Why the m50 manifold? The DISA valve and variable volume are what help give that motor such wide torque cruve, right?
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It's good for +10HP over a good range. The DISA does help down low, but the M54 intake is also considerably heavier.Attached FilesComment
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I see. Carry on!Comment
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Current status is that the IAC bracket is fabricated.
I'll be pulling the cams and then head in the next several weeks, need to figure-out what I'm doing as far as valve grind, guides and so on. It's a low-mile motor, so nothing probably needs to be done, but a good valve grind can make a big difference.Attached FilesComment
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Awesome!
The OBD1 manifold drops torque, which you will notice. Seems like the don't "feel as fast" when you decrease torque, but this is going to be good, either way. The dyno graph you posted if from a thread I read recently.Comment
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Head is removed. Everything looks good except for some scoring on one of the exhaust cam journals. There was also enough loose carbon in each bore that I could vacuum it out; like a teaspoon of carbon was sprinkled on each piston.
Valves will be removed. Port will be matched to the new M50 intake manifold, the ports will be cleaned up a little bit (mostly exhaust!) and then the head will go to machinist for good valve cut and assembly.
Attached FilesComment
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I borrowed the appropriate templates and cut the intakes to match the M50 manifold. With the right burr it took about 2 hours. Still need to plug the idle passages and do some minor work on the exhaust ports and then the head goes to the machinist.
The one on the left is done and the one on the right shows about how much material is removed. The blend goes about 1" into the port.Attached FilesComment
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Subscribed - thinking of doing an M54Comment
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I have the head ready to go to the machinist, but seeing as how I'm about to drop over $20k on siding I would't have the money to pick it up for a while, so it will go to machinist in September.
The e39 and e46 motors are the same as far as the swap. There are a few differences between early and late M54s. Some have 4 studs per exhaust port and some don't. That's an issue for me, because my euro s50b32 headers don't have the larger flanges that tie 3 runners together; they have an individual flange per port and my new motor doesn't have 4 studs per port, so I'll be getting new headers.Comment
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Steve
Are you still developing this engine for your DD?
Having followed your original blog all the way, I'm struggling to understand why you are now giving up on DISA? Once you got it set up, you repeatedly showed how it helps with bottom end torque, and how that helps make your E30 a better performing DD with a very wide flat torque curve.
The dyno graph you have posted reveals more by what you have not shown - the loss of torque below 3750rpm. This appears to fly in the face of everything you have endorsed in your current swap?
What has convinced you to go with the M50 manifold?
Please don't tell us you have finally been seduced by headline power figures, and higher revving engines??!!Comment
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You're right... DISA really does work. I'm still driving the original motor and the low-rpm torque is wonderful as it consistently chirps the tires. The downside with the entire intake is that I'm convinced it was optimized for transmission equipped cars driven by soccer moms that never rev above 4000 rpms. I remember when the car had the M50 and the way the power built into a crescendo was a very differenent feeling than what I have now.
I'm not completely lost to the dark side; I'm convinced I get achieve 250whp on this setup and the increase in power across a wide chunk of the powerband is irrefutable. It's the same effect as headers which may cause a small drop in low-rpm torque but more than make up for it with a broad power increase.
Add the fact that the m50 manifold weighs significantly less and looks cleaner; I'm willing to be a guinnea pig.Comment
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