Too Hot To Trot: PT 2

Before any of the work began, our 302 was put on an engine stand. Despite running like a champ and having gone 13.80s, the engine was on its last leg. Our plan is to rebuild the 302 and make it better than new.

The disassembly process began with us removing the connecting rod caps. When we did so, both halves of the rod bearings stayed on the crank when they should have remained attached to the rods. According to Bob Oster of B&B Performance Machine, this is a sign of excessive clearance between the caps and the bearings, and also a sign that the rod bearings were about to spin.

Oster covered the rod bolts with protective boots and then he tapped the pistons out of the bores.

Welcome back to part two of our Hot Handler engine buildup. As promised in an earlier issue, we've yanked the old engine, pulled it apart, and the rebuild is well underway. While there's an amazing list of potential parts to stuff into our 302, we decided to serve up a simple (and super affordable) engine that's a little hotter than stock. Fact is, many readers are on a budget and can't afford to build a radical small-block, so this time we'll cater to the budget-minded and rebuild the engine using a common selection of parts. By carefully picking the heads, cam and intake, we hope to end up with about 80-100 horsepower over stock and plenty of reliability.

To achieve our goal we looked hard and long at the seemingly endless list of parts found in a number of catalogs and, of course, in the pages of MM&FF. We decided to leave the bore and stroke alone and stick with the 302 displacement to keep cost at a minimum. In addition, we decided to maintain the stock EEC computer system so we had to pick parts that would keep peak power well below the 6,250-rpm redline. Once built, the engine will be returned to our corner-carving '87 LX and put to the test.

The rotating assembly we selected is right out of the Summit Racing catalog. It's listed as the Summit Racing Engine Rebuild Kit, which includes new pistons, rings, bearings, oil pump and gaskets. We also selected a set of AFR 165 heads that have 1.94-/1.60-inch valves. The combination will be topped off with a classic GT-40 intake fed by a BBK 70mm throttle body, and fuel will be injected by a set of 24-psi squirters. The combination of the 165 heads and the long-runner GT-40 intake will give the engine excellent port velocity, and that should translate into awesome throttle response at low rpm. In any road race car, especially one designed for a smaller track, mid-range power is critical and these parts should give us what we're looking for.

As you know, it's hard to get things done by simply talking about them, so let's clam up and get to work. After delivering the 302 to Bob Oster at B&B Performance Machine in Rahway, New Jersey, we set the engine on a stand and Oster walked us through the entire disassembly process. After breaking it down we cleaned the block, checked it for cracks, and started putting the new pieces into place. We stopped after completing the short-block and next month we'll complete the engine by installing the heads, intake and oil pan. The next stop will be on the dyno and at the track.

Now, go ahead and check out the photos and captions, but be careful because you may want to rip out your own engine and freshen it up.

