May 4th, 2008
I decided to get the ’68 Camaro’s engine block down to a state in which I could complete the camshaft swap and build it back up using all of the EFI parts I had accumulated. These included the Holley Stealth Ram intake and plenum, fuel rails, fuel injectors, fuel regulator, BBK 58 mm throttle body, GM small body computer-controlled distributor, and MAP, IAT, TPS, and temperature sensors. The camshaft I chose was a retrofit hydraulic roller from Comp Cams with retro roller lifters, new pushrods, and full roller rockers in 1.6:1 ratio. I started with removal of the air cleaner and carburetor linkage, followed by the distributor. I regrettably removed the alternator and attendant brackets (I had just gotten them aligned correctly after many weeks of loosing belts during SCCA Solo II events). I removed the Edelbrock 1406 carb and Chevy cast iron intake as a unit, and was able to start working on getting the heads off. Of course this requires removal of the headers, and in fact on the driver’s side the headers need to be completely removed from the engine bay from underneath the car in order to remove the head, because of how close the steering gear box is to the engine. Once the heads were off the car I inspected them and the pistons to make sure I had only the one bent valvestem. I confirmed I had only one bent valvestem and took the head to Ted’s Machine Shop here in Honolulu. Craig had them fixed up in a few days; it would be awhile before they were re-united with the block.
The radiator had to come out of the Camaro in order to pull off the cam swap, and I had substantial corrosion of the sheet metal of both the core support and the passenger’s side inner fender, particularly around where the battery tray used to be, probably as a result of leaky battery at some point in the forty year history of the ‘68 Camaro. I had purchased replacements for both from Classic Industries and I decided to take them out in order to create some room to work, figuring I would replace these while I had the front end of the car apart. This necessitated not only removal of the radiator, but the hood, front wiring harness, passenger side headlight bucket, and horns. Separating the inner fender from the outer fender yielded a big surprize: my Camaro’s build sheet! Alas, it was too far gone to recover or even to read anything off of. Nonetheless, I saved what I could of it…
With the disassembly nearly complete, I turned my attention again to the engine. It was time to remove the water pump, which was an Chevrolet cast iron pump that I wouldn’t be re-using, because I was also going to install a serpentine belt front accessory drive from a TPI Camaro on the engine block after the cam swap. I borrowed a harmonic damper pulley from Craig at Ted’s Machine Shop when I picked up my repaired AFR head, and used it to remove the damper so I could take the old stamped-steel timing chain cover off the block. I had to loosen the bolts on the oil pan and tilt the front end of the pan down to remove the timing cover. This revealed the timing gears, which were the OEM style. Removal of the timing gear from the cam allowed the chain to come off; I put the gear back on the cam to aid in removal of the camshaft. The cam started out rather smoothly, but about a third of the way out it hung up and I couldn’t seem to get it moving again. Not wanting to force the issue, I took a break and leaned back. Then it dawned on me—I hadn’t removed the fuel pump, and the fuel pump plunger was catching the cam. A few bolts later and I had the fuel pump off and quickly thereafter the camshaft was out.
Posted in Building an Autocross Car | Comments Off
April 23rd, 2008
Since I had a bent valvestem in the ‘68 Camaro and the head had to come off to be repaired, and I had three months before the next SCCA Solo II autocross event here in Honolulu, I decided to take the plunge into the Electronic Fuel Injection (EFI) realm that I had been planning for over a year. The first thing I did was make sure I had as many things ordered as I could think of that I knew I needed for the conversion to EFI. I had already ordered the Comp Cams Camshaft (PN 12-465-8), retro roller lifters (PN 853-16), pushrods (PN 7809-16), timing chain set (PN 3100), and the full roller rockers (PN 1416-16) discussed in an earlier blog, and they were all in my possession by now. Additionally, I had a Holley Stealth Ram intake, with fuel rails, injectors, a wiring harness, upper plenum, and with a BBK/Edelbrock 58mm throttle body that I had purchased used on eBay. I had to order the gaskets that mate the intake manifold with the upper plenum (Holley PN 108-119).
I had the GM small cap computer-controlled distributor with an MSD external coil (MSD Blaster GM coil PN 8226) and MSD Street Fire spark plug wires (MSD PN 5570). The MAP, IAT, and coolant temp sensors can be sourced from your local auto parts store since they are OEM for ’92 Camaro (and many other applications). I had already installed the Commander 950 along with the Bosch wide band oxygen sensor (Holley PN 534-197) and the Holley in dash Air/Fuel ratio meter (Holley PN 534-200). I had installed the wiring harness at that time and since the MAP sensor was a simple plug-in, that was installed as well by plugging it into the wiring harness and running a vacuum line off the carb to the sensor. It was not secured anywhere in the engine bay yet, just handing off wiring harness. For fuel plumbing, I had purchased a Walbro external in-line pump rated at 255 LPH (PN GSL-392), an OEM-style fuel filter (PN GF481), five feet of 3/8” rubber hose for fuel injection (rated SAE J30), and two five foot long 3/8” steel brake lines, pre-flared with tube nuts on them already.
Posted in Building an Autocross Car | Comments Off
April 15th, 2008
When it was time for the drivers of heat number three to autocross, I put my car “on grid” and prepped to race. I started off with 34 lbs of pressure in all four tires and put some chalk on them so I could see if they were rolling over at all. Since the Trans Am has a much lower torque curve than the ’68 Camaro, I decided to try my first run in second gear. Some of my fellow competitors mentioned they did this in third generation F bodies and C4 and C5 Corvettes so it seemed worth a try. In my first run, I came out of the slalom pretty hot and used the ABS before heading into the hairpin turn. I was clean with no cones and a time of 34.845 s. I was definitely not as smooth as I should have been.
For run number two I decided to go with first gear because I didn’t quite have the torque I wanted coming out of some of the slow sections of the course in second gear. The rear tires seemed to have the chalk I applied still running right onto the tread so I let air out of them all the way down to 28 lbs, but I maintained the front tire pressure at 34 lbs. On my second run my time improved by over four tenths to 34.402 s. On the grid I let a little air from the front tires, bringing them down to 32 lbs, while maintaining the rear tires at the 28 lbs. On my third run, I decided to try more speed after the slalom and came into the hairpin after the slalom too hot again, this time sliding deep into the turn with the ABS hammering away. This strategy wasn’t working as I ended up slower on the third run by about eight tenths at 35.248 s. I needed to pull it together for the fourth run or risk finishing very near dead last on the day. I didn’t take air out of the front tires, so they were at 34 lbs of pressure while I let even more air out of the rear tires down to 26 lbs. I finally put a decent run together by trying to be a little smoother and less abrupt in my inputs to the Trans Am. I finished with a clean 33.474 s, good for third in the small CP class of four drivers.
We had 113 racers show up for SCCA Solo II in O’ahu on April 13th, and my time was only good enough for 94th overall. Worse, staying in the CP class (PAX 0.864) for the points even though the Trans Am could have raced in ESP (PAX 0.841) wasn’t helping me out since with the PAX my time was 103rd! I had an overall expectation to continue to improve with each outing at the track so was a little disappointed with my finish, but given the circumstances of not knowing how to drive the Trans Am and moving into the tougher CP class I wasn’t really surprised that I took a step back either. During my fun runs I did get some level of consistency from the Trans Am: in 5 runs I was clean on all and ran a best of 33.024 s and a slowest of 33.760 s. I missed the ’68 Camaro for sure, and was determined to have it ready for the next race day. I had a full three months until the next SCCA Solo II outing—July 13th.
Posted in Race Day Results | Comments Off
