patsmx5

iTrader: (16)

Ebay rods, some decent chome moly rings, new gaskets/seals as needed. I ran 28 PSI on a motor like that. I reran rod bearings too, I checked the clearances with plastigauge (like 5 bucks) and they were fine. That's as cheap as you can build a motor that will handle serious boost.

Chiburbian

iTrader: (1)

Ok. Ebay manley rods aren't forged?

What piston rings should I get? Stock style or the wiseco ones that they are using on the supertech pistons?

18psi

iTrader: (76)

yeah I've done that before too, no issues, but...........they're like 30 bux? might as well
whatever uses chrom-moly

patsmx5

iTrader: (16)

I've run a 40 dollar set from Rock auto, they sucked (motor used a bit of oil) Used a ~100 dollar set (hell I think off rock auto too....) and they worked fine (zero oil use). I now have weisco pistons/rings and they too work fine (zero oil use). Make sure you hone it correctly, that's the main thing to get right.

Ebay rods are forged, they are beast.

aidandj

iTrader: (5)

<p>Go checkout out hi_im_seans thread, he is in the middle of a &lt;$500 rods only rebuild.</p>

patsmx5

iTrader: (16)

Well he asked how cheap can he go, so I answered that. Minimum is ebay rods and chome moly rings. And hone it. You can't do it cheaper than that.

Girz0r

iTrader: (1)

-Per 949's Site, wiseco xx rings won't fit oem.

18psi

iTrader: (76)

I think the last rings I used were DNJ chrome "premium" or something like that.
Really decent rings.
Actually NPR is good stuff too


Chib,
Maybe I'm just lost, but why exactly are you rebuilding again? Is the engine hurt or what? You really want to figure out what the problem is 100% before you crack it open

Chiburbian

iTrader: (1)

Getting ahead of myself mainly. The plan was always to do an engine build this off season but with the addition of a relationship (I had been single for about 6 years) and other life stuff I can't justify spending that kind of money right now.

Coolant issue likely has to do with ducting doing too good of a job channeling air through intercooler but not enough bypass to radiator. My lower ducting "pan" ended up pretty much touching the bottom of my intercooler. I stuck a couple shims in there to create a 1/2" gap and even that seemed to drop temps. I pulled the front off and am adjusting ducting to let more free air into radiator.

In regards to motor build it lets me do three things: replace VVT actuator and replace can seals, swap out head gasket for 99-00 model since I already have a coolant reroute, and forged rods so I can up the boost a tad to run in the efficiency range of my turbo.

Chiburbian

iTrader: (1)

Just an update. Ducting is about as good as I can get it without changing the design of the bottom tray substantially (forward of the undertray). I took it out last night and never got above 196 degrees, but that was in probably 52 degree ambient.

Today on the way to work it got up to 208 degrees but that only happened when I hit a stop in traffic and the fans brought it down pretty fast. That is partially my fault because my fans weren't set to turn on until 204 degrees. I changed the fans to come on at 200 degrees and 205 degrees. It was approximately 60 degree ambient. I never got above 198 on the highway, and I believe I have a 195 degree thermostat.

It looks like these latest mods have worked. I will update when we have a 90 degree day which should come next week. Either way, I need to update my head gasket and check compression and all that.

Oh, and last night was the first time I drove it in almost three weeks. Progress!

Chiburbian

iTrader: (1)

90 degree ambient - hits 220 degrees stopped and in slow traffic, drops to 208 degrees while moving. If I use A/C I have seen up to 237 degrees, so i'm not quite there yet in my opinion.

I did notice something funny today. Awhile back I noticed that my aux fan which is a "programmable output" had moved from 208 degrees to 20.8 degrees basically making it on all the time. Today I checked my "purge" and "VCTS" programmable outputs and they were both low by a decimal point, and matter of fact, the purge was completely deactivated. This would explain the gas smell I was getting after a pull. I started doing some auto-tuning on the way home and it seems to be running a bit better.

Also, I am working on the bias table in the closed loop system and it's going pretty well. Once my bias table is complete I will turn simple mode back on and see how well I can tune it with that. I will say though, it is pretty damn responsive now. I can't wait to post some logs and pics of the spool.

patsmx5

iTrader: (16)

I could never achieve acceptable water temps with the a/c on in 100*F weather under all driving conditions until I yanked (and in my case moved) the a/c condenser.

I honestly think the only way you could achieve it with the a/c condenser still in the front, is if you cut the stock radiator brackets out and put a bigger (taller) radiator, like 4" or more. So that it sticks up higher and lower than the old one, to get the surface area up a bunch. An place the intercooler in the usual spot, but now the bottom say, 6" has clean airflow not being blocked by the intercooler. And then duct it all in properly. If you did that, and had say 30 to 40% more surface area, and all of the new area gets clean air, it would probably work under all driving conditions.

Chiburbian

iTrader: (1)

On the way to work this morning I did a soft 0-60 to see about where I am at.

Basically I started from a dead stop and wasn't trying to launch hard as I was on public streets and there were cars next to me and I didn't want to be a jack-***.

So, 5.8 seconds to 60 is my baseline. Not terrible.

