UnderFire's 1986 FC Mazda RX-7 Project

[UnderFire]

Picked this up a few nights ago after looking for a solid daily to have while I turbo my 4Runner, it will also be a nice project for me, since I'm quickly running out of easy or cheap mods to do to my Runner.

It's an 86 FC RX7, a decently clean example, mostly stock and pretty well-maintained.

It has problems here and there, but as far as I've found, nothing major yet. I was expecting much worse when I bought it.

It came with a few cool goodies, first off, a set of the factory 15" BBS wheels off of a convertible.

And a MOMO hub and wheel already installed, not my style, but it should save me money in the long run

All happy at it's new home

This is what sold it for me, a clean, untouched, stock engine.

Which I promptly un-riced.

Venturing into a whole new world here.

And something I didn't notice until my brother in law pointed it out. Do you see what's a little off here?

 

[MarkamisPrime]

Clean
Look up the mix gas mod
It will make the car run smoother and more reliable
Those rotaries are temperamental
And remember a redline a day keeps the carbon away
Words rx owners live by
My cousin owns a 94 fd he keeps garaged

 

[UnderFire]

Clean
Look up the mix gas mod
It will make the car run smoother and more reliable
Those rotaries are temperamental
And remember a redline a day keeps the carbon away
Words rx owners live by
My cousin owns a 94 fd he keeps garaged

I think I'll be keeping the mechanical oil injection, I plan on keeping the motor stock for the foreseeable future, so fuel dilution shouldn't be a major problem, I also don't mind doing the extra maintenance needed to keep it clean, I'll be redlining it all the time, trust me...

First step is a fuel system rebuild, this car has the flooding issue these cars are somewhat notorious for, it's also running way too rich at idle, I'm thinking a leaking injector is the likely cause.

FD's are nice, but about 25 times more than my budget lol.

 

[dcoultis86]

I see the issue with your gauge cluster...... Its a Canadian car in Km's.

 

[UnderFire]

I see the issue with your gauge cluster...... Its a Canadian car in Km's.

Bingo, it started life in Ontario until it was imported to Oregon in 2002, kind of cool history, I had no idea about any of it until well after the deal was done. It also means what I thought was 19200 miles is actually only 19200 kms.

 

[Ed_C]

Make sure to check the rod bearings and piston rings


:laugh:

 

[UnderFire]

Update, actually drove it for the first time, the motor has bad coolant seals, basically the rotary equivalent of head gaskets, so it's gonna need a fresh rebuild.

I was hopeful, but also prepared, so it's going to be about a month or two then I'll be ready to get a new motor in there.

I'll be doing:

Full rebuilt motor to OEM spec (No fancy porting)
New clutch
New injectors
New aluminum radiator

and of course the little "might as well" things like belts, hoses, etc.

I will also be taking my sweet time on cleaning up and repainting everything while it's all apart, I want a fresh looking factory engine bay for the most part.

Once it's all running tip top I'll be moving on the interior restoration, getting little pieces here and there, all up to factory condition, lots of little plastic pieces are broken and a couple are missing. Then I'll move on to fixing some minor rust issues and paint work, and then I can start the fun stuff, exterior mods and exhaust.

 

[UnderFire]

Started tearing into it, removing the front clip, the problem areas for rust on this car are pretty concentrated, both of the very fronts of the rocker panels where the fenders bolt on are the worst parts, the right rear quarter has some that looks somewhat superficial, the fender lip on the other side has some surface rust, and the hood has one spot bubbling, other than that it's pretty nice considering it spent 16 years in Canada and 10 years at the beach.

The design for how the clip comes apart is awful, everything bolts through each other up front, and makes it so to get one thing off, everything has to come off, I'll be modifying that it I can find a way to do it cleanly and effectively.

Here's the inner fender, this is the spot that I was the most worried about as far as hidden cancer goes, but it's clean as a whistle!

