Reply to "If you liked the 3 deuce intake manifold, you'll love this ..."

Hi back at 'ya George.

Don't want to hijack the thread but I guess it did start out as an (SK) alloy block discussion.

Just to be clear, I was referring to push rods not con rods in my previous post. The difference in the expansion of these materials (aluminum block versus stell alloy push rods), is relevant especially in big lift, big horse power, mechanical valve train, engines. It makes it more challenging to set lash such that valves can properly seat yet not so loose that your push rods rattle and suffer premature wear (or worse) at cold.

The "quality" or particular alloy of aluminum has little affect on it's expansion coefficient. Aluminum and iron alloys have different thermal expansion rates. -The mechanical properties of metals can be very stubborn things indeed. They just refuse to cooperate!

I would offer the following comments on the example cited regarding cylinder liners in alloy blocks.

I would not assume that because Asian engines (or any other alloy engine for that matter) do not appear to have expansion problems that it wasn't a problem. It was just well addressed through design.

The liners want to grow less than the block as it heats. It's simply an interference fit that was designed to accomodate the issue. The liners stress the block as it cools. The block is just massive compared to the relatively thin liners, it constrains the liners and strains a little under the stress. It's a pretty fundamental issue when designing press fits for dissimilar materials.

On the topic of Aussie blocks here's my 2 cents. I wouldn't pay a "nickel" more for any of the so-called high nickel blocks that are essentially the same castings as all US blocks, high nickel or not. Fact is, 2-bolt Cleveland blocks are quite adequate for just about all practically streetable engines. I know, I'm about to start the debate all over again. Just my opinion guys.

The true XE or Nascar blocks as some say are different animals and interesting pieces. I certainly would prefer an XE block over a standard Cleveland block provided that either sonically tested favorably.

For Pantera owners they may make sense (except their scarcity and thus cost) because all accessories bolt directly. As all know, these blocks had substantially more material in the lower end but unfortunately no more in regard to cylinder wall thus no overbore potential.

I went with a 9.5" deck iron Dart block and I have a Fontana block. I went 4.125" (and they say they can go 4.25") bore 4.000" stroke for 427 CI. If some one offered me either an XE block or this block I'd take the Dart block hands down. It's a real nice street motor Brodix BF301 heads, makes 530HP @ 6000 rpm at the flywheel, and more importantly has an impressive torque curve that starts early and gets better. To be quite frank, as I inferred above, the Dart block is overkill for a street motor but the lower end was built to take some pounding and the top end can flow enough to support substantially higher numbers.

I'm hopeful that at some point in the future it may see some track time. That's why I went with the aftermarket block. The short block and top end were built to handle more ponies and all that would be needed to put down some big numbers would be to change over hydro-roller to solid roller and corresponding valve train.

The downside, Darts are all Windsor externally, lot's of work to convert the Pantera to tall deck and accessory interface.

Bottom line guys, build what you can afford and drive it like it was meant to be driven.

Enjoy your rides fellas.

Kelly