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Mild engine build. Goal ~225 whp MP62 supercharger. Headwork? Rods?

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  • Mild engine build. Goal ~225 whp MP62 supercharger. Headwork? Rods?

    Hey guys. I've posted this elsewhere, I figured I'd do it here too. If you've seen it on another form. Thanks for you advice!

    So I got a used 1995 engine for my Miata. I was going to tear it down and put new seals, water pump, timing belt..etc on it. Well, that turned into pulling the head, which turned into bearing and rings. So I've got an engine apart on the bench right now.

    My goal is ~225 whp from this build. It will take a while to get there. I want to work up to it. I chose that number because I have read many times that stock internals are good to about 250 whp, and should last an long long time assuming good tune. True? My goal is an MP62 supercharger and not a turbo, so I had to add parasitic losses to factor in in too.

    Rods:
    I'm not into buying 400+ rods for my engine, but I could buy some of the lower end options. Entry level Forged. Ebay Specials, whatever. I have had people say "oh, well you will never achieve 225 hp on pump gas. You wont max out the stock internals, so don't worry about it". Ive had people say they wish they did rods.

    Pistons:
    Do I need them? I have the factory 8.8:1s. Should I get factory 9:1s?

    Is it rods+ pistons that allow me to get greater power on pump gas?

    Headwork:
    This is where my questions come in. I have a good BP05 right now. I'm thinking of lapping the valves (or maybe a 3-angle), doing a mild port and polish, polish the combustion chambers and pistons to reduce detonation and throw it on. I could either do that to a BP05 or change to a BP4W. I know the BP4W is better. How much better? What I dont want to do is "waste" money on headwork just to find I shot past my power goal at X boost, and used up my engines safety margin, or put it at risk. If I can get the power from boost, id rather do that, I think.



    Comments? How would you do it? I'm leaning a bit toward a cold-side when it comes up.

  • #2
    "Is it rods+ pistons that allow me to get greater power on pump gas?"

    Well, no. The forged pistons most builders use will give you some added protection if you should ping. The rods will stand up to more torque. You are for sure addressing the most important stuff now (flowing the head and insuring good compression) Thing is that 225 number is borderline for rod health. That number is a bit iffy on pump gas too. Can you get 94 where you live?
    '00 Coldside FFSC 130mm pulley @ 18.5psi. on E85. OBX header, Goodwin Midpipe, Tein Flex, Koyo Rad, Etc.

    Comment


    • #3
      No I cant. I can get E85 some places, and I can get crappy CA 91 octane. I dont want to run E85 all the time, just in case I just suck without E85. I may have an E85 pully and tune though for more power.

      Since it seems I wont easily be able to reach the "unhealthy" limit for stock rods, I think I'll skip the rods on this build. I will focus on the head though. If I do find myself pushing 225, I'll just cut my redline a bit and watch for knock.


      At this point I don't even yet have the supercharger, or an "intercooler". So I would be running regular 190hp FFS or 170hp Moss for awhile anyway. I would build up to more power later.

      Comment


      • #4
        I think flowing the head will get you there on pump gas as it will increse air flow and decrease boost. More HP, less boost is the road to success. Rods, in my humble opinion, are easily good for 225WHP. I think their real killer is high RPM. As RPM increases, they tend to compress and stretch more. That weakens them and, next thing you know, one is sticking out of the side of the block. Stock Pistons are easily good for 225WHP as well.

        Now we come to Pat's comments on gasoline vs. E85. Up to 225 WHP, I think the success is really based on two things. The flowed head is numero uno, followed real close by octane. The reason I keep coming back to the flowed head is that I think 110-115 WHP is possible on a 95 engine with 8.8 or 9.0 pistons. The step to 225 is from the flowed head.

        By the way, did that engine come from an automatic? If memory serves, the 8.8 pistons were from the automatic engine. Not sure, but weren't the cams different as well? They detuned that engine for the auto tranny. If the cams are different, all bets are off for getting 225.
        sigpic


        1990 with FFS Coldside. At least 260 WHP NON-INTERCOOLED

        Comment


        • #5
          Awesome. Thanks Tom!

