First Shot at Building a Motor
 

So I had been playing with the idea of building a motor ever since this obsession started. I have a build threat on this forum called my turbo miata budget build in which i successfully turbo'ed my miata as close to "the right way" as I could for around $2300. I was pretty satisfied with that accomplishment but I of course started thinking about what was next. Then the budget build started to wither away and I picked up a GT2560, Flow Force Injectors, and a custom downpipe from Artech. The car made even more power and I was very happy with it. Then i started thinking, this 2560 has more it it that I would like to explore. However, I dont want to blow my motor and that would be getting close to bent rods territory.

I started thinking about building a motor on the side but i could never justify it financially. My thought was if I build a motor and make more power, I will probably have transmission issues. If i buy a 6 speed that should help but ill have a terrible gear ratio (currently running a 4.3 Torsen). Therefore I would need to source at least a 3.9 Torsen. The dollars would always add up way too fast so i always said screw it. Then I found what appeared to be the perfect deal.

I drove 4 hours south and picked up the complete drive line from a 1999 10AE that a guy had pulled out to do a LFX swap. He was just looking to get it out of his garage so he sold it all for a couple hundred more than a 6 speed alone. He said that if had been smoking and burning oil so he had the head rebuilt. Unfortunately it continued afterwards (more on that later)

Got it home and onto a motor stand (thanks to my wife who actually lifted it off the floor with me to get it on there) and started tearing it down. Its actually quite fun and relaxing to take a motor apart. I even bought some organizers to keep track of all the bolts and where they go.
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As of now I have it down to the short block.

Im sure my plans will change as this whole thing progresses but I plan to build a motor capable of around 320 whp. I dont want to start replacing all the other supporting mods I have so I don't foresee going higher than a GT2871. Initially I will just use this motor to squeeze every last drop i can out of my current 2560.

Here's where I might lose some of you, but my plan is to do a rods only build. I have talked to a few different folks on this forum who have made big power on OEM pistons and i think thats the way I want to go. Remember my aim is to build a motor capable of 320 or so whp, not 500 hp.

Right now I'm trying to decide if I should keep the 99's current 9.5:1 compression pistons, or source some used 9:1s from an NA8 and run those.



Now lets get to the tear down and some pictures.

Before i tore the motor down I did a leakdown test on it. the results were freaking terrible. It had upwards of 50% leakage on some cyliners and all were at least 30%. All of it also seemed to be coming from the exhaust valves (easy to hear that with no exhaust manifold on there!


Better still, when i took the head off, I turned it upside down, filled the bowl with water then blocked the exahust port with a block of wood with a small hole and injected compressed air to see if the valves were sealing. Sure enough all the exhaust valves bubbled like crazy when i did this. On one cylinder the intake valves were also leaking. The fact the guy said it was still burning oil leads me to believe that the valve stem seals may also be garbage. Pretty bummed that Im going to have to have a "rebuilt head" rebuilt. But I should expect these things to happen, given the price i paid for all of it.
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Also it looked like the cylinder 2 spark plug hole had a heli coil or something inserted into it....great. Its also got a good chunk taken out of the aluminum near the intake valves.

Im not sure what bad cam wear looks like but didnt see any glaring problems. there seemed to be some wear on the front most intake side cam cap and cam journal.
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Pistons look ok and the walls don't seem to have any wear. They look glazed but maybe that because they were all sucking in a ton of oil.
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If there is anything you all more experienced people see that are big red flag or things i need to look at closer, let me know. Im giving this a shot and hope to come out successful on the other end.

yay!

Also, still interested in splitter whenever you have downtime from your build :3

If using cast OEM pistons, and not running e85, you probably want the 9:1 compression pistons.

Alright well the motor is officially torn down. things looks pretty decent overall but sure enough, the cylinder with the new spark plug insert and gouge in the head casting over the piston showed the most wear. Piston looked to have some light detonation on the side. Cylinder two had what looked a bit like pitting but I couldnt really feel anything with a fingernail so Im not sure how bad it is.
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Im planning to use OEM pistons so Im only planning to have the cylinders honed. Hopefully this light damage can be removed with a hone.

All the others look like this.
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Here are a few pictures of the crank
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Alright so I picked up some used 9:1 coated pistons. Unfortunately one of them has a defect on the piston top. I've talked to several people (still need to talk to the machine shop) and I have received mixed opinions. Most will agree its not ideal (myself included), but most of these folks have also said it likely wont cause an issue to run these.

