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85mm b18c

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  • 85mm b18c

    I want to build a all motor 250-260hp daily driver and need some help.
    I Want to know if I can bore a b18c block to 85mm and run LS crank and rods for a 2.0 displacment. Along with 12:1 comp arias pistons and skunk2 stg 2 pro cams, portflow head work and .01 bigger valves and 5 angle valve cuts.
    I dont really want to go b20v since i want to have all the benifits of the b18c block over the b18a/b ls block.
    Can I get away with a 85mm bore on the b18c block without sleeving it, If I am going to need sleevs then I might as well bore it to a 86mm..

    Id be happy if I even got close to 230-240hp out of it.
    Last edited by da6xsi06; 11 Jan 2012, 02:40:05.

  • #2
    Stock sleeves won't hold at 85mm...

    With full head work (port/polish, valves, good intake manifold that is port-matched, throttle body, pro1 or pro 2s), high compression block at 85mm, a good exhaust/header combination and a great tune, you could see 230whp or so.


    • #3
      I was running a B18c1 with ITR rotating assembly (11.5:1 compression), port and polished head, extrude honed GSR manifold with butterflies removed, CNC machined TB opened up to 75mm, ITR style stainless header and Skunk2 pro2 cams. Other parts I used were MSD SCI, modiflied cap, Blaster SS coil and 10.5mm wires, a B&M fpm, Brand X cam gears and a custom built cold air intake. Dynoed tuned 235hp. At that time it was daily driven.


      • #4
        What was the bore on it?


        • #5
          Stock bore, but I did hone the cylinders, so 81mm before honing, about 81.1mm after! It was a Stock JDM ITR crank, rods and pistons. Or did you meen the throtle body? The stock bore was 68mm. I had it bored out to 75mm on a CNC and a new throtle blade cut from aluminum.


          • #6
            You assumed correct, I meant cylinder bore.

            That build seems to have put down some awesome numbers for retaining stock sleeves at a virtually stock bore.


            • #7
              It is all in the head work! the GSR heads have a smaller combustion chamber than the ITR. Add that to the ITR pistons and you get a little more compression (I think it is more like 11.8:1 but not 100% sure)! My intake ports are opened as much as you can go with it and mirror polished. The intake is matched to the head and like wish the TB!

              In my opinion, I took it as far as I could reasonably go all-motor. I am still runing the same internals, but the cam is now a turbo2 and I have a T3/T4 turning 12psi. I have not had a chance to tun it on a dyno yet, but the guy I brought it to the first time is guessing that I will be seeing hp numbers near 350 range!

              However I believe I am getting a bit of blow by in my cylinders, so before the dyno, it is getting a complete tear down and rebuild. I am planning on keeping the ITR internals!


              • #8
                Indeed.. my brother has a fully built B16.. prettymuch everything you can do while remaining 81.5mm.

                P&P B16 head, S2 Pro1s, Pro Series springs/valves/retainers/cam gears/manifold, 70mm BDL throttle body, all port matched, Crower Rods, JE pistons (look very similar to CTR dome), Tri-Y header, z10 block girdle etc etc.. and he got to 197whp@8,950rpm. Funny to see that much power-gain with the increase of displacement, while using a similar head package. Thats nearly a 40whp gain comparing yours and his.


                As far as the topic at hand goes... Im still going to hold tight and say 85mm on stock sleeves is not going to happen.

                And without touching on more aspects of this build (Intake mani, throttle body, header, etc) i dont see the current list hitting the goals of 250+whp.


                • #9
                  What intake is he running, also I got to give it up to Thunder Motorsports in Baton Rouge, LA. Their tuning guys Mark is epic at pulling power where you didn't know there was. He spent half a day maping fuel curves and adjusting timing. It seemed that he would change one degree of something and then have to re-adjust everything to match! I was the only tune he had for the day, so he kept playing with it. He stored my map and everything to sell it as a chip on ebay!


                  • #10
                    I believe its a1st gen Skunk2 manifold, paired with the port-matched TB and a generic 3" cold air.


                    • #11
                      I think the GSR, even with all of the extra passages, flows a lot more air than most aftermarket manifolds if you remove the butterflies. I know you get more low-end torq. I tried a Blox Intake with the old set-up, but my 60ft times slow down.

                      That is when I had the work done on the manifold and reinstaled it. I can't say enough about the extrude honeing process, because the fluid move through the same path as the air, it can port and polish where it is needed! I suggest if you have someone in your area that has the machine, bring it to them.

                      I am lucky that I can take an hour and 30 minute drive to a friends shop that has one and a CNC machine. He does a lot of work aviation engines, so he has an Xray machine to see inside your parts. Then he can program his machines to cut around water and oil passages to open everything as big as posible!. My intake manifold and head are micro polished to a shine! This is excessive for most street applications and most commonly found on race engines!


                      • #12
                        ok so are the cylinders on the b18c the same lenghth as the LS b18a? I found a guy selling a b18c block thats been sleeved and bored to 84mm, can I also run this with the LS crank? the guy selling the block ran it for a while but had some head gasket issuse and something about a piston hitting the head. thats why I asked if the I can run the LS crank.


                        • #13
                          Piston to head contact would be having High compression pistons with a head or block that has been milled too far or the wrong pistons for the head. I would not use an LS crank. The LS crank has a bit longer stroke. I would get the block and order an ITR crank and rods from someone like then get a set of 84mm pistons for something like 11.5:1. If I am right, which I am guessing without seeing the parts, and the block has been milled, this will put you close to 11.8 or possible 12.0:1. You can get a thicker head gasket that will fix the problem. It is best to check clearance before final assmbly. Are you planning on doing the work yourself or do you have a local machine shop that you will be having do the work? If you are having a shop do the work, don't harass them, but you want to have good communication with your machinist! Talk to your shop, let them know what you are doing excatly and they will tell you want can be done! Communication is key, but don't tell them how to do their job and don't pester them! If you are planning on doing it yourself, read everything you can about building engines. Go to Amazon and get some books about engine building basics and a few about Honda B-series engines. Get all of the knowlege you can before hand!


                          • #14
                            85mm bore on stock sleeves is NOT possible. I have myself have a 85.5mm B18C pushing 250 at the wheels.

                            B18C1 Block w/ 85.5mm Golden Eagle Godzilla Sleeves
                            ITR Crank
                            Eagle GSR Rods
                            Arias 85.5mm 12:1 CR Pistons
                            Stock Honda Rod and Main Bearings
                            P73 Head with Portflow Headwork, Toda Valve Springs, and Crower Titanium Retainers
                            Toda Spec B Cams
                            ITR Intake Manifold
                            RC 70mm ITR Throttle Body
                            RC 310cc Injectors
                            Toda Spec 1 header
                            Resonated Test Pipe
                            RS*R Exmag Exhaust
                            AEM EMS

                            It's not a simple as buying a bunch of parts and slapping them together. It's tuning, tuning, and more tuning. Get out your wallet and best of luck.

                            92 GS-"R"
                            13.9 @ 100mph
                            17" street tires


                            • #15
                              What is the max bore on a b18c sleeved before you run into over heating issues.
                              I have a buddy with a 86mm. Sleeved b18c that overheats. He can't even daily drive it And has to cool it after every pass.