So, after spending my hour mea culpa to the automotive gods (otherwise known as stripping sticky tar like gasket material from the case halves), I decided to rethink my strategy. I've opted with the "slowly forward" mentality. I'll follow the sage advice of those who have gone before me and assemble and re-assemble multiple times. It turns out that this isn't a bad idea...
I decide to remove everything but the crank and re-assemble the case. That way I'm sure of what is causing the binding. I assemble and torque. Crank won't spin. Disassemble, re-seat the crank. Re-assemble. (You are getting the idea). Crank spins! Minor success. Then I realize something that I've been secretly dreading. Because I opted for a longer than stock throw crank (74mm vs 69mm), the connecting rods aren't clearing in the case. To be precise, the rod nuts are hitting on the edge of the cylinder spigot holes. Just barely catching. Ugh. Well, off to add to my collection of tools. Must buy a die grinder.
Disassemble. Remove crank. With a new die grinder in hand, I remove just a little bit of the case where the nuts are hitting. Clean the case and, you guessed it, reassemble. This time, much to my surprise, the crank spins freely AND the rods are no longer hitting. Success!
Next step is to dry fit (again, heed the word of the good book), the cylinders and measure the deck height. To the less fortunate - rather, those of us not insane enough to embark on such a stupid thing as rebuilding a VW engine - the deck height is the distance from the top of the piston at top-dead-center, and the top of the cylinder. This distance, and the cylindrical volume it creates, combined with the volume of the cylinder head combustion chamber, are needed to accurately calculate the compression ratio. The more volume, the lower the compression ratio; the lower the compression ratio, the cheaper the gas you can drive. But there is a trade off: namely, power. Lower compression ratios have lower power. So there is a balancing point to achieve here. I'm shooting for something along the lines of 8:1 or 8.5:1. Ian will just have to suck it up and buy decent gas. At least he won't need high test.
OK, back to the deck height. What I find is that I have a negative deck height. This isn't unexpected. With an increased throw of 74mm, combined with stock length connecting rods, one would expect to result in a negative deck height. Which it did. I take a quick measurement, do some rough calculations, and go buy some spacers for under the cylinder. This yields roughly the right deck height to give me an 8.5:1 compression ratio. Yay! The small victories. Anyway, here are a couple of photos of the cylinders dry fitted. I have to take another photo of my deck height measuring tool which I stole from the Muir book. Those will be posted later.
I decide to remove everything but the crank and re-assemble the case. That way I'm sure of what is causing the binding. I assemble and torque. Crank won't spin. Disassemble, re-seat the crank. Re-assemble. (You are getting the idea). Crank spins! Minor success. Then I realize something that I've been secretly dreading. Because I opted for a longer than stock throw crank (74mm vs 69mm), the connecting rods aren't clearing in the case. To be precise, the rod nuts are hitting on the edge of the cylinder spigot holes. Just barely catching. Ugh. Well, off to add to my collection of tools. Must buy a die grinder.
Disassemble. Remove crank. With a new die grinder in hand, I remove just a little bit of the case where the nuts are hitting. Clean the case and, you guessed it, reassemble. This time, much to my surprise, the crank spins freely AND the rods are no longer hitting. Success!
Next step is to dry fit (again, heed the word of the good book), the cylinders and measure the deck height. To the less fortunate - rather, those of us not insane enough to embark on such a stupid thing as rebuilding a VW engine - the deck height is the distance from the top of the piston at top-dead-center, and the top of the cylinder. This distance, and the cylindrical volume it creates, combined with the volume of the cylinder head combustion chamber, are needed to accurately calculate the compression ratio. The more volume, the lower the compression ratio; the lower the compression ratio, the cheaper the gas you can drive. But there is a trade off: namely, power. Lower compression ratios have lower power. So there is a balancing point to achieve here. I'm shooting for something along the lines of 8:1 or 8.5:1. Ian will just have to suck it up and buy decent gas. At least he won't need high test.
OK, back to the deck height. What I find is that I have a negative deck height. This isn't unexpected. With an increased throw of 74mm, combined with stock length connecting rods, one would expect to result in a negative deck height. Which it did. I take a quick measurement, do some rough calculations, and go buy some spacers for under the cylinder. This yields roughly the right deck height to give me an 8.5:1 compression ratio. Yay! The small victories. Anyway, here are a couple of photos of the cylinders dry fitted. I have to take another photo of my deck height measuring tool which I stole from the Muir book. Those will be posted later.
