Hey guys, I found a 944s motor online. I currently have an 8v and thinking about doing a swap. Problem is, I've never bought a motor on its own before. I've gone over my engine as thoroughly as one can without actually taking it apart; belts, water pump, oil cooler seals, rms, sensors, etc. I can handle a compression test, but can you guys tell me specific things to look for?

 

Good luck, compression test will help you determine the ring life but its a tough call without taking it apart. When was the last time it ran? Can he run it?

 

Cam chain tensioner and pads are critical. Check them.

 

The motor was bought as part of a unit at auction and the woman knows literally nothing about it except that "it says Porsche on it = $$$$$$$" looks clean but that means nothing. Might not have the DME or AFM which could kill it right off the bat unless I go aftermarket.

 

Oh I should mention, plan is probably to take the whole thing apart and do all seals, hone the cylinders, check the valves, new rings, bearings, sensors if necessary. Never built an engine before but I can take my time as I have the working 8v in my car now.

 

If you plan to rebuild it then as long as the block and head are good you should be good to rebuild it.

 

Yeah, I just want to make sure it's not missing anything that's going to cost me big money down the road.

 

The entire engine management system is different...DME, harness, igniter module, AFM, etc. Technically you should be able to run it using an 8v setup if you are prepared to have the chip tuned for purpose, not a stock tune or off the shelf chip tune. Or go aftermarket.

 

Michael, you're sure the AFM is different? That could throw a monkey wrench in my plan unless I can find one at a junkyard.

 

Not 100% actually. But the entire Motronic revision is newer, so I always thought it was...could very well be wrong. It's sort of a turd part anyway, you can get a plug and play Megasquirt for not that much for 16v engines (you will need the 16v harness though)

 

Looks like it has the harness with it, god help me when I try to start sorting through that. Anyone have any good sources for a 16v Megasquirt system/tutorial on how to install/use it? Would it be better to get the engine installed and make sure it runs with all the original equipment before going aftermarket?

 

Do the 8v and 16v use the same flywheel? Just had mine machined with new clutch, would be nice to be able to reuse.

 

Yes the 16v AFM is different - it uses a "944 turbo" size housing but presumably is programmed differently. By "turbo size" I mean the opening for the flapper door is 50x60mm versus the NA 50x50.

8v and 16v use different flywheel but the same clutch disk and pressure plate. 16v flywheel has 60-2 trigger wheel built in whereas the 8v uses a single pin on the FW and the starter ring gear teeth to count.

And here you go, a Plug-n-play setup for 944S but you need the 944S harness. At that point you're rewiring part of the car anyways so it's not a big difference using just the stock 944S DME or the MSPNP but MS will get you more power and driveability in the long run.

https://www.diyautotune.com/product/...sche-944-s-s2/

Anyways there's no reason you "couldn't" run the 944S engine on an 8v DME and such. You would at the very least want to re-tune the engine via chip or Ostrich-like device because the 8v ignition timing is way different than the 16v. But you could put the 8v flywheel on the 16v motor and use the stock 8v crank sensors with the 8v DME and harness. The DME doesn't care how many valves are attached.

 

Good to know about the flywheel, and the AFM. Guess I'll have to start looking for an AFM or a maf that's compatible. Oof; that's not insignificant $. I assume I can change the tune with my computer and would need to take it to a shop with a dyno to get it properly tuned? How about exhaust, will mine bolt up from the header back?

 

With MS, there's an auto-tune feature actually. But you will need a wideband to use it with any worthwhile results. For ignition timing, the map they provide might be ok, I haven't checked it. You can also compare against ignition maps from the people who run 16v turbo engines (vacuum portion) just to get a sanity check. Since you don't have a 944S igniter module, you should wire the ignition output to direct drive the stock coil, or pursue coil packs or whatever suits your fancy. Dougs951S and I have posted a lot of literature about MS installs (we've both been running it with great success) but the information is mostly tailored to Microsquirt models. A lot of it crosses over besides the physical installation of the ECU. The threads are easy to find on google.