Few things are more annoying than the constant slow drip of a leaking oil pan--except for maybe a damaged engine thanks to an unexpected drop in oil pressure. Improper installation of either your oil pump or wet sump oil pan can cause either of these problems.
At Circle Track, we've suffered through our fair share of these frustrations. Everything from the simple stuff like that mysterious puddle of oil that appears on the shop floor (the source is impossible to trace), all the way to the spray of oil coming from the failed rear main oil seal that hit the headers and created an impenetrable fog of smoke filling a dyno cell. Hey, it's a mistake the first time it happens; it only becomes a problem when it happens the second time.
1 Many stock oil pump driveshafts...
1 Many stock oil pump driveshafts use a plastic collar to make sure the shaft stays engaged with the oil pump. This is a weak link. If you are using a shaft like this, replace it with a quality steel driveshaft that has a metal collar like the one you see here from ARP.
To help you avoid these kinds of gaffes, we gathered a few tips while rebuilding our Chevy dyno mule for an upcoming test. This is not only applicable on a new engine build, but any time you have to remove the oil pan. You may have to replace the pan if your motor is going into a different chassis, or if it gets damaged in a race. Or you may need to temporarily remove the pan if you suspect a rod bearing problem and want to inspect it without tearing the engine completely down.
Regardless, these tips can help you ensure that the oil pump is working as efficiently as possible so that your expensive race engine is receiving a constant flow of oil at a sufficient pressure--and avoid that annoying puddle of oil on the shop floor.
2 Especially with a pump...
2 Especially with a pump that has been through a few engine rebuilds, any nicks at the mounting flange can allow oil to leak past and hurt your oil pressure. A good precaution is to apply a thin film of silicone here before installing it on the engine.
3 The oil pump is fastened...
3 The oil pump is fastened to the rear main cap with a single bolt. Use motor oil to lube the threads on this bolt and torque to 65 ft-lbs.
4 Even with a new pump, it’s...
4 Even with a new pump, it’s a good idea to disassemble it and visually inspect the pump mechanism. The rotors should be undamaged without any large nicks or scratches. The cover plate should also be in good condition to ensure no leaks since no gasket is used here.
5 To help the pump prime...
5 To help the pump prime faster and get oil flowing to the engine more quickly, apply a liberal amount of grease to the rotors. We’re using Joe Gibbs Driven assembly grease because it’s super sticky and stays in place. It also melts completely in engine oil and won’t affect performance once the engine is broken in. We’ve also seen engine builders pack this cavity with lighter weight lithium grease. If you do this, make sure to change the oil after the rebuilt engine has been broken in.
6 Use blue Loctite on the...
6 Use blue Loctite on the oil pump cover bolts and torque to 23 ft-lbs.
7 Our oil pan is a racing...
7 Our oil pan is a racing pan from Champ Pans that has already been on the Dyno Mule. It comes with the pickup you see in the foreground that is matched to this pan’s sump.
8 Even with new pans—but...
8 Even with new pans—but especially with used ones—take a moment to inspect the pan rails to make sure they aren’t bent or warped. Use light taps with a hammer to straighten if necessary. Also, remove the windage tray to make sure the innards are clean and no debris is left behind. Finally, inspect any trap doors if the pan is segmented to make sure they swing freely and aren’t sticking either open or shut.
9 We’re using Cometic’s Street...
9 We’re using Cometic’s Street Pro gaskets for this build. This is a traditional four-piece oil pan gasket that is reasonably priced and provides great sealing.
10 Our oil pan is a racing...
10 Our oil pan is a racing pan from Champ Pans that has already been on the Dyno Mule. It comes with the pickup you see in the foreground that is matched to this pan’s sump.
11 Then measure the height...
11 Then measure the height of the bottom of the oil pump pickup tube (after it has been installed on the pump) down to the oil pan rail on the engine block. The difference in these distances should be 1/4- to 3/8-inch if you already have the gasket in place. If you are measuring without the gasket, the difference should be 1/8- to 1/4-inch.
12 This photo is from a different...
12 This photo is from a different build, but if you have too much of a gap it can lead to the pickup not being sufficiently covered in oil which will introduce a damaging air bubble into the system. You can change the height of the pickup by placing washers between the pickup’s flange and the oil pump.
13 Place a dab of silicone...
13 Place a dab of silicone at the edge between the rear main cap and the block’s oil pan rail. The rear main seal has a tab that should fit into a notch in the block.
14 After the gaskets have...
14 After the gaskets have been fitted together, add another dab of silicone on top. This is an area prone to leaks, so a little bit of silicone here is good insurance.
15 Repeat the process at...
15 Repeat the process at the front of the engine around the timing cover.
16 Before installing the...
16 Before installing the pan, putting a thin film of clear silicone all the way around the gasket will help seal against any scratches or small gaps. We’re only talking about a minimal amount here.
17 Before bolting the pan...
17 Before bolting the pan down, make sure it fits evenly around the seals without sitting too high off the rail. With some gasket manufactures the front seal sits too high and must be shaped on a grinder or else it will twist once the pan is bolted down or cause the oil pan flange to warp.
18 Don’t apply too much torque...
18 Don’t apply too much torque to the bolts securing the pan. You want just enough to cinch the pan snugly to the gasket.
19 Now that the pan is on...
19 Now that the pan is on you can be confident you will have a leak-free racing engine.