          As I have read, the 1994 and 1995 BPs got 8.8:1 pistons. I also have a set of 9:5:1s. I need to decide which to put in. They are both good and show no damage. It seems to come down to: a tad more boost or timing with some safety against knock, or more compression.

          Rods sound like good things to do while the engine is out, but at least I dont have to obsess over them anymore.



          I've read that Emelio as gotten 15xhp on a 10:1 with boltons, standalone, and good tune with some timing. Pretty nice NA power.

          Comment


          • #6
            Is the rod issue maybe why the MSM has a lower redline?

            I have also read that the BP4W head has softer valve springs coupled with higher lift cams. That could factor in to the lower redline too.

            Comment


            • #7
              The MSM is basically a 01-05 block with 94-97 (9:1) pistons and a 99-00 head.

              It is my understanding that the 8.8 pistons were only in the automatic transmission and has different cams. Not my field of expertise but worth commenting. I believe the 90-93 1.6L had 9.5:1, 94-97 manual had 9:1, 94-97 automatic had 8.8:1 (and de-tuned), 99-00 had 9.5:1, 01-05 had 10:1 and 04-05 MSM had 9:1. Not sure if the rods changed from 94-05.

              I wouldn't be surprised if a K&N intake wouldn't add 10-15 on the 01-05.

              We can argue the merits of a standalone for added power in another thread. LOL


              Originally posted by Mysticle31 View Post
              Awesome. Thanks Tom!

              As I have read, the 1994 and 1995 BPs got 8.8:1 pistons. I also have a set of 9:5:1s. I need to decide which to put in. They are both good and show no damage. It seems to come down to: a tad more boost or timing with some safety against knock, or more compression.

              Rods sound like good things to do while the engine is out, but at least I dont have to obsess over them anymore.



              I've read that Emelio as gotten 15xhp on a 10:1 with boltons, standalone, and good tune with some timing. Pretty nice NA power.
              sigpic


              1990 with FFS Coldside. At least 260 WHP NON-INTERCOOLED

              Comment


              • #8
                Cool. Well it looks like I've got to spend some money to make the supercharger be a danger to the rods, so I'm sticking with factory rods.

                Any ideas as to weather or not I want the 9.0:1 or 9.5:1 Pistions? I have both on hand.


                You know, I think your right. I double checked the table from one of Keiths books and it shows 8.8 and 9.0. So I've got 9.0:1. Automatic cars also got a different TPS I think

                Comment


                • #9
                  Originally posted by Mysticle31 View Post
                  Automatic cars also got a different TPS I think
                  Sort of. The 1.6 automatic cars had a variable TPS, whereas the 1.6 manual cars had the on/off switch. Starting in '94, all cars had variable TPS.

                  twj

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                  • #10
                    9.0 for sure.
                    sigpic


                    1990 with FFS Coldside. At least 260 WHP NON-INTERCOOLED

                    Comment


                    • #11
                      Originally posted by Tom @ Fast Forward View Post
                      9.0 for sure.
                      According to http://www.jspecauto.com/files/jspec...chcenter5b.htm
                      Starting with the 3/95 start of the ODB-II implementation (VIN 14193) the pistons were changed with a slight dome to increase the compression ratio to an actual 9.0:1. The '94-3/95 pistons were factory rated at 9.0:1 but actually was around 8.8.

                      Not sure if they know what they are talking about, but they sure sound like they do.

                      But the real reason for this post is I'm looking to do something similar to the OP (add more power Scotty) and this was the closest thread I found.

                      My situation is: it's a 1994, didn't have great compression when I bought it (it had 178,000 and had been raced NA for years), I put on a FF supercharger, I've gone from 105 to 115 pulley and I'm in Cali and don't want to trailer the thing around to races so I'd like it to be able to pass smog checks with a reasonable amount of un-modifying.

