Exhausting work
This month has flown by on planet Frog, as all work on the Healey 3000 has been put on hold to get the supercharged Frog beauty going for the summer.
Last month I left with a little headache of the exhaust manifold clashing with the inlet manifold. The original and very rare cast iron manifold’s branches turned very sharply as they left the head and the bespoke Shorrock inlet manifold worked around this shape.
When purchasing the bits for the Frog a number of months back I couldn’t find an original cast exhaust so went for a lovely tubular manifold that swept away from the head in a free-flowing manner... straight into my inlet manifold! I had a hunt around and still could not find a cast exhaust and therefore had to replicate the required bend by cutting up my tubular exhaust.
An online supplier provided some 90-degree bends in mild steel which I then methodically worked through, cutting and shutting the bends around the inlet manifold. I tacked the bits in place as I went and made sure I was happy before the final weld up.
I did the latter using an old head as a jig to keep the required shape, but the hardest bit of all this was keeping welding sparks and cutting dust out and away from my newly-built engine. Far from ideal but needs must and all that.
With the exhaust sorted I could move onto fitting up the charger, exhaust and radiator into my running-in rig. This is a simple rolling angle iron affair with a fuel pump, oil pressure gauge, battery and engine
mounts. Running the engine up this way allows unhindered set-up access and an ability to keep an eye on what’s going on as you run in.
I like to get the engine running at 2000 rpm where oil flow is high for about 20 minutes and ideally I would put some load on the engine but you are entering dyno territory then and rigging up a device to generate load is a bit of a faff – a project for this winter I think!
With the engine in the rig and the pump primed I cranked without plugs, fuel and ignition until I had good oil pressure. I refitted the plugs, crossed my fingers and cranked. A big pop signified incorrect firing order. I was brought up on 1-4-3-2 Beetles not 1-3-4-2 British stuff – old habits die hard!
Once corrected she fired straight away and ran as sweet as a nut. I was surprised about how little noise the charger made. I was expecting a bit of a whir at least, so maybe all the time spent ensuring correct tolerances was worth the effort. After a 20-minute cool down I went ahead and popped her in the car. The supercharger and exhaust had to come off to do so and the longer front pulley for the charger belt was a bit of a squeeze. With it all in I looked at the floor and found a spring. This concerned me and the grease looked like the stuff that was used on the clutch cover plate, so out came the engine again.
I must have just glanced the release bearing and popped the spring off, so I’m glad I spotted it sooner rather than later! With the engine in, I took advantage of a family Sunday lunch to grab a few unwilling volunteers to help me put the bonnet back on as it’s a least a three-person job. The only thing stopping me now is a change of exhaust gasket. Foot off the gas for now!
I was brought up on 1-4-3-2 Beetles not 1-3-4-2 British stuff – old habits die hard!