68 Camaro
What I've put together here is an overview of some of the modifications involved to swap a fuel injected motor (LT1) and overdrive automatic transmission (4L60E) from a 95 Z-28 into my red 68 Camaro. This is the latest in a series of engine and trans combos for this car over a period of 23 years. This swap was completed in 1997, so I've got a lot of time behind the wheel with it. I'm a hobby mechanic, not a HTML guru so bear with me as I muddle through this stuff.
As with any project of this nature there are inevitably hundreds of hours spent out in the garage and this is generally time spent away from your family. I'm a really lucky guy as my wife and daughter have shown great patience with me and have been supportive throughout. A better family a man could not have!
1. Physical swap
The motor bolts in just like any other small block Chevy on the planet.
The longer transmission required a original Turbo-400 trans cross member to be
modified (cut and boxed for clearance) Shorten the driveshaft and there she
sits. The air conditioning compressor will not fit in the Camaro as originally
mounted on the motor. (crossmember interference) This required a swap to a Corvette style accessory drive.
Perfect fit, just like back in 1968... Just a little update that's all. Here's a different view and also left and right side shots. |
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3. Wiring
I used the original engine harness from the donor Z and
cut/spliced/lengthened/rearranged as necessary to mate up with my 68's
wiring. I also used a engine bay mounted fuse box and relay panel from a 95 Camaro
to simplify the work. This will allow me to troubleshoot any future electronic malfunctions using the factory manuals. If you don't have access to a stock harness or don't want to bother with trying to adapt a stock one to your transplant victim vehicle, lots of people make custom harnesses. John Spears is one of
them, and I highly reccomend him for any "swaptronics" parts you need. I purchased a VAT (vehicle anti theft) box and ALDL (assembly line diagnostic link) plug from
John to complete the wiring on the inside. BTW, the factory Helms manuals from
the car you get the motor from are invaluable for a swap of this nature and well worth the $95 cost. There is no way I could've figured out the wiring without them. Since I completed this swap, you can now get CD or DVDs with multi-year and model service manuals. Check Ebay, things have gotten a lot cheaper since I bought mine in paper format. Another invaluable reference was the fuel injection swap book from Jags that Run (JTR). After a bit of head scratching and numerous mock-ups, I placed the PCM in the glove box rather than in the engine compartment. In this location, I only had to lengthen a few wires and it cleaned up the engine compartment a lot. I also placed an LED into my Autometer gauge cluster to function as my MIL (mafunction indication light, check engine light or whatever you want to call it). In addition, I've retained the A/C pressure and temperature inputs to the PCM to adapt to the Vintage Air unit I've installed to replace the clunky original Chevy unit. I now have a clean firewall with no large "suitcase" interfering with my headers. I installed a larger radiator (wider) than the original so I was also able
to use the Z's electric cooling fans and their associated control relays.
4. Transmission and VSS (vehicle speed sensor)
The 95 Z28 4L60E transmission originally used a VSS reluctor in place of the normal (for 68) mechanical speedo drive. The speedo on late model Camaros is electrically driven and there is no provision for mechanical drive. To run the trans properly and get it to shift on time a VSS signal must be sent to the PCM (Powertrain Control Module), ie; the computer. The PCM uses the VSS data in combination with variables stored in it's flash memory (tire size, gear ratio, etc.) to determine vehicle speed. To get the original Camaro mechanical speedo to work and also have the proper
VSS function for the PCM you must have both types of drives, mechanical and electrical. Here's what I
did. Since the original stock reluctor is pressed on the tailshaft in the same location
as the old speedo drives were in years back, I removed the reluctor,
drilled a locating hole in the tailshaft for a mechanical speedo drive (carbide bit
required... tail shaft is VERY hard) and retrofit mechanical speedo parts in
this location and in the trans extension housing. I then placed the
original VSS reluctor about 3/4" behind the speedo drive and drilled the
extension housing to adapt a smaller VSS as used on the 6 speed manual
transmissions. Works very well and the mechanical speedo was only 10% off my first try. I'll be swapping driven gears to calibrate the speedo as soon as I finalize my tire selection.. The computer 's tables for VSS indication is another matter however.
