Flash's 66 Mustang

[Flash]

Jeez, I dodged a bullet today !

So, my fuel gauge hasn't worked from day one and earlier in the piece I traced the issue back to the tank sender unit. The good news is that the sender unit sits on the front side of the tank so at least I don't have to drop the whole tank to get the sender out. The bad news is that the sender unit sits on the front side of the tank so you have to drain the tank if you don't want to enjoy a 98 octane shower.

As a result I've been putting the job off for a while, but now that the Mustang is almost about to begin duty as my daily driver it's time to address the issue. So this week I purposefully let my fuel level run low and then today I spent a good part of the morning cruising around the neigbourhood trying to run the tank dry. Yep, I know endless cruising around in a rumbling V8 is a thankless task, but someone has to do it. After a bit I started to get a hesitation on turns so figured I was close to sucking fumes. Headed home and managed to finally run out of gas two houses from our place. Bugger pushing the car home so I walked home and got a litre of fuel that I had put aside in an old milk bottle. Tipped the litre into the tank and thought I'd prime the carby with a few drops to make the starting easier. Removed the air filter for the first time ever by unscrewing the big center wingnut and carried it home together with the empty milk bottle, then back to the car which fired up easy enough and I idled her home.

Back in the shed I figured I'd refit the air filter, but when I came to fit it the threaded rod that the wingnut goes onto was missing. My first thought was that it had dropped on the road while I was walking home, so I walked back down the road keeping a beady eye out for the threaded rod, Nyet, no sign of it. Retraced my steps home and checked out the shed floor where I had placed the filter. Still no luck. Checked the valley between the inlet manifold and the rocker covers. Nope .. not there.

Got my torch out and took a gander down the carby venturies and guess what :

[Flash]

If I had given it the welly up my driveway that could potentially have ended in tears.

Quickly pulled that sucker out with a pair of tweezers and chucked a locking nut on it so hopefully that won't ever happen again.

On the plus side I managed to take a few shots of the Muzzy while it was sitting outside my neighbour's place waiting for a drink.

[Flash]

Woke up to the perfect morning for breathing in petrol fumes, so jacked up the Muzzy's arse to get the fuel sender unit out.

The tank still had about 5 litres sloshing about in the bottom, but luckily I had a clean bucket close at hand and I managed to drain that off without incident.

Popped the sender unit out and as you can see from the photos below its a fairly new unit.

Took a close peek at the little plastic float and the cause of the non functioning gauge was instantly obvious :

[Flash]

My new fuel tank sender float pitched up yesterday. I upgraded to a brass one as the plastic ones are notorious for developing leaks.

While I was at it, I ordered a new idler arm as the bush in the existing one was looking a bit flogged.

[Flash]

Fitted the new brass float to my fuel gauge sender unit and chucked it back in the tank with a brand new gasket.

I've read that the aftermarket fuel senders are not that accurate on the old Muzzy's so thought I'd do a little exercise to see how bad it is.

According to my Haynes manual the tank has a capacity of 60.5 litres so I started off by adding 15 litres to the dry tank. The good news is that there were no leaks. The bad news is that the gauge registered just above empty instead of the quarter tank that I was expecting.

I then added another 15 litres which should have taken the tank to half, but the gauge only registered a quarter of a tank.

With another 15 litres added to take the tank to three quarters full the gauge registered mid-point between half and three quarters.

With the final 15 litres added to take the tank to full the gauge reads just past the full mark.

So, yep ... reports that the fuel gauge is notoriously inaccurate are correct.

On the plus side when the fuel level is low, I'd rather have a gauge showing less fuel than is actually left in the tank. 

Oh, and the added bonus is that the gauge actually works now.

[Flash]

Cooling Issue – Chapter One

The next big ticket item on the Mustang “to do” list is to improve the engine cooling.

The 65 and 66 Mustangs are notorious for engine cooling issues. The main reason for this is a poorly designed piddly little radiator. Things get even worse when the car is sporting a/c as the condenser is mounted in front of the radiator which doesn’t exactly assist airflow.

The boffins at Ford then increased the size of the radiator on the 67 and 68 cars, but cooling was still borderline, especially in the hotter USA states. Eventually Ford changed to an even bigger crossflow radiator in the 70s and this seems to have solved the issue

Somewhere along the line my Muzzy has been upgraded to a 3 row aluminium radiator, but I suspect that the previous owner was still battling with temp related issues here in sunny old Queensland as the a/c condenser had been removed and the space filled with a helper thermo pusher fan.

