Problems, Upgrades, and Fixes

Wow, a lot has happened in the last 3 years since I notice I've updated this site.

I'll summarise and provide photos..... First up, the car toured Tasmania in early 2022 with my local Mustang Club. It ran beautifully, had a session at a race track and otherwise behaved itself over the 700+ km distance tour. This was important as I had my wife with me!

This was our group on display on the lawns of Government House in Hobart.

Second, I entered it into the Geelong Revival motor festival event. This has a 1/4 mile timed event on the foreshore. You race one at a time  against the clock, but it is a section of public road (no rubber laid down), is a right hand curve the whole way, and has just 180 meters of (a thankfully straight) braking area before a wall stops you.

I made several mistakes in this event. My lessons were:

1. Remember to take your rev limiter off  - for which i need my laptop to do, and i didn't bring it with me. D'oh!
2. Seven year old (hard compound) road tyres are next to useless! I even tried a set of Group A wet weather tyres (see photo above) but had the same issue - no grip.
3. Make sure your new Tremec TKX shifter-stub is tightly bolted to your gearstick. I went from 1st to 4th on my final run as the TKX "sprang" itself back into the central (3rd to 4th) shift plane via my loose gearstick (must have rattled loose driving to the event). 

I got a best of only 13.40 in the (sometimes wet) conditions. So there is lots of room for improvement. But that needs to come from the start, which is tricky with road tyres and rear-wheel drive only.....

Third, in early 2023 I got a lesson in trying to "do things on the cheap".

I had a roller lifter collapse and damage a roller cam. So I spent big $ and got a new cam, but just kept using my pool of existing Comp lifters (as I had a couple of sets). But they were obviously past their use-by date because once back up and running, a tie bar on a pair soon snapped with these lifters turning sideways and damaging lobes on the new cam. Ouch!!!!

Above shows the initial (bearing) collapsed lifter....

And above shows the snapped tie-bar. Both these lifters turned sideways almost immediately.

This happened when i went to fuel up, with the car packed up and ready for this years tour of Tasmania...... A disaster! We quickly unpacked and took another car - a RAV4 can you believe.

Anyway, I grabbed a new set of Crower solid rollers (offset Inlet seat), sent the damaged Comp Cam off to Crow Cams (who are local to me) for repair, and did a full engine tear down. 

I found 2 scuffed bores where metal splashed up and got wedged between bore and piston. Major bummer. I also noticed some slight movement of the Comp lifters in a couple of lifter bores. This may have been my problem causing lifter failure and would also be a factor in allowing lots of oil in the block valley at high revs - which i occasionally saw. 

So what to do?.... After much research, I settled on a D.I.Y. bronze lifter bushing kit fron Wydendorf in the USA.

It comes with a self-aligning reamer to bore out the lifter bores, and a second reamer to "finish hone" the bronze bushing/sleves once they are installed. This photo shows the kit contents.

And below I am drilling a 3mm oiling hole in the bushings (via a jig i setup to make them all consistent).

This setup lets me control oiling to the top end much better and of course renewed the lifter bores. Here is how the block ended up.

The 3mm hole was located (once the bushing was pressed into the enlarged lifter bores) such that as the lifter is on the cam base circle, this hole is just opened to the very top of the oil slot machined into the circumference of the lifter body. Then at full lift with the lifter at max height, the hole is still open, but now at the very bottom of the lifter oil slot. The result gives me 360 degree oiling to the needle bearings in the lifter. If you zoom into the photo above you'll see the oiling hole. I used a marker pen to align the bushings before tapping them into place correctly clocked. It was a bit fiddly to do all the measuring of oil gallery dimensions and lifter oil slot positions, plus dummy up the cam and lifter to verify....

Once the bushings were tapped in (and they tap/press in with a resistance a bit like cam bearings), i got the cylinders honed 10 thou' over to remove any scratches, got a new set of 40 thou' over Icon pistons (with domes machined for Trickflow A460 head valve positions), and then got the crank rebalanced - as the forged Icon units were 43 grams lighter each than the SRP's i'd been using. Ah - i also grabbed a new set of Eagle con-rod bolts as it seemed silly not to refresh them seeing I had torqued them up multiple times in all the previous dummy assemblies and subsequent inspections.

Next step of course was engine assembly, valve to piston clearance checking, decking the heads, etc, etc. Here are some photos of the short block assembled plus my "home handiman" way of decking/sufacing the Trickflow heads. Starting with a flat workbench, i layered two sheets of glass from my dads wine-glass cabinet down and secured them such that they cannot move. This gives as flat a surface as i could get at home in my car-port.

