1/3 Scale Ford 289 Hi-Po

I've never been a fan of mounting IC engines over wood boxes, but they're handy for hiding nuisances like big ignition coils. I typically use steel plates for display bases which are heavy and keep all the running accessories out in full view.

A 12" x 18" steel baseplate was prepared from some 3/8" material and a pair of motor mounts machined from what started out as 1-1/2" angle iron. An integral backing plate on the starboard side mount allowed positioning the starter solenoid up close to the starter. It had been a few years since I last welded, and some time was needed getting reacquainted with my tig torch. I really enjoy welding, but real world projects seem to have difficult or hard-to-reach joints that take away a lot of the fun.

The mounts were welded to the baseplate in opposite facing directions in order to clear the starter on the engine's starboard side and the oil filler plug on its port side. A fixture plate was used to keep the mounts aligned while being welded to the baseplate, but of course it made access to the joints difficult. My original two point mounting scheme looked doable in SolidWorks, but I wasn't comfortable with its mockup and added a last minute bolt-on support for the bell housing.

The steel radiator mounts fabricated earlier were used to position the radiator in front of the engine. I didn't do myself any favors with the minimal opening in the shroud for the fan, and the shroud's design didn't lend itself to easily being enlarged. I want the fan belts to be replaceable with the engine and radiator in place, and so the exact placement of the radiator became more important than I'd planned.

The fuel tank's location was pretty much fixed by the width of the baseplate and the location of the bell housing which in turn was fixed by the engine mounts. Drilling the mounting holes for the radiator brackets essentially locked down the locations of all three major components.

The weight of the assembly is already 45 pounds with nearly half that being the baseplate. A front lift disguised as a 289 HIPO badge was machined and bolted to the front of the baseplate to prevent using the radiator to lift the assembly.

A small console with switches for the starter, fuel pump, and ignition will probably be the last machined part for this build. After coming up with the mounts for the remaining regulator and ignition modules the baseplate can be painted. - Terry

So nice..............
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Absolutely amazing workmanship from start to finish

WOW! An amazing piece of craftsmanship!

Fantastic work!

A masterpiece . Impectable quality .Love your builds...!

Gabe J DiMarino said:

A masterpiece . Impectable quality .Love your builds...!

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Hard to describe just how good it is BUT I think you came the closest.

Gabe J DiMarino said:

A masterpiece . Impectable quality .Love your builds...!

Click to expand...

Just the best

Beautiful build, how did you find the print set?

Hockeypuck58 said:

Beautiful build, how did you find the print set?

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It's my own design. - Terry

In my builds I try to thoroughly test and fit each part as it's machined so final assembly can be assembly and not turn into a lot re-work. One 'file-to-fit' part left for final assembly was a two inch diameter bronze thrust washer whose purpose is to prevent ring gear wobble during starting. In addition to a precise thickness, both faces had to be counterbored. More time was spent making a mandrel to machine the part than was spent making the part itself.

A ring gear inspection cover bolts onto the lower portion of the bell housing and would normally be accessed by crawling under the car. On a static model it doesn't do much. The engine isn't mounted high enough above the baseplate to easily access its fasteners, and so I was tempted to leave it out. Its polished stainless surface looks great, and 304 wasn't easy to machine so a 9" hex wrench was fabricated to access the fasteners from under the front of the engine. A second shop-made tool holds the end of the crank while the front and rear crankshaft bolts are tightened.

The heavy gage wiring between the starter solenoid and starter motor was installed and the combination briefly tested. The spark plugs haven't yet been installed, and so it's not yet a certainty that the starter can actually crank the engine.

In order to make some progress while still working out the locations of the ignition and regulator modules, the baseplate which had begun to rust was painted. I've used the same Rustoleum Multi-color Texture paint on the display bases of several of my engines. This thicker than normal paint covers up deep grinding marks and will sometimes hide ugly welds. Although rather nasty looking before curing, it dries to a remarkably uniform and durable textured finish that's resistant to automotive fluids.

