Re-Flowed

Chris Ames wrote an interesting article in The Early Bird magazine about coolant flow problems in Y-Block Tbirds.  After applying some engineering rigor, he determined that the shape of the spacer behind the water pump was impeding the flow of coolant at low rpm.  He installed a professional flow meter in the radiator return line of his own Tbird and found the flow was almost zero at idle.

He then designed an improved spacer that extends the volute that is already present in the timing cover forward into the spacer.  With this new prototype spacer, he found significantly greater flow at low rpm... this info is available directly from the VTCI forum.

Chris then created the forms to have this spacer cast and machined in iron.  From the outside, it looks completely stock... but inside it provides much better cooling flow.  This is really good news for early Tbird owners in hot climates!  When other members of my local club started getting these, I decided that I should have one.  I called Chris... he's a great guy, knowledgable and enthusiastic about Y-Blocks!  He mailed me a new spacer and I got in in just a few days. 

Here's what it looks like after painting (stock on left, Ames spacer on right):

Replacing the spacer was fairly easy.  I didn't have to remove any hoses.  I drained the radiator and block, removed the radiator shrouds, fan belt, fan and spacer, unbolted the bypass line and removed the 4 bolts holding the water pump.  Briefly prying forward on the suction side of the pump easily released it from the gaskets.  Note the cardboard protecting the radiator.

Installing the new spacer was only slightly more difficult... I had to scrape the old gaskets off the pump and timing cover, "juice up" the new gaskets with permatex (both sides), and then put everything back together.  I added some corrosion inhibiter to the coolant I had saved, and poured it back into the radiator.

It was time for an oil change, so I shifted back to Valvoline VR1 20W50.  I've been wanting to lower the idle speed, but had been worried about cooling... even at 500 rpm, the 20W50 should keep reasonable oil pressure, and better coolant flow should minimize overheating.  I can always bring the idle back up again if she gets too hot.

On a lark, I purchased a set of retro hod-rod style valve cover wing nuts.  I'd been wanting these for a while.  When I saw a post on Facebook, I couldn't resist!

There is just something about the look that makes me smile!  Yes, it makes the valve covers marginally less secure at car shows, but I don't think that is going to be a problem.  No one has stolen my air cleaner yet!

Re-Braked

In a previous post, I noticed how the brake system was leaking fluid into the 'can' of the power booster.  This had been happening both with the original Midland 3400 booster, and also with the larger C490 booster.  I also wasn't very happy with the recent performance of the C490, so I pulled it from the car and disassembled the 'can' to see what was up.

The booster diaphragm had a nasty tear in it, which explains why the boost performance had deteriorated.  Combined with the fact that the seals were obviously leaking, I decided that it would be prudent to have the C490 professionally rebuilt.  Clearly the "rebuild" job (if there was one) that the original eBay seller advertised of this unit was worse than inadequate!

After some research, I contacted George at Harmon Classic Brakes.  He is very knowledgeable and provided some sage advice.  One thing he installs on power booster rebuilds is a stainless steel liner in the power cylinder to prevent rust.  Based on the amount of rust I found in my "rebuilt" 3400 unit, that seemed like a really good idea! I sent my C490 to him for a rebuild and after a minor glitch, George sent me a fully functional professionally rebuilt C490 unit.

It turns out that the C490 not only has a larger boost diaphragm than the 3400, the power piston is also a smaller diameter.  Taken together, this results in a much higher boost, and much more effective brakes.  Installing this Harmon rebuilt unit resulted in a much better brake feel, stopping the car with authority even at the end of long hills.  This is the kind of braking performance I had in mind when I installed the front disks in the first place, but really hadn't experienced until now.

Re-Fused

The burned wiring under the dash caused me to re-think the importance of installing a fuse panel.  The stock wiring has inline fuses randomly distributed under the dash, which is rather inconvenient.  The circuits I have added (4-way flasher, electric radiator fan, foglights, fuel pump, windshield washer pump) each need their own fuses, so I added more random inline fuse holders.

The mechanical brake light switch I installed was not adequately fused.  A short in the turn signal switch or steering column wiring resulted in the unfortunate smoky experience I documented elsewhere.   I had no problem replacing the turn signal and brake switch wiring, but with everything apart it seemed appropriate to sort out the fuses...

I established a few simple goals for designing a fuse panel for the car:

• Don't permanently change the dash, whatever is done must be reversible.  
• Provide fuse protection to key switched and unswitched circuits.  
• Use standard 1 1/4" glass fuses.  These are era-appropriate for the car, still readily available, and easier to check than more modern blade-style fuses.
• Convenient connection/disconnection of circuits without having to climb completely under the dash... which is awkward without removing the steering wheel.

