spectre6000

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Introducing my new-to-me RX7!






5/16/86 Build date, Luxury package, NA drivetrain. Tornado Gray (aka "rat gray" in this condition). It looks rough. Really rough. Partially because it's filthy, and partially because it's just that ugly. Paint chips with surface rust started, door dings, full blown rust behind the PSF wheel on the rocker, paint is thoroughly sun worn. Trim missing. Exhaust tip rusted off... Not pretty.



Inside isn't much better. Dirty, smoked in (still has cigarette butts in the ash tray), black xmas tree "air freshener", missing bits of trim, broken plastics, torn upholstery, did I mention dirty?

Mechanically though... From what I can tell, it's really good shape. I had it emissions tested today and passed with flying colors well under the limits without anything special. It pulls hard. Way harder than I expected 140-ish emissions choked horses to even attempt. While test driving it, I accidentally broke traction in second gear. Not leaking a drop of oil. Maybe I'm a little biased coming from cars with double digit horsepower, but all in all, it seems to be one scrappy little bastard!

spectre6000

iTrader: (1)

My automotive background is mostly air cooled VWs. My history includes a 1970 Karmann Ghia, 1972 Karmann Ghia, 1958 German market Beetle (currently undergoing a bare metal restoration), 1962 Bus, and finally a 1957 German market Karmann Ghia (just visible in the background peeking around the corner of the third photo or by doing a google image search for "57 Karmann Ghia", it's usually the first result; black and white with Texas plates). I've also owned a 1999 Toyota 4Runner (manual, locked, and until last night, the only car I've owned that was newer than myself since college), 1974 Toyota FJ40 Land Cruiser, and the M1009 CUCV visible in the shadows of the third and fourth photos above).

The M1009 cracked its 6.2L diesel block with only 30K miles, and as punishment for its bad behavior is getting paint, a new electrical system, and a new (much better) engine before next winter. The Ghia was my summer driver, but it's really too pretty and too nice for me... Turns out I'm a beater kind of guy. Also, it's worth a lot of money... So I sold it and I've traded way down to fund the truck. So now the Rat is to be my summer daily, and the M1009 my winter daily. Eventually I'll get around to finishing the Beetle...

The RX7 rounds out my collection of oddball engines that no shop will touch. I have air cooled, mechanical NA diesel, and now rotary! I'm officially a masochist!

spectre6000

iTrader: (1)

The plans for this build (if you want to call it that) are tiered. Initially, it just needs to be brought up to spec. No real deviations from stock, just make everything work exactly like it's supposed to. It is a must-run car until I get the M1009 back in operation.

Boring, I know.

To start, The Rat needs a thorough cleaning inside and out...

After cleaning, I need to do something about the brakes. There's some pad crud on one of the rotors (PSF, I think), so it'll need to be turned and get some new pads all around (I imagine the pads that are on it are cheapies). Hopefully I don't need a new rotor, because I'd like to swap out for the 5-lug hubs and get some wheels that it's easier to get good tires for. Then I'll flush the brakes and replace the DOT3 fluid with DOT5 fluid. DOT5 is nicer on paint, has a significantly higher operating temperature, and doesn't absorb water so once you get it bled, you never have to change it or flush it again. You're set! It is much more expensive, but I already have more than half a gallon of the stuff from the M1009 (all military vehicles use DOT5).

After that will be comprehensive fluid change and greasing any zerks (they still did that in the 80s right?).

Then basic engine tuneup. This should be plugs, wires, adjust mixture and whatever adjustments there are on this thing to get it super happy.

The PO two back had some kill switch installed on the fuel pump. The guy I bought it from didn't know what it was for, just that it needs to be turned on and off before and after the ignition switch. In the folder of receipts I got with the car is a receipt for when it was installed that refers to a flooding problem. Someone on here suggested it was a corner cutting type of repair to avoid having to get new injectors. I'm going to try to call the shop tomorrow (I meant to do that today, but didn't get around to it) and see if they can provide a little more insight there... If it's just because of a leaky injector, I'll just get some rebuilt injectors and pull that crap out of there...

The initial stuff will just be cleaning, repair, and PM. Eventually though... Things will get interesting.

clokker

iTrader: (2)

I have many thoughts (opinions/biases) about brakes but we can discuss them in person.

Of more general and widespread interest though would be your thoughts about brake fluid.
My understanding has always been that silicon based fluids are primarily for garage queen/rarely driven vehicles, where its hydrophobic nature is of real benefit.
The trade off is that it doesn't perform as well.

I 'll admit that I have no personal experience with it at all but also that I've never experienced fluid failure in any of my daily driven cars using DOT3/4 fluid.