A small control panel containing a couple toggle switches and the starter button was machined from a chunk of aluminum. It was designed to be mounted at the rear of the engine under the starboard side exhaust. In addition to providing 12V battery power to the voltage regulator (which in turn will provide 6V to the ignition and fuel pump), the panel supplies starter current to the starter solenoid. Battery power comes into the front of the panel through a pair of 4mm banana jacks and leaves through three connectors at its rear. After bead blasting the panel was Gun Kote'd drab olive green. - Terry

After settling on compromise locations for the voltage regulator and ignition modules, the engine and radiator were temporarily removed from the baseplate so the mounting holes for the modules could be drilled and tapped. These locations are compromises because I'd hoped to keep the electronics away from the oil drain plug and the coolant hoses while maintaining visibility of the led timing indicator on the rear of the ignition module. I managed to get two of my three 'hopes', but the regulator wound up under the input hose. Both modules were mounted to the baseplate through standoffs to keep them high and dry in the event of a fluid leak.

With the running accessories finally installed and the engine and radiator still removed, the accessory wiring harness was fabricated directly on the baseplate. Refrigerator magnets temporarily arranged on the baseplate were used as layout guides. After attaching the various (Futaba J) connectors and testing the harness with the control panel, it was strengthened with shrink tubing and wrapped with nylon wire loom for a better appearance. The finished harness was attached to the baseplate with elevated cable clamps. The motor mount on the port side was also drilled and tapped for a lug to ground the secondary side of the ignition module to the engine.

The engine was filled with 270 ml of 5W-40 and returned to the baseplate so the spark timing could be set up before the radiator was put back in place. Setting timing was fairly easy thanks to some earlier prep work. When the valve timing was set up a few months ago, the keyed crank damper was engraved with a TDC mark directly under the timing pointer along with a series of 5 degree advance marks. With an initial ten degree advance selected, it was only necessary to first turn the crank to 10 deg BTDC as indicated on the crank damper. Since the crankshaft turns twice as fast as the camshaft, there are two places where this alignment occurs for each cylinder - one is during its intake stroke and the other is on its power stroke. The power stroke is the one needed, and it was easily located for cylinder number one by removing the starboard side valve cover and selecting the one where both intake and exhaust valves were closed while the timing pointer was at 10 deg BTDC.

With the crank sitting at 10 deg BTDC on its power stroke, the distributor was inserted into the engine with the vacuum canister pointing toward the front of the engine. With the ignition ON (but the high voltage OFF), the distributor housing was rotated until the blue led on the ignition module turned ON indicating the ignition was in 'dwell'. Since my ignitions are designed to fire just as this led is turning OFF, the distributor body was rotated to make this happen with the 10 deg BTDC mark under the timing pointer. The distributor was then locked in place using the distributor hold-down. If the distributor's vacuum canister hadn't wound up in a convenient forward facing position, the distributor would have been pulled out of the engine and reinserted while rotating its shaft plus or minus a gear tooth as needed to better locate the canister. In this case it may be convenient to remember that the rotor turns CCW when running.

An important final step when setting up the spark timing is to ensure the rotor is under the number one plug tower when the number one plug fires. The distributor cap is keyed to the distributor body by its mounting screws which allowed a rotor alignment mark to be machined into the distributor housing. With the timing indicator just turning OFF while the damper's 10 deg BTDC was under the timing pointer, the Delrin rotor which was already a snug fit on the distributor shaft was rotated into alignment with this mark and secured with a grub screw.

I next discovered I had only four spark plugs (the rest are now on order). In the interim a set of 10-40 threaded plugs was machined to seal the remaining spark plug holes so I could get some preliminary information about the starter and the health of the cylinders. The good news was that starter had no problem cranking the engine at nearly 1k rpm which was twice as fast as I'd hoped. The sound the starter made while cranking was reasonably uniform indicating similar compressions among the eight cylinders. A scope trace of the starter current correlated reasonable well with an audio track of the starter noise. After an initial 70 amp surge the trace showed 30 amp current pulses at the compression bumps.

During cranking, a very healthy suction could be felt at the carb inlet. This was a relief because I'd been concerned that I'd made the manifold's intake runners too large and the intake valves too small. Even with no combustion, healthy pressure pulses could also be felt at both collectors. - Terry

Terry,
I always pre-time my engines between 10 and 15 degrees. I'm sure you've had enough experience over the years with timing engines but I have found on initial startup that the engines seem lazy so the first thing I do is start advancing the timing. Both my 302 and flathead run at about 30 degrees advance.

Ticking "like" is a blatant understatement - your work is incredible! Well done.
And I like the look of you workshop too!
Keep up the excellent work.
This build could be written-up as a book.
K2

I'm exited to see and hear that engine in action! can't wait!
-It's a fantastic job! (do you got time for anything else?)

