Hey guys got a question and search yield very little info. I know the na 91-93 auto and manual bp differed in cams and compression. Did that also applied to the bp4w engines 99-00? My 99 miata is manual and might pick up an auto bp4w to replace it since its cheaper. I just want to be sure there are no major differences if any.

 

none for the engine itself that I can think of for that year

 

Thanks. Sounds good. Weird how an-auto engine with no differences can be 200 less then a manual. My gain I guess.

 

My understanding is that the differences are different advance curves in the ECU.

Yeah, good deal for you.

 

Thanks. I just picked up the auto for 500.00. Supposedly it has 80k miles .Tear down in progress.

 

So I know why it was 500. Dame place said they did a compression check and said they were in factory range. Picked it up and being excited didn't get more info. When I got home my brother insisted that we do a compression check to make sure cause he feels 500.00 was too cheap.

Turns out on a cold wet compression piston 4 showed 110 psi and all others showed 150psi. Mothebshjdbxgvdkfk.
Just returned the motor yesterday and explained the situation and how fcked up it was for them to lie. Long story short I spent an extra 500 and picked up a jdm bp4w with cold wet 200 psi across and 195 on piston 4 from a reputable jdm importer. I'll post pictures of the new motor soon.

 

All junkyards lie. I do business with them for their big machines with forks on them they use to move cars around and get to be behind the scenes. They will have engines that are locked up and the yard guys will pull the spark plugs and put oil in the cylinders and rock them back and forth with a big cheater bar to free them up to sell. They also lie about the mileage on the engines regularly. All of them.

 

Well that settles it. No more junk yard motors. It's sad they would stoop to that level. I have to admitt sometimes they get cars with really nice parts. They had a carbon fiber rx8 mazdaspeed strut bar hanging on the wall. I thought that was very nice. I'm happy with the 2nd motor. Can't go wrong with a jdm bp4w with a bp5a cam.