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Mild N/A Build Questions

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  • Mild N/A Build Questions

    Hello all,
    Recently I have been planning to do a small N/A build on my 94 LLO. It has 56k on it and would be a great candidate for a build. I plan on refreshing it by replacing everything on the engine except the valvetrain, and rotating assembly. All of the sensors, timing chain componenets, oil feed components, seals, and gaskets will be replaced.

    Here is my plan:
    -4-2-1 OEM header and downpipe to a 2.25" thermal R&D catback
    -Port matched intake manifold
    -Geo storm TB (non GSI)
    -Twin intake cams (stage 1; reground by American Custom Cam), only retarded 1 tooth on exhaust side
    - Shaved head (.030-.040")
    -Light porting on the head
    -2000+ tie plate, oil pan, and pickup
    -Aem WBO2 Gauge
    -Aem CAI

    This is about all I can think of for a N/A build. According to the deebs guide my compression should be 10.75:1 at .040" off of the head, or 10.5:1 at .030" off of the head. I am not installing flat faced valves, nor am I changing the rev limiter, so I am not worried about valve float (thus no mention of 98 valve springs). I know the timing will be slightly retarded too from shaving the head, but I am not concerned with that. I can always adjust the timing gear by filing the alignment hole, or by purchasing adjustable gears.

    My main question is about the head shaving, how far is safe on the stock PCM? Is a compression ratio of 10.75:1 at .040" shaved asking for pinging? Will premium fuel be enough to keep the pinging away at that level, or would I absolutely need an Apexi Safc II? I dont care if the stock PCM has to retard the spark timing to keep knocking off, thus killing some power. I just want to know if the stock PCM will be able to compensate for it and keep it from pinging.

    My secondary question is about the twin intake cam regrind combination. I currently have twin intake cams in my 95 LLO, and I have the exhaust 2 teeth retarded. It runs great and pulls nicely in the higher end. My thoughts were that I would send two intake cams to American Custom Cams and get the MidPenn Stage 1 regrinds on both of them. I would then preform the nessecary head modification to allow their placement, but then only retard the exhaust side 1 tooth to keep from losing too much bottom end. Has anybody tried this? Does anybody see any potential issues? I figure it should be fine since they are far less aggressive than cams such as SDA cams, but I could be wrong.

    One last thing: this car is a daily driver, and I use it to commute to and from college, about 20 miles total per day, in every condition possible, so it would need to be somewhat reliable after the build. That is why I wanted to go N/A instead of FI. If I am making this build in the land of make believe, please let me know, but I think that reliability at this smaller scale build is attainable.

    Sorry for the novel, but I would like to get some educated answers before I jump into this build.

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