Cooling licked. Mostly

Been a serious last couple of days.   I got the cooling issue mostly sorted.  Runs cool but still has a stall issue. The stall issue I can trace to sudden accelerations and sudden stops when hot.  If I just mosey around it’s fine.  I put another 20 miles or so on it.  Still a death trap over 40-45 mph.  At 60 it goes batshit crazy on the front end.  I’ve found the reason(s) but this post is about finishing the cooling system.

I’ve got a VDO gauge and sender on the way from Summit.  I’m half temped to put it in place of the stock gauge in the dash.  In the meantime I’ll tag the sensor into the heater hose outlet on the manifold.  The fitting is pretty hammered now so for the time being I’ll drill out the top, tap it with 1/8″-27 NPT (just got a smokin’ deal on an almost new top quality SAE tap and die set) wire it up and let ‘er rip.  For now I’ll cowboy the wiring and basically put the gauge on the hump above the shifter lever.    I’ll sort out mounting later but I need to know exactly how hot it’s getting and what kind of rise it has.  When I was racing this was the kind of thing we logged every session.  Except when I ran in the Nascar Whelan All American series where no data of any kind was allowed, even on practice days.  I’d come from more than a decade of logging at that point.  I turned up at one of my first official practice days with an AIM EVO with 7 or 8 channels and at pre tech was told to go home for the day and remove it for when I turned up for the race the next day.

Here’s the fitting that will be modded, it’s been cleaned up since that pic (pre cooling system revamp) but it’s going to need a new one.  In the end I’ll either assemble something from parts at Pegasus or get another of these and mod that.  You resto mod guys could find a lot of good plumbing bits at Pegasus.  They are a go-to for many racers for race plumbing and wiring.

With the cooling system revamped, a test drive and new thermal images shot it looks like I’ve got most of it solved.  Except for the stall problem.  Looking around for tips I ran into what could be the issue in the FSM.  The dashpot isn’t really working.  The dashpot acts as sort of an automatic door closer for the throttle.  Just as a door closer makes sure the door doesn’t slam shut, the dashpot makes sure the throttle doesn’t slam shut causing a stall.  That’s new to me.  Running carbs in circle track or shifter karts we didn’t use them.

This one is hammered.  It doesn’t even pretend to dampen the throttle closing.

I did need to adjust the idle speed screw and the mixture screws and that helped with running in hot conditions.   The acceleration/stop test will stall the car every time once it’s warmed up.  I’ll get a new dashpot and take it from there.

The final tests are to check the timing and vacuum.  The timing is pretty easy.  It’s a bit more advanced than it was when I checked it the first time I fired the engine.  Or I got the reading wrong.   I went to adjust it and the distributor didn’t easily turn so I left it to another time.

A vacuum test is easy.  This is another one of those times when the Harbor Freight test tool is a go-to.  I tag the tester right to manifold vacuum connection.  It’s the nub that’s covered by the cap.  The other two go to the smog system and transmission modulator.

The reading is in the ballpark.  I couldn’t find it in the FSM but searching VMF Woodchuck had posted the specs.  It’s about mid window at 19″ but it’s steady.

It seems a bit more tuning and getting a proper temp reading is going to be the key to reliability running when it’s 105-110 outside right now.

For all my hose

I’ve really soured on reproduction parts.  Particularly Scott Drake parts.  The few I’ve purchased are crap.  The function is fine but the finish and fit leaves a lot to be desired.  Particularly for the price.  The latest disappointment/debacle    (and the last time I get that brand if I can help it) is with the radiator hoses.  Rather than get plain old Gates from NAPA or Rock I opted to spring a few bucks more for labeled reproduction parts.   Labeling that was fubar even before I opened the package.

Not any better as I installed them,

And still worse…


I’m sure CJ would have made it right and taken them back before I put them on but that’s besides the point.  I like the vendor but they carry so much Drake it’s going to be difficult to get some things from them.  At this point it’s a driver.  I wanted to make it period correct appearing but those parts many times are junk.  The hose in this case seems good quality, thick, stout molding but I can get the same thing from a Gates or Dayco.