So far I’ve made a few changes that have improved things slightly, but I’m still not a happy bunny.

First up I removed the cheapy pusher thermo fan as well as the original factory 5 blade mechanical fan and installed a 3000 CFM Spal puller fan on the back of the radiator. I was initially running a radiator shroud and whilst the car would happily idle all day on the driveway with the thermo cycling on and off, out on the open road under spirited driving conditions I noticed a drastic increase in temp. I ended up ditching the shroud and mounting the Spal directly to the radiator and open road temps decreased once again.

However, now that I have refitted the a/c condenser in front of the radiator I’m again battling with open road driving temps and I figure I’d best knock this on the head before summer arrives and I get the a/c re-gassed. I’m worried that the warmer days and extra heat dissipating off the a/c condenser might just push the engine temp into the critical zone.

So first up I needed to add some science to my investigation. I set my sights on finding something more useful than the factory temp gauge which helpfully has no temp markings. After pesting everyone on the tech forum page and getting some really good advice from the usual old school legends I got my hands on an infrared temp gun.

Let the investigation begin:

[Flash]

Cooling Issue – Chapter Two

So armed with the infrared temp gun and following the advice of @sheepers, I stuck some bits of black tape on my shiny aluminium radiator and started taking some readings.

The driveway test revealed that the thermo fan kicks in at around 170F. This measurement was taken directly off the thermo switch that sits in the thermostat housing. At that point the top rad hose measures 160F and the bottom rad hose 140F. 

The thermo fan cycles on and runs for about 4 minutes before turning off. 

Idling in the driveway for around 45 minutes the max temp measured was 185F on the top radiator tank.

Monitoring the temps at various points on the radiator I’ve been able to establish that the difference in temperature across the top tank differs by about 15F. This supports articles that I have read that criticise Ford for having the radiator inlets and outlets on the same side as they reckon that the coolant ends up taking the path of least resistance and doesn’t utilise the full radiator core to maximum advantage.

Some of the more expensive aluminium radiators are fitted with a baffle in the top tank to prevent this but clearly my cheapy radiator doesn’t have one.

Apart from the fact that my radiator doesn't have a baffle fitted, I'm relatively comfortable with cooling performance at idle.
 

[Flash]

Cooling Issue - Chapter Three

With my driveway idling test completed, I took the Muzzy out on the open road for some spirited driving. 

Worked things up to maximum temp and took a reading at the thermostat housing .... 200F ..... that's a little too high for my comfort.

So, where to start?

Well first up I'm going to flush the system. When I removed the heater core for refurbishing it was full of gunk and needed a good flushing, so I'm guessing the rest of the cooling system may be in a similar condition.

Next up I'm going to replace the thermostat. I know there is one fitted as I could see it when I pulled the top radiator hose off, but I don't know what it is rated at. From factory the 66 was fitted with a 190F thermostat. The consensus seems to be that these are a tad high and most fit either a 160F or a 180F. I'm leaning towards a 180F as a starter for ten. I've got a new 180F in stock and will fit that after I have flushed the system.

Both of these are cheap and easy to accomplish so worth a shot.

Longer term I'm leaning towards a radiator upgrade, but I'll discuss this in a little more detail later.

Thanks for reading.

[Flash]

This morning I slapped a bit of Meguiars on the Muzzy. Gave my elbow a bit of a workout and then pulled it out into the sunshine to admire my handiwork.

Doesn't look half bad, even if I say so myself. 

[Flash]

As part of my earlier fuel gauge sender repair, I filled the fuel tank right to the top. 

Last Sunday Mrs Flash and I and our wee dog headed out on a bit of a cruise, still with the full tank of fuel and with the extra weight I could feel that the rear suspension was pretty borderline. At one point we were on the rear bump stops whilst navigating one of the speed bumps along our beach front. In addition to this when viewing the car side on it looked slightly tail down.

So, this morning I pulled out the 2 inch lowering blocks and replaced them with a set of 1 and 1/4 inch units that I had lying in the shed.

Viewing the car side on it now has a slight rake to it, typical 70s hot rod look, which I kinda like.

Took it along the beach front and we are off the bump stops now, so I'm much happier.

