ClubRoadster.net banner

1 - 9 of 9 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
I figured it was time to move my projects from my own personal Facebook page to the pages of Club Roadster for everyone to enjoy along with allowing me to archive it in a better fashion than just some personal Facebook posts.
To give some background context, I put out some feelers to some good local Miata buddies of mine to keep an eye out for a 90-93 NA6 for me back in February/March of 2019. After already owning, tracking, and working on NBs for a few years prior, I figured it was time to dive into an NA as well. Now I wanted a 1.6L at the time because I was going to attempt to bastardize together some kind of custom VVT setup but eventually realized this would basically need either a lot of CNC work or a full-on CNC'd head. Obviously because of this, I didn't want to spend thousands of dollars on a mint NA just to end up either selling or eventually replacing parts that wouldn't be on the car for long. Since that fell through, I looked to pages of Hyper Rev along with YouTube, CR, etc. and finally settled to have some fun and build a 1.7L using our own custom spec of Wiseco pistons along with some other custom bits and pieces to make a fun weekend car that sort of fit a bit of a retro meets golden era Japan aesthetic.

Originally, my prerequisites were clean title and, to quote myself, "I'm not picky on the color but the further away from red it is, the better," but I guess fate decided to make me retract part of my statement and lone behold, RLRSK8T.

150051


This 1990 NA6 that had been sitting in a precious little old lady's backyard for the past 10 years. Honestly, she was quite the character, that typical sweet old lady filled with stories of her travels and life but still a lot of life left in her. The car though, was a family friend of theirs whom fell on financial hardships during the recession and had other vehicles (other cars, boats, RVs, etc.). When times got better, he took his other vehicles but left the Miata behind right where he parked it under her walnut tree. She asked him about it and they agreed the car was hers and she could do with it as she pleased. Life went on and the car continued to sit. Eventually, she wanted to redo her yard, the walnut tree was taken down, and the NA had become an impeding lawn ornament in the grander scheme of her yard.

I was put in touch with her via one of my local Miata buddies / good friend of mine and so I went to go see the car. She was kind enough to be flexible and fit in with my busy schedule, so I ended up seeing the car shortly after initial contact. For sitting for 10 years, the red paint was reasonably mint, the dash uncracked, and the interior in overall good shape. The deal was made and a few days later I returned with a trailer to pull RLRSK8T out of the little patch of dirt it had called home for 10 years prior.

150052



The weeks following turned into some of the most fun I'd had in awhile. From getting new keys, to sorting through all the things in the trunk, and even getting it started only a few weeks after taking ownership, it was a back-burner project that really lit up my desire to do so much more with such a fun, old chassis.

I think this is where I'll call it for this initial post. It's late and I think it's best if this all gets told in easily digestible chunks. I'll post more and more of the story in the coming days until we're all caught up to present day.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #2
Another day, another update to get all caught up. As you can see below, RLRSK8T made it home safely after the hour long trip back from its 10 year resting place to my shop. A quick hose-off got rid of most of the yard dirt outside of some major build-up around the bumper mouth. Next was to tackle the years of grime built up in the engine bay and interior. Nothing major but the squirrels did have a field day stashing walnuts all around the engine.
150056


After a few minutes of scooping walnuts out of some critical places and spraying some soap to help get rid of the grime, there was already some progress to be made!
Engine bay was already looking a bit better than just moments prior.
150057


Next on the agenda that was done a few days later, it was time for a final wash and rid the car of its old alarm system and fog lights. It was around this time I realized that this was about to go from back-burner project to lighting a fire under me to do so much more, even if a lot of it was just undoing years of deterioration. Oh and did I mention those ugly 17"s came off pretty quick?



Tires on the Koseis were replaced before they went on permanently with some 205/50r15 Federal RS-RRs. The wheel/tire combo will eventually be changed out in the future but for now I'm content with how they look and perform. Fast forward a month or two and the TSIs had their lenses changed from yellowed plastic to a nice new orange lens and I started to both import and locally acquire more and more parts. This included a Works Bell hub, Mazdaspeed rollbar, Pitcrew strut tower brace, Tein Flex coilovers, and more.
150058


And we'll leave it at that for today. Tomorrow, the photos of all the parts installed along with the lead up to and weekend at Miata Reunion!
 

·
Registered
Joined
·
6 Posts
Discussion Starter #4
This update comes a bit later than anticipated, but it's here none the less and it's about what I feel was one of the most rewarding weekends with this build so far. The weeks leading up to Miata Reunion were a bit hectic but this is when the car took its biggest leaps forward in aesthetics and the restoration thus far.

In the engine bay: Outside of basic maintenance, the intake manifold and throttle body were replaced with freshly painted replacements, the heat shield for the exhaust manifold was also painted. The Pit Crew Racing bar was now completely restored at this point featuring gloss black ends, polished bar, and new old stock emblem. I also added a Racing Beat Power Pulse exhaust since the prior exhaust on the car was way too raspy for my liking.

In the interior: OEM wheel and aftermarket radio came out to be replaced by a Checkman 320 on a Works Bell hub along with a Burst Craft horn delete and shift knob, a radio delete, JDM Eunos floor mats, and a Mazdaspeed roll bar along with some vacuuming to get out all those years of dust.