Hot, hot, hot like Buster Poindexter

Uncle! It’s getting too hot to get a lot done in the shop (my wife still calls it our garage) to do much work for long periods without coming in to cool off. Ironic for working on the cooling system. I’ll probably want to get one of those magnetic usb/battery powered fan/clock/thermometer off the truck to use in addition to the big fan and a porta cool. The alternative is not to work on the car(s) and that’s not going to happen. With that I decided to ditch the whole thing, get a high flow water pump, yuuge 40 gallon radiator, 10″ hoses, 2 x 4000 CFM fans and coolant made from unobtainium so I could cool my stock 200 hp engine. Naw, not really…

Done. Works well, car still runs well. It’s got some leaks. Each end of the top and bottom radiator hoses leak. Imagine that, near 20 year old rubber hoses that sat for 11 years then had corrosive back flush solution run through them have started to leak. Who’d a thunk? I was originally going to order the hoses with the rest of the parts for the refurb but thought if there was a chance I was going to have to tear the whole thing down right now anyway I didn’t exactly need new radiator hoses. And I’ll need to the get the original style clamps to be period correct. And the radiator drain seal has failed and it leaks too. I’d say that’s pretty minor in the big picture, as long as I get them fixed and not really drive it until then.

When you’re replacing classic or even older parts with current replacement parts there are bound to be some differences. We see this in the production cars that are converted to race cars/trucks and pre runners. In those cases there isn’t the mandate to maintain a period correct vehicle and many of those parts are modified, fabricated or from other like uses in that make.

The lower cost generic thermostat housing/outlet is the same Four Seasons aftermarket that Rock Auto sells. It’s also thicker at the mounting boss/bolt hole than the original or the 87 Ford part that was on the car.

With the wear, previous leaks and rust the existing bolts that came off the part and the new bolts I replaced them with weren’t long enough to catch enough threads. The originals were too hammered to use again anyway. The one that didn’t have the rounded head was caked with corrosion and hardened rust. IOW metallurgy happened.

To get a match that would work on the new part for the bolt length the replacements are going to need to go another 1/4″ or so into the manifold thread. The hole is plenty deep it just won’t allow the threads to run down that far. I only chased them to about what I needed for the shorter bolts. Now I have to chase the rest. I use a cutting tap for this because it’s hardened and corroded. In fact I rarely use a chaser and have never had any issues damaging existing threads. A chaser also won’t recut a stripped start of a tapped hole. Here’s what I pulled out of the top hole.

The bottom hole is harder to get to. Since the entry wasn’t stripped I could use a bolt. The chaser I have for that size is too long. I chased them when the manifold was off so clearance wasn’t an issue. I used Rapid Tap and ran the bolt in and out using a ratcheting combination wrench then blowing the gunk out of it.

Mounted and torqued.

If you are doing big engines or are a pro shop you’re likely using a pressure filler so you don’t get air pockets in the cooling system during a fill. I don’t do it enough to justify it though when I was racing the water/water wetter came out after every race, sometimes during an event we had to do it to work on the engine or during tech. These days not so much. You can “burp” the air from your cooling system on fill using a jack.

How I do it is jack the car up, radiator cap removed so the filler neck is the highest point of the cooling system.

I top up the system with water only until I know there are no leaks either inside or outside the engine. I start the car and let it run for a few minutes. During the run I add water as it lowers in the radiator. When the radiator no longer needs water I watch it and can see air releasing from the system. Don’t let it run too much longer than you need to release the air or I will start to run over as it gets hotter. At that point I cap it, drop the jack, check for leaks then do a road test. After the test I make sure the water is still more or less topped up. If it’s not it means there is either a leak, you didn’t get all the air out and had a larger pocket or it’s leaking into the engine. You can check to see if it’s leaking into the oil by reading the dip stick and looking for that blueish sheen in the oil or in the radiator. If so you’re going to need to figure out where it’s coming from because it can tank your engine.

After I got a mile or so on it I brought it back in for some thermal images. Remember from the last time the images showed massive heat at the thermostat housing/outlet. It looks better this time, not as much heat trapped at the base of the housing. That’s in an ambient temp over 110* F. When you look at the contrast as well it doesn’t seem to be as much heat soak into parts around the cooling system.

Except for some leaky hoses mission accomplished. Other than the hoses the next thing will be the power steering rebuild and suspension refresh.

And now the leak down test


Leak down done but first let’s do the numbers…

108 temperature when I was doing the leak down test today

111 temperature when I’ll be reinstalling the new cooling system parts and firing up the car again

15 gallons of water through the swamp cooler during the day

2 gallons of water through the swamp mechanic during the day

4 trips to McFadden Dale or NAPA during this part of the project

3 things I needed off the tool truck that weren’t in stock

2 orders from Mustang specific supply houses

1 order from Rock Auto

3 number of fasteners that needed thread repair

I’m not so sure about the leak down tool. It’s kind of tweaky setting the zero point. Much tweakier than I remember but it’s been a couple years since I’ve done the diagnostic. The couple of engines I did in the meantime (one of the is still mostly in parts delayed by getting the Mustang) came in and were stripped down and sent to the machine shop when they got here. Not tweaky enough to pay the big bucks for the truck tool or even a good brand from the online tool guys. I’m not going to be using it for absolute measurements but for comparisons to the other cylinders.

