Quiz 0 Posted June 10, 2007 I've about got my motor out and im going to have the block bored out. I know that the higher bore you go with then the potential for the engine to run hot increases. I have already had a prob with the engiene running hot on hot days running the ac. I can correct that later with other parts that you guys suggested. However i dont want to add to the prob by boreing the block. Standard sizes are of course 10, 20, and 30 over. I have heard somewhere that you cant bore a VR6 10 over. One thing to keep in mind is a live in a very warm climate during the summer. We see some 100 degree days and very high humidity. Before i order my rebuild kit i need to pick a size so i would like some input. I am trying to make as much hp as possible without causeing myself probs. I dont want to have to worry about my gf sitting in traffic on a hot day with the ac on and it start to overheat. Thanks. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted June 10, 2007 Where are you based? I guess you have a 2.8 lump as a base? 82mm gives you 2861cc 82.5mm = 2897cc 83mm = 2937cc 83.5 = 2967cc 83.5 is as large as you want to go boring wise. If you want more, you'll need a long throw crank and shorter rods. 3.2 is possible from the 12V with a combination of pistons, rods and crank throw. I use 83mm Forged Wossner pistons and they've been great. No increase in heat. Heat comes from the amount of fuel you burn and the ignition advance you use. Forced induction engines can run cooler as boost fuelling is around 12.5:1, which is rich, but keeps the exhaust valves cool. Quote Share this post Link to post Share on other sites
