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Buford T Justice -- the full tour

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  • Using my numbers in the Summit calculator I got 9.44:1
    That which you manifest is before you.

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    • Originally posted by Brian Lohnes View Post
      Using my numbers in the Summit calculator I got 9.44:1
      yes I just found my error.

      they use a + for dish, a minus for dome..I got it backwards.

      64cc is what I rudely shook a mobile home park with..cam did do wonders, I guess that is the air equation into a static number. that is something I learned alot about with subarus...
      the sideways engine can hang on all the way to locmotive sound with no increase in power.
      a v8 never has to play with that.

      your engine is going to quite nice.
      Previously boxer3main
      the death rate and fairy tales cannot kill the nature left behind.

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      • Originally posted by Brian Lohnes View Post
        Hey Tom... My poorly written point was that if the piston dish is say, 10cc instead of 12cc or the piston sits closer to the top of the hole than what I can find, the compression will be higher than the low end of the 9 range I was thinking of.

        I am using this calculator - http://www.csgnetwork.com/compcalc.html

        bore: 4.0
        stroke 3.48
        head gasket diameter 4.10
        gasket thickness .018
        combustion chamber cc - 64
        dish cc - 12cc (need to input as -12 in calculator)
        deck piston clearance - .025

        That comes out to 9.42 -- If the dish is say 10cc (instead of 12) and the piston is down .020 (instead of .25) the CR goes to 9.7:1


        Am I doing something wrong? (There is an excellent possibility I am doing something wrong... )
        Hmmm. Something isn't right. I have near the same specs, except the 3.75 stroke; and I have 9.87:1. I think I have 11cc dish, and gasket is .041 thickness.
        BS'er formally known as Rebeldryver

        Resident Instigator

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        • Pistons not as deep in the hole?
          That which you manifest is before you.

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          • Originally posted by Brian Lohnes View Post
            Pistons not as deep in the hole?
            Mine are all about .024-.026 in the hole. I measured them the last time I had the heads off.
            BS'er formally known as Rebeldryver

            Resident Instigator

            sigpic

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            • Originally posted by Brian Lohnes View Post
              Hey Tom... My poorly written point was that if the piston dish is say, 10cc instead of 12cc or the piston sits closer to the top of the hole than what I can find, the compression will be higher than the low end of the 9 range I was thinking of.

              I am using this calculator - http://www.csgnetwork.com/compcalc.html

              bore: 4.0
              stroke 3.48
              head gasket diameter 4.10
              gasket thickness .018
              combustion chamber cc - 64
              dish cc - 12cc (need to input as -12 in calculator)
              deck piston clearance - .025

              That comes out to 9.42 -- If the dish is say 10cc (instead of 12) and the piston is down .020 (instead of .25) the CR goes to 9.7:1


              Am I doing something wrong? (There is an excellent possibility I am doing something wrong... )
              Brain, my bad. I have to agree, I did exactly the same as you when I fooled around with my stuff.
              Tom
              Overdrive is overrated


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              • Originally posted by Brian Lohnes View Post
                Hey Tom... My poorly written point was that if the piston dish is say, 10cc instead of 12cc or the piston sits closer to the top of the hole than what I can find, the compression will be higher than the low end of the 9 range I was thinking of.

                I am using this calculator - http://www.csgnetwork.com/compcalc.html

                bore: 4.0
                stroke 3.48
                head gasket diameter 4.10
                gasket thickness .018
                combustion chamber cc - 64
                dish cc - 12cc (need to input as -12 in calculator)
                deck piston clearance - .025

                That comes out to 9.42 -- If the dish is say 10cc (instead of 12) and the piston is down .020 (instead of .25) the CR goes to 9.7:1


                Am I doing something wrong? (There is an excellent possibility I am doing something wrong... )
                yes, with a shim gasket... and 8.964 with a .041 composite gasket in a perfect world where the heads are 64cc exactly and not really 67, and you're not actually .030 down the hole (ECHO ECHO ECHO... are you down there?) blah blah... I'd care about that deck height if I planned on keeping the mill.

                Needs more stroke (3.75) zero deck, 5cc valve reliefs, a .041 normal gasket that doesn't leak (11.0:1) and 64cc AFR 195 aluminum heads with a 224-230* intake 110 LSA cam... with lobe lift the size of a donkeys donker and Summit stickers and a Type R window sticker and a Spec V sticker or maybe stop now and build the BBC.

                I'm glad to hear it's getting a pocket port at the least - agree with Andy, should be big help upstairs. If you're gonna keep a SBC in it, you have about a billion options which would be fun. I think a 500cid Cad mill would be fun too if you can find one of those.
                Last edited by Beagle; November 21, 2012, 06:10 AM.
                Flying south, with a flock of bird dogs.

