There's nothing exotic about a B6 or BP engine. It's just generic 16v four cylinder. If you can't get a copy of the factory service manual, drop me a line.
I'd be tempted to do the valve springs for future fun - then you can raise the rev limit and get a little more out of it if you want.
Well, found the problem! #3 and 4 rod bearings are berkeleyed. Missing material. Crank journal on #3 has deep scoring.
Is this engine worth saving? Comp and leak down are very good (~180 psi and <2%). There is a local Miata parter that has VVT engines for $1900 with 80k miles. I'd be in probably $2500 by the time the VVT swap is done once all maintenance items are taken care of. I also need a new clutch and flywheel.
I almost just want to part this car put and start over but no time to do that really. WWGRMD?
$1900 for a VVT motor seems expensive.
Here's a complete VVT motor with wiring loom and ECU for $1750 shipped to your door. If you want a bare motor, it's even cheaper.
https://www.miataturbo.net/miata-parts-sale-trade-5/1-8-vvt-engine-sale-105661/
Used cranks aren't that expensive. I think I might even have one for a 1.6
I'd just find any 1.8 that you know is good and throw it in there. Tbh though, this exact same thing happened several years ago to me and I ended up parting out the car and making money on it. Now I wish I'd kept it and fixed it if that means anything to you.
Good luck deciding!
calteg said:$1900 for a VVT motor seems expensive.
Here's a complete VVT motor with wiring loom and ECU for $1750 shipped to your door. If you want a bare motor, it's even cheaper.
https://www.miataturbo.net/miata-parts-sale-trade-5/1-8-vvt-engine-sale-105661/
BTW, thats TWO complete VVT engines for $1750 shipped in that link.
I've dealt with that vendor a couple of times and been happy with the transactions. It costs about as much to ship two engines as one, so I think they stopped shipping singles.
VVT all the Miatas... it's the newest engine that's 'native' to NA/NB (parts availability), and it makes the most power stock. No brainer.
PMRacing said:Well, found the problem! #3 and 4 rod bearings are berkeleyed. Missing material. Crank journal on #3 has deep scoring.
Is this engine worth saving? Comp and leak down are very good (~180 psi and <2%). There is a local Miata parter that has VVT engines for $1900 with 80k miles. I'd be in probably $2500 by the time the VVT swap is done once all maintenance items are taken care of. I also need a new clutch and flywheel.
I almost just want to part this car put and start over but no time to do that really. WWGRMD?
You need to look at the cost/benefit of the options. How much more does it cost TOTAL to swap in a vvt engine than the TOTAL cost of fixing the engine you've got? How much does doing so gain you in performance, reliability, etc? IIRC the vvt engines only make a tiny bit more power than non-vvt. Speaking for myself, if nothing else major was wrong I would probably be inclined to fix the engine I had and put the money I saved towards other things like tires, brakes, beer, or Hawaiian shirts.
captdownshift (Forum Supporter) said:Don't forget, your manifolds and oil pan are still good.
Protege lx/escort gt/kia Sephia BP engines are often overlooked and fairly readily available.
What year were these motors used in the Protege lx/escort gt/kia Sephia ?
seems like a good Craigslist / Marketplace thing to search for !
I mean, the head's still good, right? And from the compression/leakdown numbers, the bores and rings are good too. Seems like a prime candidate to just throw in a crank, new bearings, and a couple of rods and put it back on the road. I sold a crank for $50 a few years ago and I would imagine stock rods are basically free.
californiamilleghia said:captdownshift (Forum Supporter) said:Don't forget, your manifolds and oil pan are still good.
Protege lx/escort gt/kia Sephia BP engines are often overlooked and fairly readily available.
What year were these motors used in the Protege lx/escort gt/kia Sephia ?
seems like a good Craigslist / Marketplace thing to search for !
Escort GT: 91-96 (watch out, some 91's have small nose cranks. Has the exact same issue as the early 1.6 miata.)
Protege LX: 90-94 (see above, except all 90's and some 91's)
Protege ES: 95-97 (only the top tier model had a BP)
Sephia: 94-97 (only the top tier model had a BP)
Side note, if you find a manual transmission BP powered Sephia, or a 95 (specifically) protege ES, those gearboxes are in demand from the FWD BP folks. They are more robust than the earlier G-series used in other applications.
The second generation FWD BP's also have better flowing intake & exhaust manifolds.
The quickest and cheapest way to get it running again is to replace the crank (or even machine the one you have if it'll cleanup) and any damaged rods and put it back together.
