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M42 Head Gasket Blown, Project Thread

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    Nice work, thanks for sharing. Any plans to hit the dyno?

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      Originally posted by mike.bmw View Post
      Congrats,. Great work and documentation. I probably missed the info elsewhere, but what are the modifications to the upper intake manifold?
      The things welded onto the intake manifold are Metric Mechanic's "pulse chamber" modification. They claim improvements to mid-range torque via resonance tuning, but I have no idea what actual effect they have.

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        Originally posted by roguetoaster View Post
        An excellent end to the rebuild, at least for now, and great to see the inside of the ICV too!
        Yeah, it was interesting to see the guts of it. It is so dead simple. The motor is pretty weak, so it would not take too much oily goo to get it stuck in place.

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          Originally posted by e30sh View Post
          Nice work, thanks for sharing. Any plans to hit the dyno?
          I am glad people found the thread interesting. For now I have no immediate dyno plans, but I will see about getting some runs in at some point.

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            C’mon dont be afraid, find Dynojet
            89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

            new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

            Comment


              Originally posted by digger View Post
              C’mon dont be afraid, find Dynojet
              Ha, yeah I need to just go get on it already. There are a few shops in the area with dynos.

              I went and put some gas in it this evening, and then proceeded to "enjoy" it around town for the following 30 minutes. Between it being a Sunday night, and COVID, there is a lot less traffic than there used to be, so it was good times. I am beginning to remember why I put so much work into this thing. The low vehicle mass, even weight distribution and all-mechanical controls really make it a pleasure to drive. While the various newer sports cars I have driven in recent years are all faster and grippier, they still lack something I can't quite put my finger on compared to the E30. With that said, I am also a big fan of having a separate DD that gets good fuel economy and has air conditioning lol.

              Comment


                It has been a couple thousand miles now, and I wanted to pop back in here with an update. Well, less an update than just a note. I am absolutely loving this engine and the car is more fun than ever. Whatever was wrong with the engine as it was originally built may never be known, but it is in a lot of ways a totally different beast now. It revs smoother, makes more power, makes less "hissing" noise, gets 20-30% better fuel economy, does not leak or consume oil and just generally feels more composed. Granted, I now have a really good tune for it from Sssquid, and a considerably lighter (and dynamically balanced) flywheel, but even still the engine itself is better than it was. All said, this is the sort of engine I feel like MM is probably known for building, and while it was frustrating as hell to never really feel satisfied with the original one, I am satisfied now. MM stood behind their product and reputation all along, and I would do business with them again.

                I will probably never know what was wrong with the original engine that they built for me in 2012, and my only guesses are:
                1) I did a lousy job of reinstalling the head after they replaced all of the valve springs (the springs they originally used were defective) and there was a pinhole leak or leaks the whole time. It seems exceedingly unlikely that a compromised HG survived 7 years of my hard driving.
                2) A valve was slightly bent and not replaced when I sent the head back after the 2nd spring failed. Again, it seems sort of unlikely since they had the head totally apart to swap in the known-reliable dual spring setup (the original build used single springs).
                3) MM did not correctly mark which valves came from which port, reinstalled some into the wrong locations & didn't re-lap them to the seats. This is my leading guess and I think that it would explain why so many of the issues I had seemed like they could be explained by compression loss / combustion chamber leakage.

                Jim said that they did not find anything conclusive in the engine when I sent it back late last year after the HG completely failed. The cylinder bores were 0.001" out of round, which was not great, but is also not enough to completely explain the poor running. The current engine is built with a fresh block, with the bores matched to the old pistons (with new rings)...I sent the old engine back right around Thanksgiving last year, and they determined that it would be quicker to match-bore a fresh block than to try to get new pistons since supply logistics were a mess at the time. Completely machining the fresh block likely cost them more than a new set of pistons, but I appreciated the effort to turn things around fast. Anyway, if the old engine's problem was in fact #3 (poor valve sealing), they might have yanked the head apart before checking the sealing, or if it was messed up maybe they didn't want to say anything since that's sort of a head-slapper mistake. Either way, they put on their latest multi angle grind & new seats to match, so it is not an issue now (if it ever was).

                Last time I spoke with MM to let them know I was pleased with the engine, they mentioned that they were developing a complete ITB kit for the M42. I think that I will give them a ring in the next week or two to see how that is coming along. Dyno data I have seen from M42's with dBilas and RHD ITB kits seem to show gains across the entire RPM range, and I would certainly be happy to get a bit more area under the curve. RHD's kit is well designed, priced well and available now, so it is one consideration. I'll see how things turn out with MM's kit. I am still very eager to get out to Missouri in the spring (fingers crossed that the COVID nonsense dies down by then) to visit Sssquid and MM. If travel is an option by then, I sort of want to get the car trucked out there for some live dyno tuning, and if the ITB kit is ready by then I can install it at MM, get the throttles synchronized and have some fun with them. Anyway, if I could hit 100HP/L I would be pretty stoked, even if that is a totally arbitrary goal.