                      Also of note: this is basically a race car and I only drive it to and from local autox races so some of the longevity issues some people worry about might not apply. For instance, people worry about the tranny at 220 HP. It looks to me like the best alternative to the stock 5sp would be the 6th speed + 3.636 rear end gears. But this looks to cost ~$1300+. So unless I miraculously can crank this thing up to 240+ HP, I figure I'll just start breaking and replacing the standard 5speeds.

                      Also rods. Depending on how this looks to pan out, since it will be such a low mileage use, fatigue issues like Tom mention would not seem to be as much of a worry, especially when you consider that peak RPM is typically only reached for a max of 2-3 second at a time in autox. But rods certainly aren't off the table.

                      I'm figuring on a fresh engine build, and would like to keep it under $2k, even less would be great but this this is just my first pass optimistic WAG. FYI I have a friend with a shop so part will be wholesale and at least some of the work will be at very reasonable prices. It's good to have friends

                      It seems like the major variable to pick from are:
                      1. how much to spend on head flow work
                      2. compression ratio - 8.6:1 - 9.7:1
                      3. pulley size
                      4. redline - 8300?
                      5. fuel choice (i.e. go to E85 or not - I have access to 100 octane or E85)
                      6. increase displacement (84 bore seems way safe, 85 less so and seems to have much fewer piston options)
                      7. how many extra e-cool injectors to add (currently only has 1, figure I'll go with 1 more)

                      $$$ implications
                      1. The good thing about head (flow) work is there doesn't seem to be much in the way of increased risk (as opposed to compression or revs). But I'm guessing it is pretty limited in how much HP it can give you and will quickly approach diminishing returns in HP/$. Is there a standard guideline anybody can suggest?
                      2. C.R. doesn't seem like it will be a cost driver if going with fresh pistons anyway
                      3. pulleys look like minimal cost impact
                      4. to crank the revs up to ~8300 sounds like it requires:
                      - re-chip ecu
                      - valve springs
                      - oil pump
                      - do the powercards need redoing?
                      - maybe rods?
                      5. going to E85 seems to need
                      - injectors
                      - re-tune powercards
                      - spark plugs, hoses, gaskets and seals (only incremental price diffs since will be getting new anyway)
                      6. machining overbore, doubt I'll go with a stroke change as that seems like too much $$$.
                      7. I'm under the impression 2 injectors work much better than my 1, so this seems like a no brainer for minimal cost

                      As for which is the best route for HP, I'll wait for the experts to weigh in. As you can probably tell, I am not all that knowledgeable about any of this.

                      Thanks in advance,
                      Bruce

                      PS. It sure would be great to see the details of Tom's final build, but I haven't managed to get through all 415 posts in "Eat-your-hearts-out". Is there a summary somewhere or a few best posts in there?
                      But officer, I was only going one way.

                      Comment


                      • #12
                        Originally posted by calichtr View Post
                        ... I'm figuring on a fresh engine build, and would like to keep it under $2k, even less would be great but this this is just my first pass optimistic WAG. ...
                        I just saw
                        http://www.fastforwardsuperchargers....4831#post24831
                        Well, I did say it was optimistic ... and I'm not pushing as hard as Tom so it should be less
                        But officer, I was only going one way.

                        Comment


                        • #13
                          I could be wrong and that would not be anything new but, it was my understanding that the 8.8 pistons were on the automatic engines? 90-93 were 9.5:1, 94-97 were 9:1, 99-00 were 9.5:1 and 01-05 were 10:1.

                          My engine build used JE pistons and Carrillo rods. I also used the 01-05 oil pan and crank support. Top end has 1mm oversized valves and stiffer springs. Mine is a 99 engine so it has the solid lifters rather than hydraulic. One thing I have learned in recent times is that if you take the head off on a 90-97, take the time to pull the lifters. Take them apart and clean them thoroughly. Over time the gunk up internally and, from what I have heard, the ONLY way to correctly clean them is to take them apart. Rebello Racing did my build. All I can say is that at 21PSI, the engine has zero issues.