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                • Scott I plugged your numbers into Summit's calculator and got 9.8:1.
                  I plugged Brian's in and got 9.44.

                  Everything seems legit to me?

                  The first calculator I used was not detailed enough and skewed my numbers. But I have tried four different calculators and came up with 9.3-9.4 depending on where I set the deck height.
                  I have to imagine Summits calculator is pretty close or someone would have bitched by now?


                  Just measure your deck height to make sure you have enough piston to head clearance, find a way to make the shim gaskets seal and you're golden!!

                  It will be interesting to see if the "for every .010" of gained quench distance you gain 10ftlbs". In your case, tightening the quench by 0.023 (.041-.018) should be worth 20ftlbs....in theory. Whether you'll see it at the dyno remains to be seen.

                  Although it seems any engine builder worth his salt, zero decks the block and runs .040 head gasket. I hear that you want the pistons to "kiss" the carbon on the head at full rod stretch.
                  Last edited by andy30thz; November 21, 2012, 06:58 AM.

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                  • Some quick sneak peek photos from yesterday's adventure at the machine shop --
                    Attached Files
                    That which you manifest is before you.

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                    • Oooo....beehives, backcut, bowl work. Nice.
                      Of all the paths you take in life - make sure a few of them are dirt.

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                      • Purdy. Purdy like freshly fallen snow. I'm really looking forward to reading the blog.
                        Escaped on a technicality.

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                        • Heads look great!! What all was done for porting?
                          I totally forgot about back cutting the valves, such a cheap and easy thing to do!! I've only done intake valves, but I've heard of guys doing the exhaust valves too.

                          I see the heads are milled, how much did you take off?
                          I've always wondered...if you're using shim gaskets, would it be better to leave them unmilled unless the heads AND deck are resurfaced?
                          Do the head and deck become seasoned into matched surface over time? Would leaving them unmilled be better than having one true surface, trying to mate to a seasoned surface, using a gasket with no compression?
                          I guess you're gonna find out!

                          Talk about snowball.... What the hell happened to just getting the headers and springs on?!?!?!?
                          The only issue I see with rebuilding the heads like this is cost... This is the PERFECT route for guys "with friends" that have machine shops!! But if a guy had to pay the whole bill for porting/milling/back cutting/guide replacement?/hot tanking/valve job/new springs, retainer&keepers.... It HAS to be close to a budget set of aluminum heads.
                          Last edited by andy30thz; November 21, 2012, 07:41 PM.

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                          • Buford's gonna be bad ass.
                            Looking good.
                            Last edited by Monk; November 21, 2012, 07:56 PM.
                            Thom

                            "The object is to keep your balls on the table and knock everybody else's off..."

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                            • Andy, you are dead on with the money/price comment. Dana was saying that this is stuff he has not done in years to a set of SBC heads because frankly, it doesn't make a lot of sense with the quality of budget aluminum pieces on the market today. That being said, the bowl work could be done at home by a guy for free and having the valves back cut would be cheap if you dropped them off and had the machinist do it. You could get away with lapping the valves, but that wouldn't get you the same results I will see with a multi angle valve job on the Serdi 60 machine.

                              He was digging it because it is old school hot roddy kinda stuff.

                              I went cruising around today seeking my thin steel head gasket. I was striking out so I called over to Dana and Jon to see if they had one I could buy. They didn't either, but Jon mentioned that he cut 12-thou off the bottom of the heads to resurface them. Hitting the calculator again, with a stock thickness gasket, I should be about 9.1-9.2 compression. That's good enough for me. I am going to bolt them back on the engine come Friday.
                              That which you manifest is before you.

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                              • Originally posted by Brian Lohnes View Post
                                Andy, you are dead on with the money/price comment. Dana was saying that this is stuff he has not done in years to a set of SBC heads because frankly, it doesn't make a lot of sense with the quality of budget aluminum pieces on the market today. That being said, the bowl work could be done at home by a guy for free and having the valves back cut would be cheap if you dropped them off and had the machinist do it. You could get away with lapping the valves, but that wouldn't get you the same results I will see with a multi angle valve job on the Serdi 60 machine.

                                He was digging it because it is old school hot roddy kinda stuff.

                                I went cruising around today seeking my thin steel head gasket. I was striking out so I called over to Dana and Jon to see if they had one I could buy. They didn't either, but Jon mentioned that he cut 12-thou off the bottom of the heads to resurface them. Hitting the calculator again, with a stock thickness gasket, I should be about 9.1-9.2 compression. That's good enough for me. I am going to bolt them back on the engine come Friday.
                                Jim Evans worked over the Eddy heads for the W motor........had no idea of cost till I got
                                the final bill.....$1100.00.
                                Yeah it can be plenty costly......but well worth it.

                                What size exhaust?
                                Thom

                                "The object is to keep your balls on the table and knock everybody else's off..."

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