                The other item I am still thinking over is which stand-alone ECU system to go with. The "easiest" options are the PnP MS3Pro for M5x engines, and the Link E36X ECU, since both use the 88 pin connector and I would just need to move some terminals around. The other system I like is AEM Infinity 358 (can drive "dumb" coils directly) and the 508 (can't drive dumb coils, but has built-in WBO2 control and logging), with the major downside being the top-entry harness connection which would be tough to fit into the glove box and still clear the plastic cover. Motec and other motorsport ECUs all seem like they are likely to be entirely overkill for my application. I'm open to suggestions though.
                Last edited by bmwman91; 11-17-2020, 11:27 PM.

                Comment


                  Great to hear it's running well.

                  Have you thought about a newer BMW ECU? They seem to have MS41 figured out. Not sure how difficult it would be to code for 4 vs. 6 cylinder.

                  Comment


                    I had looked into converting to M1.7.3 since that would get me knock sensing and some improved idle control, but it started looking like more work than going stand-alone with less tunability and expandability. M5.2 would have been really cool (M44 ECU) but there is exactly ZERO tuning for it anywhere. Nobody ever bothered to or figured out how to tune it. I checked on MS41 and it is pretty impressive how much people have done with it. It does not look like it was modded to allow 4 cylinder operation. Anyway, to add all of the "modern" features I want, I will basically be building/rebuilding another entire harness, so at that point I figure I might as well start looking at the aftermarket. The main downside I see is that a lot of people never seem to get the idle to be as good as stock, but that seems like it must be a tuning issue more than an inherent problem.

                    So far, I am 90% sold on the Link E36X. They confirmed that it should work fine for the M42, as long as I move wires around as-needed in the 88-pin Motronic connector so that it matches M3.3.1 (which it was designed to replace).

                    Comment


                      Thanks for the update! Great to hear that it's running well and you are able to enjoy it!

                      Comment


                        Making a tune from scratch on MS41 is not a curse I'd wish on anyone.
                        It works well for the engine it was calibrated for +/- whatever changes are made, but between how much of the ECU is not yet defined, the lack of live editing, and the ~12Hz maximum logging rate, I think an aftermarket ECU of any kind is well worth it for something non-M5x.

                        The link is a good choice with the pnp(ish) connector/functionality/price/popularity.
                        Originally posted by priapism
                        My girl don't know shit, but she bakes a mean cupcake.
                        Originally posted by shameson
                        Usually it's best not to know how much money you have into your e30

                        Comment


                          People seem to like KDara because it's plug in to the factory harness and comes with a startup map. I think VEMs has one as well.

                          Comment


                            Well, I just pulled the trigger on the Link E36X ECU. God help me, I am once again violating the ancient wisdom of "it if ain't broke don't fix it" but so it goes with the E30. It turns out that there are a number of aftermarket ECUs out there that run the 88-pin Bosch connector.

                            - Link E36X
                            - MS3Pro PNP for E36 M50/S50
                            - Life Racing F88 series
                            - PECTEL SQ6

                            The Life and PECTEL products are really intended more for pro motorsports applications, and are considerably more expensive (Life's base ECU prices are not bad, but some basic functions are costly "option" upgrades). Also, I think that it is probably the case that the tuning software will be less commonly known by tuners. MS3Pro probably has the most widespread user base of all of these, with Link being close behind.

                            This is the ECU that I ordered:
                            https://dealers.linkecu.com/E36X_2
                            Full specs of the ECU series that it is based on:
                            http://linkecu.com/documentation/Xtr...InECUSpecs.pdf

                            And I got it from this distributor, who seems to sell it for $100 less than most other places:
                            https://panicmade.com/link/p/e36linkx



                            Anyway, I have lots of planning to do, spare M42 and M44 harnesses to obtain and harvest bits and pieces from, and that'll keep me busy for at least a couple of months. I'll be starting a separate thread for that, maybe in the projects subforum, but it'll be later this year once I have things planned out and worth sharing.
                            Last edited by bmwman91; 11-19-2020, 05:25 PM.

                            Comment


                              Would be interesting to see before and after gains of the ECU. When i did this removal of the AFM and stock air filter/silencer box was worth good gains. I replaced mine initially with a smooth silicone elbow and a bmc cda style filter. The gains were from airflow as the timing map i started with was hopeless
                              89 E30 325is Lachs Silber - currently M20B31, M20B33 in the works, stroked to the hilt...

                              new build thread http://www.r3vlimited.com/board/showthread.php?t=317505

                              Comment


                                Yeah, I gotta stop by the local dyno shop and get a couple of runs in. The car is running smooth and strong now (so of course I need to start a new project that will render it inoperable and not running great for at least a year lol). I am not sure if it will make much more power, although switching to MAP will clean up the intake a bit. The biog reason is that I plan to run either the RHD or MM ITB kit, and even without the ITBs (just the super light flywheel) Sssquid is about out of parameters to tweak to give me a clean idle. An aftermarket ECU will give me more options for idle management, and I can run an M44 or M50 stepper-type ICV.

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