Eric Anderson's Supercharged SSM Miata
 

I'm just about to finish up my motor project for next season and wanted to share some pics of my head. It's a MSM Head that I have "mildly" ported and polished. I unshourded the intake and exhaust valves, "softened" all the sharp edged and mirror polished the combustion chambers, blended the bowls and tear dropped the guides on both the intake and exhaust ports, Raised the port roofs on both the intake and exhaust ports as high as the gaskets would allow and then mirror polished the exhaust ports. I'm dropping it off at the machine shop on Monday to be trued up and the valve job completed. Hope you enjoy the pics and I hope it makes at least 1/2 of 1 HP more than a stock head would.

Intake Port
https://www.miataturbo.net/attachmen...ine=1325979420

Exhaust Port
https://www.miataturbo.net/attachmen...ine=1325979420

Intake Bowls
https://www.miataturbo.net/attachmen...ine=1325979420

Exhaust Bowls
https://www.miataturbo.net/attachmen...ine=1325979420

Combustion Chambers
https://www.miataturbo.net/attachmen...ine=1325979420

Full Head
https://www.miataturbo.net/attachmen...ine=1325979420

All the best

Very nice work!

Thank you sir. I just hope it works 1/4 as well as it looks. With head porting its all about the shape...not the shine. I didn't do anything out of the box. just simple tried and true steps.

From Hakuna Miata's anecdotes, you'll notice changes in the butt dyno.
What am I seeing about halfway down the intake?

injector ports

Do you mean the valve guides?

Looks real nice. I did almost the exact same stuff on my 96 head. It definitely added more power up top.
I would recommend that you CC each combustion chamber to ensure that the compression ratio is not greatly changed or is changed by the amount that you intended it to. I ended up dropping my compression a good bit with all the material I removed while deshrouding the valves. It will probably be beneficial once I go turbo, but running NA right now it makes the low end a little weak, but once it hits 4000rpm it pulls real strong.

what bits did you use for the combustion chambers and polishing? i tried doing that to my head but i couldnt get the bits i have to get in the little nooks and crannies nor could i get the exhaust ports so smooth

So.. how did you figure out that your compression ratio was drastically changed? Compression test numbers drop?

I have 9:1 pistons and a very ported FM head. Stock height head and block. From day one I have only had 145psi on compression test.

My compression on the rebuilt motor (stock rebuild) was less than what it was before I pulled the engine. This was with an overbore and a slight head shave to clean things up. It also feels like it has less power down low than before, but that's the butt dyno speeking. This might be accentuated by the very strong pull above 4k though.
The big thing is to check each chamber to make sure your combustion volumes are the same. After all you are increasing the chamber volume by hand, not by a controlled process like CNC or whatever FM uses.

agreed on checking for consistency across all 4.
otherwise looks like real good work for a diy
good job

Bauce

Did you knock down the sharp corners at the very edge of the combustion chambers?

Have you ever tried a different gauge? I get ~160psi cold on my 8.6:1 motor, and the 10:1 block in the Rental tests in the 190+ range.

145psi does seem a little low. I read ~165ish with my calculated 8.6 CR ratio and cheepo HF gauges.

I used a mix of an air powered die grinder and a dremmel tool. To get the ports and the chambers that smooth you have to do it in stages. I did "mass metal" removal with a carbide cutter, the moved on to a fine stone, to coarse sand paper, fine sand paper, finishing wheel and polishing pads. I't very time consuming and tedious. You have to be aware that every stage is taking away metal. So you don't want your final port shape to be what you cut with the carbide cutter. You want your desired port shape when you are finished. You need to keep one thing in mind when you are doing head work....it's all about the shape....not the shine.


Good catch. I did cc both the chambers and the ports. The chambers are all within .5cc which is as accurate as my tools were. the ports are all within .5cc's as well. Thanks for the compliments.

Thank you sir.

Yes. All the "once sharp" edges are now smooth. This motor is going to have an actual static compression ratio of 10.13:1 with 16psi boost from a M62 blower on C16. So I needed to get rid of anything that could make a hot spot.