I'm interested in the opinions of those of here. Keep in mind, I understand this imperfection is not ideal. At the same time trying to source a single piston in good condition with the same compression and have it coated would start moving towards not being a cost effective solution. Bring in the "your halfway to forged pistons" argument.

The imperfection is in the piston iteself, not the coating. Possible a casting defect, does not appear to be detonation damage based on location and shape but its always possible still.

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That area is one of the highest stress parts of the piston, right over top of the pin. It's tough for me to say it will or won't work, but it would make me a bit nervous.

I have literally zero knowledge or experience, but I wouldn't run that piston in any scenario.

Just think: when it fails, all your hard work and much of your money will go down the drain.......

I would replace that piston

I would JB Weld a quarter over the bad spot to protect the piston.

^hahaha. LOL'd.

Why didn't you deal with the scoring in the cylinder before you got pistons? If they need to bore the cylinders to remove all the scoring, you're looking at aftermarket pistons anyway.

What are you planning to do re: oil pump and harmonic damper? I'm building a motor with a '95 bottom end and a '99 head with similar power goals as yours. I haven't made up my mind. Some say it's essential, some people are running stock oil pump up to 400hp without issues.

I had much more scoring on the cam journals than you. The guys at the machine shop didn't seem too concerned about it.

:bowrofl:

I got the pistons for a pretty reasonably price so i rolled the dice that the bores would only need a hone. Time will tell. I have also talked to folks running the OEM harmonic damper and/or OEM oil pump on pretty high horsepower motors. I will likely end up just running the OEM damper and replace the oil pump with an OEM unit. In the future, should I decide to go for a 2871 or something, i will likely look into an upgraded damper.

In a perfect world I would run the BE pump and ATI damper, but its not a perfect world is it?

Talked to the machine shop about the piston today. This is the same shop that has built two 400+whp motors on this forum so I imagine they know a thing or two as well. They weren't worried about.

At the end of the day, these are all just opinions, some based on more knowledge and expertise than others but all worthy of consideration.

I bet you would.

If you're buying an oil pump, get the NB2 replacement.
I think all the NB pumps are NB2 pumps now though. I think they replaced them, but I'd make sure it was for the NB2 motor!

Bob!!

Ross?

I handed off the head to Bob himself!

Haha, stoked. My engine has been pretty happy so far.

Glad you might be able to use the Pistons after all. You should see if you can find one that's fine and get it coated for the peace of mind if that's going to bother you.

I'm still having second thoughts about having sold those since I'm planning on doing the exact thing you are!

While i wait for word from the machine shop i figured i would start cleaning the partts i had removed from the car. They were filthy. Everything was covered in oil and scale. The intake manifold was a real treat. It actually had standing oil in the runners and was full of grease and grime. Wanting a fresh start i looked into ways to clean them. The one thing I didnt try was oven cleaner. Figured i would try various things to see how they worked. I tried

Carb cleaner
Brake cleaner
Kerosene
Mineral Spirits
simple Green
Dish Soap
Eagle one Mag wheel etching cleaner

I also picked up a siphon gun for de-greasing motors at harbor freight. Basically you hook it up to you compressor and feed the line into the solvent you want to use and it sprays the solvent like a mini power washer. Used this with mineral spirits with pretty good success.

kerosene and Mineral spirits both work pretty good. I found carb cleaner broke down the grease better than brake cleaner. I don't understand why Simple Green gets so much love, I think it generally sucks and always seems to leave a film on things. The Mag wheel cleaner is amazing on metal that has already had the heavy grease removed but it makes the aluminum look brand new (because it etches and is made of acid) However, its potent stuff, I would rather not use it if i can help it.

I got the insides of the manifold pretty damn clean, still some slight areas of grime but im not worried about it.

I also hit the manifold with a wire wheel to get off some of the deposits. Oddly enough (or perhaps not) it began polishing the aluminum. I had planned to paint the manifold black but for the hell of it i just kept going with the wire wheel. I actually like how it looks. Its not polished smooth to a mirror finish, but certainly has a lot more shine than the regular casting. I think I will keep it this way.

Before:
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After:
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The previous owner had broken the VICS actuator, both the nipple and the entire circumference of where it attaches. I could not seem to find replacements anywhere for one of these so I said screw it and bought some plastic bond epoxy stuff by permatex. I also noticed that the clear straw piece on spray bottles was exactly the right size to fit vacuum hose. I drilled out the nipple to the outer diameter of the plastic "straw" thing and epoxied it in. It aint pretty but perfectly repaired the actuator and saved me some headache and money.

