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    #16
    Awesome stuff. Check it out at M42club.
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    Save the manuals!
    '91 318i
    '86 635CSi

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      #17
      Originally posted by DesktopDave View Post
      Yeah, lots of really knowledgeable folks on M42Club.com.
      Parts Collector and Former Houndstooth interior junkie.

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        #18
        Any updates on this???

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          #19
          . I spread it out over 2 years so the wife barely noticed......

          We must be related!!
          NASA
          BMWCCA member
          PCA member 25yrs




          1991 318IS slick top
          1997 M3 sedan
          2001 325CI DD

          “whoever turns the wheel the least, wins"

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            #20
            She still noticed but didn't care too much. Anyway some progress after work today:

            Rear and wideband o2 bungs are welded in. With the rear o2 hooked up now, it seems to run a bit stronger in the mid range like it was keeping it too lean to protect the cat. When I install the wideband I'll know for sure. Overall it is much torquier than a stock m42 and it pulls a lot harder up top also even without a much-needed tune. I hope to be able rev the piss out of it soon without worrying about how lean it is. For now its just 2nd gear pulls and only on cold days.

            Probably going to put colder plugs in and change the fuel filter for good measure too.
            You say "Where are your other two cylinders?"
            I say "Where's your other camshaft?"
            Frankenmotor: if an M42, M44, M20, S50, and S52 were to have a kid.

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              #21
              This is awesome! A M44 just popped up for sale near me for $350, and after finding this thread I really want to pick it up and build something out of it. I just don't have any engine building or machining skills. Do you think it would be worth investing in aftermarket pistons instead of milling s50 pistons? Is the m44 head really much worse than a m42 - I read that it has less friction than m42s? And I'm confused about what engine management to use.
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                #22
                I spoke to Metric Mechanic. He said the downfall of the M44 head is that it can't keep up with high RPMs. The roller rockers start to vibrate left to right so it depends on your purpose build. I would buy aftermarket pistons if the budget allows it.


                Sent from my iPhone using Tapatalk

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                  #23
                  Originally posted by E30 Wagen View Post
                  This is awesome! A M44 just popped up for sale near me for $350, and after finding this thread I really want to pick it up and build something out of it. I just don't have any engine building or machining skills. Do you think it would be worth investing in aftermarket pistons instead of milling s50 pistons? Is the m44 head really much worse than a m42 - I read that it has less friction than m42s? And I'm confused about what engine management to use.
                  I went with s50 pistons for a few reasons: 1) they're inexpensive 2)BMW knows how to make a light, well-designed slipper-skirt piston that is an even better design than the m44 piston. 3) I have access to an end mill. 4) I was very and I mean VERY disappointed with the custom set I had made for my datsun some years ago. Not that the quality was poor, but they don't spend millions engineering a one-off piston. 5) I'm done with cold piston rattle and oil consumption issues common to forgies.

                  As long as the stock m44 pistons are in good shape, put a set of total-seal rings on them and be done with it, the extra 1mm of bore wont matter that much and raising the compression ratio like I did is walking a fine line of driveablilty vs power vs reliability.

                  I like the late m42 head the best, with an e30 intake cam. Friction be damned, buckets take the side loading off the valves and basically the guides and, subsequently the seats, last forever.

                  I'm noticing that the DME 5.2 on the m44 is finicky when modifying. I kinda knew better. It is superior to the 1.7. But I wonder if the 1.7 more tolerant to a cam upgrade since it seems to ignore some of the inherent 4-cyl intake pulses already. I'm not sure though. Either one would work well with less cam and compression im sure.
                  You say "Where are your other two cylinders?"
                  I say "Where's your other camshaft?"
                  Frankenmotor: if an M42, M44, M20, S50, and S52 were to have a kid.

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                    #24
                    Originally posted by benz-tech View Post
                    I know the lowly 4 banger isn't too well received here but I will share anyhow.
                    That was the case maybe 5+ years ago, but the M42 has earned a bit more respect as of late. The 318iS is recognized for its light and nimble front end, as well as being a little lighter overall from having less sound deadening and that sort of thing. The 318i/iS is probably the hardest E30 to find after the M3 because everyone was ripping out the M42 for M/S50 swaps for a decade.

                    Anyway, it looks like you have a fun project going. Keep up posted! Also, how far do the pistons hang out past the cylinder skirts at BDC? It was something I had never thought about until I watched a pro LSx engine builder talk about the pitfalls of stroker builds (was on Jalopnik last week, maybe you know which vid I am talking about).

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                      #25
                      Originally posted by bmwman91 View Post
                      That was the case maybe 5+ years ago, but the M42 has earned a bit more respect as of late. The 318iS is recognized for its light and nimble front end

                      Anyway, it looks like you have a fun project going. Keep up posted! Also, how far do the pistons hang out past the cylinder skirts at BDC? .
                      Thanks. Turn-in is fabulous as is overall grip.

