve never had a big block, I’ve always wanted one, and I started kind of doing a cost benefit/comparative analysis of a viper vs a bbc c4 corvette, and the c4 stacks up incredibly well.

    Phase 1 of the project is going to be just getting the engine in there and running as cheaply as possible. Proof of concept if you will. Probably stock L29 with factory efi, mated to the 700r4.

    Once I get that sorted out, it’ll be time to build a motor and adding the t56. (Phase 2)

    Gen 2/3 Viper

    488-512 cubic inch aluminum v10 making 450-515 hp.


    Dana 44

    3250-3400 lbs. depending on the model.


    Blake’s proposed Phase 2 86 corvette

    489 cubic inch gen vi bbc 500-600 hp


    Dana 44

    3400-3500 lbs.

    Proposed budget 16k

    When you start considering other factors like durability and longevity, ease and cost of service, parts availability, etc. etc. the Vette starts to pull away. I could still elect to do the turbo sbc, but I really want a big block.
  9. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    you will enjoy a properly assembled BBC c4 corvette,
    I don,t know a single person who has done that BBC C4 swap that has regretted doing it!

  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Big Block Chevy is the way to go if you can wing it.
    Quirks to work out.
    Grumpy knows how to do it in a C4 Corvette.

    Pontiac vintage muscle you want to keep Poncho powered.
    Value is very high today.

    Potential to run true 11s on street with a C4 Powered by a BBC 496 is there.
  11. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    Welcome Blake. Good to see you are doing your homework first.:thumbsup::thumbsup::thumbsup:
  12. MarauderPrime

    MarauderPrime Member

    Grumpy, do you have any videos of that car cruising around? Also, I’m assuming the black one is yours. Do you still have it?
  13. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    no thats NOT my black c4 corvette,
    but yes Id love to own it! but Ive been supporting both my own and my sons family with a wife and three kids, for over a decade (hes got serious medical issues)
    Ive helped at least 7 guys do this swap over the last 25 years , most of those swaps were done in the owners home garages,
    and in most case it took months of off and on random, weekend work, as most guys just don,t have the finances, and tools, to do the job in a few days,
    so the swap process is done step by step, as time and cash flow allows,potential problems like exhaust systems,
    larger radiators, higher stall converters, oil coolers and accessory drives are added or swapped as the owners finances allow.
    the corvette in the pictures was a linginfelter built high dollar car
    youll occasionally see them used, for sale and if yourr not mechanically inclined purchasing a used one might be a good option,
    but theres certainly no reason a semi skilled hotrodder can not build something similar ,with his own unique mods and tweaks.
    to me the swap should start with, looking over the cars interior and over all body condition should be assessed , as you certainly will be
    investing a good deal of time cash and effort into the project. on the up side youll have a unique and rather impressively fast car once its complete,
    so you dont want to be driving a car with a crappy interior,rusted frame and body that needs massive reworking and paint or a new drive train.
  14. MarauderPrime

    MarauderPrime Member

    Look what the mail man brought me.......

    Attached Files:

  15. MarauderPrime

    MarauderPrime Member


    Attached Files:

  16. MarauderPrime

    MarauderPrime Member

    So that’s the c4 ZR1 evaporator cover I was talking about, that takes care of the valve cover clearance on the passenger side with standard l29 Vortec valve covers.

    Through my hours of reading and research, I have found that some folks say that the wiper motor fits, as long as you take it out for install and then reinstall it after the motor is physically bolted in place. Other people have said it doesn’t fit, then the other day I found a thread where someone referenced a “low profile” wiper motor. Is there a particular motor I am looking for from a c4? Is there one from another vehicle that fits that I have to use?
  17. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    do you know where to purchase a second
    similar evaporator cover? what was the cost?
    I've been trying to find a wiper motor thats a direct bolt on and plug in,
    replacement for the c4 corvette to give more valve cover clearance, even the SBC,
    with tall valve covers won,t easily clear the O.E.M. damn wiper motor,
    yes there are options like some other chevy / G.M. wiper motors,
    they can fit and function, but they all take rather extensive fabrication/modification
    Id suggest you, do what Id do, in that case..
    take careful measurements of the existing wiper motor and pictures, of the original O.>E.>M.
    motor and linkage connections,
    then visit several local salvage yards looking for likely potential candidates,
    and if you find one please post pictures and detailed info
    most guy have gone the (USE LOTS OF RAINX route and left the wiper motor off)
    Last edited: Jan 22, 2019
  18. MarauderPrime

    MarauderPrime Member

Share This Page