Read this before you buy anything to SSD your 4k, 2018 edition
i almost did a similar thing with a fan but found the sunon one mpc stuff sells for cheap on ebay. it is ball bearing so it should work well and for a long time. it wont be quiet as the noctua fan but its fine. it is still in the mail. It has the two pin connector instead of the 3 pin you find on pc ones, so no re-wiring.
i actually had a compact flash to IDE adapter, a SD to compact flash, and a Sandisk Ultra 64GB SD card lying around already. I just bought a molex to floppy style power adapter for the cf-ide adapter, and it's much smaller and even less power consuming than a SATA SSD. plus you can screw the cf-ide adapter down to one of the mount posts for the hard drive.
It works perfectly and has no reliability issues. It is just as fast as a SATA SSD in the mpc4000.... both max out the transfer bus speed completely... unless you are using a very crappy SD card.You might think the SSD is a better choice because its more expensive but the truth of the matter is SATA and IDE/ATA are totally different interfaces. Any performance gain the SATA SSD might provide is negated by the adapter having to translate it to ATA format. Whereas compact flash is already using the IDE/ATA specification. So you just hit the SD card directly.
I left the CD drive in place.... i do like to use it from time to time.
If you don't believe me a SD card in the adapters is good enough, see the speed tests for youself... And remember the MPC 4000 uses the ATA 100 standard which means the highest possible transfer speed is 100mbps. below you see a test showing a Sandisk Extreme Pro SD card pushes nearly 250mbps. Thus it's good enough for even the most hardcore mpc4000 user
PS If you insist going the hard drive route, which you shouldn't for several reasons, but if you need that space, you can get the toshiba p300 for very cheap and it rivals the WD Black and Red in terms of speed, those WD greens are sloooow and i know because i have about 6 of them. The spin up to load something on the p300 is nearly immediate versus the lag time on the wd green.Shopping listhttps://www.amazon.com/StarTech-com-Com ... pact+flashhttps://www.amazon.com/C2G-Cables-Go-In ... oppy+molexhttps://www.amazon.com/Optimal-Shop-Ada ... pact+flash
MY 4000 recognizing a 32gb Sandisk SD card
Messy install pic before i screwed the SD adapter down in place where the HD was, and covered the adapter it in electrical tape on the under side.
If you want to access the card without opening the 4000, you can use one of those Compact flash bays that go where the floppy goes that the MPC 2000 guys use. Dont tell me you guys forgot that removable plate in front on the hard drive bay was intended for a zip drive too?