                      The s50 pistons were pretty similar to the m44 slugs IiRC. It's been a while but I seem to remember that the wrist pin would slide through with both skirts flat on the bench. They are shaped the same underneath so the squirters line up as they should also.
                      You say "Where are your other two cylinders?"
                      I say "Where's your other camshaft?"
                      Frankenmotor: if an M42, M44, M20, S50, and S52 were to have a kid.

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                        #26
                        Originally posted by benz-tech View Post
                        I'm noticing that the DME 5.2 on the m44 is finicky when modifying. I kinda knew better. It is superior to the 1.7. But I wonder if the 1.7 more tolerant to a cam upgrade since it seems to ignore some of the inherent 4-cyl intake pulses already. I'm not sure though. Either one would work well with less cam and compression im sure.
                        Are the DME interchangeable with each other? What wiring harness are you using, m44 or m42? The wiring and engine management is what most confuses me, dealing with EWS and different locations for things like the cps and such.

                        I can't stop thinking about buying that m44 and getting all this figured out. M50 power (maybe more?) from a m42 in my lightweight slicktop sounds like a lot of fun for next years autox season.
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                          #27
                          Originally posted by bmwman91 View Post
                          That was the case maybe 5+ years ago, but the M42 has earned a bit more respect as of late. The 318iS is recognized for its light and nimble front end, as well as being a little lighter overall from having less sound deadening and that sort of thing. The 318i/iS is probably the hardest E30 to find after the M3 because everyone was ripping out the M42 for M/S50 swaps for a decade.

                          Anyway, it looks like you have a fun project going. Keep up posted! Also, how far do the pistons hang out past the cylinder skirts at BDC? It was something I had never thought about until I watched a pro LSx engine builder talk about the pitfalls of stroker builds (was on Jalopnik last week, maybe you know which vid I am talking about).
                          What were the pitfalls? Just curious what was said.

                          Making sure you have proper squish (and no interference with the head) is critical and difficult to do without custom pistons. You have to do all the maths to make sure the piston does not stick out too much above deck, or too much below deck.
                          -Nick

                          M42 on VEMS

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                            #28
                            Originally posted by E30 Wagen View Post
                            Are the DME interchangeable with each other? What wiring harness are you using, m44 or m42? The wiring and engine management is what most confuses me, dealing with EWS and different locations for things like the cps and such.

                            I can't stop thinking about buying that m44 and getting all this figured out. M50 power (maybe more?) from a m42 in my lightweight slicktop sounds like a lot of fun for next years autox season.
                            No they are not interchangable. Some of the sensors are different and the DME cannot interpret the signal. The crank and cam sensors as well as the airflow meter come to mind quickly.
                            -Nick

                            M42 on VEMS

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                              #29
                              Originally posted by wazzu70 View Post
                              What were the pitfalls? Just curious what was said.

                              Making sure you have proper squish (and no interference with the head) is critical and difficult to do without custom pistons. You have to do all the maths to make sure the piston does not stick out too much above deck, or too much below deck.
                              The big issue seemed to be ring wear. As the piston skirt protrudes past the bottom of the cylinder walls, it can cock slightly which puts a lot of wear on the rings and cylinder walls, and it can also increase the possibility of damage to the piston/rods at top RPMs.

                              Here's the video. I think it's toward the end.
                              Learn on Monday, wrench smarter on Sunday.Introducing a NEW series on /DRIVE, aimed at educating you to build a faster, better, more reliable car: /ENGINEER...

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                                #30
                                Update:
                                I was forced to install a 2.04 hg to drop the cr to 11:1. CA gas sucks. This completely solved the pinging I had at tip in and in real hot days. Lars just say the knock sensors were pulling more than their share of the weight. After the hg went in, it felt like it could handle more timing. I bought the 91 oct flash from midnight tuning and it really woke up the mid range and felt much better overall. I am also running an SAFC from Apexi since I have addtl fuel needs. In a nutshell, the engine specs are as follows:
                                Late M42 head, hotter e30 cams, delta intake cam + 10* and .020" lift. 6mm valves, S32 33mm buckets, cam bridges and conical valve springs. Mild port/polish.
                                Stock e30 intake manifolds, w/ m44 flashed DME, harness, MAF sensor.
                                M44 short block, 360* main bearings, fully balanced. S50 pistons milled to fit(not enough since 11:1 would have been better)
                                12.5 lb m20 smf conversion (too heavy still)
                                2.25" exhaust, including the cat. Dyno max 20" muffler that got buzzy after the first month- thumbs down. Wanting to try the 20" 5x8 magnaflow.
                                You say "Where are your other two cylinders?"
                                I say "Where's your other camshaft?"
                                Frankenmotor: if an M42, M44, M20, S50, and S52 were to have a kid.

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