the c4-bbc engine swap

grumpyvette

Administrator
Staff member
hood scoop related info
viewtopic.php?f=35&t=353&p=5243&hilit=hood+scoop#p5243

viewtopic.php?f=55&t=8961&p=31945&hilit=hood+vents#p31945

viewtopic.php?f=55&t=8961&p=31945#p31945

a custom built side exhaust would be an option

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grumpyvette

Administrator
Staff member

some options on building a custom built 9" ford based center section for an independent rear suspension differential, now if you can weld and have access to a decent machine shop you obviously have other options but its nice to see new suppliers


http://www.currieenterprises.com/cestor ... px?id=3498
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http://www.driveshaftshop.com/kit-car-m ... r-self-kit
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Product Description
We have been getting a lot of calls from people wanting to put our Independent 9" kit under everything from a Subaru WRX to a Street Rod, so we decided to come up with this do-it-yourself kit that will allow a talented fabricator to put this diff under just about any car. The rear will be 17.25" from flange to flange when assembled and comes with the bare case, the 31 spline 1400HP stubs (new 33 spline stubs coming soon) and also a ring that will mount on the front of the differential pinion support so you have something to weld your front brackets to. Give us a call for more info!!!
 

grumpyvette

Administrator
Staff member
cutter1 took this pictures of his big block chevy C4 corvette install process
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hood scoop related info
viewtopic.php?f=35&t=353&p=5243&hilit=hood+scoop#p5243


we all make mistakes, but if you never try anything new with out some risk,
you can never hope to learn or add skills, most of us learn by, hands on, experience.
and it helps if you watch, and learn from other people success and failures
you can significantly lower the risk by simply finding a knowledgeable mentor ,
(Ideally local) if its a skill that requires manual dexterity, or visual acuity,
that can point out the things you need to to look for,
in how the jobs done and the best tools required.(and what to avoid)
that has already made those mistakes and knows how to avoid most of them,
who might be willing to pass on those experiences and skills

TEST FITTING THE BIG BLOCK ENGINE IN THE c4 CORVETTE
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modified HEADMAN bbc 1970 corvette headers to fit the 1985-96 corvette with a big block

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modified evaporator cover in pass side engine compartment to get clearance for big block engine install
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CUSTOM ACCESSORY BRACKETS
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remember the lower radiator hose has an internal spring to prevent it collapsing under suction from the water pump, failure to use a re-enforced lower can cause a flow restriction and potential over heating issues

IF your going to need to fabricate a custom lower radiator hose, you might want to install a convenient drain

lowdrain1.jpg

http://www.jegs.com/webapp/wcs/stores/s ... ator+drain

When you go to look for a lower radiator hose you can either use a long flexible generic radiator hose or two shorter hoses clamped to as short section of stainless exhaust pipe curved section, or you might find that the only reasonable option is to fabricate /weld some curved sections of appropriate size stainless exhaust pipe, and use short sections of rubber hose with clamps to route coolant

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or fabricate something similar to that new exhaust header primary pipe after careful measurement and test fitting
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grumpyvette

Administrator
Staff member
FOUND THIS POST ON A DIFFERENT FORUM

viewtopic.php?f=55&t=8961&p=31945&hilit=duct+hood+cool#p31945

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"Did this swap on a customers car (it was more of a race car).

Details of my experience doing a C4 BBC swap:

1) Custom headers make the swap a BREEZE. (I have some custom used 2" jethot coated longtube headers for sale for a BBC c4 swap for sale, email me ltmotorsport@hotmail.com) They give you more room than the small block headers did! you can work on the motor EASY.

2) Dont move the rack. Just use a flat single groove crank pulley, short 64 396 chevelle style water pump (use pulley spacers to line up) and make your own altenator bracket etc.

3) Take out the A/C box and life is easy.

4) The windshield wiper motor is going to hit. i just took it off.

5) Use the stock small block motor mounts bolted to the BBC engine.

6) Cowl hood or a REALLY low intake.

The headers are the hardest part really. Its really just a drop in easy swap.

The car weighed 3300 lbs (/w driver) and dynoed 468 rwhp on motor. It ran a 10.7 @ 125 on pump gas. 12 mpg. Dana 44 3.73 gears, TH350 3500 converter.
 

grumpyvette

Administrator
Staff member
there have been guys that have the financial resources or connections and or skills to have built an independent rear differential , based on the far stronger DANA 60 vs the factory supplied dana 36 or dana 44 , which are comparable to the G.M. 10 bolt rears, hardly impressive or known for strength or durability, to fit the corvette frame, obviously this takes a good deal of time,effort and money but it also can result in an exceptionally strong rear differential
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yes its very unfortunate that there's no commonly, available, and reasonably priced, independent rear differential,available to the performance car enthusiasts,with large disc brakes in the compatible width, and easily retro fitted suspension mounts that I'm aware of, in most local salvage yards , similar to the corvette rear suspension, that has the strength of the dana 60 rear differential.
yes there are custom fabricated solutions, if you have a very healthy bank balance , but nothing based on a dana 60-70- or ford 9" or heavier duty independent G.M. differential
 
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Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
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While not exactly a subtle-looking '91 from the outside due to the exterior body kit and 3-inch raised hoodscoop, Cleon Stull's Corvette hides a big punch: a 509ci big-block engine.


