Moonchopper

To skip all the explanation crap, go to the bottom of the post

I've recently (well, maybe not too recently) acquired a $500 '83 rx-7 (12A 5-speed) with what I think, after reading the "End All for No-Start Threads", is a blown side seal on rotor-2 and a blown apex seal on rotor-1 (I still have to take the engine out and check the extent of the damage). However, I don't know if the inside of the rotor housing has been damaged, so I'm keeping my fingers crossed.

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At first, I was planning to do a 327 or 350 swap (couldn't afford an LT1 or LS1, although I would have LOVED to do that.), but the time that it would take to save up cash for it didn't appeal to me. I decided that it would probably end up as either a half-assed job in a rush to get it done (I'm not very patient), or as a half-done project that I would end up having to sell. (I'm a senior in High School, and plan on either going to a community college or a 4-year college. If I had did the latter, I would have to get rid of it, as my parents wouldn't allow me to leave it at their house.)

After I ruled out the V8 swap, I delved into the possibility of a TII swap into my 1st gen 7, but again, I was afraid of time/money constraints, even though both would be less than the V8. I also found very little information on how to actually do it. Most posts/articles I have read on here and other websites wrote about things like "Here's what I took from the junkyard/car: ECU Wiring Harness, the motor, blah, blah, blah.", but never actually said what would actually be needed for the swap. So, the problem with this was time, money, and lack of information. Bummer.

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So, now, I have decided to just rebuild the 12A that I have right now. While I have it out, I've decided that I'm going to do some performance enhancements so that I can have a little extra power at my finger tips (or toe-tips.) Here are my questions:

1. How hard are streetports? I don't want to do a bridge port, because I want to be able to drive my 7 around daily. I plan on doing the streeport myself, because we have all the tools (I think) necessary to do a streetport, and because I want to keep the total cost of getting the 7 to where I want it to somewhat of a minimum. (180-200 hp seems a fair number to me.)

2. Templates vs. No Templates? I don't want to mess the engine up by cutting somewhere I'm not supposed to, only to find out that I've just fawked up the engine.

3. Are there any articles/posts that explain how to do a streetport (Intake, Exhaust, or both) thoroughly (and on a 12A)? I've found many articles/posts that show pictures and explain the porting somewhat vaguely. Something that actually makes a list of everything needed would be nice. This is mainly because I don't like buying one thing, start using it, only to find that I need something else for the next step.

4. Smoothing the cut areas and resurfacing the rotor housing? I remember seeing a vendor who providing porting services with the option of resurfacing. What purpose does resurfacing serve, and would it be able to be done by oneself? Also, I would assume that after cutting/grinding the ports out a bit, there would be some smoothing/sanding involved?

5. How labor intensive is it? Will there be times when I will need to get a tiny area, i.e. some little crevice/corner that would be too small for most tools?

Those are all the questions I have right now. Sorry for making it so long, I just want to make as few posts as possible and try to cover all my bases.

coldy13

A streetport is very easy to do. It can be done with a dremel, but it goes much faster with a dye grinder. Use a big CARBIDE bit to rough out the port. Make sure the bit is carbide, steel will not hold up and will be very dull after 1 port. Get some stones and small sanding drums to finish the port with, but don't use them to remove much material since they wear quick.

Use a template. I'd suggest one from www.racingbeat.com, get the one for intake and exhaust since this is your first port job. Now I only use the intake port and I just go crazy with the exhaust But I wouldn't suggest that for the first time. Also, make sure on the closing edge of the port you put a nice smooth bevel. If you don't do that it can cause the side seal to break. You need to do the intake and exuast ports, just doing one or the other will not give you much of a gain in power. Also, the shape of the port isn't everything. The shape determines the opening and closing of the port, but the transition from the runner to the port is just as important for flow. I would suggest using a sanding wheel on the dremel to clean up any casting marks in the runner, but don't make the runner bigger, it's already plenty big. Try to find a carbide bit with a long shank, it will make cutting the transition area mch easier. I did it with the same bit I used for roughing, but it made it harder.

There's no need to resurface the plates unless your motor has been severely overheated. If it hasn't been then your plates should still be flat. Hell, my motor was overheated on a regular basis and it's plates were still flat.

Porting all 4 intake ports and the 2 exhaust ports will probably take you around 6-7hours with a dremel. It's not hard work at all, but it takes a while and you need to be careful all the time. It's really not too big of a deal if you slip a couple times and mark the plate around the port, as long the marks are small and shallow.

You won't see the full power of the porting without a good intake/exhaust. I suggest sending your carb to carl/sterling and getting a racingbeat streetport exhaust.

Moonchopper

Well, as of right now, I have some plans for my 7. On the to do list:

That still isn't the definite list of things I want to do, as my wants change quite frequently. I'm pretty much just looking to have a semi-fast, streetable car. Overall, it will still cost me ~$2000, which IS a little expensive to me, but I figured I can be patient just as long as I get the engine up and running. That way, I can have fun while waiting

Also, thank you much for the advice. I'll make sure I keep that somewhere safe so I can use it for later.