Читать книгу LS Swaps - Jefferson Bryant - Страница 9
ОглавлениеOnce the motor mounts have been sorted out, the next step is to choose an oil pan. Many stock oil pans are available for LS engines, each one designed for a specific chassis. With so many different oil-pan options, there is confusion as to which oil pans fit which chassis.
The relationship between the front crossmember and the motor mounts determines the fit of the oil pan. Each brand of motor mount is different, and the engine-mount towers used on the frames can differ by application as well. Although there are several stock pans that fit certain vehicles, they don’t always fit as is, and there are different depths and clearances. In the end, there will probably be some trial-and-error test fitting to find just the right pan.
Usually, a stock oil pan and stock crossmember can be modified to a particular chassis. In many cases, cutting a small notch on the back side of the crossmember, then filling it with 1/4-inch steel (boxing it in), reinforces and strengthens the crossmember while allowing the engine to sit in place. However, this does not work for every application.
Using a stock oil pan can greatly simplify the installation, provided it’s the right one. There are many designs, but only a few are desirable for engine swaps. These are the 1998–2002 Camaro, the 2002–2006 truck, the C5 Corvette “Y” (also referred to as the “batwing” due to the dual kickouts on the sides), and the Cadillac CTS-V pans. These stock oil pans have proven to be the most versatile and fit many vehicles without modifications. There are, of course, many other pans that might fit.
The 1998–2002 F-Body LS1 pan is the most commonly used LS oil pan. Typically referred to as the F-Body or Camaro pan, it works well with custom chassis crossmembers, and it is also the most frequently modified pan. It fits most 1958–1964 GM cars without any modifications. (Photo Courtesy Chevrolet Performance)
Popular LS swap platforms have had the oil-pan fitment issue hashed and re-hashed since the first LS swap was done. The problems arise when you swap an LS engine into something that is not a typical GM A-Body, truck, or F-Body. These issues must be addressed when mocking up the motor mounts and modifying or building the front crossmember. Sump depth also needs to be considered, as several stock pans may clear the chassis itself, but ground clearance can become an issue when the sump hangs below the crossmember, especially on lowered vehicles.
In a typical installation, more than one pan probably fits the vehicle. Case in point: the LH8 oil pan (a special pan for the 5.3-powered Hummer H3) easily fits GM A-Body cars. However, with a typical adapter plate and motor mount installed, the LH8 pan rear sump hangs about 1½ inches below the engine crossmember. This is acceptable for standard-suspension-height cars, but if the car has a low ride height (especially an air-ride suspension) there may not be enough clearance between the pan and the pavement, and it could be damaged.
This diagram shows the three most common LS pans and their measurements. In order to select the right pan for your swap, consider the engine bay, crossmember, and steering clearances. Each pan requires a dedicated pick-up tube and windage tray. (Photo Courtesy Street & Performance)
The Brewer’s Restoration and Performance motor mount kits use the LH8 oil pan, but the motor mounts are specialized and position the engine differently in the car than most other adapter kit installations, allowing the LH8 pan to work quite well. Additionally, each oil pan requires its own specific windage tray, pick-up tube, and dipstick. When selecting an oil pan, make sure it comes with these parts so they don’t have to be purchased later.
Several blocks and oil-pan configurations place the dipstick tube in the pan rather than in the block. In order to use a non-dipstick tube pan on these engines, the machined boss on the passenger’s side of the block must be drilled out. Using a 3/8-inch drill bit, drill it through (about 1/8 inch of material), and slide the tube right in.
One more note on factory oil pans: they can be swapped from engine to engine, but there are a few points that need to be considered. The pick-up tube and windage tray go with the oil pan, not the engine. These items are a matched set, so anytime an oil pan is swapped, the correct tube and windage tray must be swapped as well.
Additionally, displacement on demand (DoD) engines have an oil-pressure bypass valve built into the oil pan. If the DoD system isn’t going to be used, then it doesn’t matter. For engine swaps using the DoD system, however, an oil pan with the bypass valve must be used.
F-Body Camaro/Firebird Oil Pan (PN 12558762)
The most commonly used stock oil pan is the Camaro/Firebird pan. According to Street & Performance, the 1998–2002 Camaro/Firebird IROC pan fits 1958–1964 GM cars without modification, though the fit is tight.
All 1955–1957 and 1965–up GM cars require modifications to the Camaro oil pan. The problem here is that the oil pan interferes with the front crossmember, keeping the engine from sitting down on the mounts. About 2 inches of depth must be removed from the front edge of the rear sump, along with a large section of the front of the sump. The aluminum oil pan must be tungsten inert gas (TIG) welded, and even an experienced welder can quickly ruin an oil pan. Therefore, consider buying a modified or custom aftermarket oil pan.
Some builders have used the Camaro pan in 1965-up GM muscle cars without modification. They used their own custom-built motor mounts. It depends on the particular engine/transmission package and chassis as to whether this pan fits unmodified.
The Camaro oil pan also fits well, unmodified, in the C2 (1962–1967) and C3 (1968–1982) Corvettes. The F-Body oil pan’s rear sump measures 5 inches deep, 11½ inches long, and 9½ inches wide. The shallow front section is where most of the interference occurs. The frontmost section is flat for 4¼ inches, and then slopes at a steep angle for 4¾ inches. About 1½ inches of the sump’s depth must be removed from the first 4 inches of the front section of the rear sump to allow it to fit into the 1967–1969 F-Body.
Many swappers use this pan in stock form for Fox-Body Mustang swaps.
2002–2006 C/K Truck Oil Pan (PN 12579273)
This oil pan is fitted to all 4.8-, 5.3-, and 6.0-liter C/K trucks and Escalades. This pan features a long, shallow front section (12¼ inches) with a crossmember-friendly, short, 8¾-inch-long rear sump. The rear sump is quite deep (8¼ inches), making it a poor candidate for most car applications. It is, however, a great pan for trucks, and it fits without modification in 1960–up Chevy and GMC trucks and SUVs (Blazer, Suburban, etc.).
Early Vortec oil pans fit many vehicles, but the deep rear sump can be problematic due to lack of ground clearance. Most trucks accept this pan with ease. (Photo Courtesy Street & Performance)
The 2007-up Vortec pan works well in the 1960-up GM truck swaps, but the deeper pan can be an issue for lowered trucks and cars. (Photo Courtesy Paul Chiver)