It doesn't really take the proverbial shoehorn to install a big-block Chevy in a C4 Corvette. What it really takes is talent and an eye for details. But it doesn't hurt if you're a tool-and-die maker like Cleon Stull of Frederick, Maryland.

Stull's garage has provided shelter for many Corvettes in the past, including a '65 roadster and '86 and '96 coupes. Currently, he owns a '91 ZR2 coupe, a '72 454ci convertible, and an '01 convertible. But, even with all those interesting Corvette configurations, Cleon was looking for something a little uncharacteristic, a car that no one else had. The solution: build a big-block C4 Corvette.


For those not versed in the intricacies of such a swap, let us assure you that the challenge is very real. Our resident engineering expert, Chris Petris of The Corvette Clinic, (see sidebar), will attest to the difficult modifications that are required. But for Cleon, his apparent satisfaction with the final effort validates the old adage: Anything worth doing is worth doing well.

Cleon started with a well-worn '91 Corvette he found on the Internet. While the body was clean, the paint was tired. He installed a Side Effects body kit and applied Twilight Royal Purple paint. Inside, Cleon added saddle leather upholstery but retained the stock configuration for all other components.

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The 509ci engine has been modified with a number of high-performance parts including Edelbrock cylinder heads and intake system, Lunati rods, pistons and camshaft, and a Comp Cams rocker system.

Clearly, the biggest changes occurred underhood. The 509ci engine (built by Jeff Bane of County Engine) features a host of horsepower improvements including Lunati rods and camshaft (0.578-inch intake lift, 0.595-inch exhaust lift), and Comp Cams rocker arms. Compression is 10:1, courtesy of Lunati pistons and Edelbrock cylinder heads.

An Edelbrock Performance intake and a Pro-Flo EFI unit provide the induction, while customized Hedman headers show exhaust gases the way out, complemented by 3-inch-wide stainless steel tubing and Lawrence-Keech mufflers. Cleon machined his own distributor to clear the firewall, and added an HEI electronic distributor. The huge power is transferred to the rear tires through a manual six-speed transmission controlled by a B&M Ripper shifter.

While the car logged 140,000 miles previous to Cleon's ownership, the current configuration is still in shakedown mode with only 500 miles so far. Regardless, Cleon has great confidence in the abilities of his engineering. He, along with technical consultant Bob Loch, have engineered a seemingly bulletproof combination. So well built is the car that we suggested Cleon offer a prepackaged kit so that other Corvette owners could re-create his efforts.

No doubt, a shoehorn will not be part of the package.

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The interior of the '91 is very much as the factory delivered, with the exception of saddle-leather seating and the B&M Ripper shifter to command the six-speed manual transmission.

There are two major challenges when attempting to install a big-block into an '84-'96 Corvette. The first is being able to close the hood while preventing the oil pan from hanging dangerously close to the pavement. The second is to retain all the vehicle options we hold so dear.

Specifically, the biggest problems are the power-steering pump and air-conditioning compressor, which come close to the lower crossmember, power-steering rack, and chassis brace. This is where Cleon Stull's 509ci effort shines. All of his custom-made accessory brackets were well planned, with adequate bracing. Cleon even designed and created a self-adjusting serpentine-belt tensioner. If you've ever installed an aftermarket accessory such as air conditioning, you know how difficult it can be simply to ensure belt alignment. Cleon did an excellent job of making all the necessary components come together and fit in tight confines.

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The Twilight Royal Purple paint is a unique color for Corvettes, but not shocking since Cleon's big-block machine is full of surprises.

The crossmember, or K-frame, that supports the engine required modification to allow clearance for the lower crankshaft pulley and harmonic balancer. Anytime a crucial chassis component is modified, safety is critical, and it's obvious that Stull went that extra mile. The oil pan is close to the pavement, but clearance is adequate. An engine swap requires a careful balance of engine and component placement.

The air cleaner and air-intake system are also well thought out. Obviously, the clearance between the intake system and hood is minimal. The Edelbrock Pro-Flo fuel system allows adequate fuel control and air filtration with minimal hood rise. The billet ignition distributor built by Cleon shows his attention to detail. He machined a completely new housing for the application, which keeps engine rise to a minimum. It is this kind of elaborate workmanship that's required to ensure proper engine placement and chassis compatibility.