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Well not quite sure what to do from here. If you noticed in the original pictures I posted the head had a helecoil for the spark plug hole on cylinder two. However, it was too short for the miata spark plug. The machine shop just finished my head rebuild and said they installed a new helecoil of the correct length. They said they had to use another helecoil because the hole that was drilled in the head was now too big for other inserts. Problem is when i went to pick it up it looked awful. Im not a machinist or an expert by any means but this looks like its so full of sharp edges I dont know how it wouldn't cause det.

The coil itself seems to extend too far into the combustion chamber and has sharp threaded edges exposed. No idea what to do with this.

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Wow you got screwed. What a terrible job. Det from sharp edges are the last of my worries. The area between the valve and the plug is already prone to cracking. That thing is GOING to crack.

that strange crack in the side corner of the combustion chamber looks terribad too.

:(

Sorry dude. That really blows and I'm sorry that shop brought some bad luck.

Hate to say it, but I would junk that head and buy one that's in good condition, or at least rebuildable. That crack at a minimum needs to be ground out, welded, and then ground to the correct shape, then surface the head to get it flat. The spark plug problem... I bought a head on here a few years ago, and then noticed the same BS problem you have, a big helicoil in the head that had been done wrong and ruined the head. That head is now a paperweight of mine, and I had sunk about 12hrs of porting into it before noticing the helicoil mess. So I feel your pain there.

Are you referring to the "crack" on the edge of the combustion chamber? Because that's actually where some debris knicked it. Also upon a second look I think the chiseled helicoil was there prior to the machine shop. This is a pic before machine work of that cylinder. You can see the gouge.

The head was resurfaced which took out most of it.

the head was also pressure tested.

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that head is done

I hate to say it.. but I would not run that head either. The jagged edges around that helicoil give me serious heeby-jeebys

Yes I was referring to that crack. How can any shop let that go out the door?

well looks like I'm off to a good start. What about looking into the machine shops that do aluminum head welding repair? ie they weld the spark plug hole closed, then re-tap. No idea on cost but I already paid for a full head rebuild only to get a head back that is apparently worthless. Assuming thats a valid option would probably be cheaper than sourcing another head and paying the rebuild cost all over again.

lesson learned I suppose.

If they did that, I would at a minimum install new seats too as welding right next to the seats that are pressed in can distort them, and also cause them to later drop out of the head. I considered the same on my head, and decided to scrap it instead, but in theory it could be fixed, but the amount of time/money to fix it right (my way of right) isn't worth doing for me.

My friend had that done. Twice. It cracked, twice. After spending $1000+ on all that garbage, he ended up getting a new head. we all learned something from that.

This was a n/a NB1 too, never saw boost.

I wouldn't even put that head in a shop car, and I'll run stuff in shop cars I would never, ever send out the door to a customer.

After a lot of time and work, it’s finished! Big thanks to several people on this forum who have gone down, were willing to experiment, and shared their insight.

Right off the bat, I wanted to put out some of the lessons I took away from this project that may be applicable to others. As many on here have said, building a motor is not cheap, even if you go the “cheap” route, the little things here and there will nickel and dime the hell out of you. I knew that going in so it wasn’t a surprised, just very true. I’m talking things like new hoses, adapter fittings, tools, small replacement parts like sensors, it all adds up.

Another take away is that it was a lot of work, especially if it’s the first time you’ve done it and if you are paranoid that everything you just did was somehow wrong. I probably caused myself a lot more stress than I had to during this build.

Also know that this forum is a great resource for a ton of information. But there are also a lot of opinions, and plenty of them aren’t backed by anything beyond what they heard someone else say. When it comes to building a motor, when in doubt talk to a machinist. Your machinist, an unbiased third party machinist, whoever. What they say is usually quite a bit different than what the forums will tell you. For reference, throughout this project I had a dialogue going with three different machinist to double check I wasn’t wasting time on something that was a lost cause.

Lastly, if I had to do it again, I might consider building everything with all the good parts. Not because I needed them, but because for the amount of time and effort that goes into it, it might be nice to know there wasn’t anything I could have done differently. Of course I say its easier to say that now with that money still in the bank.

Anyway lets get to it. Below are the specs of my build. I basically just did a “rods only” build.

Motor:
BP4W out of a 99 10AE. Car had roughly 110,000 miles on it.

