1955-57 SMALL BLOCK LS1 INSTALLATION
1955-57 SMALL BLOCK LS1 INSTALLATION
In 1955, the a/I-new overhead valve 265 ci small block Chevy was all the rage and really put Chevrolet on the map. The small block Chevy soon replaced the flathead Ford as "the" hot-rodders engine. Ever since then, car-guys have been pulling the stock engines out of their cars and installing larger, more powerful engines. Next to the 1932 Henry, the Tri-Five Chevy's have become the most modified car on the planet In the '60's and '70's it was a hot 327 or 350 small block. In the 1980's it was time to shoe-horn in a big block Chevy. Now with a few more years of technology behind us, it's time to install an engine that requires no maintenance, is super lightweight, puts out unbelievable horsepower and torque yet gives you a car you can just jump in, hit the key and go. No pumping the gas pedal, adjusting the choke, mo setting the idle air acrews, no setting the points (what are they?). It's now time for a reliable engine with electronic fuel injection and a transmission that you just stick in gear and go. In the last few years, the LS1 engines used in Chevy F-body cars (Camara and Firebird) and Corvettes have become readily available at all salvage yards. It's time to get our hands on one of these engines and drop it into a Classic. The LS1 engine is part of the GM LS series which includes LS1, LS2 and LS6 small blocks. This installatoin procedure will work for all LS1, 2 and 6 series engines. In this article, when we refer to the LS1, we are referring to the LS2 and LS6 as well.
1O Millimeter Wrench
7 Millimeter Allen Wrench
14 Millimeter Wrench
Image #2: Prior to 1997, the non-LS engines had three bosses on the side of the engine block for the motor mounts. The 1997 and newer LS1 engines have four bosses on the side of the block for the motor mounts that will not bolt directly to the early style side mounts.
Image #4: The adapter plates are held to the side of the engine block with three 8 millimeter countersunk Allen head bolts. The lower forward hole is not used. When installing the bolts use a small amount of thread locker on the threads.
Image #5: The early style (pre-1997) side engine mount PIN 57-131968-1 is held to the adapter plate with two lock nuts at the top of the plate and one Allen head bolt at the bottom. The lower Allen head bolt will pass through the adapter plate and screw into the lower forward hole on the side of the engine block.
Image #6: The rear sump on a stock LS1 oil pan is far longer than the original small block pan. With the leng th of the sump, the steering drag link or rack and pinion mounting support will not clear, so a custom oil pan must be used.
Image #7a, 7b, 7c: We carry a modified GM cast aluminum oil pan PIN 18-228 that is designed to clear the steering component. This pan includes the oil pump pick up and pan gasket. For a more custom look, fully fabricated sheet metal oil pans are also available PIN 18-374 in steel or PIN 18-375 in aluminum. All three pans will work with the stock drag link or the CCI rack and pinion unit.
Image #8a, 8b, 8c: With the new oil pan installed, the engine can be set down into the frame. The side engine mounts are held to the frame brackets with 7/16" x 3" bolts and lock nuts on each side. There is a large rubber grommet between the engine bracket and frame bracket and a smaller one on the bottom of the frame bracket. (See Assembly Diagram below left.)
Image #9a, 9b, 9c: You can see how much steering linkage clearance there is with the modified oil pan. The left photo shows the stock drag link and the right photo shows the rack and
Image #10: The back of an LS1 engine block has the same bolt pattern as an early Chevy V8 engine with one exception, there are only five bellhousing bolts instead of the normal six bolts.
Image #11: The hub on the crankshaft for the flywheel or flexplate is specific for the LS1 engines. PIN 08-278 is the bolt kit for a standard transmission flywheel and PIN 57-176394-1 is the bolt kit for the automatic flexplate Torque the bolts to 45 ft/lbs. We installed the PIN 08-104 two-piece aluminum flywheel. This flywheel weighs just 12 pounds for quicker throttle response and an improved friction surface for a much better grip on the clutch disc.
Image #12a, 12b: We are installing the Centerforce II 11" clutch and pressure plate kit PIN 57-177348-1. The clutch disc has 21 splines to fit the Muncie M21 or the Tremec 5-speed transmissions.
Image #13: Along with the Centerforce II clutch kit, we are going to install an aluminum bellhousing, PIN 57-171998-1 which is a reproduction of the late 60's early ?O's big block bellhousing. The bellhousing has the standard bolt pattern that will accept a Saginaw, Muncie, Tremec or Richmond transmission and will bolt to small or big blocks and provides room for an 11" clutch.
Image #14: The Tremec 5-speed transmission PIN 57-175594-1 is a perfect compliment for the powerful LS1 engine. The Tremec transmission bolts to the PIN 57-171998-1 bellhousing with four 1/2" x 1½" course thread bolts and lock washers. The tubular transmission crossmember PIN 19-153 and transmission mount PIN 57-132252-1 will support the tail shaft properly. Refer to January 2006 Classic Chevy World for the complete Tremec installation.
Image #15a, 15b: Headers for the LSI PIN 24-137 are available painted black or silver ceramic coated These headers will work with a stock steering box, 605, 670 power steering box or a CCI rack and pinion unit. The headers will not work with manual clutch linkage, so if a manual transmission is going to be used, a hydraulic clutch system must be installed. Refer to October 2006 Classic Chevy for complete instructions.
Image #16: The driver's side header has an 02 sensor bung welded into the collector to be connected to the computer for the LSI.
Image #17a, 17b: Using the CCI side mount kit PIN 57-131968-1 and adapter plates PIN 18-400 to locate the LS1 engine there will be plenty of room between the back of the cylinder heads and the firewall. Installation of an automatic like a 700R4 is similar.
With everything mocked up we can't wait for our real engine to come back from the machine shop and so we can drop it into the frame. With the power, torque and smoothness of an LS engine and the durability and overdrive capability of a Tremec 5- speed the car will drive like a dream!