Stimulus Check Miata

Round here, its been cleaning,

cleaning,

and more cleaning.

I drilled out some seized studs, and started cleaning up the welds inside the exhaust manifold. I'm not kidding myself into believing I'll get massive gains in power here, but I'll give everything I touch a bit of love.

So, Dusterbd's guy is sending a crank. He had it turned, and is also including all pulleys, trigger wheel, and the flange. It wasn't my cheapest option, but should be the equivalent of taking off and nuking the site from orbit. Gotta be sure. I'll do a new keyway, and maybe even a new bolt.

Tearing it down, the engine looks clean. Bearings were okay, and other than the aforementioned damage to the crank, it looks good. Wristpins are good, and everything is clean as a whistle for a high mileage engine.

I've spent some time measuring the bores.

From what I can tell, they are dead on. My calculations actually have them at the smaller end of in spec (3.2678"). I'm going to sleep on it and remeasure tomorrow. Pistons are soaking in thinner and getting the occasional scrub. They look good, but I'll measure once they are clean to be sure.

The old oil pump had some contact marking from the also marked crank. I'd guess that is an effect of the wobbly pulley. So, I got a new Melling unit. Parts are coming in on a near daily basis, as are things like valve grinding stuff. 

Baby steps.

Today, I gasket matched the intake.

Mostly, I just used a wood file, finished with a sanding drum on a drill, but a lot of credit has to be given to Mazda. The ports matched the gasket pretty well. Maybe 1/16" on half of each port, and it was good to go. 

Result.

I cleaned up and clear coated the outside while I was at it.

Behind the scenes, it's soaking and scrubbing of pistons, and I swear I'm going to get by with just a hone on the cylinders.

Tomorrow I go back to my normal 5 day schedule, which has me home at just after 2 PM, and I hope to get back to doing a little every day, split between this and the challenge car.

This is going to look downright nice when you're done with it!

There really are things I dislike about living in the South.

The other news is completely boring. The manual wants one more decimal of accuracy, but what I've got looks to be in spec.

Cue more soaking and scraping...

I'm still sweating the bores and pistons.

Are my measurements good enough? Am I wasting my time if I don't take the final step and do a .010 over and new pistons? Should I hone and throw a set of stock pistons at it? 

I'm still waiting for parts, so while I agonize over that particular detail, I've been balancing the rods.

This is the same method I read about years ago in "How to Keep your VW Alive for the Complete Idiot".

Weigh both ends, using a pivot at the centerline of the opposite end.

Gently remove material until they all reach the lowest measured weight (I'm only going to one gram accuracy, as that's the best my postage scale can read). The old angle grinder and a well used flappy disc was my implement of choice. 

I'm eyeballing the pistons, too, but the battery in my scale died before I could get to the small end of the rods

Edit: I just ordered a micrometer. That should help my confidence in what I'm putting together.

Since our last episode, I've been balancing the reciprocating mass, and more cleaning and painting.

I got a crank from Dusterbd's guy. 0.010 under mains, 0.020 under rods. He also sold me all the pulleys, trigger wheels, and such for the front of the crank. 

My forensic studies tell me the PO, or his mechanic put a new "harmonic balancer" on the car, not the new crank pulley and mounting flange it needed. It was so out of whack, it wore a point off the trigger wheel, and this all contributed to the broken alternator mounts and bolts. I do remember him saying he couldn't get the belt tight, but his guy could. 

Anyway, I have two pulleys. The one I got with the crank, which is heavier duty, and the one the PO replaced, which has a small washer, and just seems a bit chinsier. Any opinions on which one is better? They appear to be "timed" the same.

The rest of this update will be everyone's favorite. An Internet unboxing! Don't judge me.

Glad sam hooked you up. Hes a good dude in my experience. 

In reply to Dusterbd13-michael (Forum Supporter) :

Very good guy. Thanks again for the hook-up.

Noice.  I had a 1991 Miata for years.  Great fun.  Anyway, it had both a short crank snout and a smaller diameter snout than later years.  The problem is there is not quite enough surface area on the tapered crank to have a strong enough press fit grip to bear up to the rotational forces over time.  The toothed cog just can't maintain quite enough grip.  Pulled mine and the keyway was widened to the retarded side.  The keyway is just there for timing, NOT fighting the rotational forces.  The other keyway shoulder was fine.  So, new key, new bolt and new cog (likely unnecessary).  Slathered the snout and inside of the cog with Loctite 660, held the cog tight to the remaining keyway shoulder, tightened up the new bolt to spec then left it alone for 24 hours. 

Loctite is anerobic and cures in the absence of oxygen to a chemical bear-hug, GI Joe Kung Fu death grip.  How good you ask?  A year later, I needed to pull it again because: why do it  right the first time and replace the front seal?  So I needed to replace the front seal.  I BENT a steering wheel puller trying to remove it.   I tried steady pressure and percussion.  Nothing.   With daylight fading, I started the engine with the crank bolt removed to pull it back into my tight & crowded garage.  It was NOT coming off.    When all else fails, read the directions.  The MSDS says apply heat, a few seconds to the crank snout with MAPP gas, and it slid off like melted butter.  Holy crap that loctite 660 is good stuff.