Block
96 OEM 9:1 pistons with Calico Coatings Ceramic top coating and moly skirt coating
Ebay Maxspeedingrods forged rods with 5/16 ARP2000 bolts
Sealed Power Chrome Piston rings gapped .016 top .019 bottom.
ACL race bearings throughout.
Polished Crankshaft
New OEM BP4W Oil pump
Gates water pump with cast impeller.
All OEM seals (Front, Rear, cam)
Trackspeed oil feed adapter
Block plateau honed (at least that’s what I asked for) and deck resurfaced
OEM Headgasket, Head bolts, main bolts.

Head
VS855 valve springs
Felpro valve seals
OEM valves, cams etc
Decked .004-.005
Valve job
Supermiata Qmax Coolant Reroute.
Slight chamfer to the combustion chamber edges.

Everything else:
Garrett GT2560
Artech custom divorced Downpipe
2.5 inch exhaust, magnaflow (big muffler)
200 cell metal core cat.
FlowForce 640cc injectors (Sequential)
Toyoya COPS (Direct Fire)
Hydra 2.6
TacoTaco Manifold
Rev9 intercooler (Amazon/Ebay)
Forge VTA BOV
Hallman MBC

Transmission
Going to run the 5 speed and 4.1 Torsen for now as the power levels I hope to achieve may still be feasible on the 5. However I have a 6 speed and 3.9 Torsen on standby if needed.

You may have noticed the first few posts in this thread. Well these weren’t the last imperfections I found

Here are all imperfections living inside my motor

Some of the bores had slight pitting in them even after honing. It was pretty shallow, but I could see it if the light hit it right. Guessing moisture sat in the combustion chambers for a while.
Don’t forget one of the pistons had a tiny bit of strange pitting in the top of it. Likely already filled with carbon. Consulted with some machinists on this one
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I tried to weight balance my pistons, and initially took weight off the worst place, the bottom of the crown. There is a thread on here that discusses different places you can remove weight, and this is listed as one of them. DON’T DO IT. That part of this piston is critical for strength and the amount of weight you can remove there is minimal. That said I drilled 3 small dimples in one of my pistons. Guess what, it’s in the motor. This was one of those scenarios that I talked to a couple machine shops about.
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When I opened up the motor the first time I noticed there was a helicoil in one of the spark plug holes and it looked ugly. The machine shop replaced it with a timecert, which is supposed to be better. But it still looked ugly. This is what I posted on early in this thread and was told the head is junk and it will crack etc. It’s probably too early to say, but again I talked to several machine shops about it and they told me it wouldn’t be a problem if I grinded the insert as close to flush as I could. I also used a punch to peen some of the aluminum and round it off. Here is the result.
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You might also notice how I chamferd the edges of the squish area and combustion chamber. Used a small flapper wheel very delicately on a dremel. Heres a better shot, this softens the edges a bit to help eliminate any potential hot spots.
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While I was trying to install the head on the block, I screwed up and scratched the freshly surfaced head mating surface. Again, consulted the machine shop and they felt that because the scratch did not cross into the combustion chamber or cross one fluid jacket to another, there shouldn’t be an issue and it should still seal fine. In the picture below I traced the outline of the headgasket to see how close the scratch got to the edge.
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All this to say, not every imperfection means your motor is going to explode. That being said. If I were looking to build a 400-500whp motor, I would probably want to think more seriously about addressing some of those things. Additionally, there are probably guys on here that still think my motor will explode. In honesty, if that happens, I will come in here and admit it. However, I was willing to take a chance on it based on feedback I got from people that know there business,

Head assembly

I picked up a digital micrometer to do the valve shims. Pretty cool tool. I had fun doing this. However, it can be a challenge to find replacement shims at a reasonable price. Mazda charges something like $8 per shim. There are other shims from other cars that will work and are cheaper, I forget them now but essentially they just need to be the same diameter. I basically moved around the existing shims I had, after that I traded the machine shop my extra shims for some in the size I need. After all that I ended up have to buy a few mazda shims and a few of the others.

Lesson learned here: I had my machine shop just do the valves but not install cams or do valve clearances. I thought I was saving money doing it myself. However, I didn’t realize machine shops “tip” the valves when they do the clearances. This is essentially machining off a little of the lifter to get the right clearance vs having to source different shims. Ultimately, my way was still cheaper, but it was more work and more expensive than I thought it would be.

Block assembly

Cleaned the block really well with high pressure soapy water and a soft bristled scrub brush. A lot of left over crap from the machining process was washed out. This is an important step.

