NASSEX

Ok so I am fairly new to the forums. My name is Vince I registered a while back but was unable to post new threads and wasn't able to figure out why. But on with the story!

I own a 1995 1.8L BP Miata, I turbocharged it after 3 months of hard work and it lived for about 2 days.... Lol

The problems were (and there were many)... 1) Didn't run a blow off valve. (also didn't port the wastegate on a ebay turbo) 2) Ran stock PCV valve which was very old and broke rather fast 3) ran stock ecu with vortech fmu & o2 signal modifier but wastegate was set to 10-11psi........ So clearly there were a lot of problems here.

However, when it was in boost, the AEM wideband never showed lean. It was a little on the rich side during full boost. and it ran great! and then all a sudden it started smoking very very BAD. I did some research and deleted the pcv valve, routed to a catch can and then went to try and run it some more, I only got away from my house when it blew. so I smoked my way home and there she sits at her final resting point.

The turbo was leaking massively and the engine was pouring so much steam out of the valve cover, it was also running on 3 cylinders. I did a compression test and cylinder #2 cannot hold ANY compression what so ever, while the other 1, 3 & 4 cylinders are normal. She has over 200k miles I think by the way. I say "i think" because supposedly the mileage was inaccurate when I bought the car.

I think I blew a head gasket maybe near a cooling jacket or somewhere and I think I also blew cylinder #2 piston rings.

Currently the motor is almost prepped to get removed, and I have a engine stand that's supposed to arrive today. I want to rebuild her!!! And I want to aim to do it within 1 month or less from the moment I start disassembling parts from the engine, and talk to some machine shops around my area. I live in Baltimore, Maryland btw.

I am wondering if anyone has any recommendations for me with my situation... I can't seem to find data for miata engine spec measurements so that I can try to gauge how much work it will need at a machine shop. It would be very helpful if someone could share some resources with me that give good data for the 1.8L BP engine so when I take it apart I can see how out of spec things are and such.

Because ideally I'd like to keep within a $1,500 budget give or take 250$ but if it really really looks like it will need a LOT of machine shop expense, then I might just look for a used engine, although I REALLY REALLY want to rebuild it. Big time. I've been watching almost endless rebuild playlists and trying to get as best of an understanding so that I can try to foresee how much it will cost at the machine shop..

I think I would like to just replace all the studs with ARP, and replace all the bearings with good brands, all new gaskets, and sealing rings, and probably all 4 pistons & rings. Maybe bore&hone the block but if I can get away with only that, I would be soooo happy!

In a perfect world for me, she stays within enough spec that I can put money towards parts. But I won't know until I take everything apart and check measurements, correct?

Anyhow yaw have a great day. I am stoked for this project.

Zsanz

in b4.

NASSEX

Sorry what's in b4 and what is b4? lol

Zsanz

Unfortunate to hear it blew on day two.
Buy everything off Miataman00. Bore and Hone,

https://www.miataturbo.net/build-thr...-90239/page49/

skylinecalvin

iTrader: (2)

That's a lot of "I Thinks". In your position, I would figure out what exactly what wrong and what to do to prevent it. Most likely standalone for easier/better tuning. A good amount of people also do rod only builds.

bahurd

iTrader: (8)

sshamrockk

Simple solution, take motor out, put in stock motor with no turbo bits, sell the miata, and never look back.

Savington

iTrader: (31)

Your current plan has you well on your way to wasting $1500 on a half-baked motor which will last about 3 days instead of the original 2 days. Buy a junkyard motor, spend your motor building budget on a Megasquirt, and spend your time doing a substantial amount of research before posting further, lest the locals tar and feather you.

ryansmoneypit

iTrader: (6)

Please tell us you were running 10psi on stock injectors.

borka

iTrader: (1)

Define was running a little rich on the AFR gauge?

no Blow off valve, stock PCV, has NOTHING to do with blowing the engine.

stock ecu + FMU + stock injectors have EVERYTHING to do with engine blowing.
If you dont get a tunable ecu + bigger injectors, you will blow your newly rebuilt engine just as easily as the stock one.

get a good running junk yard engine, and spend the $1000 that you have left over on a megasquirt and flow force EV14 injectors.

matrussell122

iTrader: (1)

+1 For junkyard or used motors they are just to cheap and easy to get. Hell i got my 1.8 for a set of fender flares or he would have took $200 cash. And the best part he will probably give the flares back so free motor

sshamrockk

+1

Get a cheap used motor if yours is fubar, then megasquirt and ff injectors new motor.