And before you all get your panties in a wad....C16!!! Not pump gas :)

Rods and pistons have arrived. Hope to have the short block assembled this week, in the car over the weekend and delivered to DIY autotune for a tuning session in early Feb.

https://www.miataturbo.net/attachmen...ine=1326239331

https://www.miataturbo.net/attachmen...ine=1326239331

https://www.miataturbo.net/attachmen...ine=1326239331

https://www.miataturbo.net/attachmen...ine=1326239331

https://www.miataturbo.net/attachmen...ine=1326239331

those pistons are just lovely, just eff'ng lovely

Very nice work. Im hoping to get my hands on a spare head to port this summer. Are you goin to port the manifold runners to match? Also what intake manifold will you be running?

^^^ The Intake is still up in the Air. I spent about an hour and a half on the phone with Corky on Friday. If he doesn't build me something one off I'm going to use a squaretop. The price is right on the squaretops right now through Mazdamotorsports Development...and they have them in stock.

Ok... so I don't know anything about head porting and it looks really nice, but I thought I read somewhere (while researching porting on my own which I decided not to do) is that a perfectly mirror finish is not actually what you want and it can actually hinder flow? Correct me if I'm wrong.

Compression ratio is not measured with PSI from a compression test. All that does is tell you how well your rings are seated.

To get your "true" compression ratio you need to cc the head and measure how far the piston is below or above the block deck. Then do some fancy calculation and you get your true compression ratio.

That would be correct. You will notice that in the ports there are little scratches left by the sanding process. You do not use too fine a grit with your polishing scrolls.

The combustion chamber itself however, often has a more polished appearance.

You don't want a polished finish on the intake side. You want the exhaust as smooth as you can get it. The reason you don't want a smooth surface on the intake side is the mixture going into the chamber has liquid fuel suspended in the mixture. If the boundary layer of air against the port wall is not turbulent the liquid fuel can "fall out" of suspension and pool against the port wall. The rough surface of the wall creates that turbulence much like the dimples on a golf ball. The exhaust port has somewhat the opposite problem. The burnt gasses leaving the combustion chamber are carrying carbon. That carbon can deposit itself on the port if the boundary layer of air isn't kept at a high velocity. Secondly the smooth surface doen't give the carbon something to hang on to. You want the combustion chamber as sooth as possible and you want all the sharp edges in the chamber to be softened. Any sharp edge in the combustion chamber can get extremely hot creating a source of detonation. The second reason you want the combustion chamber smooth is the same as the second reason for the exhaust ports. You don't want to give the carbon in the combustion exhaust a rough surface on which to deposit itself.

Eric - and all this time I thought the fuel injectors injected directly through the open valve port into the combustion chamber, little did I know that the air flow coming out of the intake plenum and through the head passages was a fuel-air mixture [FFS excepted].
I think that satin finish logic is now an old wives tale, a carry-over from carburetor days.

For me, I want my intake and exhaust passages as smooth as possible, but I want the passages for the charge air to have the satin finish to aid in heat transfer.

But I do admire your work, and since you are so close I am tempted to bring a head to you to duplicate the effort again - :)

No worries. I will need the head, 2 intake vales, 2 exhaust valves, the intake gasket you are going to run, the exhaust gasket you are going to run and the head gasket you are going to run. I work with a machine shop down here that only does head work so if you bring me a complete head that is what you will get back. If you are serious let me know and we can work something out through PM's

Just a note of interest, if you want to go larger than the manifold gasket, you can easily expand the gasket with a die grinder by a reasonable amount.

I guess you would need to stay far enough from the raised portion that is designed to crush when torqued.

I have not explored the limit, but I had to cut the gasket so it was not protruding into the intake tract. I have not encountered issues with sealing.

Just finished CC'ing the head, measuring the deck height and a compressed head gasket. It looks like the final compression ratio is 9.9501:1

I love how inaccurate advertised compression ratios are.

