Chris McKitterick (mckitterick) wrote,
Chris McKitterick

Newport update: heads & cam

First the good news: The cam is installed and the heads are bolted down!

Now the bad news: The car won't be done before the middle of July, because I discovered that my beautiful, vintage, "universal" headers won't fit this car. That would have meant the soonest (after the test-fit) I could have gotten the correct headers was about today... and people start arriving for the Workshop on Friday. Too much left to do after that to make it go, and no time. So the car will have to wait to hit the road until later this summer.


Here's what the non-fitting headers look like:

I'll have to order a set of headers designed especially to fit the "B-body" (Newport, 300, etc.) Mopar chassis. This is a bit ironic: The B-body is the largest Chrysler and uses the big-block engine, but the exhaust area beside the block is the tightest.

Hmph. Anyhow, progress to date:

After painting, cleaning, and prepping, I began reassembling! Head gaskets went on first, then the Edelbrock Performer RPM heads. Here's the first step after placing them onto pegs that orient them atop the block - slipping the new ARP bolts through the heads into the block:

Note the silvery goo coating the bolt threads and spread over the heads where the washers go; this is a lubricant and anti-seize compound (the bottle sitting on the suspension right beside my hand). This stuff ensures that the bolts torque correctly (that's how tight they pull down the heads) and don't freeze or rust; it also ensures that the hardened-steel washers don't grind into the soft aluminum of the heads as I tighten the bolts. Note also the red goo on top of the valvestems (at the top-center of the black spring assemblies); this is an assembly lube that reduces valvestem friction against the rocker arms until the oil pump properly lubes the valvetrain.

Next, I installed the big ol' Thumpr cam! By the way, Comp Cams designed the cutest-ever logo for this camshaft:

Parenthetically, here's how a camshaft works:

Click the image to see the story.

Essentially, a camshaft - the engine's brain - works by pushing open the valves as the cam rotates. There are lots of other parts involved (lifters, pushrods, rockers and all their components, valves and all their components, etc.), but the cam controls what they do and when. It determines if you have a low-RPM truck engine or a high-winding Grand Prix engine. Mine will be somewhere in the middle. /parenthetical

Here's the first step in installing the camshaft:

To install a cam, one essentially inserts a two-foot-long shaft into the block. Besides having to remove everything that stands within two feet of the front of the engine, this seems straightforward, eh? Well, here are a few complications:
  • The cam bearings (where the cam's journals ride within the block) are the same size as the biggest parts of the cam, within a thousandth of an inch or so. Luckily, the rear-most bearings and journals are smaller than the front-most, so there's more room when first inserting the cam than when finally seating it.

  • This cam's lobes (the bumps that open the valves) are really tall to open the valves a lot. Therefore, one has to be really careful not to mar the cam bearings when installing it, because those lobes act like big hammers on the way in if you're not careful.

  • To keep from ruining the bearings and cam during the installation or first few seconds of running the engine, one needs to coat the bearings with assembly lube (thicker than oil - in the photo above, the white bottle on the radiator support in front of the cam) and coat the entire cam with engine oil. (Note the oil drips on the garage floor below the cam.) This also makes the unit slippery as hell. Oh, and keep lubricating it as the cam journals wipe the oil off the bearings on their way through.

  • A cam is made from solid steel. It is not as light as a sunshine. So to control the installation, one needs to hold a handle (in this case, a long bolt) on the front end of the cam while supporting the rear end of the cam as it slips through each bearing (see photo below).

  • Finally, one must seat the cam all the way to the back of the block. My new cam was a bit stubborn about this, but one mustn't whack it with a hammer; instead, keep oiling it and spinning it while gently shoving it deeper into the block. Eventually, it seats.
Here's me supporting the back of the cam as I slide it into the block. Note that there's enough room under the hood for me to stand inside the engine compartment:

Oh, and before I even started that, I changed the oil, replaced the oil-drain plug that has a magnet in its center (to capture any ground-off steel from new parts finding a comfy fit with one another), refilled the oil with a nice semi-synthetic, installed the new bronze-gear oil-pump shaft, and used a screwdriver head and low-speed drill to pump oil through the engine and pre-oil the bearings. I also installed that cool, finned-aluminum oil-filter cooler near the bottom of the engine.

Then you can install the timing chain, which rotates the cam via dual gears and chains at half-speed, thus opening the valves once every couple revolutions instead of each revolution - the magic of the four-stroke engine! Mine took a bit of convincing to bolt up to the cam.

Then it was time to start hooking up the exhaust... whoops. And then my Dad came for a short visit. Now it's time to resume reading for the SF Workshop about to start this weekend. So: No more hot-rod Newport updates until mid-July.


Tags: hot-rod newport, vehicles

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