It is obvious that Cleon thought about the project before any wrenches were used, and it paid off with a nice, clean, workable installation of a big-block in his C4. My hat is off to Cleon for a job well done. Happy motoring!

-Chris Petris
 

Maniacmechanic1

solid fixture here in the forum
THE BIG BLOCK/C4 SWAP JUST GOT EASIER, THESE GUYS HAVE AN ADAPTER KIT THAT ALLOWS YOU TO INSTALL A 4l80e AND USE THE ORIGINAL DRIVE SHAFT, NO COMPUTER,AND THE STOCK c-BEAM THE ADAPTER AND THE HARDENED 4L80E OUTPUT SHAFT ARE SOLD AS A KIT FOR ABOUT $750, THE
4l80E trans set up for full manual control with that kit and all the best internal parts will cost in the $4500-$5300 range

the 700r4 will eventually fail if your running over 450 ft lbs of torque, PERIOD!

there ARE FULL MANUAL CONTROL SHIFT KITS AVAILABLE FOR THE 4L80E
so you don,t use a controller
this requires you to change gears manually but theres no clutch pedal to press

http://www.artmorrison.com/multi-link-IRS.php

there are also 6 speed versions
http://www.summitracing.com/parts/TCI-2 ... mage=large

http://www.performancetransparts.com/in ... &ProdID=71

http://www.transmissioncenter.net/4L80E.htm

http://bowlertransmissions.com/
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the C-beam differs between the dana 36 and dana 44 rear differentials
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"4L80E in C4 Corvette Adapter (1984 - 1996). Swap your 700R4 / 4L60E transmission to the much stronger 4L80E transmission with our new double strength case hardened output shaft and adapter kit. At this time we have in development an adapter kit for the C4 Corvette to replace your 700R4 / 4L60E transmission with the much stronger 4L80E transmission. This 4L80E transmission will be the same length as your 700R4 / 4L60E transmission making it possible to reuse your existing 27 spline driveshaft and C-beam. This is the worlds first 700R4 / 4L60E to 4L80E swap direct replacement. All that needs to be changed on the 4L80E transmission is the tail housing and output shaft. The full manual shift model works without a computer.'
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BIGGER
https://transmissioncenter.net/shop/patc-innovations/

2006 – 4L80E in C4 Corvette Adapter Kit (1984 – 1996). Swap your 700R4 / 4L60E transmission to the much stronger 4L80E transmission with our new double strength case hardened output shaft and adapter kit. At this time we have in development an adapter kit for the C4 Corvette to replace your 700R4 / 4L60E transmission with the much stronger 4L80E transmission. This 4L80E transmission will be the same length as your 700R4 / 4L60E transmission making it possible to reuse your existing 27 spline driveshaft and C-beam. This is the worlds first 700R4 / 4L60E to 4L80E swap direct replacement. All that needs to be changed on the 4L80E transmission is the tail housing and output shaft. The full manual shift model works without a computer. We are also working on a C4 Corvette 4l80e
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https://transmissioncenter.net/shop/patc-innovations/
BIGGER
http://www.transmissioncenter.net/HPIM1242.JPG
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driveloop2
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THIS GOES A long way TOWARDS REMOVING MUCH OF THE POTENTIAL PROBLEMS THE WEAK STOCK 700r4 TRANS POSED

RELATED INFO
http://garage.grumpysperformance.co...lt-center-section-installed.11491/#post-53588

add one of these aluminum big blocks and LOOSE 100LBS off the front end compared to a small block, and more than double the power, even with the 4L80E the car will weight about the same but the center of gravity will be lower and further back
http://www.theengineshop.com/pdfs/merlin.pdf

SIX SPEED MANUAL WITH OVER DRIVE

http://americanpowertrain.com/i-8521636 ... or-gm.html

you can use a computer to control the trans

http://www.sallee-chevrolet.com/fram...60E_4L80E.html

http://www.compushift.com/

http://www.highperformancecars.com/crosley/transize.htm

http://www.levelten.com/store/gm/ite...8000_trans.htm

http://www.duramax.bizhosting.com/My...on_control.htm

BUT the 4L80E can BE converted TO FULL MANUAL CONTROL

http://www.drivetrain.com/transgoshiftkits.html

http://www.eatmyshifts.com/combo_kits.htm

http://www.txchange.com/tgp.htm

http://www.automatictransmission.com...sp?NewsId=8611



http://www.transmissioncenter.net/4L80E.htm

#C480. 4L80E in C4 Corvette Adapter (1984 - 1996). Swap your 700R4 / 4L60E transmission to the much stronger 4L80E transmission with our new double strength case hardened output shaft and adapter kit. At this time we have an adapter kit for the C4 Corvette to replace your 700R4 / 4L60E transmission with the much stronger 4L80E transmission. This 4L80E transmission will be the same length as your 700R4 / 4L60E transmission making it possible to reuse your existing 27 spline driveshaft and C-beam. All that needs to be changed on the 4L80E transmission is the tail housing and output shaft. The full manual shift model works without a computer. This tail housing is made of 6061T6 aircraft aluminum. Cost $599.00