Having been involved in a few military contracts, the phrase "milspec" doesn't impress me much and I don't believe silicon fluid is much favored in motorsports (it was illegal in GP racing when I was involved, lo those decades ago...), so why are you such a fan?

(This is not an attack or a trap, just a question)

spectre6000

iTrader: (1)

I too come preloaded with a billion biases.

It's popular for show cars that don't see a lot of use because it doesn't attract water. Glycol-based brake fluids attract water over time just sitting in the brake system (brake systems are not air tight) and will eventually corrode the brake system from the inside out. Since show cars don't see a lot of use and sit in museums or whatever for long periods of time, it makes sense to use a fluid that's good for the life of the system versus having to do a flush every few years for a car that's maybe driven 3 miles total. Also, brake fluid is hell on paint, and show cars usually have very expensive or very valuable paint that would probably best be kept in situ. Silicon brake fluid is just another insurance policy in that regard. These are positives for me because I typically have at least a few cars at any given time, and they don't always get driven every day. The Rat will undoubtedly get put away next winter once the truck is good (or maybe just once the truck is good). They should get about the same fuel economy (the truck gets about 25mpg stock, and I aim to improve that), and I'll want to have time to debug the truck before I truly NEED it.

As for performance, it performs far and away better than glycol based fluids. It takes a lot more to get it to fade, and it's always consistent. Brake fade comes from the fatigue of two difference components of a brake system: pads and fluid. The pad material can essentially melt and basically ruin stopping ability in an obvious way, and the brake fluid can boil and reduce pedal feel and brake pressure. DOT3 boils at a minimum of 401°F, DOT4 at 446°F, and DOT5 at 500°F. As water is absorbed into the brake fluid, the boiling point drops. Since DOT5 doesn't absorb water, it is always consistent. DOT5 has a similar foible to DOT3/4's water issue in that it likes to form emulsions with air... Bubbles are hard to get out, and air compresses. Fortunately, once the air is out there's not much of a way to get it in there in practical use. So basically just don't shake the bottle, pour smoothly, and bleed slowly, then come back a day or two later and bleed again (or just bleed a lot the first time). Additionally, DOT5 is less dense than water, so if water DOES somehow get into the brake system (what the hell is wrong with your brake system?), it will technically pool at the lowest point and cause corrosion there. I'm not sure how you would go about getting water in your brake system like that since it doesn't absorb from the air and would have to actually be installed in liquid form, but I'll have more to say on that later.

You can't mix DOT5 with DOT3/4 because they have different densities and will go tequila sunrise on you. If your system is not DOT5 and you want it to be, you have to completely flush out the old stuff. You don't want to drain the DOT3/4 completely out either, because that means a lot of bleeding and air bubbles in the fluid. Some say the silicon reacts poorly with internal brake components, but it's never been my experience and I'll touch on that theory at the same time as the water pooling one. I would posit the opposite effect would likely be the case (preservative versus corrosive where the glycol would be more corrosive than preservative), but I have nothing to back that up save conjecture.

I'm honestly surprised to hear that it's banned from any sort of motorsport; this is the first time I've heard that. I was given to understand that was its initial use case. I've read that DOT5 likes to get "blended" and air gets emulsified in regular use; especially with ABS (I'm guessing because of the pulsing?). I've read that it eats rubber seals. I've read that it causes water to pool and eat the brake lines from the inside out... I know it's the factory fluid on pretty much all superbikes (and I truly thought it was what was in every racecar), so that it's bad for motorsports is totally bunk (rules are completely arbitrary and often complete bullshit, so bad and regulated out are different things entirely). The ABS blending thing is bunk, it's the factory fluid in many new cars and bikes with ABS. If it eats rubber seals it must take a helluva long time. I'm still waiting with firm happy brakes... Same thing with the pooling water... You'd have to have a terribly maintained brake system or a malicious saboteur to get water in your brake system like that. As for the military part of it, they use it in all of their vehicles because it's required on the seriously heavy vehicles in situations where brake fade could equal death, and a long running requirement has always been uniformity across equipment (24V, diesel, NATO plugs, DOT5 brake fluid, other lubricants, etc.). So the cheapies like mine get the good stuff because the expensive rigs need it.

I've read lots of things, but I think the only negative thing about DOT5 I've read that's actually true is that it's really expensive (and people on the internet like to justify their life choices). Call it my own little misanthropic insight into the human condition (I can be a cranky old man too).