This is going to be probably the worst rust spot on the entire car, which isn't bad at all, this is where the fender bolts to the rocker, the hole is actually only where the thread insert broke out, it didn't just rot through, there's probably a 10" long piece of cancer there I'll be able to cutout and remake the fender mounts no problem.

Not bad when this is how both fenders look. (This is supposed to be where it folds under the rocker.)

 

[UnderFire]

Gotta love when you just stumble across something and you don't even know what you actually just found.

This is from the very first FC I've looked for parts on at a junkyard, this car's been sitting out at the yard I frequent for 3rd gen parts for a good year or so.

To put it into simple terms, every FC RX-7 left the factory with a retracting steel panel sunroof, Mazda had a dealer add-on replacement glass panel that would replace that steel panel with a glass panel instead, as well as an aftermarket company producing some for a few years.

Neither one was extremely popular, which made both very rare, and by extension very expensive. A good condition one is easily 500$ or more, if you can even find one for sale.

I didn't know any of this, until after I bought it because having a glass sunroof makes way more sense and is cooler than the steel one. I picked up the entire sunroof assembly for 10$. This is one of the Mazda add-on ones. I plan on fully refurbishing it to 100% working and cosmetic shape and installing it in my car.

 

[UnderFire]

Got a new console all swapped in, most of the interior plastics are cracked or generally F'd up in this car, whoever installed the radio basically just tore out the dash panels and console from the looks of it, and it sun was not kind to the plastic vents and panels in the dashboard. So I'll be finding the bits and pieces as I go.

Put my decent lid on this decent console, unfortunately most of the clips are broken on my little weird controller thing, but once I get rid of the factory suspension setup I'll be able to swap the non-control one into the hole that came with the new console.

And I finished getting the other fender and bumper off, gonna get it all cleaned up, and figure out a better way to re-attach it, the way it comes up from the factory is really stupid, niether fender can be taken off without removing the bumper first, which wouldn't be a problem if the bumper wasn't held onto the fenders by the lip, and 3 of the nuts on either side to get the bumper off are inside the fenders, along with like 12 other bolts, which means it all comes off, or nothing comes off basically. The fenders are also way overkill attached, with about 14 bolts holding each one on, as opposed to my 3rd gen which has about 8 on each side and is a larger fender as well.

All of the electical connections are made in the engine bay rather than at the lights which I'm going to try and change as well. Need to figure out a sleeker way to do the front plate and mod the headlight motors too, I think this is a good looking height for my sleepy eyes. I'll be making this the down position and the motor functions fully and goes all the way up when on, I'd like to figure out how to turn the headlights on when down as well.

 

[UnderFire]

So after being torn for a while, I went ahead and added stuff all up.

What I'm thinking of doing is an LS based V8 engine, be it a 5.3, 6.0, LS1 etc, whatever I can find, and a Tremec T56. If I did do this, I'd go a different direction with the interior, fully stripped down, street legal race car style.

Because of this I'd be saving money finding all the little hard to come by dinky things that are broken. but, I'd want a 6 point cage and bucket seats with harnesses, along with a full set of aftermarket gauges. It probably evens out in the end.

The motor swap would be pretty damn close to the price of a fresh ported 13B with everything that needs replaced on my motor. It adds up like this:

13B:

Rebuild w/ Porting - 2400$
New Injectors - 3-400$
Shifer - 100$-150$
Tensioner - 75$
Header 200$

= ~3225$ most likely

LSX:

Engine 800-2000$
T56 - 1000-1500$
Harness conversion - 450$
LUK 04-905 LS7 Clutch 290$
Headers - 450-730$
Clutch M/C 90$
Driveshaft - 285$
Mount Kit - 420$

~4185 most likely

BUT, if I took the time, and bought a clean tahoe, yukon or pickup that was pretty nice with nice interior and whatnot, I might actually be able to get the motor for free (or maybe even make a bit on it)

So it comes out nearly dead even.

Each one has obvious pros and cons, and I have no problem with either one, but honestly I think the LS would suit me better than the generally "unreliable" rotary (I tend to be rough on shit).