Installed my adapter from yesterdays post

I’m only testing a few holes, the two that showed the most issues in the compression test, #1 and #5 and random test of another to validate the first two.

Test of #5. It’s the one with the best compression specs of the bunch but the most carboned plug. Just as I suspected, leak in the intake valve and rings. Sounded stronger in the dipstick hole than the carb. Exhaust and cooling good. It’s got to be more than the percentage shown but still enough to want to rebuild after the summer.

Here’s #1. It’s a bit hammered. Big leaks from the rings and exhaust. The head gaskets seem good all around. Will be interesting to see if that heat signature from the cooling diagnosis was part of damaging that cylinder. It was the weakest one by far. My guy measures all the cylinders (and I do before I send them in) before he calls with the news on what needs to be done. I’m sure this one looks nothing like the rust bucket of an Olds 350 I took in some years back and he was able to pep that one up.

The random cylinder tested a bit better than #5. No valve leaks to speak of but a definite ring leak.

With that I’ll back burner the rebuild as originally intended. I can’t paint now until Sept, too hot. The catalysts won’t cure properly. I’m going to refresh the engine bay, suspension, the whole shebang once it gets cool enough to paint again. Meanwhile I’ll get it back on the road then focus on the the steering system rebuild.

The leak down adapter

Was hoping to leak down today but…

My HF leak down kit has no adapter for the olde tyme plugs. (that would be 18 mm for those keeping score) It’s not a bad kit, available and affordable. It can only take about 15 psi before the leak down gauge freaks out. The good ones can do 100 psi. They are also quite a bit more money. I did the Miata and Ranger with this one and it worked fine. Because 14 mm plugs. I did at least one of the hobby stocks with one I borrowed from the truck at the time which was eons ago.

No adapter so I start calling and looking. Nothing on the truck, he can order but knows the thread size on the HF hose isn’t the same as the SO hose so that will require hose and adapter. Maybe and air fitting as well. And he doesn’t have one on the truck to borrow. Amazon yes. Three piece, under $15 two day shipping. NAPA, no. Chain parts stores don’t have one to loan.

I think I’ll make one out of a spark plug. I don’t want to butcher one of my new ones. I dig through one of the trash cans in the shop to find the old rusty plugs that were in the car.

Gonna need to cut that neck off to get the porcelain out. Hopefully I’ll be able to cut some 14mm threads in the plug carcass. I’ll use Mr. 3″ cut off wheel. One of my go to tools for this kind of thing.

If you don’t have a compressor or much of a need for a specific cut off tool I recommend an electric angle grinder. Having one is a must have for any toolbox. It’s versatile, can cut, grind, brush, sand. Those that fab all the time have at least four to six each with a different wheel so you don’t have to change or different sizes and the like. I’ve had this Dewalt for 8-10 years, rebuilt once. I’ve got about half dozen angle grinders of various sizes, mostly this kind of Dewalt. The HF grinders, even the older one’s work well. I had one for a few years using it regularly until it burned up. The new ones are supposed to be pretty good.

Shoulder removed and ready to separate.

Just pull it out. Grind the electrode contact off and we have a core.

No joy for threading another adapter or even general air fitting. So what to do? Weld in the smaller adapter in the kit I’ve never used. First I need to grind the chrome off the part. It’s hard to weld and the fumes are hazardous. Then I need to clean up the plug fitting so they’ll cleanly weld.

It’s cleaned up, washed with acetone and ready to be fixtured.

I’ll weld this one using the TIG process. Need to prep a tungsten, I use gold for this (1.5% lanthanated) and ER70S2 filler because that’s what I had in front of me, argon and DC- at 125 amps.

Tack it all four sides before the finish pass. That’s a standard way to join tubing.

Now for the finish pass. Not my best work. The small diameter and the thick wall tested my ability on this one. Not the cleanest but it will work.

I now have an adapter but I’m out of time in the shop today. Had to skeedaddle to my day gig.

I’ll get to the leak down tomorrow and hopefully finish before my cooling system parts get here.