I then used some contact adhesive to stick 3 sheets of 800 grit wet& dry to the glass and once this had set, i liberally sprayed degreaser on top as lubricant. I then carefully lowered the heads onto all this and just shuffled the heads back and forth. I did this in 2 directions (90 degrees to each other) until i got a nice consistent surface. The photos tell the story of the results better than i can.

After assembly, i took the engine back to the dyno as i simply cannot bed new rings in with the engine in the car - it would just smoke the tyres trying to hold the engine under load and at low rev's.

We only did one dyno run after breaking the refreshed motor in, bedding in the rings and tweaking the EFI tune for the repaired camshaft. This cam is a bit of a Frankenstein actually.... The repair meant an inlet profile from one cam and an exhaust profile from a completely different cam was used. I lost 0.026" lift from the 0.726" lift (I and E) i originally had. Duration stayed pretty much the same, but the LSA was also tightend up slightly to 107 degrees. I used the "intake lobe centerline" method of degreeing the cam in this time too, to 105 degrees. The cam sheet itself is shown below.

In the end, here are the results as evidenced on the dyno sheet. This internally balanced engine is good for 7000+ rpm, but we weren't looking for ultimate power at this stage. I had the car booked in a show the following weekend, so i needed to wrap things up on the Friday right after we did this run. But you can see on the graph below how HP was still heading north at the 6250 rpm cutoff. In the few weeks since this engine refresh, I must say this car is awesome to drive. 

Balancing Throttle Butterflies

Since getting the car registered i have had to do some sorting that was always inevitable.

So here are the areas that have needed attention.

• Engine Intake
• Oil Pressure Failsafe
• Panel Fit
• Exhaust Fit
• Balancing Throttle Butterflies
• And more........

First some photos of my fabricated "throttle balancers" and a description of the problem I had that I bet I am not the Lone Ranger in having.

On the last dyno session, while trying to tune for suburban traffic situations (very light load, low revs) it became quickly apparent that my throttle butterflies were all over the place. At idle, a flow meter showed 4 cylinders had zero flow and the 4 others had all different readings. I knew it was always going to be very tricky to try and get them the same (when going by eye via a feeler gauge and trying to be careful and consistent when tightening the throttle arms to throttle shaft), but I was very surprised to see I was that far out!

The trouble is that as you tighten up the arms on the shaft, the arm may or may not pull around the shaft ever so slightly. And with my big 55mm butterflies, even a tiny variance makes a big difference. At least this explains why I would fowl some plugs up and not others. So what to do?

Over a couple of nights thinking, and finding ZERO on the internet, I decided to build an "adjuster cage" for each throttle arm - and run 4 of them per bank. This means the common throttle rail that pulls open 4 throttles on each bank, opens the cage, and the cage then pulls open throttle arms.

The trick is that the arms have some adjustable movement inside the cage so you can adjust each throttle arm individually. Here is what I have fabricated as a set of prototypes until I can swap over to some nice CNC machined units. The first issue is to make 8 of them, and to have them be as identical as possible with just home handyman tools. Here is what I did:

1.    Cut 16 pieces of 1.5mm stainless sheet into a suitable "cage shape" (after creating a cardboard template using the throttle arms, shafts, adjuster screws, etc to get the overall shape correctly done). I then sandwiched them in the vice and ran a bead of stainless weld across all plates at each end to keep them all aligned and stable for drilling and shaping. This gets them all pretty close to identical.

2.    Create a jig to drill 3mm holes in a 10mm diameter brass rod in prep for cutting threads in these holes. The thread needs to be pretty fine to give yourself good adjustment fidelity. 

3.    Mine are threaded for a 4mm stainless hex head screw. Once the brass rod has all these holes threaded, slice the rod up into 7.5mm sections ensuring the threaded hole is in the centre and these will be each actual throttle butterfly "adjustment mechanism".

4.    The width of the cages needs to be a hair bigger than the width of the 8mm throttle arms, so I cut some 8mm stainless strips, then drilled a 4mm (for the adjuster bolt to pass thru) and 12 mm further along a slightly bigger 5mm hole (for the 3mm Allen key to pass thru). This strip will "capture" the hex head of the 4mm bolt. But when bending this strip, slide the bolt into its 4mm hole then bend the strip into a "U" shape back over the head of the bolt. Use the Allen key located in the head of the bolt as you are bending this strip to ensure its adjustment hole lines up as you bend it. Weld the "U" to one side of the cage such that the threaded brass adjuster can run up/down the bolt thread along the lower edge of the cage. In the photo below, imagine the lower edge of the cage has its "side" in position. This stops the brass adjuster dropping below the bottom edge of the cage. I trust you can see that (for the bottom cage in the photo below), as the bolt is turned clockwise, the brass adjuster draws up the thread and the throttle arm can rotate downwards.

