Watterson02

I recently sourced an NA8 motor that I was going to tear apart, swap the rods with some Manley ones, and then reassemble with my old BP4W head. Unless the cylinder walls are in bad shape, I plan on reusing the stock pistons with a dingle berry hone job. I will also have the head shaved, block deck cleaned up, and crank polished. Also including a new BE oil pump (was thinking 2 or 3 shims, any advice here?) and possibly an ATI fluid damper.

so my questions:

1) Once the head has been refreshed by a machine shop, assuming the cam journals check out, is there anything I need to be mindful of when putting a BP4W head on an NA8 block? Just use the 99-00 headgasket and it should work out fine right?

2) My garret 2560R was on the motor when it spun the bearing. After a 20 minute drive home after the knock had begun, and a short start up to get it on the trailer, what are the odds my turbo is blown? I used a T-fitting on the oil pressure sensor for the turbo oil feed. Does anyone know if the oil pressure sensor is before or after the oil filter? If not could I flush the oil out of the turbo somehow prior to the first start with the new motor?

3) lastly. Is there anything else that needs to be cleaned out to prevent metal shavings from getting in the new motor? The car didn’t have any aftermarket oil cooling/filter relocation kit.

The first question is probably something I could find through searching, but I thought I’d just throw it in here since I was already going to ask about the two.

Any tips or thoughts would be appreciated, and please grill me if anything there sounds dumb/incorrect

LeoNA

I would not use a ball hone. Bring it to a shop and have them hone it, this will help to correct some of the discontinuities. If you spend the money on rods you should get some forged pistons. If the turbo was plumbed correctly, it was getting filtered oil and should be alright.

der_vierte

Oil pressure sender is AFTER the oil filter. Get some engine brushes and soap, clean where you can. Blow out with compressed air. Clean oil pickup/oil pump very thoroughly. Ultrasonic cleaners work wonders, could even put a piston in it.
BP4W head can take your old CAS, but you need 4W fuel rail and intake manifold. I THINK you can make your old FPR work on the new rail. Have to look it up.

Are you planning for a reroute?

I've built the same engine as you two years ago, happy at just over 300whp, but with very good fuel.

Flush your turbo, check for radial shaft play, if good, put it in. If it's not smoking and making good power, everything should be fine.

VertBert

From what I've seen, the head should match the chassis for stock ECU's, so as long as you're putting it in a NB1 everything should be fine with the BP4W head. The cam sensor and fuel rails are different between the generations, and I'm sure there are other things.

Before taking the block to the shop, pull the oil galley plugs. I drill a hole, tap it for 3/8" thread, then use a socket and some washers to walk them out. You'll be able to clearly see the oil passages and understand what you need to clean before assembly.

Since you are taking the block in for resurfacing, just have them break the glaze on the cylinders for you. It shouldn't be more than maybe $15/cyl, and it'll be more consistently straight than using an dingle ball hone.

For cleaning, I had an old rifle cleaning kit with brass brushes and cleaning patches. I ran the brushes through all of the oil galley passages, the oil pump feed passage, and the main bearing passages, brake cleaner and compressed air, then followed with cleaning patches dipped in fresh ATF to keep everything from rusting. Then I ran cleaning patches through the passages until they came out clean. That should be the very last step before assembly.

Watterson02

Thanks for the input on the oil supply. I've found a local shop that has experience building all sorts of motors including Miata engines, which I couldn't find before. I will be taking it to them. From what I've read the stock pistons should be good for my power goals, but ultimately I will see what the machinist thinks and am already leaning towards just going with low comp 1mm over Supertech pistons.

Thanks for the info, especially on the oil feed to the turbo being filtered. I wasn't really clear about this I suppose but the chassis is a '99 and the old motor was a bp4w (I plan on reusing the head from this motor), and the new motor is out of a '97 (I only plan on using the bottom end). I'll be taking it to the previously mentioned machinist for a valve job and have him clean the head. Reroute has already been done (on the first motor, this is the third one haha oops)

Also, may I ask what turbo and boost level? I'm on a Garrett 2560r hoping for 270+ on 93 Octane (no ethanol around here rip)


Great info. Thanks! One question, will the shop be able to replace these or should I talk to my machinist to make sure prior to removing the plugs? I've not contacted the guy yet. I was going to try to get all my eggs in a row before taking it to him. If I don't already have my 84mm low comp Supertech pistons in hand, I'll at least have the money to order them.