1.) Polishing the exhaust ports and combustion chambers will net you some gain in heat rejection, but the gains will be immeasurably small. Endyn did some testing with port finishes once upon a time, and published dyno data showing that for all the work involved in polishing/ finishing the CCs/ exhaust ports, they produced no measurable improvements over the same port left at carbide cutter finish. Think about it, after 30 seconds on a running motor, no surface rougher than WPC treatment won't be so covered in carbon deposits that the surface finish itself will be totally obscured.

2.) The difference between 10.13:1 and 9.95:1 could easily be lost in the casting variance/ headgasket/ machining tolerance mix. You're talking 1cc difference. You also lost a little compression in the chamber porting process. I won't disagree that compression ratio numbers from piston manufacturers often seem to be totally arbitrary. I've even found that some of their own advertised dome height and compression numbers don't agree. I'm just saying that I wouldn't sweat that tiny bit of compression ratio difference.

It's been about the same across three different gauges. Who knows, maybe they were all HF gauges though.

Maybe my rings never seated that well. My engine had a hard first 5 minutes of it's life where we were trying to run it on 6 month old atmosphere-exposed gas. I did put boost in it and suck a lot of vacuum as soon as it was on the road with fresh gas though. Maybe I will do another test. I haven't done one since I ran 30psi.

I should prob have the title of this thread changed to Head porting and a few other projects. I know it's "off topic"...but hey it's my thread. So here are some pics of the new wing and splitter.

Bought this wing off a now wrecked XP car that has trophied at Nationals a few times. I rebuilt the end plates out of Alumalite and added the greyhound stickers.
https://www.miataturbo.net/attachmen...ine=1327277611

Homemade gurney flap. I "stole" this idea from Brian Johns
https://www.miataturbo.net/attachmen...ine=1327277611

And the first stages of the splitter. Building it out of Alumalite too. I have moved some things around since this pic was taken...but my cell battery was dead.
https://www.miataturbo.net/attachmen...ine=1327277611

Gangster.

Just out of curiosity, why XP instead of Street Mod? Seems like it would be even harder to keep up with the FDs and Corvettes when they can legally lose even more weight.

Oh the car is a SSM car. The wing just came off a XP car that has since been wrecked.

Got it. What do you weigh, and what kind of power do you make?

Right now the car is about 1370lbs and makes 0hp and 0ft lbs.

At the Nashville "Road Tour" it was 2163lbs and the goal with the new motor is 325+ on C16

:drool:

Just out of curiosity... why C16? E85 is a much cheaper solution.

C16 is leaded so it eats oxygen sensors pretty quickly, and has an octane rating of 117, and has a cost of about $17/gln.

E85 is unleaded, easy on O2 sensors, has an average octane rating of 113, and costs less than $4/gln.

Not to mention the evaporation rate of the ethanol helps to lower charge temps, which basically makes up for the slightly lower octane rating. I dyno tune cars for a living and can honestly tell you that I'm usually within 5%, power wise, between C16 and E85. Food for thought....

If you really have to run race gas, I'd recommend Q16 over C16. It's basically a highly oxygenated version of C16. Tends to be easier on sensors and consistently makes more power than C16, for about the same price. Also if you're going to be touring nationally and visiting sites with varying altitudes/climates, Q16 will perform more consistently due to the higher oxygen content. It also has a wider range of "acceptable" AFR's, which can cut down on the need to re-tune for different weather.

I'd guess availablility and consistency. E85 isn't nearly as common in the south as it is in most of the rest of the country. As such, turn over on gas station tanks is slower, and batch consistency isn't as good around here. Plus there's all the fuel system contamination and corrosion issues to keep up with, especially on a car that sits for long periods of time.

And where are you getting your octane numbers? I've NEVER heard or read anything reliable claiming more than ~105 octane from E85, and you usually see more like ~98.

The closest station to me with E85 is over 120 miles away...the closest BP dealer to me is 2.6 miles away. Second I have never seen published, repeatable tests showing E85 with motor octaine ratings that high. Third. O2 sensors are cheap...that said I have been using the same sensor for the last season and a half with ZERO degradation in performance. On Q16...go read how corrosive that stuff is. You should mpletely drain your fuel system after every race and for the extra cost of the fuel, coupled with the added maintenance required it isn't worth is for the less than 2% increase in power it MIGHT net.