5.    Next clamp both sides of the cage together to weld the cage into a single unit. Note that the throttle arm is put into position and I also have thin slice from a flexible paint scraper in there to give me some clearance once only the throttle arm remains. 

6.    It is important not to overtighten as you weld and make sure everything moves freely at each step. 

7.    With all 8 units fabricated, a good test was to sandwitch them all together and run an 8mm brass shaft thru the lot to mimic them being connected to a throttle shaft. This way I could see how much rotation the throttle arms had and how uniform they were to each other. In the photo below, this shows the throttle arms on the right in a more or less "equal" position with the brass adjuster sitting in the same position on its "adjuster bolt", while the left two arms have been "adjusted" to show the angle of throttle arm rotation available within each cage.

8.    The "underside" shot below gives another view and shows how I have run some of the adjusters up/down the threads and how it allows the throttle arms to rotate a few degrees within each cage. Again, the two adjusters on the very left show the movement angle possible with the end adjuster at full thread and the next adjuster at half thread.

9.    Now seeing this throttle arm movement within the cage means the stainless cages rotate slightly on the throttle shafts, I thought it best to run the cages on bearings so they did not "dig into" the softer brass over time. Here I have my new jig in place to line up the bearing cups. To create these cups I purchased some 8mm I.D. and 14mm O.D sealed stainless bearings which determines my cage bearing cups need to have a 14mm I.D. The simplest solution was to purchase some 18mm O.D. 2mm wall stainless stainless tube that i then sliced up to size (the size of the bearing thickness). I lightly hammered a small dent in the outer edges of the cups after inserting the bearings to keep them in place.

10.    To install, i just put the adjusters at approximately "half thread", connected all 4 up to the common throttle rail and simply held each butterfly shut as I thightened the throttle arms to their respective shaft. Something I thought that would be important is to have a stiff spring inside the cage that pushes the throttle arm back against the brass adjuster. This ensures the arm does not "flap around" inside the cage and creates a slight resistance to the adjuster bolt so it stays in place and does not "self adjust". Note that I have designed these adjusters such that as the throttle is opened, the common throttle rail pulls on all 4 cages, and each cage pushes against the brass adjuster, which pushes the throttle arms around (rotates them). It is a solid connection of one component pushing on the other. I did not want to get this backwards and have the cage push on the spring, which then pushes the throttle arm around, as this would introduce variance across the butterflies. FYI, these springs are 7.5mm diameter and 15mm in length, similar to an idle adjustment screw spring on a Holley carb, but a bit stiffer.

11.    So finally, to adjust the position of each butterfly, I now have very fine tune adjustment capability for each of them simply by turning the adjustment screw in each cage. The stiff spring within each cage pushes each throttle arm back against its brass adjuster. A keen eye will see the adjuster hole for a 3mm allen key on the nearest cage in this photo (No. 1 cylinder in this case). I can now adjust all 8 butterflies to equal flow in approximately 1 minute using a CFM flow meter as the measuring tool. And i can do this repeatedly in 1 minute each time i pull things apart for inspection or otherwise fool around with throttle linkages, or to get into the engine valley, or whatever! Well worth the effort I say.

As for panel fit, I got some time to get things back to where they were before it all went to the paint booth, and I also got the bumpers re-chromed. What a difference the new bumpers make! I cut and shut them, so they needed a lot of work, but they came up beautifully. The next few photos shows things as they are as of November 2020 and it seems to be a real head-turner.

Notice the Frenched in reverse lights in the rear bumper. They are nice and bright when in use and clean up the rear of the car in my opinion.

Progress Photos 2020 - Part 1

For those who follow this blog, I would prefer to give more frequent updates. But finding the time, or simply remembering to do so when I do have time - is the tricky bit.

So the latest news is............

I recently had my much anticipated "final inspection" from the vehicle engineer. I have been delayed by the local government department (VicRoads) in regards to being able to fully register this car. The problem being that since i started the project, the rules have changed to limit engine size. I pointed out that I was given the green light when I started, and that I have not deviated from that project plan, and that a 1967 car would pass the new rule but my car with the same chassis wont, and, and, and - multiple other points.