NASSEX

Alright thanks everybody. Sorry took so long to reply. I understand how much better of an idea it would be overall to get a used motor but there are no junk yards around me with any miatas what so ever. Not even within 50 miles. People love miata parts they Don't remain in the junk yard for long if ever.
The prices I'm looking at for a used engine so far is around 400+400shipped
Or 1200$ for one from usedjdmengines.com which is local to me. I might be able to try calling around and probably find one for 800. Mayybbee.

As for my theory of how this happened, the reason why i included a bad pcv valve and running no bov as how i think this happened was perhaps (i never ported my wastegate) so everytime i let off throttle the boost likely krept into the crankcase or valve cover pretty harshly and the pcv valve definitely failed. But by the time i came to this conclusion, it had already begun smoking ww2 smokescreen status.

The turbo was also leaking a sh*t TON of oil i realized after i finally disassembled it. But prior to that, i swapped pcv valve for a catch can and blocked off intake manifold pcv port. And routed both sides of valve covers to a single catch can which rerouted pre-turbo intake piping. Then i started her up and a TON of steam and i mean a lot of steam was filling the catch can rapidly. It condensed and was definitely coolant. (As well as smoking from the exhaust) So i turned it off and drained oil + coolant and inspected. The coolant had zero oil but something was wrong with the oil.

It seemed way too muddy where as 2 days prior it was brand new. And I'm a chemistry major. The 50/50 antifreeze is 50% water (non soluble in oil) but the other 50% is glycol which is soluble in both oil and water. So there was a pretty fair chance i thought that i may not get to see the typical blown head gasket milk cloudy emulsions that most people get to use to diagnose.I tried to seperate a cap full of the used oil and added a small amount of antifreeze to it, and it did create a clear emulsion.

Then just as i assumed, after a small stirr, the emulsion disappeared and it looked like regular old brown oil. So i tried smelling my old oil and it did smell like antifreeze+ oil along with some fuel too.

So i kinda just said ok Let's heat her up all the way lol and hope for the best.... Maybe the moisture that's venting out will just evaporate and I'll be ok. Maybe the smoke out the tail pipe and under the hood will just burn up and go away. So i went to see if it would letup and it wouldn't. So i said **** it and revved to like 6k/11psi and went from 4 cylinders with good compression to only 3 at that very moment. :F
Which btw it ran completely fine before i finally decided to blow it for good. Just made a crap ton of smoke which i couldn't tell if it was oil or coolant because the turbo turned out to be leaking a TON of oil like i said.

I do want to rebuild it. My hopes are that it is only a head gasket and piston rings. It still runs fine. Just only on 3 cylinders. Lol. And~ it never over heated so idk you think i *might* have a chance at it being still in decent shape?

Sorry for the long reply. Just wanted to make up for the long absence. Thanks everyone. Cheers

NASSEX

Also i must clarify i do plan to get ms and learn how to tune. That's ALWAYS been a part of my plans. The hopeful 1500 budget i mentioned is for the engine rebuild. That way i can still try n afford ms, injectors, etc afterwards. Like i said, used engines are around 800$ minimum for me around here (unless somebody can hook me up with a seller), so i am simply hoping mine might still be in enough spec to do a clean oem rebuild on it and have a guarantee on the quality rather than spending half as much minimum and not really knowing what condition engine I'd be getting.

P.s thanks for the miata spec data resources. That was just what i was looking for!

Cheerz

PSI

Then drive 100 miles? I mess with a lot of old motorcycles and cars, sometimes you just have to drive to get what you want. I will ask the seller to recommend something to go see or a good restaurant.

themonkeyman

NASSEX

Thank you
it always helps seeing how others source engines. Appreciate everyone's tips n recommendations
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borka

iTrader: (1)

Keep an eye on lkq pick a part, you can pull the engine yourself, and they only charge $260 for a full motor.

get one from a crashed car, so you know it was running before being junked.

if you are set on rebuilding, a regular OEM type rebuild can be done for around $600 including the machine shop work, that if you take apart and assemble it yourself.
also consider adding eBay rods, they cost $200 and a good thing to have on a turbo motor, as rods are the first thing that breaks on a high horsepower build.

NASSEX

I'm at work right now so can't reply to every thing you said yet. But which ebay rod/piston would you say may be equivalent to oem or perhaps maybe better?? That would be sick. So far i have my eyes on some used ones for cheap if it ends up that i need to replace them but what kind are tried & true to not be so bad? (Oem equiv.)

Thx I'll reply to some more once I'm home in several hours

NASSEX

Update: So 3/4 of the pistons blew up in a special way that they didn't damage/scratch or glaze the cylinders. Only one of the pistons blew in a way that it effected the rings. As shown below. This was cylinder #2. The worst one that lost all compression after the incidents.