BIN IT! That was the first thought which came to mind when I saw the hole in number one cylinder, and I must admit the block came real close to becoming scrap metal.
I was digging around for a decent 265 Hemi to slot into my VG Valiant wagon and under the parts shelf there was a motor that used to make around 200 horses at the back wheels in my Centura many moons ago. So I dragged the short block out to give it a degrease and that’s when the trouble started. The water pump wouldn’t turn.
This is the sight that confronted me when I removed the water pump; at this point I was ready to toss the standard bore 265ci Hemi block in the tip
Okay, I thought, it hasn’t been in a car for the best part of eight years so maybe the pump has seized, but after removing the pump I saw my problems were a whole lot more serious than that. At some point the water pump had been given a big enough hit to knock the pump shaft back through the bore of cylinder number one. Shit!
How and when it happened, I’m not totally sure, but the engine has been several house moves and some of those moves have been pretty rough and ready.
Once it was decided to save the block the first job was stripping it down to a bare core which included removing the rods, pistons, crank, camshaft and all the bearings (inc cam bearings) and block plugs
None of my other Hemi sixes were ready to drop in, so my choices were bin this one and build one of the others, buy one in good condition, or save this block and build it up. Given that good 265 Hemi blocks aren’t exactly falling from the skies these days I’ve opted to try and save this one.
Loading the short block into the back of the Falcon wagon, I headed down to Johnny Pilla at Powerhouse Engines in Warragul and showed him what I had; “Yep, we can save that,” he said straight away. Then he pointed me towards the spanners and said, “Strip it down, and we’ll throw it in the tank.”
Fresh out of the hot tank the block wasn’t looking any better, but at least it was clean for crack testing to see just how far that crack extended down from the main puncture
So that’s our starting point. Follow along as we spend a day sleeving and saving this Hemi six from the scrap bin. Just because it’s got a hole in the bore doesn’t mean it’s ready to be hung off the end of a boat chain just yet, and with original iron getting harder to find, it’s applicable to all brands. So don’t go tossing that genuine XU1 or GT block just yet; check out what we started with and ask yourself, “Can I save it?”
Fluorescent magnetic fluid is sprayed on the offending area and an electromagnet attached. Under an ultraviolet light the crack shows up clearly, the boys drilled both ends of the crack to stop it extending further
The Hemi block is a seriously heavy piece of cast iron so it’s a two man job to lift on to the AZ VB182 borer/miller. Chook and Trev manhandle the block into position for machining
Johnny’s apprentice Trevor centres the borer over the first cylinder; he’s watching the dial gauge on the front of the machine. When the needle stops flicking it’s ready to go
The impact from the water pump deformed the cylinder inwards so offending material was the first bit to be removed by the borer
The cast iron sleeve was 4.098in externally so Johnny bored the block 4.095in for a 3-thou interference fit. The step at the bottom of the bore stops the sleeve from slipping out the bottom
Johnny applies some Irontite cooling system sealer to the cylinder wall to provide a water tight seal between the sleeve and the block
In the 60-tonne hydraulic press the sleeve is pressed in carefully. A deft touch is required because the huge press has more than enough capacity to totally destroy the block
Before fitting, the sleeve was trimmed to an approximate length in the lathe; the excess will be removed by the borer/miller
Once the sleeve has been trimmed, boring can commence. The lack of piston choice means the first oversize is 40-thou (3.91 + 0.040 = 3.95in bore). Johnny bored each cylinder to 3.946in to allow some meat for honing
After all the cylinders have been bored, the block was decked slightly. Johnny found that the deck height was significantly taller at one end compared to the other
The tops of the cylinders are given a slight bevel with an abrasive cone to break the sharp edge at the tops of the cylinder bores
Then the engine block was shifted over to the pride of Johnny’s machining fleet – the Sunnen SV10 honing machine. This thing will scrub your back, cook you breakfast and give you the most accurate hone possible
What’s next? Well we’re going to build it up and throw it on the dyno. Johnny reckons we shouldn’t have too much trouble making 300 horses with a hydraulic cam and a single four-barrel carb. Yeehah!
In part two, we take the Hemi six to Powerhouse Engines to match and balance the internals