The result is that I had to wait more than 6 months for a new official bulletin to be issued that allows my project to move ahead. That bulletin (limiting power to weight) was issued just a few weeks back - thank goodness. So here are a set of photos that depict what I have had to modify this car in order to pass the various tests needed to get full Victorian registration (not club registration).

• Noise Test.

I have had to add another muffler on each bank to pass the 96dB(A) limit that is in place for this car. The current exhaust setup is as follows.

• Extractors: 2" diameter primaries joining "4 into 1" that then neck down over about 12" into a 3" pipe. The extractors have O2 bungs welded in just downstream of the 4 into 1 join.
• Mufflers (primary): Just in front of the differential I have 3" diameter Flowmaster "FlowFX" units which have the offset inlet and center outlet.
• Mufflers (secondary): Squeezed in after the diff' and before the rear valence I have 3" diameter Flowmaster "Hushpower Pro Series" units.

The Hushpower units are nice as they are very compact, and there is so little room in the early Mustangs back next to the fuel tank, plus they have a heat insulation layer built in. But I have still gone to considerable effort to add extra heat shielding and also to clearance my fuel tank to provide at least a 50mm air-gap between these mufflers and the fuel tank.

• Fuel Tank.

The fuel tank modification required to add these mufflers (and provide clearance) was a particularly painful exercise. I'm sure you know the risks...... stainless tank construction, surge tank residing inside the tank itself, plus multiple baffles within the tank - so lots of spaces to trap petrol fumes. Yet I still need to cut and weld new "scalloped sections" into the tank, which is a recipe for a bomb.

My "safety" measure is to use my compressor, industrial vacuum, and even garden blower to clear it of fumes. This takes several hours. And just to make sure, I checked it (remotely) with an ignition source (a butane burner flaming directly inside the tank cavity). Only then did I start cutting/welding - and with my ventilation setup still running!
Here are some progress photos showing the new rear mufflers when first installed to meet the noise reg's. Then as the tank was scalloped to gain the clearance I needed and finally the heat shielding.
Now for the uninitiated, bending flat stainless plate to the meet the curved contours required is not easy. I built my own jig (two lengths of different diameter pipe) and pushed it around by hand.

• Registration.

Once I got the final inspection done I needed a set of documentation to present to VicRoads in order to get it legally registered. These items were:

• Engineering Certification slip (1 copy stays with the car, 1 copy is given to VicRoads)
• Tamper proof engineering sticker with the list of "Mod Codes".
• Original "proof of vehicle purchase" receipt.
• Dep't of Transport Vehicle Importation Certificate.
• Roadworthy Certificate.

Now things were going nicely until this bloody Coronavirus hit town. I had my VicRoads appointment booked, but they started cancelling services and mine was at risk. Learner driver tests were all cancelled in the week before my Monday test, but thankfully it all went ahead.
So ironically now that I am legal, I have nowhere to go during this lockdown! Well - I guess there is no law against what car you use to do the shopping, lol.

So what now?
I need to get the bumpers re-chromed, the front valence painted gloss black, and various interior items such as door trims, kick panels, run pinchweld, etc. Ah - and I also have some "sorting" to do now that it is finally running and I get to hear a rattle here & there, or I need more heat shielding in certain spots, etc. But these can happen over time and are purely cosmetic or comfort related.
What a journey, I have learned so much that if I did it again I would do it so much faster and no doubt a bit better. But this car is awesome to drive, so well worth the wait. This last photo shows the front as it currently looks. You can see the new spoiler I've added as well as the tow points for getting me out of the kitty-litter at a race track. I'm luke warm on the spoiler though as I think it takes away from the clean lines of the original car that I am after.

Progress Photos 2019 - Part 1

As promised, photos. This time with minimum words...…. Apologies if any photos are repeats.
First up, my fuses residing in the glove box. They swivel out for access (on a chopped up nylon cutting board) and rotate back in to hide away nicely.

And now the instrument cluster as you view it from the driver seat. It nicely fits inside the radius of the steering wheel. No swinging your head left to right to "look around your hands" to see the outer gauges like you need to do on the standard early Mustang gauge cluster.