After removing the bearings from the crank we saw the damage to the journals. Each journal had scratches (commonly called scores), which tells us there was some foreign matter flowing through the oiling system.	Oster removed the main bearing caps and lifted the crank out of the block. We'll use the same crank, but first the scores must be removed. Our crank will be undercut .010-inch and thicker bearings will be used to retain the proper clearance. Having a crank cut means the journals will be machined until they are smooth and round. In addition, the crank will be checked for cracks and the oil holes will be chamfered.	The block was turned upright and the lifter guide hold-down bar (also called a "spider") was removed along with the lifters. Oster recommends taking special care to reuse the original retaining bolts for the spider. The block is threaded all the way through to the cam bores in this area and using longer bolts will result in the bolt contacting the cam bearings.
With the lifters out of the way we removed the camshaft along with the oil sender seen sticking off the block on the left side of the photo.	The block was flipped over once more and we removed the cam bearings. Here you can see the tool that was used to knock out the cam bearings. The tool is inserted into each bearing and then it is spread to grab the bearing.	With a tap of a hammer the bearing is driven out of the bore.
The remaining oil plugs and freeze plugs were knocked out of the block or unscrewed and the block was sent to the cleaning tank for a bath.	After doing time in the hot tank the block was devoid of grease and grime. Oster checked the block for cracks and/or any other damage. Late-model 5.0 blocks are prone to cracking between the main webbing and the cam tunnel. Our block was okay.	The next stop for our block was in the honing machine. Regardless of application, Oster uses a torque plate when honing blocks. The torque plate simulates the load or stress on the block that the cylinder head and head bolts impose. This helps to make the cylinder bores as round as possible when honing. Round cylinders equate to improved ring seal and that means more power and longer engine life.
After the cylinder walls were honed, Oster chased the threads in the entire block with a thread chaser. He cautions not to use a tap, as this will open up the threads rather than just cleaning them. The block was then thoroughly cleaned with dish soap and hot water and a variety of brushes to get in every crevice and galley.	Prior to assembly Oster checked the deck surface for straightness using a straight edge and a feeler gauge. The allowable tolerance is .004-inch and our block was within spec.	Waiting in the wings was the rotating assembly. This included the Summit Racing Engine Rebuild kit and our freshened crankshaft.
Earlier in the text we made reference to the worn engine bearings. This is a comparison between the old and the new.	In addition to rod and main bearings, we also installed new cam bearings. The slot in the bearing must face the top of the engine to allow proper oil flow.	This is what the front cam bearing looks like once installed.
After installing the cam bearings Oster checked the part number on the main and rod bearings (to make sure they were not boxed wrong) and then he pressed the main bearings into the journals. Note the position of the tab on the bearing and how it fits neatly into the notch in the block.	Each main bearing was coated with a liberal amount of assembly lube (not engine oil)...	...and then the crank was laid into place. Bob Oster spun the crank by hand to make sure it turned smoothly, and it did.
With the crank in place and spinning free, the inner lip of the rear main seal was lubricated and the seal was installed. Oster suggests you install the seal with no silicone on the outer edge.	The other half of each main bearing was placed in the main caps and the bearings were lubricated and the caps installed. Each cap is numbered and features an arrow, which should face the front of the engine. After installing each cap, remember to check to make sure the crank turns freely. If the crank hangs up or binds, remove the cap and inspect. In the case where the crank will not turn at all, it may be necessary to align hone the crankshaft mains.	Oster applied a small amount of assembly lube to the ARP bolts and he ran each one down by hand. ARP moly lube is used to lubricate the threads so you can get an accurate torque reading. Notice the Canton main girdle that we're using to add strength to our short-block.
The next step is to tighten the crankshaft and to check the crank thrust. Using a pry bar, Oster applied slight pressure and levered the crank rearward to take up any slack.	Next, the crank was wedged forward, and the crank was tightened to 80 ft-lb.	Oster then used a feeler gauge to check end play. The proper specification on a used crank is between .004-.008 inch, and our crank had .006 inch. Another way to check this is by placing a dial indicator on the snout of the crank and moving the crank back and forth.
With the crank torqued down and spinning freely, we tapped the crankshaft key way into the crank (not shown) and slipped the lower timing chain gear over the snout. Next, we cleaned the cam, then coated it with assembly lube and slipped it back into place. Since new bearings were installed we spun the cam by hand to make sure it turned easily and smoothly.	Next, we installed the camshaft retainer.	Following this we popped on the timing chain. Notice that the single dot on the lower gear is lined up with the dot on the larger cam gear. This indicates the cam is neither advanced or retarded. By repositioning the lower gear you can advance or retard the camshaft timing events. Advancing the cam by a few degrees will lower the powerband and favor torque, retarding the cam will raise the powerband and favor horsepower. Whenever moving the cam you must check piston-to-valve clearance.
Now it's time for pistons and rods. Before slipping in the slugs, we checked the end gap on the rings. In our naturally aspirated street/track application, Oster recommended going with .018-inch end gap on the top and second rings. Engines that will see boost or nitrous require more end gap. Oster suggested running between .020 and as much as .032 on some special applications. Check end gap by carefully sliding each ring into a bore and squaring it off about 1-inch down. Then use a feeler gauge to check the gap. If you need to open up the gap you will have to grind the end of the rings using a ring grinder.	Now it's time for final assembly. Before popping in the pistons, the cylinder walls were wiped clean with lacquer thinner and a clean rag.	Next, the rings were installed on the pistons. Oster recommends maneuvering the rings so the end gaps are opposite of each other. He also recommends you rotate the crankshaft so the journal for the piston and rod that is to be installed is at the bottom of the stroke. This will make it easier to attach the rod caps and screws.
The cylinder walls were then coated with engine oil...	...and the pistons and rod assemblies were slid in. Note the protective boots on the rod bolts.	Once you get the piston partially in the bore be sure the rod is square and the piston is facing the correct direction. Most pistons have some type of mark that indicates the proper direction. These pistons have an arrow, although some have a small dot or impression. Get the piston most of the way in the bore and coat the rings with some oil.
Using a ring compressor, Oster squeezed the ring package and then tapped the piston into the bore. It's important to go slowly all the while making sure the rod bolts go around the journal in the crank.	Once the rod bearing is seated against the journal you can remove the boots.	Then install the rod caps and torque the nuts to the proper specification. Be certain that the rod cap isn't installed backwards. The tangs on the bearings should be on the same side. We finished Part One by installing all the pistons and rods, and next month we'll bolt up the heads, intake and the oil pan. We're also shooting to have the engine back in the car and dyno tested, so stay tuned as we put the heat in Hot Handler.
Just a few months ago our engine was old and tired.	The rebuild was kicked off with a complete dissassembly.	Once the rotating assembly was removed we pulled out the freeze out plugs (shown) and all the oil galley plugs.
The 302 block was honed using a torque plate. Honing the block prepares the cylinder walls with a cross-hatched pattern which holds a small film of oil and allows the rings to seal to the cylinder walls.	Our crank was cut .010-inch under and it was cleaned prior to installation in the block.	If the deck is not totally square, you can "true" it using a sanding block and fine-grit paper. If this is necessary we suggest that you go slow and clean the block with soap and hot water before you assemble it.
Use a liberal amount of assembly lube on all bearing surfaces.	We dropped in the crank, main caps and the Canton Racing main girdle.	The pistons are forged and they came in the Summit Racing Engine Rebuild kit. Also included was new bearings, gaskets and rings.
The short-block is ready to go. Next, we'll install AFR 165 heads, a GT-40 intake and a Canton oil pan.