SCCA Camaro

I had just a few things left to do on the 68 Camaro before I could fire it up.  I had to wire the fuel pump, and hang the radiator support and passenger side fenders, and install an air filter and intake to the BBK/Edelbrock 58 mm throttle body.  I also needed to sort out some of the wiring and reroute a few wires that were originally routed to the passenger side via the core support but would now reside on the driver’s side because of the relocation of the alternator when I installed the TPI serpentine set-up.  I would also take this opportunity to put the Spal fan relays on the driver’s side to keep the wires to the alternator short.  Wiring the Walbro 255 external fuel pump (PN GSL-392) went pretty quickly:  I grounded it right at the rear frame rail it was mounted on; the Holley Commander 950 is pre-wired to run a fuel pump.  I merely ran the wire under the door sill and drilled a small hole in the floor under the rear seat.  I used a rubber grommet around the wire passing through the floor of course and crimped a connector on it there.  Rerouting the wires of the front wiring harness was just a matter of cutting my cable ties, unwinding some of the wires, laying them back out headed in their new direction, and putting cable ties back on. 

Hanging the core support was equally uneventful, as was putting the passenger side inner and outer fenders back together.  I measured the diagonals across the engine bay and had to push the front end around a bit to make sure it was perfectly square.  I had saved the shim pack for the fenders so it was easy to get everything lined back up properly again.  I put the hood back on by myself, which is a little less fun than with a helper by the way.  I purchased a cone-type air filter with plumbing for the throttle body on eBay and I had to do two slight modifications to make it work.  The first was that I needed to get a larger diameter, six inch worm clamp, because I was running the 58mm throttle body.  I found an inexpensive stainless steel clamp at Home Depot.  The second was the tubing didn’t line up well with my core support and radiator.  I cut about two and half inches off one of the aluminum tubes to fix this problem.

At this point I was ready to test the fuel plumbing.  I reconnected the battery and put the ignition in the accessory position so the fuel pump would develop some pressure.  Several cycles of the fuel pump revealed minor leaks at a few of the couplings, all of which were stopped by simply tightening up the connections.  It was time to load an appropriate program into the Holley Commander 950 ECU and attempt to start the Camaro!  I decided to use the Wbmp3008 base map, which was described as: 355 small block Chevy, 30 lb./hr. injectors, Stealth Ram intake, 58mm throttle body, 20 degree Holley heads,

Lunati 30142 cam (235/245 @ .050, .507/.534, 112 LC), 9.5:1 compression, 43 PSI fuel pressure, 418 HP @ 5500 RPM, 422 ft./lbs. @ 4700 RPM.  While the duration on my Comp Cam (PN 12-465-8) was a little shorter at 210/218 @ .050, I had higher lift at .560/.555”, so figured it would be pretty decent base map to start with, although volumetric efficiency for my car would probably be a little higher at lower RPM and a little lower at higher RPM.  I figured my AFR heads would perform similarly to the Holley heads.

The 355 sbc roared to life on the second cranking attempt and then it was time to start tuning!  I had exactly one week before my next SCCA Solo II autocross event.

The next order of business was to put a serpentine belt system on the small block Chevy in my 68 Camaro for Autocrossing in SCCA Solo II.  I had just completed the cam swap and the Holley Stealth Ram intake installation, including plumbing all of the fuel lines, installing the sensors, ECU, injectors, and wiring harness.  I couldn’t yet start the car because I didn’t have the accessories installed and I didn’t want to put the old water pump and alternator back on the car, I wanted to go with a modern serpentine belt set-up.  I did some research on the aftermarket pieces, which look nice, like the Front Runner from Vintage Air that Detroit Speed and Engineering distributes, and some from March Industries, Billet Specialties, and Zoops.  I also looked at the GM replacement/upgrade piece offered by GM Performance Products.  In the end a used TPI set-up made the most sense to me mostly because I am not building a show car and I’m mostly interested in low cost, high benefit options.  The best deals I found on complete TPI serpentine set-ups were on eBay, where several sellers offered all the brackets plus the idle puller for the AIR pump and all of the bolts for less than half of the GMPP serpentine set-up and about a quarter of the cost of a new aftermarket set of brackets and pulleys.

I worked with my eBay TPI serpentine seller who told me exactly what water pump or order.  I needed the long style reverse rotation pump, which I also found on eBay.  My TPI kit arrived with all of the brackets, pulleys, and bolts as advertized plus the idle pulleys for both the AIR pump and the air conditioning.  While trying the brackets on the Camaro I realized I would have to clearance the holes a bit because they didn’t align perfectly with the accessory bolt holes on the AFR heads.  The brackets also had to be clearanced a bit around the water pump.  What I didn’t figure out until I was trying the brackets on the block was that I couldn’t reuse my alternator since the alternator housing is different, so I sourced a new alternator off eBay as well.  The vendor I found rebuilds them regularly and built a 140 amp TPI alternator for me with one wire hookup with the correct housing in a matte finish.  He also had them in chrome for the bling set.  I was hoping to find a way to run my Detroit Speed and Engineering power steering pump with the TPI serpentine belt set-up but there was no way it was going to bolt right up.