This next photo shows a custom crank scraper i built to peel oil off the rods/crank. It seems to work nicely and gives about a 3mm gap to all rotating parts. The extra angled strip you can see that I've added directs windage/oil down the side of the sump and simply "away" from the crank. The sump uses windage in the shallow middle section to drive oil to the rear via those angled baffles, while perforated/vented plates (not shown) that cover each end of the sump keep oil down near the pickups. The pickups themselves are slots cut into the bottom of pickup tubes at each end of the sump. You can the curved front pickup tube below. The natural angle of the engine in the engine bay means oil accumulates at the rear of the "humps" in the sump - so this is where the two pickups are, You can also see some plates that i've added (that sit about an inch above the pickup tubes that (in theory) stop oil rising back up to the crank on acceleration. This combo works a treat now, no oil starvation evident at all, no matter how the car is flung around.

To reduce noise I used these standard silencer cones but modified them to make sure they stayed centred in the 3" pipes.

Ah! Now some relatively recent photos of the car coming together. It's looking ok.

Now the photos below show an annoying problem i found that was tricky to diagnose and fix. The front of the motor had an oil leak.....

If you look closely at the photo below, you may notice that the upper part (the upper lip) on the camshaft seal (which with the motor in this photo sitting upside-down, is in fact the bottom of the bottom hole), is damaged.

Why? Because the whole front cover was mounting itself about 3mm too low on the front of the block. This "crimped up" the cam and crank seals along their top edge, plus causing a gap for each at their bottom edge. Oil just..... well.... leaked out and got flung about by the spinning crank & external cam drive. It was only a dribble leak, but very annoying. The fix was simple enough. Elongate each bolt mounting hole in the timing cover downwards by 3mm, clean everything up, then use new cam-drive and harmonic balancer seals to "center" the front timing cover before tightening up the bolts to bolt it back in place in the correct position. Not a drop of oil leaks now - much better. 

Oh - and I have built a cold air intake now to draw air in thru the '67 hood scoops. See an "in progress" photo below. That little inner frame now contains the foam air filters. The outer edges of the box you see below and top of the filter frame (not yet built in this photo) seal against the underside of the hood so air can only enter via the hood scoops, then flow around the front and sides of the inner "filter frame", then pass through the filters to enter the central area where the 8 trumpets sit.

Below was a brake fix (an upgrade) I made by swapping out the old 6" diameter single diaphragm booster for an 8" twin diaphragm unit. The mechanical roller cam just didn't have enough vacuum for the 6" diaphragm in stop/start traffic for my liking. I also changed the pedal to pushrod ratio to better balance the entire setup. Brakes work much better now.

And now for the 4-Link setup.....

Only after the chassis got its "gold star pass" on the chassis torsion test did my vehicle engineer say... "just make it a 4-Link". So I did and here are the photos of the results.

In the photos above and below, the RRS rear torque arm is still attached to the nose of the diff. This was removed before final installation to clean things up and give a bunch of room back in the driveshaft tunnel.
Oh - and the teeny weeny rear disks you see here will be replaced with much bigger units...… These just came with the floating hub kit. I didn't realise they would be so small at the time.

Once the chassis and diff "link mounts" were tacked in and mocked up to ensure I had lots of adjustment options, I bolstered the frame-rail mounting points to spread load over a much larger area of the chassis. The photos speak for themselves I hope. All steel plate and 35mm right-angle was 3mm thick.

I can't tell you the difference the 4-link has made over the 3 link as I simply didn't get to drive it enough to be able to compare. All I know is the new 4-Link works just fine and the car seems to hook up ok. Well - depending on your right foot that is, as the engine simply overwhelmes street tyres if you give it some stick (as you can imagine).

Also, here is how I made the lower control arms on the front suspension adjustable...… See below.
Years ago I cut off the inner ends of the original control arms and welded in two lock nuts to give me thread for screwing in a heim-joint. But I always worried in the back of my mind that I never had enough thread. So rather than hack into these, I bought two new after-market control lower arms and modified them. As you can see I used some spare chrome-moly tube I had left over from the 4 links, and welded these in. So now - no matter how far you screw in the heim joints - they only engage more and more thread. Much more comforting.

Boxing these arms makes them much much stronger too.

Now for the front valence...…
As you can see, I have welded the stone-tray and valence together into a single unit and this includes a cols air scoop for the lower half of the radiator and engine oil cooler. But as you can see, the fit to the front fenders was initially awful. The photos below this miss-alignment and then resultant fix for each side. First the Australian passenger side.

And now the drivers side. Had to fix some big gaps here!

As I write this I am just mounting the front bumper with its custom mounts after cutting/shutting the bumper to tuck it in, in a much more flush manner.
More photos to come as well, seeing I am about to get the car thru engineering tests and rego'.
Stay tuned.