Can anybody give me some knoledge on street porting my 12a. It has 86 000 km on it and I have the racing beat full exhaust(not street port header but collector)

1. What are the pros/cons of street porting a 12a?
-horsepower gain
-durability
-gas milage
Or more

2. What other upgrades should I make if any while doing this?

3. Where should I get my template from, I plan on doing it myself?

Feel free to tell me more about the after math or the process I am up for, Thank you?

 

i also Iam thinking of street porting my engine when i crack it open. The only thing is I dont think it will be able to pass emissions if i do so i guess thats a con

 

1a. Not for sure, but I have seen figures of 175-180 fwhp posted, along with supporting mods.
1b. If driven the same, durability remains the same.
1c. What, did you think it would go up? lol. I still get low 20's highway on the 1/2 bp, but it can be as low a mid 8's in town. Streetport won't be that bad.

2. Street port headers and 2-1/4" exhaust. Carb and intake. Sterling would be a good option. Ignition.

3. RB templates are mild. If you wish to learn more about porting, head over to NoPistons.com and peruse the 'Engine Building and Porting' section.

 

Find JudgeIto over at www.nopistons.com

He is selling some agressive streetport templates that may be an improvement over RB. They have a really nice Rebuild/Porting section where you can learn most of what you need.

 

Ito is the man when it comes to porting, especially his bridgeport templates.

 

That section of the forum is the only place I hang out on that site. Lynn E. Hanover is AMAZING with his information.

 

I have a set of irons that are ported using Judge Ito's template and my 12a is ported using the same template. Everyone thinks its bridge ported. Ito san is the man....Seek his rotary wisdom and you cant go wrong!

 

Right now I get 17 mpg around town and 32 on the highway, I was wondering if i kept the stock carb or else went sterling and had my normal jets on that my gas milage wouldnt drop or would it drop either way. Also same with power, would i need a better carb or would it increased some by street porting? I want to street port first so I Know what i wanna get. Also It is cheaper then getting a knew carb and probly gives more horse power. Also when rebuilding should I think of some different engine parts for better performance, durability??

 

The Sterling is going to give you lower mileage no matter what. It will also increase your performance no matter what.

You can't have both. They don't just rejet the carbs and call it a day, there is a list of mods the length of my arm which help with air flow and fuel atomization that make the carb a powerful though slightly more gas-hungry beast.

Porting cheaper than a carburetor? how do you figure? To port the engine you have to rebuild it. The most basic rebuild kits cost $1,000, then you have to add the cost of the porting (or the porting templates if you do it yourself). The Sterling costs less than half of all that!



Think of it this way. Your car burns air and fuel. Making more power involves making sure the car can get more air and fuel in and more exhaust out as efficiently as possible. Anything you do that's a power improvement will lead to better VE, and thus burn more gas and air, lowering your mileage. Most of these improvements will also kill any chance you have of ever passing an e-test again.


There are three main areas of improvement. Your Intake, Your Exhaust and Your Porting.

Intake: Get a Sterling. Don't argue, just do it. You'll thank yourself. Along with it you'll want to upgrade your fuel system or it'll be starving for fuel at the top end. I recommend the Mallory Comp 70 fuel pump and a fuel pressure regulator (I use the Holley 1-4psi Fuel Pressure Regulator). Sterling and Carl also offer ported manifolds now, you'd have to PM them for more info.

Exhaust: For street, RB all the way. It'll outlast the life of the car, it's basically plug-and-play (so doesn't cost much to get installed, no custom fab work) and it gives more than 20% improvement over stock hp.

Porting: Most expensive mod by far, requires you to tear the engine apart and rebuild it. Can yield huge gains, but you should read more about it first. If you want to strengthen your internals there's a huge wishlist of things you can do. Search for "Ultimate Streetable 12a" and you'll find a thread I made listing EVERYTHING that the absolute perfect 12a would have in it. Of course, that ULTIMATE 12a is well beyond most people's budgets, but by reading up on each item in that list you can make the decisions on what to keep and what not to keep.


Jon

 

Cant you rebuild the 12a without buying parts?

 

No, You will need the gasket kit at a minimum, a little under $200. Going this route will give NO performance improvement over stock. Cleaning up the ports, with out porting, will produce minor gains, that's all.

As they say, you can't have your cake and eat it too. If you want more performance, you WILL get less fuel mileage. 32mpg highway mileage is the highest number I have seen posted here, great job, you're doing something right.

 

Yes but I am more concerned about power, that gasket kit would allow me to rebuild without problems correct? Because then I can get it ported because i know a good machinest so porting would probly run me 400 dollars right? Then there will be decent performance gains but lower gas milage, correct?

 

How much more horse power would I expect with street porting my engine, with the stock carb and the racing beat exhaust, collector header? And then, How much could I expect with a sterling included?

 

depending on your final setup, you're probably not going to exceed 180-ish HP at the flywheel.

