Eagle Race Car! 81 SX4 Project

[shaggimo]

Gotta pic? I'm thinking you mean the choke pull off? If so there is just two bolts that hold it on.

[blk-majik]

Sure, here ya go. You can see my screwdriver prying on the part that's stuck. It has some play, but wont pull out any more. I can pull the horn up, then it catches on something, but nothing I can see. I even bent the tabs on the bottom a bit to make sure there's plenty of clearance. Whatever its catching on, I cant see it



Here's some other related parts that I was able to work out around the stuck part:



And here's a shot of how it's stuck from between the main body and air horn

[mudkicker715]

I think I have a better throttle plate. I have so much stuff its unknown. But the carb might be available it seems I have 2 torn apart carbs. Let me know as I am stateside.

[blk-majik]

Thanks, I'll let you know if the restoration doesn't go so well. So far, it's not looking good  

At this point, I'm really starting to think I might be better off just doing a head swap and going EFI. Maybe I'm a bit strange, but I find that stuff easier. I'd still love to get it working with what I've got, if for no other reason that learning experience and to know that I can do it I started pulling the intake manifold. That should give me a better idea.

In the mean time, if anyone knows why I can't get that vacuum piston out, I'm all ears!

[GRONK]

Psssssssssssssssssssst...  Psssssssssssssssssssssssst...  A 2150 sure would look nice on there.............

In leu of your budget race project, I have a setup I can take $100.00 off of. 

Let me know. 

[blk-majik]

lol i know i know I got a guy locally who is willing to sell a full 4.0 EFI head assembly with intake and exhaust manifolds. He's asking $200, pretty sure I can get it for less. tempting...

No wiring harnesses or sensors, but if I went the megasquirt route, I dont need any of that junk, right? just run everything to the MS. I've never built a megasquirt controller myself, but I've worked on a few have a few friends in the area that have and would be happy to look over my shoulder. has anyone on here use megasquirt in an EFI conversion on a 258 yet? with a 4.0 head swap?

[eaglefreek]

lol i know i know I got a guy locally who is willing to sell a full 4.0 EFI head assembly with intake and exhaust manifolds. He's asking $200, pretty sure I can get it for less. tempting...

No wiring harnesses or sensors, but if I went the megasquirt route, I dont need any of that junk, right? just run everything to the MS. I've never built a megasquirt controller myself, but I've worked on a few have a few friends in the area that have and would be happy to look over my shoulder. has anyone on here use megasquirt in an EFI conversion on a 258 yet? with a 4.0 head swap?

I've got everything in a box ready to be installed but I haven't got to it yet. I already have the 4.0 head installed and have an assembled MS, a harness that needs to be completed, 2000 intake, bored throttle body, injectors, AEM O2 sensor and gauge and fuel pump. I have to find the time and guts to go for it.

[shaggimo]

Sure, here ya go. You can see my screwdriver prying on the part that's stuck. It has some play, but wont pull out any more. I can pull the horn up, then it catches on something, but nothing I can see. I even bent the tabs on the bottom a bit to make sure there's plenty of clearance. Whatever its catching on, I cant see it

No wonder it won't run   that piece is suppose to move freely (should slide up and down to move the metering rods in and out of the jets, stuck closed like that it can't fuel). There's nothing that holds that in, it's spring loaded, douse it with a penetrating oil and leave it be for a few hours, maybe you'll be able to break it free. I agree with others here, it may too late for that carb, you might be further ahead getting another one, even if it's a junkyard carb to rebuild.

[blk-majik]

This carb is likely toast then. I really pried on it, even bent it a bit. It's soaking in penetrating oil now, but my hopes aren't high.

I had the guy with the 4.0 head read the casting numbers off it. It's a 0630, which is pretty similar to the 7120. Anyone know the exact differences? Will the 0630 work well for the swap?

[shaggimo]

Aparently, some do not have the hole for the coolant temp sensor, that is the difference that is claimed, as far as flow and all that  supposed to be identical. My 97 4.0 does not have the hole, (0630 head), but at any rate it will work.

[blk-majik]

is the coolant temp sensor necessary? is there room to drill and tap to add one?

[shaggimo]

The boss for it is still there, so I don't see why not, it may just have a cap over it too, I'll have to look at mine a little closer.