Before and after side views :

 

[Flash]

Cooling Issue - Chapter 4

I'm the first to admit that I've never really given much thought to thermostats and the role that they play in the cooling system, but over the past week I've been doing a bit of internet research on the subject and I've come to realise just how little I know.

Now we all know that there is a lot of mis information out there on the web, but during my meandering I came across a guy called Walter who owns a Mustang GT350 and he has posted a number of interesting cooling related Youtube clips specifically covering the early Mustangs. I've got to say that what this guy says makes a lot of sense.

I've always thought that the role of the thermostat is purely to get the engine up to optimum operating temperature as quickly as possible. But, Walter enlightened me to the fact that the thermostat's primary function is to regulate the flow of coolant between the engine and the radiator with the goal being to keep the coolant in the radiator as long as possible in order to cool it down. I'm embarrassed to say that whilst this may seem pretty obvious to most of you reading this, it was news to me.

Another thing that Walter confirmed is that the little 289s like a bit of heat in them, so temps in the early 200 F range should not seem scary. The gents at Ford fitted the 289s with a 195 F thermostat from factory and Walter reckons they were bang on the money. Anything less and the coolant doesn't spend long enough in the radiator to drop the temp sufficiently. Walter further states that 80% of all cooling related issues experienced are attributable to either a faulty or incorrectly spec'ed thermostat and since this is the cheapest and easiest component to replace he recommends that this should be the first port of call.

Now I'm not saying that what Walter is saying is gospel, but he makes a lot of sense, so I'm going to follow his advice. I mean, what have I really got to lose.

So, with renewed vigour I popped the Mustang up on my ramps this morning and dropped the coolant. Pulled the thermostat that is currently in the engine and sure enough .... it's a 160 F jobbie. Looks to be pretty new too, so I'm guessing the PO has been in here already.

Anyhoo, I've got a new 180 F thermostat on the shelf but I'm thinking I might just source a 195 and give it a whirl.

Stay tuned for the next exciting episode as Flash shares more of his cooling related ignorance. 

 

[Flash]

Okay, so I chickened out and have ended up fitting the 180 F thermostat that I have in stock. Figured it was worth a try.

Flash, over and out.

[Flash]

Cooling Issue - Chapter 5

I'm now running a 180 F thermostat in a freshly flushed system. I've also bypassed my fan switch so that my Spal runs permanently.

Took the car out on a 50km open road journey and at first things looked promising. Then during the last 5km of the journey whilst travelling along at around 80 km/h at steady revs with no cars ahead of me, the temp needle suddenly started to inch higher until it reached the highest that I have experienced so far. Got home and quickly grabbed the infrared temp sensor gun. Yep, sure enough 209 F on the thermostat housing. That is almost 10 degrees higher than my previous record. Checked the top radiator hose at idle and that was sitting at 184 F compared to the bottom radiator hose at 163 F.

So, although the 180 F thermostat seems to hold the temp down for longer than the 160 F thermostat did, it's definitely not the silver bullet I was hoping for.

[Flash]

Cooling issue - Chapter 6

Spent a few hours yesterday pulling the front of the car apart and have temporarily removed the a/c condenser that is located in front of the radiator. My thinking being that this may be impeding airflow.

Time will tell, I guess.

[Flash]

Cooling Issue - Chapter 7

Took the Muzzy out for a hoon this morning, whilst taking some readings with the infrared temp gun.

Maximum top temp on the thermostat housing - 183 F

Upper radiator hose - 156 F

Lower radiator hose - 145 F

Looks like the removal of the a/c condenser from in front of the radiator has drastically improved air flow to the point where my cheapy 3 row aluminium radiator can now cope.

Since running without a/c is not a long-term solution I'm thinking a radiator upgrade is on the cards.

I've read some good reports about the Scott Drake (Shelby licensed) 2 row aluminium radiators. Even although it's only a two row, the tubes are 1 and 1/4 inches each and they have fitted a baffle in the top tank that aids coolant flow across the whole core. At around the $600 mark it's worth a punt I reckon, so one of these is top of my list for next month's Mustang spend.

[Flash]

Still ticking a few small items off the "to do" list.

I spent a few hours knocking up a bracket for a fire extinguisher which I have tucked up in front of the passenger seat.

Hope I never have to use it.

 

[Flash]

Another quick and easy task today.