I use it when and wherever I can on my cars because it's just better. I don't like flushing brakes. It takes two, and I'm usually just one. That means my wife coming out and counting to three a bunch, and I'm sure she'd rather be doing other things. If you buy the little quart bottles off the shelf, it's pricy stuff. It used to be something like $20 for a little tiny bottle, and to flush and fill a system you'd need a lot of those little bottles, but now that it's the standard fluid in many new cars, the prices are coming down. I just looked at O'Reilly's website, and a quart is $25 instead of the little tiny bottle being that much (granted, the same quantity of DOT3 would be maybe $4). I buy it by the gallon for about $75. Unlike DOT3/4, it doesn't attract water so you don't have to toss what you don't use. Just hold onto it for the next job. It took me about 1/3rd of a gallon to flush and fill my truck (the cheap *** PO put DOT3/4 in it for some ridiculous reason... probably so his mechanic could make his boat payment). I'm sure the economics work out eventually, but that's not really the point. It's a job for lazy people who just want to drive their cars and be comfortable in the knowledge that they're in top condition and ready for whatever they might be asked to do.

invinciblejets

No offense but you might as well upgrade the entire old tired brake system and paint the car while your at. if not what's it matter that a ratty S4 NA has dot5? Lol.
Beg my pard tho.

clokker

iTrader: (2)

Are we perhaps conflating DOT 5 and DOT 5.1?

5.1 is glycol based but meets/exceeds DOT 5 standards, with none of the compatibility issues and I think that's what's used in most ABS cars, not the silicon stuff.

Anyways, have your wife gift you a set of speedbleeders for Christmas and she'll never pump brakes again.

Finally (this may appeal to your fondness for watchmaking...), I really see nothing wrong with and much to desire in being required to "fettle" your car. You had wondered previously if FCs had zerk fittings and the answer is no, they do not and as a result, no one ever goes under the car unless something bad happens.

I use an annual brake fluid flush as a start point for a general inspection of the chassis, it's in the air (one way or another) with the wheels off, so you can see/touch a lot of the car normally inaccessible.
It forces one to be more hands on with the machine.

The American railroad pocketwatch was a marvel of mass produced precision that required regular maintenance and adjustment but no one considered this a flaw, that was just the way it was.
A properly cared for watch can be just as accurate and reliable at 100 years old as it was when new.

Today however, we're used to digital/electronic devices that cannot be fettled or cared for...they work until they don't and then you toss 'em.
And increasingly, cars are more electronic than mechanical devices.
Manufactures see warranties and extended service intervals as major sales incentives and prioritize them over sound mechanical practice.
Case in point would be 100k mile service intervals for coolant...yeah, the engine might make it but the entire cooling system will be totally fucked and useless by the end.

Or you could take a half hour every year and flush/replenish the coolant and probably never fail.

Jeebus, you'd better do something substantive soon or I'll ramble out of control.

spectre6000

iTrader: (1)

Probably part of my biases. When I get a new car (usually at least 40 years old), they pretty much all get a whole new brake system (often including hard lines) and a whole new electrical system. Paint? It'd be nice but that comes after I'm done with my mechanical and electrical modifications. Engines going in and out can be hard on new paint jobs.

@Clokker

Haha! I'm right there with you on 99% of that. I like fettling (or fiddlefucking as you often put it) with things, but I'd rather be fettling toward some improvement instead of just routine maintenance. I genuinely enjoy adjusting valves on my air cooled cars. I used to LOVE pulling the engine out of my VW bus nearly every weekend and throwing it on the engine stand for some minor little improvement. If it's to add a new exhaust or upgrade a distributor or something, it's fun. If it's to do something because I HAVE to, it's less fun.

As for annual inspections and the like, I sort of go through a mental checklist as I run through the car and bring everything up to my standards. Start with the safety stuff (brakes, installing seat belts if it didn't come with them, basic structural stuff), then base performance (bring the engine and drive train up to spec), then electrical, then suspension. Things can take priority based on impact on use case, but that's the general order. Once I get everything up to new car or better condition, I move into upgrade mode (though some things tend to get upgraded during the first phase if I know where I'm going with a build).

DOT5.1 is glycol based. It has the same temp ratings, but still absorbs water. It's possible the stuff in new cars is 5.1, I'd have to go look. Honestly, not being one for new cars I may have taken someone's word on that one. I don't recall personally seeing it in any manuals or anything because when would I have done that? I'm still pretty sure on the bikes though. As long as you completely flush the system, I've never had any compatibility issues even when leaving in old components. Worst case scenario, consider me a willing guinea pig. I've already got more than I need paid for and ready to go. I also generally run all synthetic lubricants and shoot for top of the line when and wherever possible. Since this is being burned, I'm going to have to look a little deeper into that when I can find some time here... My diesel gets as rich a bio blend as possible to boot (more expensive, but better lubricity for the old rotary injection pump).