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5. PCM stuff I have 3.73 gears and 15" tires on the Camaro so I had PCM indicated speed and trans shifting problems at WOT. Around town it was seamless and perfect.... Would never know there was a mismatch..........At WOT however, a different story...... The computer would not allow me to shift at full throttle at anything less than 6100 rpm. A little history here... I got my PCM from a car that did not have Z rated tires so there was a top speed cut off at a PCM indicated 124mph, which due to my gearing I reached at an actual 84 mph..... total injector shut down....... |
Fits well, here's a tighter shot |
Wonder if the local constabulary was curious about the evidence of my tirespin problem I left around the area? It's been long time since I've last talked to Ron and I have long since lost his contact info.
6. EGR and LT4 heads
The LT4 as installed on the 96 Corvette did not use any external EGR. Enough "internal EGR" was available due to the overlap of the cam so the external EGR valve could be deleted. On the 96 Corvette the EGR openings were covered with block off plates and I have done the same with plates procured from Street and Performance. I originally had planned on using EGR and had a fitting welded onto the passenger side header. I never got around to hooking it up however and ended up deciding against it. If you look at the right side engine picture you'll see the unused fitting. The LT4 heads came with lightweight 2" intake valves and revised intake ports improving the injector targeting somewhat. Since my car has been running with the swap, I have only once got a code for EGR and that was under a very high load, low RPM condition. I cleared the code and it has not repeated. Additionally, since swapping to the "HOT" cam even with the "lope" at idle, no codes have popped up. Here's a few shots and more details on the uninstalled heads and intake.
7. Driving impressions..
Wow!!! Lots of fun around town and a relatively quiet on the
freeway due to the overdrive. I'm extremely traction limited so I pretty
much walk it off the line for now until I get my tire situation
straightened out. It idled smoothly with the original LT1 cam (too smooth actually, that's why the
upgrade to the HOT cam), sets no PCM codes, gets great mileage and never
comes close to overheating even in Las Vegas 110 degree temps in traffic. Now that the LT4 head and HOT cam swap are complete, I have increased my traction problem a great deal....
50% of the folks who try to read my plate |
Once upon a time I was trying to learn HTML... Much to my dismay, learning by hacking and copying takes way too much effort....... Talk about a time-waster..... And I thought IRC was bad!
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John Spears for technical guidance relating to VATS and VSS along with procuring the oddball electrical parts. WEB PAGE
Dave and Don at K&L Auto Wrecking in Las Vegas. (702) 644-5544. My number one source for early Camaro information and parts. They don't do fuel injection or computers but if you need early Chevy muscle car parts or even a complete rust free car ready for restoration, these are the guys to call. They have helped me out of more jams than I can count with expert advice and the right parts when I needed them.
Louie at Fairway Chevrolet in Las Vegas for invaluable help and patience while researching innumerable parts for the conversion. On many a day I would be in there for hours poring over the parts listings for Camaros, Corvettes and any other donor we could find in order to find parts to smooth the swap. Often I would only walk out with $5 in parts....But other days much, much more.....
Terry Martin for the uncanny ability during the engine installation thrash to say "Hey we won't be able to finish it tonight, go sleep on it and figure out the problems tomorrow." Needless to say his guidance was exceptional 'cause a break was just what I needed and the car was up and running the next day.
Dal Slabaugh for incredible prices and service second to none on dealer Chevy parts.
Billy Graham at Graham's Camaro/Firebird Salvage in Alabama for lot's of nit-noy this and that, saving me a few dollars over new parts. Give him a call if you are thinking about an LT1 conversion. He's a neat guy to talk to and he's got the parts! (1-800-824-3897)
Please feel free to Email me with
any questions or suggestions regarding this work in progress. (either the Camaro or this beginner's attempt at a web page). My Camaro has been a driver in it's current configuration since April 97 but I'm
continually making changes and improvements... Most recently completed is a swap to 3.73 gears, Moser axles and rebuilt posi unit.... I need to do some "track testing" to if I can lower my E.T. a bit more.
I've got a few more things to do and then I'll scan some more pictures and get this web page up to speed. It's hard to type with dirty hands ;-)
Questions? Drop me a line.... (spam free address, remove the x's)[email protected]