The leaf spring shackle bushes were looking a bit flogged. 

I pulled them out and whilst the exposed ends looked pretty shabby the inners were still in decent condition. Replaced both sides with new ones anyway and chucked a bit of lubricant on them while I was at it.

It seems to have cured an annoying squeak that was coming from the back whilst negotiating speed humps, so I'll take the win.

[Flash]

Bless me Father for I have sinned. It has been two weeks since my last confession.

I've been driving the tits off the old Mustang and it's running really well. Even took it along to a local burger meet last Saturday night and got to swap a few yarns with the owner of a '65 that is similar in colour to ours. Started to rain before I got a chance to take a side by side photo, so you'll just have to take my word for it.

Anyhoo one thing that I had noticed during my travels is that the starter motor behaves quite lazy on warm starts. Shoved it up on my ramps for a look see and sure enough the right hand side exhaust branch is hard up against the body of the starter motor. Noice !

A bit tricky to photo, but you get the idea:

 

[Flash]

Some have solved the starter issue by fitting an aftermarket high torque mini jobbie which supposedly provides more header clearance, so I ordered one in.

It arrived late last week so I chucked the Muzzy back on the stands. Had to pull the header off to get the original flapper style starter out, then mucked about with the angle settings on the new high torque to get it tucked as close to the engine block as possible.

Offered up the exhaust branch and ...... instant fail.

Not even enough clearance to fully tighten the header bolts.

Tried all of the possible adjustment settings on the mini, but the pics below show the best I could manage and again I wasn't able to fully tighten the header bolts.

Okay so that's not going to work.

Ended up ditching the mini and have reinstalled the original.

Not really proud to admit this, but I ended up spanking the offending header tube with a BFH to create a bit of clearance and I'll order in one of those silver heat shield blankets that are supposed to help.

Thanks for reading. 

[Flash]

Cooling Issue - Chapter 8

I’ve been running the Muzzy sans a/c condenser unit for just over a month now and the cheap and cheerful 3 core radiator is coping really well with the engine temp barely making it past the thermostat opening threshold.

So, to my simple way of thinking all indications seem to point to an air flow issue.

I’ve spent a good bit of quality time with my good friend Uncle Google and have come across some interesting info.

As previously mentioned in 1965 and 1966 the 260 and 289 equipped Mustangs were fitted from factory with a 17 inch radiator. A/c equipped cars were fitted with a radiator shroud. In 1967 Ford moved to a 20 inch radiator with a 24 inch option for a/c equipped cars. Then in 1968/9 they moved on to the 24 inch radiator across the range. Although by this time they were offering big block power plants as an option they were still fitting the larger radiators to the small block equipped cars as a standard offering. Now you have got to ask yourself why would Ford spend the extra money on a bigger radiator if they didn’t need to. The general consensus from those “in the know” is that the cooling on the first cars was marginal at best and borderline critical on cars fitted with a/c especially in the warmer states.

I then spent a good bit of time researching how to upgrade one of the earlier cars to the 24 inch radiator and it’s a pretty straight forward exercise.

Apart from having to cut open the radiator support panel to suit the bigger radiator the only other major issue is the battery which is in the way. Many have overcome this by cutting a chunk out of the inner fender panel and welding in a shaped panel. That together with the installation of a ’69 battery tray results in the battery being tucked up against the inner fender rather than the radiator support panel.

The other option is to relocate the battery to the boot and this is the way that I intend to go. Not only does it solve the space issue but it also allows me to add an extra level of security as the bonnet on the earlier cars opens from the outside and with a starter solenoid conveniently mounted in plain sight on the inner fender and no steering lock the old Muzzy is a prime target for a spot of thieving. Having the battery tucked away in a locked boot with an isolator switch fitted will hopefully make things more difficult for any teenage joy rider who is ballsy enough to take on a left hooker.

So, with this all said I’ve ordered an ACP Maxcore 2-row Performance radiator from Custom Mustang in Victoria. Even although it is only a 2 core the unit is fitted with 1 ¼ inch tubes so the flow is equivalent to a 4 core but with a narrower profile. It still has the inlets and outlets both on the right hand side so from a plumbing point of view all that is needed are the standard upper and lower radiator hoses from a ’69 Muzzy.

Anyhoo, here is an image of the sexy looking Maxcore which will hopefully reach me sometime next week.