Figured I would paint the block even though no one would ever see it.
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Followed all the mellens FSM manuals for this and plenty of YouTube. I used Permatex the Right Stuff for all the RTV points. Removed backing plate on oil pump and put assembly lube in it. That seems to be what Flying Miata does so I figured it was worthwhile.

Did my best to weight balance the pistons. The rods were all within .5 grams of each other which I thought was pretty good for Ebay rods. I got the pistons all within .6 grams and all the pins were the exact same weight.
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I set my ring gaps by pushing them flush with an old piston and then hand filing them on a flat file (bastard file?). I didn’t want to buy the tool for this. It was a little tedious but it didn’t take too long. Be sure to check them though to make sure your filing them flat. Easy to file at an angle when doing it by hand. Knocked off the edges with a fine file afterward.

I can’t say enough about the Wiseco piston ring compressor. I picked one up after watching thecarpassionchannels video and it was incredibly easy the get all the rings in their proper orientation and even easier to smack the piston into the bore. In fact, I realized one day that I had put the wrong piston in the wrong bores and was not worried at all about having to do it again with that tool.
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Lined the rings up according to the FSM.

Used assembly lube for all the bolts to get proper torque. My machine shop measured all me clearances when they were doing their work so I didn’t do any plastigauge.
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Assembled the engine slow and steady. And it all came out looking good.
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I painted the valve cover using wrinkle red and filled in the concave letters with black using a needle to suck up the paint and fill in the letters. Got this idea again after watching carpassionchannel on youtube.
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Installation
Had a friend help me pull the old motor and drop the new one in. Used a huge hoist he had at his construction site. Bought a load leveler from harbor Freight as well. Wasn’t the smoothest thing but it got the job done. I picked up different links for it and home depot to avoid using the akward mounts.

Pulling the motor was pretty simple. Dropping the new one in was a little more challenging. Had a hard time getting it to slide into the PPF as I left it on. Eventually we got it.
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The rest was just hooking everything up. Did a lot of new things from my old set up.

All the sensors Im running on the car are from the 99 (throttle Body, Cam, crank, etc). I even have the VICS system running. Thank you standalone EMS!
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Starting.
This part gave me a ton of problems. I was having a ton of kick back, smoking, horrible sounds, you name it. Got the car to run at one point but was only on two cylinders. Needless to say I was panicking. Started checking injectors and ecu singals etc. Well turns out I had the wrong sequencer value set up in my ignition triggers settings. Basically the ecu was not properly syncing the independent signals it was getting from the crank and cam. Changed one value and what do you know, she fired right up.

Followed the Flyin Miata break in procedure and all seemed well.

That’s enough typing for me. So far the car has 500 miles on the clock. I just compression tested the motor tonight and got 187, 189, 183, 187. Pretty damn happy about that. All the spark plugs looked great as well. Car hasn’t burned a drop of oil in these 500 miles either. No smoking whatsoever.

Im easing my way into boost. Been running it so far with the wastegate wired open. Probably don’t have to but after all this work I feel better this way.

The car actually feels really strong. Which I was surprised by considering I’m running no boost. If this is any indication, I can’t wait to see what it does when I max out the 2560.

This is a great thread and great write up. I'll be referencing when I rebuild mine this year.

Awesome update! I'm so stoked to see you off of ground and running with this!

This car is wonderful.

well the results are in! finally got a chance to get on the dyno and dial in the tune. Im very happy with the numbers the car put down.

This was at 16 psi tapering down to around 14.5 by redline on my GT2560. The differences between the two plots is purely timing. Boost and AFR was exactly the same.

AFR was between 11.5-11.8.

Looks great man, congrats!

How does it drive?

Post a video!

Just to double check, you're still running a 2.5 exhaust with a big maggie right? Does the muffler exit into 3 inch piping or is it just straight 2.5 throughout?

great numbers!

Great numbers. Solid setup.

very similar to my ex 2560 setup powerwise. Only difference I hit 200wtq 300rpm earlier. Probably due to vvt, manifold and 3" exhaust.

Were you running the same amount of boost he is? Honestly, I'd have expected the difference to be higher!
Or was that before you swapped over to Kraken?

thats before the Kraken and EFR stuff.

i was running a 2560r and AVO cast manifold, 2.5" downpipe, 3" catless exhaust and vvt. boost about the same, maybe ~1 psi higher or so.

https://cimg3.ibsrv.net/gimg/www.mia...4c1ac120a7.jpg

great numbers! Post your timing map, I always like to see what people are doing with timing. Im running the same turbo but with a FM manifold. Glad it turned out so well for you, I bet the car drives great!