 

[UnderFire]

She's dead in the water, after sitting a few weeks it won't idle, and puffs massive clouds of fuel/condensation vapor when I run it. Oh well, I've decided on the LS1/T56 combo as soon as I find a decently priced donor car. I love the idea of rotary power, but the turn key and go nature of the 4Runner has spoiled me.

So here's my list:

LS1:

Complete donor motor
3-wire harness conversion
Shorty/Block Hugger Headers
Cam
LS6 Intake
Dual 3" exhaust with Dynomax race bullets

T56:

LS7 Clutch
Remote TOB Bleeder
Wilwood Clutch master cylinder
Short Throw Shifter

Mounting:

Ronin Speedworks Supreme Mount Kit
C4 Corvette driveshaft with u joints swapped
4 core aluminum radiator w/ custom mounts and e-fans
Battery relocation

Other stuff I need:

Bride seats
Crow 5-point harnesses
6 Point cage
NRG quick release and different steering wheel
Autometer sport-comp gauges (Already have tach, oil pressure, water temp and fuel level)

 

[UnderFire]

Project starting soon, first part arrived today. Found this Racing Beat front sway bar and LS swap sway bar relocation brackets at a solid price.

 

[Roody]

Nice car, the FC is widely underappreciated.

 

[UnderFire]

Ooooohhhh baby, parts been flooding in over the last couple days. I've already located basically everything to adapt the motor and trans into the chassis, all at great prices of course.

Granny's speed shop motor and trans mounts
Brand new Granny's speed shop T56 to NA rear driveshaft
Ron Davis Aluminum 6-Core radiator with Granny's speed shop bolt in mounts and a e-fan
Brand new Wilwood 7/8 Bore clutch master cylinder
BBK Stainless Shorty headers w/ EGR blockoff plates

I've started slightly tearing into the car and am definitely looking for parts actively, Ideally I'd like to have this project really going ASAP.

 

[UnderFire]

Most massive update possible for today. Browsing craigslist finally led to me finding not one thing, not 2 things, but basically EVERYTHING.

Here's what I picked up today.

01 LM7 5.3 Vortec longblock with upgraded trunions
T56 Tranny with a Pro-5.0 Short throw shifter already installed
LS6 Intake with injectors and rails
Brand new water pump, power steering pump and a few gaskets
Complete used front drive and starter from the truck
New accessory drive bracket for the F-body location
New car harmonic balancer

That gets me like 90% of the way there, already basically have a camaro oil pan on the way, then it'll just be clutch, throttle body and harness, and get it all jammed in. I'm now so close I can smell the tire smoke.

 

[UnderFire]

Rotary is on the way out. Got pretty much everything off the inner fenders and firewall, radiator out, intake out, hoses undone, just gotta get a couple little things, motors mounts, tranny brace and pull it.

 

[UnderFire]

Ordered nearly everything I needed to get the motor refreshed and then dropped into the car all at once, stuff's already coming in.

Got the LUK LS7 clutch and flywheel package real quick, this is a heavy mofo, I nearly blew out my O-ring when I picked it up. 62 friggin pounds.

And I luckily located this F-body oil pan, fun fact: this pan in used condition goes for around 250$ dollars normally, holy balls, no way in hell I would pay that much, this would've held me up for ages if I hadn't known where to find one.

 

[UnderFire]

Rotor-ectomy completed...

Pretty much all the parts are here now too, got the Clutch throwout bearing, throttle body, head gasket set, billet coil brackets, 411 type ECM, and full exterior stainless bolt set.

And got this from a guy who picked up some of the parts I took off, a custom aluminum tow hitch, might as well have a hitch with my V8 truck motor right?

 

[UnderFire]

Crossing off a couple more big ticket items, finally found a solid deal on the right pair of seats. A like new set of Sparco Fighters picked up today.

Wheels are also on the way, which will get tires as soon as they arrive.