If you are a pro engine builder, skip this article. If you have built upa few engines with some success, then read this lightly. If you've neverput an engine together with your own hands, this article should give youthe help you need.
COMPONENTS Some components make horsepower. Some components offerinsurance that the power will live. Be sure to spend your money wiselybecause insurance is expensive. Purchase only what you need. Let's sayyou know you're going to build a 350 Chevy engine. Get out the rule bookfor the track where you plan to race. It may specify the type of liftersthat can be used on the cam as well as the type of pistons (flat-top, 4eyebrow, etc.). The rules will probably spell out the type of cylinderhead to be used. You should know all of these things before buying anyparts. Once you've gathered the appropriate information, call up a camgrinder. Companies such as Comp and Crane have experienced staff thatwill point you in the right direction, making your engine fast andhelping you keep it legal. The cam is the heart of the engine. Selectingit first will allow you to match other components for the best power.
THE PARTS Now you're ready to get started. All of the parts for yourengine are laid out neatly, but the block must be cleaned. First, besure to keep all the main bearing caps in order. They should have anumber on them, but check to be sure. Since the block will need to bebored to fit your new pistons, be sure to have a machine shop clean itand check it for cracks before it is bored. The cleaning process willrequire the removal of the cam bearings. At the same time, take alongthe old pistons, new pistons, and rods. The wristpins are press-fittedin the rod. The machine shop can press the old ones off and install thenew pistons on the rods.
Here is where you can start spending money. Themachine shop will be able to align-hone the main bearing bores. Thecylinders can be bored with torque plates in place. The block can bedecked square with the crank and also flat. These are good things to do,as they unleash a little power and provide some insurance. But in yourStreet Stock engine, these things may not be necessary. If the enginewere in running condition and you paid a little attention to the piecesas you took them apart, the aforementioned steps should be easier. Ifthe main bearings on the crank were worn but not worn to one side, thenthe main bores should be straight enough. How straight is straightenough? How much do you want to spend? The engine ran a lot of miles theway it is now.
Be sure to inspect the rods carefully. After removing thebearings, look inside the bore on the big end. You should see somecrosshatch marks and the imprint of the brand of bearings used. If thesemarks are not present, and especially if there are radial marksindicating a bearing has been spun, then the rod needs reconditioning.
At this point, you will begin making decisions about insurance. The rodbolts hold up well in stock engines, but they become a failure point aspower levels rise. If the rpm level is held to 6,500 and horsepower isaround 350 (stock heads, good cam, four-barrel carb, and headers), thestock bolts hold up fairly well with good torquing procedures. However,a set of ARP rod bolts that are installed before the rods arereconditioned can be a real asset to bottom- end life.
The main bearing bores are...
The main bearing bores are checked for size. This is done after thebearings are removed and the caps are re-torqued.
Connecting rods take a lot...
Connecting rods take a lot of abuse. Good bolts such as ARP should beinstalled. The rod should be resized after changing bolts.