THESE THREADs may give you some info

http://www.digitalcorvettes.com/foru...ead.php?t=1756


http://www.joby.se/corvette/mods/2004-12-26_4l80/

http://www.joby.se/corvette/mods//2001-0X11_diff/

BTW if you think your corvettes dana 36 or dana 44 independent rear differential will stand up to a Healthy small block with nitrous or a well built big block engine swap,once you used slicks with decent traction, you might be rather shocked, at what might result.
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$5k seems to be a magic number for the good stuff Grumpy.
That PATC Monster 4L80E Tailshaft kit for a C4 is no longer made.
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
RAMROD 92 posted this info


yes thats an aluminum BBC and it weights about the same as the stock O.E.M. SBC that came in the car

Atually, the ZR1 weights the same at the front. It starts to widen at the doors. Here's Phil Tobin's 555 in his 93.
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And if you do go that route, you'll need more time and $$$ for stuff like this
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And when that's not enough, you start adding nasty stuff like this
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It's an addiction....
 

Maniacmechanic1

solid fixture here in the forum
A mechanic can not get the money anytime soon typical Grumpy.
Need A Race Car to go do battle with.
Get the sidework then for the Corvette project.

Pontiac Trans Am with a Solid axle rear.
Nothing to break doing Street Outlaws.
 
Grumpy, do you have any pictures of the rack mount modifications to relocate the rack forward? People keep complaining about reverse ackerman and bumpsteer. The .75” won’t be noticeable. These people have clearly never driven a g-body, or any of the rwd mopar products from 2003-now.

anyway, I have a gen vi L29 with the stock truck “4 qt.” Pan (it looks relatively easy to fit). That I want to make a run at installing in my 86.
 

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Where do I get a crank pulley like the one in the bottom poc? I’m ordering the qwik performance sbc to bbc adapters and their crank pulley adapter. They confirmed via e-mail that the c4 accessories will bolt up in basically the stock locations with their adapters.

i already have the LT5 evap housing. Will the stock gen vi bbc short valve covers clear the wiper motor assembly?
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
https://marchperformance.com/chevy-...ance-ratio-6-rib-serpentine-crank-pulley.html

Im not 100% sure as its been over 10 years since I bought the lower pulley but I think this is it,
used with the short style bbc water pump, they sell the matched upper pulley also.
remember theres standard and reverse rotation water pumps so you need to be sure what belt config you use matches pump rotation direction

https://www.jegs.com/i/JEGS/555/51067/10002/-1

https://www.ebay.com/i/114247504163...MIgP-bpJPX6wIVDtvACh3AMwT-EAQYASABEgJVZPD_BwE

"Will the stock gen vi bbc short valve covers clear the wiper motor assembly?"

generally NO! but you have options Ive seen most guys, doing the swap, just use RAINX on the windshields,(It works fine)
and do without, but Ive also seen guys adapt windshield wiper motors, and I have not found the source yet, but Ill pust when I do.
 
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Do you want me to start a new thread for the build, or do you think an install would dovetail nicely with the info in this thread, and then I can make callouts to specific post numbers in it?
 
Also, in that very bottom picture with the pretty crankshaft pulley, has that rack been moved forward, or were you illustrating that that pulley cleared without modification
 
I Just ordered the Kwik Performance sbc to bbc crank pulley adapter. I am going to bolt a Stock C4 crank Pulley onto this L29 and take some measurements. Keep your fingers crossed.

Patc no longer sells their 4l80e c4 kit.

I have been trying to get ahold of PeteZR1 for one of his tailshaft kits, to no avail.

Recently i have been considering running a zf6 since the car is basically an empty shell start from scratch thanks to “The Vette Doctor Inc.”

A fair anount of research leads me to believe I can physically bolt an L98/LT1 flywheel to the L29 since they are both 1 pc rms motors. The only difference being that the 454 is externally balanced.

https://www.holley.com/products/drivetrain/flywheels/flywheel_accessories/parts/RM-526

That sandwiches in between the flywheel and the crank and gives it the right weight. Will that part allow me to run the l98 153 tooth flywheel on my gen vi?
 

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
I don,t see why the separate balance plate won,t work, with the smaller 153 tooth flywheel,
on a 454 bbc engine if the assemblies been balanced with that,
but personally I'd balance my whole rotating assembly before using it in any engine I built, just to be sure.
 
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