And here is more off topic in my own thread. Got the splitter finished tonight.

https://www.miataturbo.net/attachmen...ine=1327371016

Looks like a gay uncle's miata to me!!

Why dont you just change the thread title to "TNTUBAs Faster Than Your Miata Build"?

Made some progress this weekend. I debured the block, painted it then proceeded to clean it

https://www.miataturbo.net/attachmen...ine=1327877406

Got the crank in. .0017ths on the mains is just where I wanted it.
https://www.miataturbo.net/attachmen...ine=1327877406

As I was starting to check the rod bearing oil clearance I discovered that the oil jets were hitting the bottoms of the new Weisco pistons. So a quick trip to ACE Hardware Racing Supply for some 10mmx1.25 bolts and the oil jets are deleted.
https://www.miataturbo.net/attachmen...ine=1327877406

And having not checked the mail yesterday I missed this came in. 70mm throttle bodies are SOOOO last year.
https://www.miataturbo.net/attachmen...ine=1327877406

That TB is HUGE!

I meant to ask you last night if the Miata throttle cable gets along with the Mustang throttle cam, or did you have to commit chicanery to get them to work together?

I absolutely abhor the throttle linkage nonsense that the Uber kit uses, but I haven't sat down and figured out if I'm going to have Motion Pro make me a cable, or if I'm going to have to figure something else out.

I had to make some very minor mods to make it fit my application. The stock throttle cable will slide right in but you need to make some minor mods to prevent the cable from coming out.

Short block is together
https://www.miataturbo.net/attachmen...ine=1328449248

https://www.miataturbo.net/attachmen...ine=1328449248

Just waiting on a few more parts before the head and blower go back on. So I went ahead and installed the RunCool hood louvers.

https://www.miataturbo.net/attachmen...ine=1328449248

https://www.miataturbo.net/attachmen...ine=1328449248

Car is bad ass.

Are we going to get to see pics of finished engine compartment?

The supercharger got back from the HighSpeed Lab this evening. I'm VERY anxious to see how it works out. I have VERY high hopes.

Go ahead and show them the outlet. They're gonna ---- sideways bricks.

I'm going to wait for dyno numbers before I post those pics ;)

The new engine, new transmission, new clutch and new diff are all in the car now. New dlerin and spherical bushings are installed as are new ball joints and inner and outer tie rod ends. Still have to install the cooling system, new blower and intercooler...then it's off to DIY in Atlanta on Tuesday to be tuned. I hope it makes about 175-180hp.

https://www.miataturbo.net/attachmen...ine=1330177390

https://www.miataturbo.net/attachmen...ine=1330177390

and a couple shots of the porting work on the blower.

https://www.miataturbo.net/attachmen...ine=1330177390

https://www.miataturbo.net/attachmen...ine=1330177390

And I had someone ask me about the Greyhound stickers all over the car. Well if you think the car is fast...here are some pics of the ONLY really fast thing at my house.

https://www.miataturbo.net/attachmen...ine=1330178065

https://www.miataturbo.net/attachmen...ine=1330178065

https://www.miataturbo.net/attachmen...ine=1330178065

https://www.miataturbo.net/attachmen...ine=1330178065

And here are a few races from before she retired. Here track name was Mulberry Semerun.



So to the earlier comment in this thread..."TNTUBA's dog is faster than your dog too" :)

That is amazing...imagine what goes through those dogs heads when they trip. They are so full of determination!!!

They can go from 0 to 40+mph in 3 steps.

lulz

No two step launch I guess?

WOW...it has been a LONG 3 months since I started gathering parts for this build. I am REALLY glad the motor ran when I turned the key. Took it to the CRSCCA Test N Tune and was able to get the rings seated and some rough tuning done. Now I just have to change the Oil and filter again and get it to Atlanta to see what kind of power it will make. I can tell you just from driving it around today it's A WAY LOT STRONGER than it was with the other motor.

What'd it put down? Dyno graph?

Did I miss updates on this somewhere else? I'm really curious to see how it all turned out when tuned.