I still have a lot of research to do before I tackle much any of this. Unfortunately, I have a big consulting gig tomorrow that I need to prep for AND some of the more mundane day-to-day work junk... It's almost 11 and I haven't even gotten started!

spectre6000

iTrader: (1)

The Rat has a rocker switch under the steering column that the seller told me was a fuel shutoff switch. He said it was a common mod, but that doesn't actually seem to be the case. I've been going with it because it seems to have been working as used, and I'd rather not upset the trolly. As I was going through the folder of receipts and documents (about 15 years worth), I found the receipt from when it was added! "What luck!" I says.



It's a "fuel modification kit" with a NAPA part number that, sure enough, is the switch. It mentions flooding in the history (not attached), and that's all I got. I called the number, but it's changed in the past 11 years or so...

A little Google Foo found me the current name of the shop, a phone number therefor, and after walking my fingers across the keypad I find myself talking to the proprietor. I send him the above picture of the receipt, and a little while later he calls me back to confirm its use. Clokker nailed it right on the head and down to the letter. Mickey Mouse fix for a leaky injector and nothing more. Simply installing some quality injectors will allow me to put that back the way it should be (assuming the install didn't hack up too much of the wiring). Excellent. Now to find the time (and some warm weather) to tack that sort of thing...

xtremeskier97

Wow, over $200 for a fuel cut off switch....poor....err....rich bastard.

clokker

iTrader: (2)

The "kit" and the switch are two different things but both were attempts to mitigate a bad injector.
The switch is exactly as you'd imagine but the "kit" was some sort of piping modification to the fuel lines, spliced in somewhere in the bay.
I think maybe Mazdatrix sold it...not really sure, I've seen it a few times but never seriously paid attention.

spectre6000

iTrader: (1)

Talking to the guy on the phone, he only mentioned the switch being a fuel pump shutoff to reduce pressure so the injectors wouldn't leak after the engine was shut off and cause it to flood. He blamed it on a bad injector design... Whatever. Nothing was mentioned of anything beyond that. What do you think the "kit" part does or is comprised of?

EDIT: Nevermind...

https://www.mazdatrix.com/c-bleed.htm

spectre6000

iTrader: (1)

Does that look stock? It doesn't look quite like the Mazdatrix link, but it would be a decade old at this point, and I'm sure they could have changed it up a bit.

scathcart

That it's not stock; definitely an anti-flooding bleeder band-aid.


I think you should tell us more about why you're choosing DOT 5 brake fluid.

spectre6000

iTrader: (1)

What do you want to know?

scathcart

Sarcasm.
Pretty sure between this and the other thread... We've got it.

spectre6000

iTrader: (1)

Clokker asked, I replied.

scathcart

Was meant to just be a fun poke.

How about pics of the engine bay? We might be able to spot a couple more oddities to look into.

spectre6000

iTrader: (1)

Why not. I'm stuck waiting for people to write me emails and need to take some paperwork back out to the car awaiting transport...

BRB

spectre6000

iTrader: (1)

I know it's rough. I'm sure I overpaid. Barring that, if anyone sees anything interesting or noteworthy, let me know. It's pretty stock and unmolested save the wear and tear and the fuel line/switch business.

zukskywalker

iTrader: (2)

In your video I see that you have the near uber rare "foldable" rear cargo cover. Only a glimpse, and it looks like it might be a bit beat up. Do not toss it...it's worth a few bucks. And, if you put it up, I'll take the mounting hardware off your hands.
(Do us/me a favor and post some pics of that cover and close ups of the mounting gear.)

(Rat grey '86 GXL here.)

spectre6000

iTrader: (1)

It is a foldable cargo cover. Didn't know it was rare. It's definitely in rough shape. What can you tell me about it? What mounting hardware are you talking about exactly?

scathcart

The water temp sensor you mention at the top of the radiator is actually a low level coolant sensor; sounds a visual and audible alarm in the clock cluster.
The ecu water temp sensor is in the back of the water pump housing, and the gauge water temp sensor is in the rearmost iron of the block, below the oil filter.
Engine bay looks mostly stock, minus the aftermarket alarm.
I also spot an (empty) aftermarket fuse holder spliced in by the trailing coil... Curious where that runs.

spectre6000

iTrader: (1)

I was thinking that might be it given how fast it cools. Take a highway run, park it for a very short amount of time, then it's halfway to cool again... If the temp sender were mounted on top of the rad like that, it would make sense for it to cool as fast as it does. Do they all cool down that fast? Is it just because it's generally really cold here right now and the engines are small with a low thermal mass?

zukskywalker

iTrader: (2)

I was just curious about the crossbar that mounts into the hook at the speaker covers and also where the elastic hangers clip in. I got a decent cover with no mounting hardware.
Thx.