In 1998 I bought a Triumph Herald 13/60, here you can read about it's restoration and share in a few photo's from it's travels. Please feel free to leave comments to any of the posts, of even email me if you want to.

Monday, November 5, 2012

Engine Rebuild (Part 2)

The lack of any update on the engine rebuild had been because I hadn't done anything, but in the last couple of weeks I've managed to get a bit of quality play time to get things moving again.

Firstly I finished off the bit of light porting and polishing of the head, then lapped in the larger valves that were supplied by Jigsaw Racing.

Larger valves lapped and fitted
Next was to fit the new, warmer camshaft, a quick 2 minute job.

The crankshaft had already been reground by 0.010", it was well within tolerance so just needed a polish. I then fitted NOS +0.010" main bearings which I picked up for a bargain price on Ebay. The bearings were lubricated and crankshaft was then carefully put in place and main bearings caps 1 & 2 were fitted and the bolts just nipped tight.

Thrust washers are fairly cheap, so I bought a selection of sizes as it's not uncommon to mix and match to get the correct end float. Comparing the existing thrust washers with the new highlighted a problem, a previous owner for some reason had the main bearing cap machined and a pegged thrust washer fitted.

Non-standard thrust on the left, standard item on right
Herald engines should only have 2 half thrust washers fitted into the block either side of No. 3 main bearing, the main bearing cap overhangs preventing them from spinning around. This modification was providing 360° on the flywheel side, trying to match these custom thrust washers was going to be impossible so I wanted to get as close to standard as possible. I achieved the required end float by fitting 2 of the correct type  +0.010" items into the block, I then removed a few thou from the modified thrust on the main bearing cap, this in practice puts the main bearing cap back to what it should have been. Time will tell if this will work, but I see no reason why not.

I'd had the crank, flywheel and clutch cover balanced as a single unit, so thought I may as well balance the conrods as well. I bought a cheap set of jewellers digital scales which claimed to be accurate to 0.1g, so I set about removing small amounts of metal from each conrod to get them all weighing the same.

I then used a press to fit the 4 small end bushes, being careful to ensure the oil holes were lined up. These are currently at the engineers as they have to be reamed to fit the gudgeon pins.

More to follow soon.....

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