Brand New NB Turbo Engine Cranks but Won't Fire- Low Compression?
#1
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BACKGROUND
So there's been quite a long saga with this car. Bought it relatively stock, immediately the engine spun a bearing at a trackday after about a month of ownership, so I decided to use that as an opportunity to tear down the engine myself and learn more about the Miata drivetrain. Got everything machined and replaced everything that was broken, put in all new forged internals, megasquirt, slapped a turbo on it, etc. Put that engine back it the car, started up perfectly and immediately, but then it just ran like **** for a whole weekend and then destroyed itself.
At this point, I'd invested a lot of money and like 5 months into this project, I was pretty emotionally exhausted with the whole thing when it blew up. So I decided to just throw money at the problem and get the engine sorted by a professional. I had a performance shop specializing in spec miatas build me a completely new engine. They sourced a new BP4W block for me, got all new parts, did all the machining, modification, and assembly. I picked up supposedly a Plug-and-Play engine, even down to all the hoses being connected.
SO NOW
Dropped it in my car the other day and connected everything up. Go to start it for the first time, and it cranks freely but doesn't fire. It really sounds like it's got no compression, as if I'm cranking it with the spark plugs out or something. My first thought was maybe the timing, like maybe the valves are open during the compression stroke, but I can't believe that a specialty shop would mess up something so trivial as the timing. I'll obviously check if you all deem that worthwhile, but I'm hoping that there's a simple solution I'm just missing, or maybe there's a megasquirt setting or something that just needs to be adjusted.
I've linked a video of the sounds of the engine cranking, and I've attached a brief datalog of a cranking attempt.
Thank you for your help!
So there's been quite a long saga with this car. Bought it relatively stock, immediately the engine spun a bearing at a trackday after about a month of ownership, so I decided to use that as an opportunity to tear down the engine myself and learn more about the Miata drivetrain. Got everything machined and replaced everything that was broken, put in all new forged internals, megasquirt, slapped a turbo on it, etc. Put that engine back it the car, started up perfectly and immediately, but then it just ran like **** for a whole weekend and then destroyed itself.
At this point, I'd invested a lot of money and like 5 months into this project, I was pretty emotionally exhausted with the whole thing when it blew up. So I decided to just throw money at the problem and get the engine sorted by a professional. I had a performance shop specializing in spec miatas build me a completely new engine. They sourced a new BP4W block for me, got all new parts, did all the machining, modification, and assembly. I picked up supposedly a Plug-and-Play engine, even down to all the hoses being connected.
SO NOW
Dropped it in my car the other day and connected everything up. Go to start it for the first time, and it cranks freely but doesn't fire. It really sounds like it's got no compression, as if I'm cranking it with the spark plugs out or something. My first thought was maybe the timing, like maybe the valves are open during the compression stroke, but I can't believe that a specialty shop would mess up something so trivial as the timing. I'll obviously check if you all deem that worthwhile, but I'm hoping that there's a simple solution I'm just missing, or maybe there's a megasquirt setting or something that just needs to be adjusted.
I've linked a video of the sounds of the engine cranking, and I've attached a brief datalog of a cranking attempt.
Thank you for your help!
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TorqueZombie
Engine Performance
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08-05-2015 02:41 PM