Rebuilding NA engine anything else I should add while it's apart?
 

First off I'll say sorry, but I honestly couldn't find anything through the search function. Maybe I didn't look hard enough...but it is late.

Anyways I'm rebuilding my engine and so far the only thing I'm going to have done to it is new housings with intake and exhaust porting done by Mazdatrix. So basically while I have the whole thing apart is there anything else I could add on to get just enough power out of it? Things like bigger injectors? If so what cc rating should I go with? The car is going to be a "saturday night special" sort of deal so anything that might affect daily driven cars in a bad way won't matter to much. But one thing, I do want to keep the bolt on mods to a maximum while at the same time things that don't require ecu tuning and the sort. And I am on a little bit of a budget as the rebuilding is already sapping my money.

well theres no way you can add bigger injectors as for you will need to tune that, you dont want to stick to bolt on add a new clutch ,perhaps some light weight pullies ....anything to help you out without tuning...now how much are you spending on mazdatrix if you dont mind

You don't need bigger injectors on an N/A anyway. The stock injectors can easily handle 200 HP which you won't reach with a Mazdatrix port. These cars run rich anyway, the last thing you want is to add bigger injectors to make it spit out gobs of unburned fuel.

How much porting will the N/A injectors allow? I was hoping to get a mild-street port on my main ports.. and a more agressive porting on my secondaries... will stock injectors keep up?

/hijack

If we are talking about an N/A, your stock injectors will be fine with any street port. Now if you get into bridge porting or a peripheral port, that's a whole different can of worms.

coolio.. I will, however, be replacing the fuel pump with a TII fuel pump. I've heard that the fuel pump is more of a bottleneck than the injectors.

Thanks for the replies. So basically I should just try to lighten up components around the engine?

I'm spending damn near 3k at mazdatrix. Which includes things like seal and gaskets packages, lapping side and intermediate housings, one rotor, two new housings with porting, and a few other things.

With two new housings, porting, lapping, a new rotor... thats actually a pretty damn good deal.

You should also try and grab a TII oil pump. A TII pump plus a quick mod to your regulator will raise your pressure up to 100psi. A great mod to prolong engine life.

may as well throw a flywheel/clutch combo on it too, quicker revs, more power to the ground... i'd throw out my sales pitch from the for sale section, but i've been thinking of keeping the setup..

Do you have the write up for this mod? Link please? :)

Aaron always has the best write up's

http://www.aaroncake.net/rx-7/shimoil.htm

Thanks for the oil pressure info Newbs. I will attempt that asap.

I have an aux bridgeport large streetported engine and with the stock ECU im pretty sure im running the ragged edge of the injectors. The primaries will only run at 40-50% duty cycle with the stock ECU after the secondaries kick in. So without a standalone or larger secondaries and an SAFC anything larger than a streetport will probably push the limits of the na injectors.


As for the TII fuel pump you will run rich at idle with it unless you replace the fuel pressure regulator int he process. The TII pump runs on a reduced pressure at idle on the TII. Its the same regulator as the NA but the pump runs at a reduced preswsure to keep from flooding the engine, so you will need to either pull the regulator or add the relays to reduce the fuel pressure.

BC

bah I run an FD fuel pump on my n/a (got it for free, so why not?) with stock FPR and it still idles around 12.5:1 on my wideband, which is normal with no ACV or cat.

You can put in the pineapple racing auxilary port sleeves. They're not very expensive. I run them, and I make pretty good power on my n/a . Also you want to get rid of the exhaust diffuser in the engine.

and get an SAFC. they are not expensive and will be able to lean you out for a few hp.

dam... 3k at trix? sigh* im on the road of rebuilding my engine... and you said 3k for an na? can you list everything you've come up with for the rebuild. Parts and stuff, how does it add up to 3k?

How long is this estimated to take? When did you drop it off

Read the freaking post man.

i did... but its hella expensive

Housings are about 500 bucks each give or take... rotors are about the same. porting is usually a couple hundred dollars.... and the full rebuild kits are usually almost 1k for a good one (including install gasket set) I'm not 100% sure about those prices.. but I'm pretty sure I was aleast in the ball park.

Have you done it cheaper? If so.. HOW?

You want to cut the guts out of the diffuser or install a turbo sleeve, not get rid of it entirely. Your header would not line up properly and it would be incredibly loud.

Brian

nope, this is my first car. I just looked at it as an expensive fix, I dont know how much it usually costs to rebuild... i was thinkin somewhere between 1200, and 2300 never thought over 3k.

Is there any other places in LA that does rebuilds for rotary? or Surrounding LA area?

Well, if you do it yourself, and have no damaged parts, 1200 could do it...

16k for rebuilt N/A core..............i go for that route better.


or


12k for a used TII............damn............to many choices.

Uhm........ What?!

16K sounds right for an N/A core. I must have got a good deal on mine because I got the core plus a car for $1,200...

Ichaidez, it's pretty much like in my first post a few things listed would be:

-Rebuild Kit which is pretty much the seals springs and you name it for the internals of the engine
-Gasket Set which is for the rest of the stuff external
-Lapping all four sides of the Side and Intermediate Housings
-Two new Turbo Housings (current ones are shot)
-Porting on the new housings (Exhaust and Intake)
-One "Very Good Used Rotor" as one of the Mazdatrix employees told me
-Main and Rotor Bearings

All that comes out to a ballpark figure of around $3k...

The rest of the rebuilding is being done by me.

Also anyone that has experience with Mazdatrix porting, when they quote me $290 for porting the Intake and $90 for porting the Exhaust, is that a street port or bridge port? I'm not too sure on the difference of the two, I'll go look that up. And exactly how much gain should I be looking at through just the porting? Maybe Higher RPM operation? I don't know...

O and another thing I bought the Engine Stand Adaptor so tack on another $100 for whoever is doing the math.

For $290 Mazdatrix is going to give you a streetport. It isn't very aggressive but it will be a noticible difference over stock. They will enlarge all six of the intake ports. I forgot what year we are talking about but you should make about 15% more horsepower from a good streetport.
Your RPM operation will remain the same. Don't go over 8,000.
If you are going to assemble this motor by yourself I think you should pay the $20 and buy a rebuild video from either Mazdatrix or Rotary Avation.

Why are you using brand new rotor housings? I guess if you're will to pay an arm and a leg it's worth it but I bet half you rebuild costs are in those two housings.

*LChaidez
I see, Thanks for taking time and explaining it to me. Good Luck, and if its possible can you take pictures of the progress and post them here. I would like to see it. Thanks again, and good luck!!

The housings that came with the engine are shot to hell. It's been rebuilt once and whoever did the rebuild reused the original housings so there's a huge groove on them. So ultimately I'll have to replace two housings anyways and the price difference between the NA housings and Turbo housings are a mere $50 or so. Thus I figured might as well go with the Turbo housings and port it while it's all apart which means dropping about $300 more. All in all not that big of a dent compared to what I'm paying already just to get the engine in good running condition.

Hopefully with that extra 15% and whatever I decide to put into the car it'll be in great running condition when I'm done with it.