Using the Detroit Speed and Engineering power steering pump with the TPI serpentine belt had two problems: the integrated pump/reservoir that I had didn’t bolt directly into the brackets, and the TPI pulley had the wrong diameter for the shaft from the power steering pump, which was 0.620” nominal.  For solutions I first figured out a pocket in the brackets in which I could mount the pump.  With some minimal cutting off of mounting tabs and clearancing I figured out a nice place for it down low on the driver’s side of the block.  Initially I thought I might have to mount it at an angle and I called Stacy at Detroit Speed to talk to her about how well it would work.  She confirmed up to 10 degrees might be OK but obviously less is better.  I decided to take the bracket that Detroit Speed had originally sold me to mount the pump to a small block Chevy with traditional belts and weld it to the TPI bracket.  Once I figured out where within the bracket it needed to be to mount the pump correctly, I machined a channel in the bracket to receive the bracket and then took it to Ted’s Machine shop here on O’ahu to weld the two together since my little mig welder was not up to the task of welding a few half inch thick pieces of aluminum together.

I sourced the serpentine belt power steering pulley with the correct outer diameter for pump RPM and the inner diameter for correct press fit from Vinatage Air.  The results looked great and bolted right up.  All of the accessories were in place although I had to re-route a lot of my wiring harness because the alternator was originally on the passenger’s side and now resided on the driver’s side of the car.  The belt (GM PN 10105246) went right in and the accessories worked great.  You can get it anywhere by referencing the application of 1992 Camaro with V8.  I did need to adjust the flexible radiator hoses to route them away from the belt on the bottom and away from the alternator fan on the top but otherwise the TPI install was nice and neat.  I took this opportunity to machine a few 1.3” spacers from stainless steel to set the radiator back from the core support to improve weight distribution in the Camaro.

I had installed the Holley Stealth Ram in my 68 Camaro SS for SCCA Solo II autocross competition in the CP class, but I still had fuel plumbing to do.  I started with a Walbro 255 external pump (PN GSL-392) rated at 255 liters per hour, some OEM-style fuel filters (WIX 33481), some 3/8ths steel brake lines from NAPA, some 3/8ths tube nuts, 3/8ths barb fittings, 6 feet of 3/8ths SAE J30 rubber fuel hose rated for fuel injection, and some couplings.  I also had a tubing bending tool, and a double flare tool but did a lot of the tubing bending by hand.  The basic drill was the 68 Camaro is an original SS, so had a 3/8^ths fuel line from the tank to the engine bay already.  I decided to use this as my supply line.  From the factory it was a single tube from the sending unit all the way to the fuel pump on the block.  This was unwieldy for taking on and off the car so I cut it in the middle and made a coupling there with a couple of double-flares so it would be easier to manage.  The front half I left alone for now, and the rear half I bent and cut to put the Walbro pump in line.  I initially put a fuel filter in line upstream from the pump as you can see in the picture, but later changed this by putting the filter downstream in the engine bay.  I had already welded a return line into my sending unit and put a flare on the end to act as a barb.  The original sending unit pick-up line had a flare on it with a rubber coupling to the fuel supply line, so all I had to do was use some of the SAE J30 hose here.  Then I cut the back half of the original supply line, put two flare nuts on the ends and flared the tube.  The local NAPA had a coupling to go from the tubing flare nut to the in and out ports on the Walbro pump so I was in business.  I also purchased some tubing clamps from NAPA to secure the tubing. 

In the engine bay I merely bent the fuel supply line up away from the headers, cut it, and flared it for a connection via rubber hose to the supply side of the fuel rails on the Holley Stealth Ram.  Mine was missing the fitting, so I purchased an AN-6 to 3/8ths barb 90 degree fitting to connect the supply line to the supply rail using the fuel injection-rated hose.  Next in the plumbing was the connection from the passenger side rail to the driver side fuel rail, and again I was missing this connection.  Two more AN-6 to 3/8ths bard 90 degree fittings and a length of the SAE J30 hose got the job done here.  At the pressure regulator on the driver side fuel rail the unspent fuel starts its return path to the tank.  Here my eBay-sourced Holley Stealth Ram was also missing the fitting I needed for the return line.  It turns out it was a Saginaw fitting, a metric fitting GM uses for power steering and fuel lines with an odd shoulder flare and an O-ring.  This was very difficult to find locally here in Honolulu, but I did finally find a fuel line repair fitting at Red-Line Auto.  This I screwed directly into the fuel regulator; I flared the other end so I could use some more of the rubber SAE J30 fuel hose to my fuel return line.  For the fuel return line, I used two pre-fabbed 5 feet long sections of 3/8^th steel brake lines from NAPA.  I bent them both by hand to more or less follow the fuel supply line on the passenger side of the car along the subframe and back to the fuel tank.  When the bends were tighter I switched over to the tubing bender so as not to kink the tubing and secured both of the lines to the car with the tubing clamps from NAPA.  Another short section of the SAE J30 rubber hose isolated the fuel return line from the 3/8ths fuel line of the sending unit.  I wasn’t sure yet what I’d do regarding a fuel pressure gauge but thought the rubber hose in the engine bay would give me some flexibility to do that later…