 

porting your engine "correctly" is going to require more than just a gasket set and water seals. do yourself a favor and read the thread that Vipernicus42 mentioned or check some of the things i mentioned in your thread at nopistons. if all you do is open the engine, port it and put it back together, then you'll be opening it again in a relatively short time - i promise.

 

That's an extremely liberal estimate for a stock intake and fuel setup, and not the full RB exhaust.

180ish is what I'm aiming for with the "Ultimate Streetable 12a" (ported of course), a Sterling Carb, ported intake manifold, Mallory Comp 70, and a full RB exhaust.

But you will get some power out of it.

Honestly I think you're braking up the wrong tree. If you're looking to make power fast and cheap, Street Porting is not the way to do it. If you don't do things right, you'll end up having to tear it apart and rebuild it again in the near future. Not to mention, you'll find yourself wishing you did take the time to do it right once you start learning about all the stuff that you can do inside an engine.

It sounds to me like you haven't been working on this car a very long time, and you're looking for the fast-track way to the end.

I'd concentrate on getting the full RB exhaust and a Sterling on your car. Remove the rat's nest and clean some things up. Trim back the wiring harness, get an FC fuse box in there. Doing the little things like the cleaning, harness and fuse box won't bring much performance per se, but they will bring confidance, satisfaction on a job well done, and time in the engine bay.

You'll get a kick out of the change just the exhaust and intake can do, and it'll be good preperation for the street port (which you won't get the full power out of without those mods anyway)

And remember:

Power, Reliability, Affordibility

Choose any two.

Jon

 

that's why i prefaced with "depending on your final setup." i guess maybe it was worded a bit awkwardly. i was trying to say that his final output will depend on which intake, ignition and exhaust configurations he decided to go with when everything was said and done, but he would be hard-pressed to make much past 180-ish, if at all, regardless.

 

I have full racing beat exhaust just to let u know, but I need a carb

 

and street strip clutch from racing beat, that clutch is very fun when I wanna bag

 

If you stated the mileage on the engine, I missed it. If you are going to go to the trouble fo cracking the keg and porting, this is the time to freshen the hard seals too. I realize this can increase the cost of the rebuild parts 2-3 times, but what is the point of building up the engine to increase hp, only to have to do it again soon, because the hard seals are past thier sevice limit?

Even with a well maintained engine, anything over 70k miles should get new apex, corner and oil control o-ring seals, along with all new springs. Then, depending on porting and rpm goals, the appropriate oil mods should be done too.

Not trying to be insulting here, but half-assed is still half-assed. How long do you want the engine to last after the considerable amount of time, labor and expense you've put into it?

You could easily spend 600 your way and have a 20k motor, or spend another 5-600 and have one that may last 100k. Trust me, if you have to go back in and rebuild a 2nd time, it will cost more than doing it right the 1st time.

 

Ic You guys are totally right, I should probly stick with just a carb for now and make sure i know what i want to do if i plan on street porting. Just a question, the way u guys make it sound that after u rebuild the engine looser durability or is it the streetport that calls for some parts to help with durability??

 

And I guess waht I really need help with is finding the right carburator and intake manifold

 

Set your goals for the car. Is it going to be a DD, with a little extra kick? Do you plan on tracking the car, SCCA, autocross, drag strip, etc? Hp goals? Driveability?

Once you decide these, then we can go from there.

 

I want to do this over the coarse of a couple years...
First of all, this is a DD but I want it to be able to beat a v8 mustang, I want it with about that much kick. Also decent for the odd drift(odd) whenever Im really bored I would like to car to be able to do this pretty easily.

I dont know what order I should do this in too however these are the things I want to do, maybe you guys can help with the order. And or what I need to do if extra or less.

1. A carb, not sure what kind but I want one where I can change the jets for more power back to better economy, One that can handle a fairly aggressive streetport if I decided to go aggressive, also a fuel pump, not sure what kind, and fuel regulator I believe you need as well.



2. Street port maybe next thing but might not/Ignition upgrade forsure wants I figure it out

3.15-16 inch rims

4. performance suspension and strut bars

5. maybe a small rear spoiler, but im not sure

6. Street port forsure by now

7. paint job

Theres more little things but the list is pretty long already, sorta along the lines of what I want to do.

 

The street port is just changing the shape/size of the opening in the side housing, so it won't directly affect durability.

However, chances are when you've got a car that's making more power you'll be more tempted to beat on your engine. Plus, you've got more air/fuel mixture coming in more efficiently at a larger range of RPMs (higher VE), which is why you make more power. That means more and more powerful explosions to higher rpm numbers. Why wouldn't that put more stress on an engine?

Even if everything went back together *exactly* as it came apart, the engine still already has wear on it. It doesn't make sense to just slap the engine back together. You've already removed everything off the keg, taken the time and effort to pull it out of the car, and brake it all apart. A full day's work later you're ready to start porting, but when you're done you still have to reassemble everything and put it back together.

There's no reason not to refresh things while you're in there. We're not suggesting that rebuilding your engine will cause it to self destruct within a year, but why take the chance?

Jon