                          If you only do the block, DO NOT USE WISECO pistons. JE pistons and Carrillo rods and clean the lifters and you will be good to go. At the power levels we run, even the stock pistons and rods are fine. 8.8:1 pistons might actually lose a few HP. Remember, you spend most of your time off boost.
                          sigpic


                          1990 with FFS Coldside. At least 260 WHP NON-INTERCOOLED

                          Comment


                          • #14
                            Yeah, I've heard the same thing (probably here) re: 8.8:1 for automatics and I have no independent info so I'll leave that subject as is

                            And my goal of staying around $2k quickly died. Already looks like I'll be pushing double that and I'm sure there is still more out there

                            I made it all the way thru your "eat your heart out" thread; sounds like you've had quite the adventure! Glad you managed NOT to use the gun

                            From what I gleamed (relative to my list) you went with:
                            1. how much to spend on head flow work ==>> relatively a lot, although I'm not sure what that entaled beside going +1mm diameter
                            2. compression ratio - 8.6:1 - 9.7:1 ==>> 9.0:1
                            3. pulley size ==>> started with 130/65 -> ended up at 140/65
                            4. redline ==>> balanced engine to 8500, but limiting it to ~8000 max
                            5. fuel choice ==>> E85
                            6. increase displacement ==>> 0 (leave stock displacement with 83mm bore)
                            7. how many extra e-cool injectors to add ==>> you went with 2 in plenum + 1 pre-blower

                            But I'm still guessing you spent quite a bit more than I am looking to spend and it seems like you had quite a few headaches along the way, and for all of this you ended up with a bunch more than I am looking for.
                            So I guess I'm looking more for the "easy fruit" to pick.
                            It seemed like a fair amount of your tuning headaches were related to using E85. Would you say that is accurate?

                            But E85 also seemed to be something that kept everything safe and in general helps out a LOT! So this seems to be the #1 decision to make: to E85 or not to E85.
                            Can you please comment on how hard it will be / what all needs to be done to go to E85, after reading you tales I'm a little chicken to go that route. Is there already another thread on the ins and outs of going E85?

                            FYI, regarding your stories on raising the rev limit, I had a guy that could burn new ecu chips for cheap and adjust a number of parameters, including could only raise the redline if that is what you wanted. To make sure that actually happened I just took the following video (mostly because my gps estimate of my top speed [~62.6mph] seemed as if he hadn't)
                            https://www.youtube.com/watch?v=jAVCCz2xfNw
                            Unfortunately he has switched cars and sold his equipment to do this, but he tells me you can get it here
                            http://www.moates.net/
                            or ebay for ~$100 and that the chips are cheap. When I find out more I'll let you know.

                            Originally posted by Tom @ Fast Forward View Post
                            If you only do the block, DO NOT USE WISECO pistons. JE pistons and Carrillo rods and clean the lifters and you will be good to go. At the power levels we run, even the stock pistons and rods are fine.
                            I have a vague recollection of someone (maybe you) saying that the important choice in pistons is to have them thermally match the block (expansion-wise) and some are better than others. The odd thing is, I know a guy with that built one of the baddest miata motors I've heard of (400HP turbo) and he says Wiseco is fine and it is 1 of the 2 brands Emilio sells. What's so bad about Wiseco?

                            Out of curiosity, when you are running the 2+:1 pulley ratios to 8k, how fast are you spinning the blower and what is the max speed they are supposed to handle?

                            Thanks again,
                            Bruce
                            But officer, I was only going one way.

                            Comment


                            • #15
                              95 engine and 225whp is relatively easy on a stock engine. I would simply do head work. I would find a 99-00 head and send it to Rebello. Don't hold me to it but $1500 should do the job and get rid of those pesky lifters at the same time. Put the kit on and run 93 or better fuel. 100 octane with a 120/65 pulley. Better yet, switch to E85 and run a 130/65 pulley. Probably north of 240whp. On E85, even the stock engine would probably hold up. To be extra safe, pull the stock rods and replace with Carrillo. Some 315cc injectors and three extra injectors would be plenty of fuel. I would replace the fuel pump with a DW200 and a new adjustable FPR. All of that should be under $3000?
                              sigpic


                              1990 with FFS Coldside. At least 260 WHP NON-INTERCOOLED

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