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The following photos so far are of the engine in my 1984 Corvette during reassembly. Originally it was an RPO# L-83 engine, but now its a little more aggressive due to some modifications. The cylinders have only been bored .030" to clean the cylinder walls making it a 355.1 cubic inch block. The pistons are hypereutictic 9.78:1 compression pistons with valve relieves and the cam is a Cranes computer-cam with a 114 lobe separation and .490" and .501" lift. Its a great cam! Good power down low and great mid range. When I installed the cam I was a little afraid that it would cause all of my power to be high in the RPM range so I advance the cam 8 degrees so that it would have some power down low; after all, it is a street car. The biggest add on though was the intake manifold. I purchased an X-Ram intake manifold from www.x-ram.com. Go there and check it out. It has so much better volume flow than the stock cross-fire and allows you to open up the throttle bodies to get more than the stock 400 cfm. I opened my bodies up to 2.15" using a boring tool on a verticle mill and made new butterflies using the same verticle mill and simply angling the head of the mill to 10 degrees. I angled the head of the milling machine to 10 degrees because the butterflies when closed are at a 10 degree angle from the horizontal. Therefore the plates are egg shaped and the edges must be vertical when the plate is at 10 degrees. I figured the best way to do it was to turn a piece of stock aluminum to 2.13" on a lathe and then chopping a section of it off and fixing it on a mill with the head angled at 10 degrees and "choppin'" off the material till it was flat. This process was a bit wasteful but I couldn't think of any better way of doing it. The key to it though was to make sure when its all said and done and you install the butterflies in the body; make sure you cannot see any light around the butterfly and the body. If you do, it will cause the computer to not be able to accurately control the idle of the engine by means of the idle air speed motor. By opening up the bodies to a 2.15" diameter it takes your volume flow to approximately 670 cfm, or there about. I would recommend the X-Ram to anyone! Now X-Ram is even selling the oversized throttle bodies with larger injectors. Those guys are great. The heads on this engine are the stock steel heads with oversized Manley valves and "hogged" cavities. Hogging, or fully porting the head, is simply boring the heads out for more volume; doing this allows the larger valves to flow to their full potential, or at least near it. To pull the exhaust out of the heads I used Hooker long tube headers. They are probably the nicest set of headers I have ever had, and they fit the vette flawlessly. Finally during some fine tuning stages I replaced the stock fuel pump with a pump from a 1985 vette (has much higher pressure becuase 9 out of 10 cross-fire fuel pumps don't have high enough pressure or volume to do the job). The TBI version of the vette only requires 13.5 psi to run where the 1985 vette has TPI and that uses approximately 80 psi to run. But have no fear about the increase in pressure; that's the fuel pressure regulators job; to regulate the fuel pressure. During my tuning bout with the car I also adjusted the fuel pressure regulator to accodomate for the higher amount of cfm flowing down the bodies. I am still running the stock ECM (electronic control module) with an over the counter performance chip and stock injectors; however, my plan is to next up date the ECM with one from a 1990 vette and adapt it to "Julie". I"ll also try a custom chip and probably fuel injectors from a 1992 1 ton chevy pickup with a 454 in it. (the guys at X-Ram suggested putting larger injectors in, and the best, and most cost effective way of doing it is pick up some injectors off of another stock application that has the capacity that your looking for.) That's all for now, but feel free to e mail me and ask me questions or give me comments! |
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