Cheap Street Chevelle

After pulling the engine from our Chevelle, we completely disassembled it to check its condition before taking it to the machine shop. Make sure the block isn’t cracked, and check the condition of the various bolt holes–make sure none of them are stripped.

The stock crankshaft from our 140K-plus-mile 350 V8 was in bad shape. Notice all of the pits and cracks in the journals. It was just a matter of time before the bottom end self-destructed.

While none of the rod bearings actually spun, they were severly warped and gouged. The condition of this rod/bearing combo was representative of the entire bottom end of the engine. Not good.

We took our engine block to Skercevik Automotive Machine to have it cleaned, bored and honed. Even though the engine had a lot of miles, the cylinders were in decent condition. All that was required was a 0.030-inch overbore to clean up the cylinders. When machining a block, always opt for the minimum amount of overbore so more material is left for a future engine rebuild.

Our crankshaft and rods were complete junk, so we used a low-buck crank kit from Performance Automotive Warehouse (PAW). Our $464 kit came with forged aluminum pistons, moly rings, reconditioned connecting rods fitted with chrome-moly rod bolts, rod and main bearings, and a custom-ground cast-iron crankshaft. If you order the kit with cast pistons, the cost is about $80 less, but we recommend using forged pistons, in case you want to add nitrous or a supercharger later on.

Once our block was back from the machine shop, we used sanding items from Standard Abrasives to deburr different aspects of our block. Here, we use a cartridge roll to smooth out the pan rails and knock off minor casting flash that could lead to improper gasket sealing. You may also wish to deburr areas such as the lifter valley to aid in oil flowback.

Even though the block has been cleaned (usually by hot tank), always use a tap to clean out and/or straighten the bolt hole threads. You’ll be amazed at the amount of gunk that will be removed. With clean threads, the bolts will easily thread in when parts are installed.

We recommend using a cross-buff (available from Standard Abrasives) to fine-hone the lifter bores. In addition, the cross-buff deburrs the oil galley holes in the lifter bore. A clean, non-burred lifter bore ensures a long life for the lifters.

Before installing the crankshaft, thoroughly clean it to remove any dirt and shavings that may be left over from the machining process. Running a small bottle brush through the oil holes in the crankshaft journals removes any small metal shavings that are hiding. If you don’t clean the crank properly, chances are you will ruin the bearings within a short time period (sometimes even upon engine break-in).

The rings in our PAW engine kit are sized and end-gapped to match the 0.030-inch-overbore forged pistons, but always double check to ensure that clearances and fit are correct. We used a feeler gauge to check ring end gap--everything was spot-on.

Many times rebuilt rods will have their markings ground off during the machining and/or balancing process. Thus, we re-marked each rod and rod cap to ensure they wouldn’t get mixed up at any time during the assembly (or at a later date if we had to tear the engine apart).

We installed our new main bearings (part of our PAW kit) and then installed the crankshaft. Always tighten the main bolts progressively, in sequence, to the proper torque spec. Our main bolts were torqued to 75 lb-ft.

Many people install the crankshaft and never check the endplay. If endplay is too tight or too loose, you could hurt the bearings or create unwanted friction in the reciprocating assembly. Always check endplay with the mains torqued to spec. Our crankshaft endplay measured 0.009 inch, which is fine. In general, if the clearances are less than 0.007 inch or more than 0.018 inch, problems may result.

When rebuilding an engine, always use new freeze plugs. We opted for brass freeze plugs, which are a few dollars more than steel plugs, but the brass won’t rust out through the years. Our plugs, from Pioneer (available through PAW), were easy to install. You can install them dry, but you should use a sealant to ensure a leak-free fit. Some guys even use Loctite Red to seal the plugs, claiming they’ll never leak.

Installing the moly rings on the pistons is easy, but don’t stretch them too much, or they could break. Once the rings are on (including the oil rings), be sure to phase them properly--usually with the end gaps 180 degrees apart.

Just before installing the pistons in the bore, oil the piston’s side skirts to prevent any scuffing and/or seizing. Then, carefully slide the piston in the bore, making sure the rod end or rod bolts don’t scuff the cylinder bore as the rod/piston combo goes in. Here, we are using (and highly recommend) a tapered ring compressor from Tavia Machine Company.

Once the rods and pistons are installed, torque the rod bolts to spec (45 lb-ft, in our case). Then, on each journal, check the rod side clearance. In general, you should have a minimum clearance of 0.010 inch or problems may result.

Although the parts might be sold as "matched," always double-check clearances to avoid mishaps. Here, we are checking true top dead center (TDC) and measuring the deck height. Deck height is the distance that the piston is below or above the top surface of the block.

Before installing the camshaft, always apply plenty of cam lube. Without enough lube, chances are the camshaft will go flat (destroy itself) on engine startup. We installed a new PAW camshaft in an earlier stage of our Cheap Street Chevelle buildup, but since we upped our compression, and since we are installing a higher stall speed torque converter, we wanted to run a different camshaft grind. This time we installed a 0.462-inch intake/0.482-inch-lift exhaust camshaft from Competition Cams (PN 275DEH-10). The advertised duration is 275 degrees intake and 277 degrees exhaust with 110 degrees lobe separation, which should deliver a good rumpity-rump idle without sacrificing streetability.