Sadly your snout looks fragged.  On the new to you replacement, use loctite 660 and fegetaboutit.

Ah, the cast vs stamped crank pulleys. Used to be a big deal when we were doing supercharger overlays. No significant functional difference of which I am aware.

In reply to Keith Tanner :

Thanks for the input. I plan on keeping one as a spare. Good to know they're functionally identical.

BrianC72gt: I appreciate the anecdotal evidence of the loc-tite's effectiveness.

To the hive in general: Now that I have a good 1.8 crank and all the parts up front, should I still loc-tite it?

My inclination would tend towards clean, dry, and torqued to spec, but I don't mind a good slathering of the good stuff.

The early crank 1.6 was the most prone to failure the double whammy of short snout and smaller diameter.  Loctite 660 was the standard fix.  Coin toss for the later ones.  I'm a once bitten twice shy type so I would use it, but I'm paranoid, or am I?   Who said that!?

I saw a lot of failed "big nose" cranks due to loose bolts. That's the start of the failure, a crank bolt that's not torqued to spec. So put blue Loctite on the bolt, torque it properly and you'll be fine.

Comments appreciated, guys.

Not much of an update, but inching forward.

Cleaned the E36 M3 out of the block and painted it.

And installed a new input shaft seal.

My micrometer finally showed up, so I can really figure out my next step. Lots of lubes, sealers, and the like keep trickling in. Going almost totally mail order on a rebuild in the time of Covid is weird to say the least.

One note about those two pulleys - make sure you use the appropriate bolts. The cast pulley uses longer bolts that will bottom out before they tighten if used with the stamped pulley. The shorter bolts may not have sufficient thread engagement on the cast pulley.

I once lost an accessory pulley bolt at 7000 rpm at the top of Vail pass in - well, I don't know if was winter but I do remember snow - at night. The whole pulley falls off shortly after. Pulled over, bolted the pulley back on using some spare hardware scavenged from the engine bay and limped it home by letting it idle on the long downhills. That was a long night.

In reply to Keith Tanner :

Thanks Keith, duly noted.

The last time I drove Vail pass, it was in a V6 auto Mustang rental. With me driving. In the snow. At night.We spent 6 hours staring at the back of a tanker. Both of us were sliding all over the road going 5mph downhill. Good, white knuckled times

As stated, I got hung up rather badly here, questioning to bore, or not to bore. Also, last week was back to school for both my Special Lady Friend and I. Let's just say the Community College we both work for is an adventure. Multiple positive Covid tests, some questionable behavior from both students and staff. Maybe that should be all I have to say about that. This is Tennessee, and we're wide open til we're not. What I'm prevaricating about is I didn't feel like working on the projects for a minute there. Long rejuvenating afternoon walks with my old pal whiskey took priority. Moving forward, I'd like a balance of both-after my work obligations are taken care of, of course.

So yeah, measured the pistons. All fall squarely in spec with a difference of 1/10,000th largest to smallest. I quit balancing their weights at 290g for #1, 291g for #2&#4, and 289g for #3. so that's a difference of two paperclips heaviest to lightest. Good enough.

My new mic allowed me to set my bore guage to the minimum acceptable bore.

Dead nuts, and no taper that I could measure.

So, I moved on to dingleball honing.

I started out with motor oil as lube, but figured out PB Blaster worked better. I'm quite satisfied. Next came a liberal coat of motor oil and tamping the powder on the parts cannon. I have now more than doubled what I paid for this car, and I've driven it maybe 15 miles, including the teat drive. Edit: TEST drive. I wish there had bean the former.

My takeaway as a first time Miata engine re-builder:Very impressed.

I don't know if this was the original engine or not, and the "crystallization" on all the engine parts tells me thing saw regular synthetic oil changes, but if this is what a 265K BP8 looks like, they're anvils. I'm convinced the crank nose was poor reassembly at the 210K timing belt change, and somebody put a new pulley on that wobbly E36 M3 recently, possibly hastening the sale.

I like the oil squirters, and am pleased there is no Torque To Yield BS going on (please tell me if I'm wrong about that-I'll research further), and I love hydraulic tappets. 

I'll leave you all with an engine building selfie. I very seldomly take selfies. Kind of hate the word.

Still doin' stuff. First off, as the previous mold shot showed, this thing's still taking on some water. Now, I know I may have poorly installed the rain drain on that new top, and we'll return to that, but I knew the holes in the trunk for the luggage rack were letting in some water. When I opened the trunk, some would dribble out from the framing. Also, I hated the look of the thing. The leaky bit was just the excuse I needed.

Stainless 1/4-20s, washers, and rubber to plug the holes.

The result is far from perfect, but I wasn't prepared to go to a flat black trunk just yet. 

In real news, I have been working on the engine. All rings were checked, and installed.

