And why I currently have no time to work on cars...bathroom remodel

I received the new thrust bearings and oil pump in the mail yesterday, so assembly of the motor is just waiting on me to make time for it. Naturally the weather has turned so now it's cold in the garage...

In the mean time I tried to pair up the pistons, rods, pins, ring packs and pin clips to get each cylinder as balanced as possible. I weighed everything on a calibrated laboratory scale and then matched up the various parts to try to get the same weights.

In my OEM world we call the piston, pin, rod, and rings the powercell. So I was trying to get equal powercell weights for each cylinder. Attached is the "worksheet" I made up as I went.

The lightest powercell came out to 949.69g, the heaviest was 950.08g. The other two were both 949.93g. The lightest will go on cylinder 1, the heaviest in cylinder 4. The others will go in 2 and 3. That way the "firing pairs" are extremely balanced.

That was my logic at least. The crankshaft is probably 5+ grams out if balance, but whatever. I had time over my lunch break to weigh the stuff so I figured I might as well try to "balance" everything.


Never mind, picture upload won't work from the phone right meow...

Wouldnt it make more sense to put the perfectly even ones on the outer ends and the two that are off in the middle? You'll get less vibrating moment that way

Let me know how many hours you put into that valve cover :p

holy crap did I hate polishing my valve cover, lol good luck with that

also love the wheels

Yes that probably makes more sense.

I figured having the heaviest in cyl 4 would be best for the cars polar inertia.... Ha!


And yes, the valve cover sanding/polishing isn't going as well as planned. Not really enjoying it. If I can get a really good polish on it I have some very nerdy plans for it.

Sometimes it is just worth the money having these sandblasted.

I started on my intake manifold and a couple hours in just said "fuck this" and called my powder coater.

Of course that was after hand grinding and painting 3/4 of my car...so I had hit "the wall" in regards to desire to sand paint etc etc.

Yea, unfortunately I DID sandblast it. But either the shot size was too big or the air pressure was too high or something.

All of the sanding I'm doing now is smoothing out the artifacts of the sand blasting...

Different castings on different valve covers are different quality.

I sand blasted 1 valve cover and it came out flawless looking.
Did the exact same with another, same year engine too, and there were all sorts of casting imperfections in it, so I "brushed" it. Its weird

After much ado, the aforementioned "Powercell Weight Calculation Sheet". You probably shouldn't try to follow the logic...


Attachment 239320




Also finally got around to installing the old wheels and new tires. Gen 1 15x8 6ULs w/ 225/45/15 BFG Rivals. Emilio thinks I'm a huge dbag and thinks I have it out for him on the internetz, but I was one of his first customers and have been supporting his business from the early days. Effing OG 6UL owner.

https://www.miataturbo.net/attachmen...ine=1394998537




ALSO, if you were ever wondering if an OEM hardtop will fit in the back of a 2005-2010 Honda Odyssey...it will.

Attachment 239321


Engine assembly should continue tomorrow morning, might take another morning off of work to get some alone time...

Rage posting from phone

RINGS DON'T FIT WORTH A SH"T!?!?!

Like 1.5mm ring gaps.

Me = cornfuzed

At least the new thrust bearings went in fine, and crank end play measured 0.018mm. Right in the center of the OEM spec.

GWAR

DUDEBRO i'm loving your build and all of the updates. Sorry I'm not help with the rings, but with the ST pistons I would go with ST rings. Tried and true with that setup.

Y U NO arp hardware?

Also, which ball hone is that and what grit did you get? Do you want to sell it (considering you outsourced your hone work), I need one for the stock bore size that is the right grit.

So apparently the 83.5 Supertech pistons I bought are actually 84mm. And the 0.020" overbore I got is actually 0.040"?

My machinist had the pistons when he did the bore job, so he correctly (afaik) bored the block to match the pistons. He just forgot to mention to me they were actually 84mm.

At least I think they are 84mm. I pulled out some calipers and measured the bores and the pistons and I sort of consistently got 83.8-83.9 mm readings.

Closer to 84 then 83.5 I guess...

SO, just ordered some 84mm Supertech rings (Part# GNH8400) from No Limit Motorsports on here, they were great. And the price was very fair, I'm sure well worth the little bit extra cost over the RockAuto stuff.

I hope I can return the other rings, otherwise I'll have bought three sets of rings for this dang build...hahahah....:cry:

Oh well, sometimes learning costs a little money.

Just read up on the proper piston to wall clearance for Supertechs...and for turbo track motors. Seems 0.003 - 0.004" is the recommendation. My machinist and I never discussed this so I have no idea what he set them at. Another thing I need to check now and hope (pray?) is OK. :cry::cry:

Lots of learning

I'll be at Road Atlanta racing this weekend, so engine build likely won't continue till Monday, maybe later. Dang it

:makeout:

See above post, that's exactly what I did, ordered some ST rings.

Had to draw the line somewhere...needed to stop the bleeding. Honestly, of all my years reading this forum I've never come across someone stretching the stock head bolts and/or lifting the head. Maybe I've never come across it because anyone building a motor and running >250whp always uses ARP head studs? :dunno:


Here is the exact one I bought,
$34 shipped if you have Amazon Prime.

I think I want to hold on to this one in case I ever need to "re-hone" a miata motor (which I think is likely).

As for the grit, I'm not really sure if 180 grit (the one I selected) is "the right grit" or not. 240 seemed like it would be too fine, and 120 seemed like it would be too aggressive. That logic was/is based on absolutely no experience or research...


I have more pictures to post but they are A)not very good and B) on my phone which I don't like posting from.

So I'll try to post more pics later for your "benefit"

Everything laid out yesterday morning...it wasn't to be

And yes my garage serves as a diaper storage facility...

Savington actually recommends running the Weisco rings over Supertech rings. He says he has noticed that they seem to be a bit better in some way, not sure how exactly. I know when I ordered my set of rings a few weeks ago it was about the same price as the Supertechs.

Hmmm....everywhere I looked the Wiseco rings were like 2x the cost of the ST rings.

Whatever, I bet the ST rings are better than the Rock Auto specials I was going to run.

quoted from 949's website

Thanks, I researched the wiseco rings.

I'm sure they are great and I don't doubt they are the best available.

How many people have engines with supertech pistons and supertech rings? I'm betting there are a handful on this site, and I've never heard of anyone having excessive oil consumption/blowby/etc.

Also, OEM ring tension was set based on OEM Mazda boring and honing capabilities of 199-whenever. Just because the OEM ring tension is 15 lbs doesn't really mean a whole lot when you have a completely different bore and hone finish.

Emilio (and Sav?) have found that the wiseco's work the best and I believe them because they have built lots of miata motors.

I chose the supertech rings because I'm cheap.

K? thx

I'm sure they will be fine. What did you do with the first set of rings you bought (OEM size) ?

Were they chrome ones?