In reference to Pat's input, my next step will be venting the hood and we will see how that does. If nothing else it should cool down my engine bay and maybe reduce intake air temps.

Chiburbian

iTrader: (1)

Yesterday morning on the way home from Mexico...

5th gear pull

RPM PSI

1997 1
2120 2
2227 3
2336 4
2495 5
2642 6
2791 7
2990 8
3075 9
3191 10
3278 11
3372 12
--- boost control solenoid comes out of "full closed" ---
3445 13
3496 14

I had to do the pull in two segments.

Here is the "combined" virtualdyno numbers and only until 6,000 rpm or so.





Allegedly 241 lb/ft at 4100rpm on the second pull, but that could have something to do with the lie of the road. The road wasn't completely flat. This is on virtualdyno "Dynojet" calibration.

Chiburbian

iTrader: (1)

Both logs with cursor at torque peak.

Spool from 2,000 rpm


Pull from highway speeds to 6,000rpm

Chiburbian

iTrader: (1)

The car has been down for about a month while I am building my second megasquirt. I thought I messed up my megasquirt but it turns out I only shorted my jimstim which is why my megasquirt wouldn't power up. $5 fixes are much preferrable to $230 fixes for sure.

Anyhow, I am going over my setup and I see that I had the JP7 (cam pull-up) jumper installed on my expander board when I did my previous build. I am so confused lately I just want to know if I am correct in running that jumper or not.

Also, I am unable to get down to 2.5-3v on the upper leg of R54 when turning R56. The lowest I can get is 5.something volts. Do I need to have the ECU installed to do this part of the setup?

If I don't get spoonfed I will just figure it out, but I am just hoping someone might help me figure it out so I can get it on the car by Saturday.

Chiburbian

iTrader: (1)

Car managed to get on the road today. Had some headaches with R56 and R11 again, but I will make a post tomorrow about that.

In the meantime it looks like I am having some problems with spark "blowout," or if not that, something that seems to have similar symptoms.

I am seeing indicated 10.3:1 AFRs with consistent pulse width at high rpm and high KPA. This is a new thing since building the new board, but it could be a coincidence.

Posting log in case anyone wants to take a look.

EDIT: Also take a look at my VVT on the two "pulls." On one the VVT sticks close to target and my AFRs are fine. On the second pull the VVT sticks at about 4% no matter what duty it is being fed. Strange.

Chiburbian

iTrader: (1)

Still haven't figured out VVT issue but the car is doing into storage tonight so not worth fussing about considering an engine build is coming this winter.

Though, check this out:



I have no idea where that injector timing map came from or how long I have been running it. I bet this is going to completely change my tune VE map for the better.

Btw, picking up a MSpnpPRO for my car today. I plan on putting the 02 sensor in via serial using the CAN/OBDII box when I can afford it.

EDIT: I think this is the Rev ignition timing map and I found the thread below about this very issue.
https://www.miataturbo.net/megasquir...-tuning-84981/

Chiburbian

iTrader: (1)

The Miata is in storage for the winter and now that the holidays are done I am starting to put together a plan for the engine build.

It won't be a "rods only" build because I want to replace the oil pump as a precaution and I may have worn my bearings down when I had my oil line mishap. Plus, I got a bit of a raise at work so... yay me!

My build parts list is here:
https://docs.google.com/spreadsheets...it?usp=sharing

Cliff notes to the build:
Manley or similar rods
Wiseco pistons in 10.5:1
ARP hardware for head and mains
Boundary VVT oil pump
ATI Superdamper

I plan on keeping the head 100% stock unless you guys can convince me otherwise. In the future I plan on sending my spare head core for a full CNC port job, valves etc. I'd rather not spend unnecessary money on the head in the interim.

Do I absolutely need to pull my flywheel and clutch off of my car for the engine build/balance? It is the 949racing lightweight flywheel with a stage I Flyin' Miata Happy Meal clutch and pressure plate on it.

I have never done an engine build before. Where are some good resources to look at? I will start looking for build threads on here over the next couple weeks but it would be easier if there was a "step 1,2,3" list. Any good books?

What head gasket or engine rebuild gasket kit should I buy? It has a coolant reroute so 99 head correct? Can I use a full 99 rebuild kit or do I need to mix and match?

Any other advice?

Chooofoojoo

iTrader: (7)

I built my first built motor last winter with only help of reading here, and some google-fu for more generic topics such as proper ring grinding procedure. It was shockingly easy.

Tips :
-Buy all OEM gaskets/seals. (Flyin Miata has a very thorough engine rebuild seal/kit package. On the expensive side, but if you call them and tell them goals, and what combo of engine parts they can tailor build you a kit.)
-Invest in a torque wrench, and follow torque specs and general wisdom (i.e. ARP head stud torque values, do what Andrew says, not what the spec-sheet says to.) If you have access to precision measuring tools- use them.
-Don't forget about consumables like nitrile gloves, lint-free towels, etc. etc.
-If you go wiseco pistons, give thought to deleting the oil squirters.
-Take your time, do it right. If you're unsure, google/ask about it.

-If you're getting your block machined for new pistons, I would have the machine shop do a basic refresh of your head. I would at least look at getting some stiffer valve springs to have installed during the refresh.