[Baskinator]

Boy, I was gone one day and you got a ton of replies! Yes, I used the Berryman's Chem-Dip from advance auto which my brother had sitting around (not many ways to get rid of it). It looks like you've got a lot of rust inside there, probably what's keeping that pump from moving. If the chemical dip is going to remove any of that, it will have to sit overnight, piece by piece because the 1gal bucket isn't close to big enough for the whole carb.

Even if you can get it all cleaned up, it still might need a new metering pump and most likely a new spring with it. You already got a new rebuild kit, so I'd say go for it. It doesn't come with that pump, but if you can get that carb to work you'll save hundreds of dollars. If you use the chem dip, which I think is completely necessary in your case, soak every little part (as long as it's metal) for as long as you can.

Just like shag said, the pump isn't held in by anything- it just sits around that rusty spring you can see. If you get it out without bending it too much, it should be fine with a good chemical soaking. Maybe try tapping on it lightly with something to loosen it and then use some needle nose pliers. You could always try bending those tabs back after you get it out.

I was under the impression that you should never media blast a carb. Even if it's a soft media, you can do just about the same thing with chemicals and very high pressure air, and not risk destroying the thing for good. I was amazed at how well my air gun worked by itself.

As for the intake manifold, I'm not quite sure what to do about the corrosion. It doesn't look good, but it ought to still work as long as the carb is fine.

[blk-majik]

So I have my hands full with engine stuff at the moment, and it's going to take a bit of time to get sorted out. Thats fine, but to keep things moving along, I'd like to switch gears and start discussing gearing (see what I did there?   )

First off, I need to figure out exactly what I'm dealing with. Lets try to identify my trans, transfer case and axles

For the trans, it's a Torqueflite 3-speed auto. It's a model A727, right? Either way, it's on its last leg... maybe even already shot. Since the car isn't titled (and not even currently running), we haven't had much time to test it, but we know it doesn't like to shift out of first, or stay in 2nd very long.  When changing the fluid, the valve body look pretty much destroyed. The fluid holes are worn way larger than they're supposed to be, and I'm pretty sure some of the holes we have aren't supposed to be there at all! The amount of metal shavings in the bottom of the pan weren't a good sign, either. Either way, in endurance racing, the heat concerns with an auto are a big problem, so swapping for a manual has many advantages. More on that later, as it's a whole nother can of worms

From what I've read, the transfer case is a New Process of some sort. My 81 SX4 has 2wd mode, so I know its not a NP 119. That means it's either a 128 or 129, right? And the main difference is that the 128 uses an open diff, while the 129 uses a viscous coupling diff? I REALLY hope its a 129! An open diff will be horrible for racing as it'll give us a lot of wheel spin in corners and make ti hard to put power down on exit. Viscous diff will be pretty forgiving for less skilled drivers on the team, and pretty durable. Any easy way to tell which I have without an running motor (ie: can't lift 1 wheel and see if that one spins when in gear)? I know there's a marking somewhere, but the it's caked in gunk and I can't find it. I can take a wire brush to it, but where is it, roughly? Either way, just to know my options, its there any swap potential?

For the axles.... this is where I start to get REALLY clueless  I believe I have a Dana30 in the front and a Dana35 in the back. No clue with my axle ratios are. Being a 1981 SX4, can we make any assumption? I understand that there might be some benefit in swapping to a Ford 8.8 rear axle.I might be able to justify that as a safety thing if I get one with disc brakes. That said, for crawling a lot of guys go with high-ratio 8.8's out of explorers. I think for me, a lower ratio would be better. I know a lot of Mustangs came with the 8.8 axle as well, with disc brakes and a locking limited slip rear diff! Would those work? No idea how wide they are.

What about a Dana 44 swap in the front? Any advantage? Again, gaining a limited slip diff would be my biggest wish. Any other options for the front?

[Baskinator]

If your trans is a 3spd automatic, it's probably a TorqueFlite 998. I believe they were used after 1980 or so.

The transfer case is most likely an NP129. They are pretty easy to identify. If you remove the skid plate (if it has one), there is a red, circular tag on the side that says the model along the top. It's probably a bit gunked up in your case, so just wipe it down to read it.

I don't know so much about what the differentials are, but I'm pretty sure the Eagles had Dana 30s in the rear.