Looks fantastic! I always get Rustoleum Textured mixed up with Hammered. In any event, I suspect their 'rust' paints might be a similar resin base anyways. Did you clear coat over the Textured or leave it as is? Did you do a prior test to see if gasoline or oil stained or softened it? I'm sure I've been down this path before but it may have been methanol glow fuel & maybe a different brand.

While waiting for the spark plugs to arrive, a pair of Tygon fuel lines covered in a protective wrap were installed to connect the fuel tank to the carburetor. The bundle was secured to the bell housing with a clamp that keeps it out of the port-side exhaust. The .018" restrictor used in the earlier fuel pump tests of the fuel pump was installed in the pump's output hose.

An issue with the elongated Cobra style air cleaners was that they extended over the distributor with very little clearance and as a result required right angle boots on the cap. Dorman 47408 soft vacuum elbows were repurposed for use as right angle high voltage boots. The 289's cap was designed with conical towers to closely resemble the original Ford cap, and this created problems fitting them to the towers. The boots had to be chilled in dry ice and manually opened up with a tapered end mill for acceptable fits.

Another issue with the cap involved the high voltage wire contacts. Each tower electrode is a pressed-in brass insert center-drilled to accept a particular mystery connector pin that I've used many times before. After finishing the cap I realized I didn't have any more of these pins, and the ones I did have had difficulties with the 90 degree bends inside the boots. Instead, I simply tin-soldered together the stranded ends of the high voltage wires to make a crude pin. Even though the eighth inch diameter high voltage wire is a snug fit inside the boot, the wires were doubly secured to the boots with heat shrink tubing. The actual electrical contact is simply a tinned wire supported inside half inch deep hole in the center of the brass electrode.

The spark plug ends of the wires were terminated with straight boots as I've done many times before. A half inch of insulation was removed from the end of the wire which was balled up into a 'spring' contact inside the boot. Shortened Dorman 47400 straight fittings happen to fit snugly over Viper Z1 plugs and were used as straight plug boots. Heat-shrink tubing around the ends of the boots doubly secure the wires to the boots. The plug wires were routed below the valve covers so the covers can be easily removed for valve lash adjustments without disturbing the wires. An assortment of miniature wire looms machined from plastic stock tidied up the plug wiring and kept them off the exhaust manifolds.

A pair of coolant hoses were fabricated from 1/4" silicone tubing. Both the upper and lower hoses need springs inside them to prevent the tubing from collapsing at the sharp bends needed between the engine and radiator. The radiator will be re-installed later.

With everything finally in place for a first start I decided to perform a brief check before finally installing the radiator and adding coolant. The good news was that the starter had no problem with extended cranking times and never got warm during all my testing. The engine wanted to run and eventually did but only for several seconds at a time. So, there's a fuel problem somewhere. The fuel level inside the carb remained where it should while running, the needle valve has an effect, and there's plenty of suction at the carb's air inlet at all throttle angles. Sustained running was only possible though at nearly closed throttle. When it did run it sounded great, and eight warm exhaust runners told me all cylinders were firing.

A large amount of oil being spit out of the exhausts indicated the initial 270 ml oil in the sump was probably too much. I reduced the oil in the sump in steps and eventually arrived at 80 ml which seems low but for now is giving an acceptable light smoky exhaust while the engine is running.

A unexpected problem with the belts coming off their pulleys also showed up during the many starts and stops. In the process of removing the crank pulley to see if its grooves could be deepened, I discovered I'd never installed the bolt that was supposed to secure the keyed damper to the crankshaft (yikes!) The pulleys may or may not need addressing before the radiator is installed.

Feels like a carburetor problem . . . - Terry

petertha said:

Looks fantastic! I always get Rustoleum Textured mixed up with Hammered. In any event, I suspect their 'rust' paints might be a similar resin base anyways. Did you clear coat over the Textured or leave it as is? Did you do a prior test to see if gasoline or oil stained or softened it? I'm sure I've been down this path before but it may have been methanol glow fuel & maybe a different brand.

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Peter,
No clear coat. As I write this I've been wiping oil and gasoline off it with no degradation. Don't know about methanol though. - Terry

I discovered I that can rev the engine up and keep it running by opening the throttle a max of a couple degrees from idle with the needle valve opened about 2-1/2 turns. (The air bleed hole is currently blocked off.) This particular needle opening is more than twice what I've used in my other (but somewhat smaller) engines. The puzzling thing is that rpm is so sensitive to throttle position. From idle to what may be 3 krpm or so the throttle range is maybe only 2-3 degrees. - Terry