Rods, too, along with some assembly lube.

And I started measuring the crank oil clearance.

Plastigage says it's good.

As an aside, I have a confession to make, I've built quite a few engines-to the point I'm not sure how many, but I've never measured ring gap, crank end play, pistons, or bores before this one. I always found a trusted machine shop, and let them do the heavy lifting, while I simply assembled them. That might be why, near the turn of the century, I has a 10 year run where I was the only person on earth who couldn't keep a Toyota 22-R(E) running. I had a run of bad machining done. Wrist pin slap, piston slap, that kind of stuff.

Well, I'm determined to up my game with this build, so I'm sweating my tolerances quite a bit.

Case in point:

I've just spent a few hours measuring crank endplay. I got a repeatable 0.006". Tolerance is 0.0032 to 0.0111, with 0.012 being the service limit.  I started a thread in the midst of my neurosis that eventually convinced me I was in spec, so I deleted it before it was even posted. It just seemed like a lot of play. I bagged it for the night. Tomorrow, I'll clean it up, and begin the final assembly.

Today, short block.

Hondabond is good, goopy stuff.

I wanted to get as much bolted together as I could before I tear the head apart. Gotta get organized to tackle that one.

A question for those in the know: Should the water pump have locating dowels? I am certain none came out, but the pump had quite a bit of slop. I have another water pump seal, so I really don't mind doing this bit again.

My neurosis got the better of me. I started a thread asking if there were originally locating dowels or the like on the water pump. The results were inconclusive, so I crammed some copper tube in two of the bolt holes.

It would have likely been fine, but the 1/16+" of slop was more than I could stand. 

Other than that, it is pathologic cleaning, painting, etc. Here's a picture of some hardware ready to go back on.

Realizing that anyone reading this is almost definitely bored to tears, I figure I might as well drop some pictures I took so I could redo hose routing and wiring .

Enjoy

I'm waiting for a cheap valve spring compressor to arrive, then on to the head.

Today, organizing, cleaning, painting the slave cylinder, and just the smallest start on the head.

I found 3 collapsed lifters.

X=Bad (ie, I could slide a 0.015 feeler gauge between the cam base and the lifter. Everything's soaking in Seafoam for now.

Which brings me to another question if anyone can answer: is there any truth to the videos I've watched claiming a good cleaning will bring these back from the dead, or should I replace the 3 bad ones (or all 16)?

I figured they could soak while I decided.

I've always wanted to try the thorough cleaning thing on em, but I never got to it, so I'm no help...

But we are still reading!  Good progress!

Today, my $19.99 Amazon valve spring compressor arrived. 

So I got to it.

One single valve keeper ricoched away, seemingly across the room, and I finally gave up looking for it until I lost a head locating dowel prying it out. In search of that, I found my keeper, and eventually the missing dowel. I did learn the hard way to hold a rag over my work as I tightened the valve spring tool.

The collapsed lifters seem to be leaving the Seafoam dirtier than the other ones, so maybe that's a good sign? 

More Seafoam is on the way so every lifter will get a good soak, then the valves.

After stripping the head, round one of cleaning is complete- Simple Green, tooth brush and a pressure washer got me here.

On to round two (note, no dishwashing detergent was used. It corrodes the metal rather quickly, and I didn't want to risk ruining my cam journals).

Should be clean enough to move on to a light porting job.

I love the shop dishwasher idea, great idea! I'll be coming back as at some point I'll be refreshing a Miata engine. The one in my parts car at some point will go in the automatic NA and I really need to go through all of it like you are doing, rather than bolt a questionable high mileage motor in our tired NA. Are you doing anything to the transmission? I have two 5 speed Miata transmissions all with over 100K miles on them, seem to be good, but who knows? 

In reply to dherr (Forum Supporter) :

1. That's not a shop dishwasher. It's still in our unfinished kitchen. The house we bought was so incredibly nasty, we'd never send something we intended to eat from through it. The cage is rusted through in some places. Perfect for car parts, and once I get around to installing a new one, this will likely go to the shed for occasional use. The old oven is in the shed for future powder coating.

2. I'm not doing anything to the transmission other than new seals, fluid, and the shifter rebuild I did a while back. It worked fine. I will be on the lookout for a used 5 speed for when the inevitable happens.

3. After seeing the inside of this, I'd consider just running it. Your engine has 160K on it, right? I believe this one was original to the 265K chassis, and had the crank been okay, I'd have just run it. I bet you could get another 100K out of yours. Definitely new seals, water pump and timing belt, check the crank, and a compression test. Maybe pop some main/con rods and take a look- Plastigage if you're particularly froggy. You could add Seafoam or run ATF for a few hundred miles do clean out lifters/ oil passages, etc.

I don't mean to poo-poo your plan, but from what I can see here, these engines are solid. Another thing to note, my Maximum Effort/Minimal Cash Outlay rebuild is getting near 3 grand in investment at this point. That doesn't include a new clutch or pistons/bore job.