So, I pulled the easy(ish) button. I found a 2002 VVT engine with 87k miles, and I was able to hear it run and see the car condition before purchasing. It was a clean car and engine bay, and it ran smooth and quiet. Not the cheapest option, but now I know I have a good engine and can work on the other one as time permits, or just part it out.
Now to figure out where how to wire in the VVT. I found the VTTuner standalone controller and will go with that option and read their tutorials. I haven't really found great documentation on the swap though. Where are some good resources to go to that actually give some steps, i.e. I'll need use connector from the NA harness on the NB harness, etc.
Thanks for the advice!
I've got a couple more links stashed on coil wiring if I can find them...
EDIT: Unfortunately, the link I had for NB2 coils on an NB1 is dead. If anyone knows how to do the internet deep dive for archived pages this was the link:
https://www.mostlymiata.net/1999-2001-vvt-engine-swap/vvt-engine-swap-ignition
You guys are awesome! Thanks!
If you've done one, please share your story, reasoning and post swap experiences https://showbox.bio/.
If you plan on doing one, share your plans and what you are looking to get out of it, besides the obvious speed.
I am unfamiliar with VVT engines. Is this a stock clutch and flywheel setup? The clutch plate is Excedy and not OE.
Looks OE or OE-replacement.
Just set my credit card on fire at Flyin' Miata (you're welcome Keith! :) ).
Timing belt kit, water pump, front and rear main seals, clutch and flywheel, and other misc. seals. A few parts on back order, so hopefully they're here before Xmas week when I plan on getting the engine back in.
No surprise that the disk was changed out to aftermarket. The early 6 speed/VVT's had a problem with "lumpy" clutches and the factory went through a bunch of revisions before they got it right.
No surprise that the disk was changed out to aftermarket. The early 6 speed/VVT's had a problem with "lumpy" clutches and the factory went through a bunch of revisions before they got it right.
I'm researching this swap and hoping I didn't screw up by not planning well enough (my fault completely). From what I was told and read up to buying the engine is it is a fairly straight forward swap. But after further reading, more parts and mods may required. Please let me know if I'm missing something.
- Most threads show that a stand alone ECU is needed. I plan on using the stock '97 ECU with the VVTuner controller. Is this possible? I have seen yes and no, but haven't found a definitive answer.
- Can I use the variable intake? I kept the vacuum controls from the donor car. I'll probably need some kind of trigger.
- Most threads state that I cannot use the '02 fuel rail, but don't clearly state why? Is one a return system and one not? Can the '02 rail be modified? Can I use the '02 fuel rail and injectors and stock '97 ECU? I know a connector will probably be required.
- Wiring from the NA8 coils to the NB2 coils is pretty straight forward from what I've seen and there seem to be diagrams available. Is there a "best" one?
- I will need the coolant sensors and oil pressure sensors from the old engine.
- I will need the alternator and starter from the old engine.
- I've found a hack to use the NA throttle cable in the cruise control portion of the throttle pulley.
- EGR from the old engine needs to be modified to fit the new engine with old engine's header (Racing Beat)
I've been reviewing the "Definitive" thread, but it is for a stand alone ECU. I'm still trying to find a thread with stock NA8 ECU and VVTuner control. I also found this old GRM thread but it seems to be incomplete.
What else am I missing? Thanks GRM!
- yes
- yes, but the VTCS in the VVT engine is not the more beneficial VICS from the 99-00 cars. It's basically a tumble generator for emissions. I'd recommend removing the butterflies instead.
- it is indeed a return vs returnless problem. The 97 ECU will be expecting the fuel pressure to change with vacuum so it won't like a non-referenced returnless system. It's been a while, but I think you can use a 99 rail with the NA FPR in place of the damper. Packaging prevents this with the 02 rail. Alternately, run an external FPR with a vacuum reference and make what is essentially a very short returnless system. I think my "high performance Miata" book has diagrams.
- I have no opinion here, but the difference in a naturally aspirated build will likely be negligible. I guess maybe I do have an opinion, just not a preference :)
- yes for oil pressure. The coolant sensors changed from one two-wire and one one-wire sensor to a single three-wire unit. Electrically, that single sensor is two separate ones.
- yes, especially the alternator. Starter is more related to the transmission.
- cool.
- yes. EGR tubes are quite easy to cut and weld in my experience. Do this with the engine out of the car :)
In reply to Dashpot :
I thought the OE clutches on these were Exedy
Dashpot said:No surprise that the disk was changed out to aftermarket. The early 6 speed/VVT's had a problem with "lumpy" clutches and the factory went through a bunch of revisions before they got it right.
90% sure that was due to bad flywheel machining, but yes. They shuddered.
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