Thread:

Blown 502 build

Well, after dealing with a problem with a certain shipper who uses big brown trucks, I am about ready to get a serious start on assembling a Gen 6 502 long block for John Rork to set his 8-71 blower on. Baring unforeseen difficulties, it should go pretty quick.

Here was the shipping problem, note the damage to not only the aluminum blower intake, but the steel harmonic balancer has thread impressions. I can only guess how high they had to throw the box to imbed the bolt into the balancer that far!

Ok,, fast forward a couple of weeks, got just about everything to put this together now.

Here are a couple of shots of the flash on the block before I pull out the grinders, better get rid of some sharp corners and "meat hooks"

After a thorough 3 stage wash (which I can't shoot while I am rushing to get it done without letting it get dry enough to rust), I mask the gasket surfaces and install plugs in all the appropriate holes to keep paint out of them. I traced the head gaskets onto the masking tape on the block surface, used the IMCO timing cover to trace an outline on the front, and the pan gasket on the bottom of the block to try and insure that there is no bare exposed metal, but that the gasket surfaces won't be contaminated with paint. It was too windy to paint it this afternoon, will need to catch that in the morning when it's calm.

Prior to the masking, I went ahead and measured main bearing clearance. The crank was freshly polished from the balance shop, and I also had them champher the oil holes, and check for straightness. With the crank measuring 2.7484-2.7485, I was able to use half a set of standard bearings, and half a set of .001's to give me clearance ranging from .0029 to .0031. From experience, I started with that bearing combination, so I was pleased with those results.

I also put the freshly reground GM roller cam into the block because I wanted to check to make sure the factory style lifters and "dogbones" would work properly. Everything looked find, didn't take any time to shoot photos now, but will do that when I get to actual assembly.

Ok,, caught a break from the wind earlier today and got the block painted, It's still black, but I think it looks a lot nicer with the sharp edges removed and no bare metal that will be exposed.

I went ahead and drilled the "Obnoxious" valve covers for the billet Rex Marine breathers, so that I can send the valve covers over to the polisher in the morning. I like those particular breathers even better since they started supplying them with an o-ringed base so that a gasket or silicone is no longer needed.

I filed the piston rings tonight also, so that I should be ready to assemble and complete the shortblock tomorrow. I got tired of filing rings by hand some time ago, and got one of the high dollar machines that measures the cut in thousanths. That takes some of the guesswork out of the chore, and also means less times in and out of the bores with the rings. I use a standard tool to square the ring 1" into the cylinder and measure the ring gap with a feeler gauge. I chose a Total Seal moly ringset.

I shot a couple of photos as I was talking to John on the phone, thought I might see if I could get them posted up before he gets home.

Got the pistons and rods almost ready to slip into the block. Note "Outlaw's" cylinder head on the bench behind them,, to nice to set it on the floor. Also a shot showing the "ARP lettering on the rod bolt", and one of the piston. It has some swirl marks from cleaning off carbon (remember, these are used parts), but much cleaner than it was. I used cratex rather than sanding or scotchbrite.

The shortblock went together smoothly, since all the measure, cleaning ring filing, etc were already done. I will probably wait until tomorrow to degree the cam and start looking at the heads.

The bearings are laid into the block,, pretty difficult to show them with assembly lube without getting the camera lubed. The clean crank gets set in position, and a magnetic fixture with a dial indicator set against the front of the block. End play is checked, and I had to loosen the rear cap and move the crank back and forth a couple of times with a large persuasive screwdriver to obtain .007" endplay.

Don't be concerned with the "dirty" looking smudges in the cylinders in some of the photos, simply protective oil that was carefully removed before the cylinders get a final light coating of oil. Meanwhile, the other four main caps were set in place paying attention to markings of position and direction. The caps all get torqued, and then I run the torque wrench around all of them a 2nd time to make sure. Then I rotate the crankshaft with my hand, feeling to make sure there is no binding. The Clevite assembly lube is sticky enough to keep the crank from just spinning, but I do have a pretty fair idea of what it should feel like, and I trust my measuring techniques.

Ok,, installing the pistons into the block means having oily hands, so no photos. I have a dedicated 4.470" piston installing ring, instead of an adjustable tool that always seems to let one of the rings hang up before it gets into the bore. After the rings are put on to their respective pistons (I number 1st and 2nd rings when I file them so they go back into the same cylinder they were measured for), I put the rod bearings into their housings. Since I had a split set of standards and 001's to get the .0026-.0027 clearance I wanted, rather than over .003" had I just used the standards, I made sure to keep all the .001's in the rod, and the standards in the caps, just for uniformity. The bearings get a liberal coating of the Clevite assembly lube, protective boots are put on the rod bolts as each piston is knocked into the block to make sure the steel ARP bolts don't put dings in the freshly polished crank. After all 8 are in the block, I flip the block over to torque and double check the rod bolts. I had previously checked with the shop (Revco) that installed the ARP bolts and resized them,, and used their same 75 ft lb torque setting.

Guess that's it for tonight, heading to Mooneyham in the morning to pick up the intake that they resurfaced for us, to fix the brown truck damage.

I got the heads pulled apart, cleaned and painted today, but will be waiting for John to show up with valve springs tomorrow before I can assemble them and bolt them onto the block.

Meanwhile, I degreed the cam. We just used a new GM single roller chain, and I was pleased to see that it was one degree advanced from the cam spec, which I would normally do to try and offset chain stretch. I wanted to bolt on the IMCO timing cover, but managed to mangle the seal when I tried to install it, so am stuck waiting until I can go buy a replacement tomorrow.

I shot a couple of photos of the Boostpower oil pan before I put them on the engine, right before John and Ian showed up yesterday. I like the way the windage tray fits into the pan, with the built in crank scraper. The screw in dipstick looks like a great idea, will see what needs to be done to make it work with tube headers. John may have to shorten it up, but should be relatively easy measuring equal amounts off the tube and dipstick, and from the "full" mark up to a new full mark on the shortened stick. The pan is black powdercoat over gold cad plate, so it should last a long time.

One last shot of the bottom end with the oil pump in place prior to bolting on the pan