On the exterior: The 15x7 Koseis finally received new 205/50 Federal 595RS-RRs that tucked away nicely after installing some Tein Flex coilovers. I also got around to installing a Racing Beat Type I front half bumper that I had laying around from some months prior, and the car finally got a proper wash along with our own shop banner in homage to RS Aizawa, who's NA6 has always been a big inspiration to this build.
150088

PreMRExt.jpg


And with all that completed, we headed off to Laguna Seca! We've hosted a small caravan from our shop out to the track on Saturday morning for the past few years so the group made its way down without much trouble. I ended up spending both Saturday and Sunday there as I was just enjoying the event and filming on Saturday and then had track time for Sunday's hot laps. I don't want to fill this thread with a bunch of photos from the event but here's a photo of RLRSK8T parting ways with what would be the last Miata Reunion at Laguna Seca. I don't think words can ever really describe the feeling that event brings, from the joy of seeing all the builds and friendly faces, to the adrenaline of driving on track (in my NB2 track car, not RLR), it's a weekend I always looked forward to and heavily planned for well in advance.
IMG_4246 (Edited 2).png


And so we close a big chapter of this story based around one of arguably the best Miata events to be held. But the months that follow really start to shape RLRSK8T and it's where I go off the deep end into a pretty nifty engine build. More on that in the next update!
 

·
Registered
Joined
·
6 Posts
Discussion Starter #6
I figured this may be a longer post or at least a bit dry since most like to hear engines than actually read about them, so if you're a motor nerd, this post is for you. If you just like to look at photos, then it'll more than likely be a bit of a quick scroll through. And at this point, we also get into how 1.7L starts getting added into the mix of this build. So, after Miata Reunion, the car sat for a bit for some basic maintenance parts that needed changing. In addition, it was time to update a few things that had been sitting including a Jackson Racing header, Rod Millen sways, braided clutch line/CMC/slave (installed after the photo), and a full factory A/C delete.
150151


At this point, I'm super content with how the car sits, both aesthetically and mechanically, but I always have some extras goodies up my sleeve to keep me occupied. I'll cover some of the aesthetic changes planned in another update since I strictly want to keep this post all about the future engine in RLRSK8T. So, as mentioned in the original post of this thread, I wanted a 1.6L exclusively at the time of purchase because I was going to attempt to bastardize together some kind of custom VVT setup onto the 1.6L. Eventually though, I realized this would basically need either a lot of CNC work or a full-on CNC'd head and obviously because of this, I didn't want to spend thousands of dollars on a mint NA just to end up either selling or eventually replacing parts that wouldn't be on the car for long. Since that fell through, I looked to pages of Hyper Rev along with YouTube, CR, etc. and finally settled on a very era correct build. Now I didn't want to have to source some old, used pistons or somehow managed to track down a new-old-stock set, so because of my own shop's connections, we got in touch with Wiseco and had a custom set of 81mm pistons made. We didn't need to push clearance or compression to the max so we settled on an 11.5:1 to give a nice bump along with what the bore increase would bring. This is partially due to 91 octane limits (don't want to go e85) along with easy ability to go to higher lift cams in the future.
150152
In addition, Cometic is sending over a custom sized head gasket, and we're just waiting on a Boundary pump and some rods before we start bolting together the short block together. Since I managed to get ahold of a long nose crank, I do also still need to purchase a different harmonic balancer, which will more than likely be an ATI unit.
Now onto the head. This is where the thought of staying "mild" comes into play with our prior calculations. While waiting for the pistons to be produced, I was on the hunt for cams of any sort (within reason of being street driven). A gent in the UK posted up a set of Mazdaspeed 9B1A cams and I immediately snagged them, not only due to their rarity but their mild nature promotes great midrange gains without a rough idle. These cams feature 256º duration and 8.5mm of lift for both intake and exhaust sides. While these are "OEM" cams in a way, I still wanted some adjustability if need be, so in my usual fashion of irresponsible spending, Maruha cam gears made their way to my door.
150153

For the head itself, it's planned to stay pretty mild, with mainly just a bit of polishing work on the runners and intake plenum, but who knows, by the time it goes together, it may end up with some CNC porting and oversized valves. It really just comes down to what shop may do the work as how financially irresponsible I feel like being. I do still need to get either NB6 shim over buckets to replace the NA6 HLAs or I may go full Supertech shim under buckets to allow for even higher revs than shim over would allow. Ignition system will still be OEM to start but will eventually go to coil-on-plug once I can confirm reliability.
IMG_7997 (Edited).jpg


Any who, stay tuned for more updates in the future on the assembly of the 1.7L along with the planned update on the aesthetics that'll more than likely be the next post to go up.
 

·
Registered
Joined
·
18 Posts
keep up the good work(y)

I'm going 1.7 with my '91 Eunos but using Honda B16 pistons & conrods - I like doing things the hard way:ROFLMAO:
I'm also building gsxr1300 Hayabusa throttlebodies & now decided on dry-sump so pushing it backwards instead of progressing foreward....

Rich.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #9
keep up the good work(y)

I'm going 1.7 with my '91 Eunos but using Honda B16 pistons & conrods - I like doing things the hard way:ROFLMAO:
I'm also building gsxr1300 Hayabusa throttlebodies & now decided on dry-sump so pushing it backwards instead of progressing foreward....

Rich.
Thank you, will do! Yeah that's where my search originally started as far as the Honda B series stuff goes, but by the time I figured I'd be buying pistons and rods and doing the machine work, I figured may as well go aftermarket and just stay with Miata components. I don't think I'll ever go ITB but if I do, it'll probably end up being Toyota ITBs as well as a proper intake box setup instead of just stacks to the engine atmosphere.

If you want some dry sump inspiration, look at what Mazda did for their Formula 4 1.6L.
 
1 - 9 of 9 Posts
Top