Installing a camshaft without hurting the cam lobes or the cam bearings can be tricky. We recommend using a cam install tool, such as this unit from Tavia, because it gives you a good grasp on the camshaft. Plus, your hands won’t get all slimy with cam lube when you use a cam install tool.

Because most street machiners are on a budget, they opt to reuse many items, like the oil pan. If you do reuse the oil pan, thoroughly clean out the sludge buildup inside. In addition, check for any cracks or dents that could wreak havoc later on. If the pan is in bad shape, you may wish to update to a new oil pan, such as from Milodon. Milodon pans can even be ordered with special oil-control baffles, if that suits your fancy.

Even if you are doing a budget rebuild, don’t skimp on the gaskets. Running no-name or cheapo gaskets will only cause trouble later on. On this engine, Fel-Pro head gaskets (PN 1003) were used. These gaskets will handle the high-rpm street/strip rigors that our engine will endure. In addition, if you can muscle up a few extra bucks, invest in quality head bolts such as ARP offers.

We cleaned up and reused the World Products S/R Torquer cylinder heads that were installed in an earlier segment of the Cheap Street Chevelle buildup. Once the heads are clean, paint them with a quality engine paint like VHT’s. The S/R heads are a cost-effective (actually cheaper) alternative to rebuilding a stock set of heads. Plus, the heads flow better than stock units, have hardened exhaust seats and feature 2.02/1.60-inch valves.

Once the heads are torqued to spec (65 lb-ft in our case), install and adjust the rocker arm/pushrod combo. With the lifter on the cam lobe’s base circle (piston at TDC firing), twist the pushrod with your fingers as you tighten the rocker arm nut. As you start to feel drag on the pushrod, you’ve reached zero lash. At zero lash, tighten the rocker arm nut approximately three quarters of a turn more.

Besides pre-lubing the camshaft, always add plenty of lube to the lifters before installing them. The lube prevents the lifters from scuffing or seizing when the engine is started.

With the cylinder heads in place and the rocker arms adjusted, install the intake manifold. We reused our Edelbrock Performer dual-plane aluminum intake manifold, because we had great results with it previously. We opted to use a Fel-Pro reusable thermostat housing gasket in case we needed to change thermostats at a later date. The gaskets provide a perfect seal without use of messy sealants.

Our good friend Jim Sanborn put the finishing touches on our engine buildup. Sanborn re-installed the Performance Distributors HEI distributor and the Jacobs spark plug wires that we bolted on in Part III (CC, December 1994), but he added a set of Made For You spark plug wire holders to avoid any burning mishaps. The stock Quadrajet 750cfm carb was also reused, along with a fresh Fel-Pro carb-to-intake gasket. Notice the good looks of the various pulleys and brackets. Just because you’re on a tight budget doesn’t mean that you can’t clean up and repaint the parts so they look good.

Before installing the rebuilt engine, the engine bay was thoroughly scrubbed to remove the 25 years’ accumulation of gunk. Then the engine bay was treated to a bath in VHT paint. Sanborn guides our low-buck PAW engine back into the engine bay.

Although we tried to stick to a tight budget with our engine rebuild, we upgraded to (and highly recommend) a new oil pump. In addition, our stock flexplate and harmonic balancer were shot (the balancer had spun a quarter of an inch), so we upgraded to new units. The flex plate is made by Pioneer, and the balancer is a new GM unit. All of these parts are available from PAW.

Even though we installed DTS 3.73:1 gears in place of the stock 2.73:1 gears, we didn’t pick up the e.t. gain that we hoped for, because our stock torque converter would only allow us to stall to 1500 rpm. The low-rpm converter was killing our launch as well as our e.t.’s. Thus, while the engine was out, we ordered a new torque converter from TCI. The new 11-inch Break-A-Way converter (PN 241502) features furnace-brazed fins and needle bearings and stalls between 2600 and 2800 rpm. Plus, the unit was a direct bolt-on.

Check it out. Avid CC reader Joseph Reyes of San Lorenzo, California, sent us this barrage of goodies for our Chevelle. During the first three installments of our Cheap Street Chevelle buildup, Joe noticed that our side marker light was busted, we were missing some emblems, we had burned some spark plug wires and that our stock valve covers were all bent up. Thus, he sent us some used Chevelle parts from his garage and some Thermo-Tec header wrap, and he even included a new (still in the bag) GM dome light lens, which we were missing. We installed most of the parts--check out the valve covers in the completed engine shot! Heck, he even included Polaroid snapshots of a few tech tips along with a photo of his street machine. Notice the 307 emblems; he wants us to run a mega-cube, mega-hp small-block but tell everybody it’s "only a 307." Thanks for the goods, Joe. To all of our other readers, we don’t need any other parts. Thanks.