With these goals in mind, I designed a clamp-on panel to attach underneath the dash, near the ignition switch, found a way to install 5 screw-type panel fuse holders, and also mount terminal strips to accommodate ring terminals to attach the wiring.

A strip of aluminum, attached to some scrap steel strap, held together with thumbscrews and clamped to the bottom edge of the dashboard under the ignition switch.  Note the headlight switch hanging in the background.

Fitting panel fuse holders.

Adding terminal strips to the steel scrap, and wiring supply side to the fuses.

If anyone is interested, here's a brief tutorial on early T-bird wiring.   

If you aren't interested, you may want to skip this part.  The headlight switch is the first stop for battery power coming into the dash.  Note that  power for heavy loads (starter, window and seat motors) don't come directly into the dash, but instead use relays.  The control circuits for those relays DO originate under the dash, however.

It should also be noted that only 3 circuits in the car have absolutely no form of over-current protection (fuse or breaker): the main starter circuit, the horn, and the cigar lighter.  To be fair, the cigar lighter has a built-in circuit breaker as part of the removable part of lighter, but nothing attached to the car.  Keep in mind that when powering other devices using the cigar lighter plug, they need to have their own internal fuse!

The headlight switch has two 20 amp circuit breakers in it: one for stopl/tail/parking lights and the clock, the other for headlights.  It also has a 9 amp fuse for the courtesy light.  None of these circuits rely on the position of the ignition switch.  Unswitched battery power (always a yellow wire) is fed from the headlight switch to terminal B of the ignition switch. Terminal C ("on" and "start" position only) is connected to the ignition and the idiot lights, and terminal S ("start" position) is connected to the starter solenoid.  All other circuits are connected to terminal A ("accessory" and "on" position).

Wiring up the Panel

I carefully mapped these circuits, along with all the circuits I have added to the car, to the new fuse panel.  I decided to take power from terminals B (yellow, unswitched) and A (red, "acc+on") of the ignition switch, and wire these through the appropriate fuses to the terminal strips.  Note that the 4-way flasher, stoplight, and backup light circuits are unswitched... I wanted them to work even if the ignition was off.

Mapping key circuits to the 5 fuses I have available on the panel.

Labeling the panel came in handy when wiring it up.

The panel detaches from the dash, and hangs down conveniently exposing the  terminal strips.
Note how each circuit is identified with silver sharpie on the heat-shrink insulation.

 I have invested in a good set of wire stripping and terminal crimping tools, and a heat gun.   This made quik work of reterminating each of the circuit wires with the appropriate lug and heat-shrink insulation.  I made sure there was room for all of the wires under the dash, and nothing would short out to the ignition switch terminals, then carefully connected it all together and clamped the panel in place.

With the panel clamped under the dash, it seems like a lot of extra wires under there... but in fact it is much easier to identify and isolate any particular circuit.  It is also very convenient to have all the fuses available in a single location!

Was it really worth the effort?  Well, probably not... the panel is completely invisible unless you deliberately look under the dash.

This effort has, however, helped restore my confidence in the car's wiring.  That is certainly worthwhile.  Just because something isn't immediately visible doesn't mean it isn't important.

Cover Girl

Nell is now a covergirl!  Thanks to the Early Bird editors for accepting my submission and my story, and to Skip O'Donnell photography for the photo shoot!

Letting the smoke out of the wiring...

Smoke coming from under the dash.  That's never a good thing!  This happened in traffic about 8 miles from home, so I quickly pulled over and disconnected the battery.

A quick look under the dash, and I knew this wasn't going to be a 'side of the road' kind of repair.  Time to use the AAA towing coverage.

With the car back home, I took some pictures under the dash.  The wiring to the mechanical brake switch is fried, but it looks like most everything else is OK.

I noticed my mistake in wiring the brake light switch... I connected it to the hot terminal of the ignition switch without any fuse!  I definitely should have known better.  The brake switch wiring was much lighter gage than the rest of the original 6V wiring, and ended up being it's own fuse.

For the last year or so, I have noticed a tendency for the turn signal fuse to blow sporadically.  Just before the "smoke" incident, the fuse had blown again... in fact, I was on my way to Pep Boys to get a replacement fuse when it happened!  I noticed that the turn lever was down (left) after the fuse blew, indicating that the short is in the left stop light wiring.

This won't take much work to fix.  I'm mad at myself for not taking care of it sooner, before it rendered the car inoperable.    This is a good opportunity to put in a fuse block, rather than have so many fuse holders hanging off of the ignition switch!  That would certainly make maintenance a lot easier.

Sometimes, I let little things go without tracing them down... things like why I'm feeling triggered, or why I'm having a moment of lust.  Sometimes I just don't have time to deal with it, or at least that's what I tell myself.   But, deep down, I know something isn't right, and will need some attention.  Something may need to be rewired... an opportunity for an upgrade.