L82 Bottom End.
Thread Starter
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
L82 Bottom End.
I'm looking for material on the L82 bottom end. I know some were four bolt and some were two bolt but is there a way to tell without pulling the pan?
Anything special about the rotating assembly that's different from an L48?
Did all L82s come with the splash shield bolted over the tops of the mains and did all L82s have the extra baffling in the oil pan?
Anything special about the rotating assembly that's different from an L48?
Did all L82s come with the splash shield bolted over the tops of the mains and did all L82s have the extra baffling in the oil pan?
Race Director
Joined: Jun 2000
Posts: 10,040
Likes: 672
From: FL
Not sure about the oil pan but believe that al L-82's had the windage tray.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
Le Mans Master
Joined: Mar 2004
Posts: 7,470
Likes: 1,491
From: Little Rock AR
Include the larger 8" harmonic damper with the L-82 vs. the 6.75" damper on the base engine.
All L-82 bottom ends have the forged flat tops, upgraded rods, steel crankshaft, 4 bolt mains, extended main cap studs and the windage tray. The engine suffix stamp would indicate the L-82 so that external ID method is about as good as it gets. Second only to pulling the pan off.
An L-48 could be found with a 4 bolt main but it would be very rare. There would have to be a shortage of 2-bolt blocks in the engine assembly plant and some spare 4-bolt blocks available. They both use the same casting but they are machined differently. L-48 4-bolt main possible? yes, likely? not very.
-Mark.
All L-82 bottom ends have the forged flat tops, upgraded rods, steel crankshaft, 4 bolt mains, extended main cap studs and the windage tray. The engine suffix stamp would indicate the L-82 so that external ID method is about as good as it gets. Second only to pulling the pan off.
An L-48 could be found with a 4 bolt main but it would be very rare. There would have to be a shortage of 2-bolt blocks in the engine assembly plant and some spare 4-bolt blocks available. They both use the same casting but they are machined differently. L-48 4-bolt main possible? yes, likely? not very.
-Mark.
Race Director
Joined: Jan 2003
Posts: 15,175
Likes: 86
From: State of Confusion
Not sure about the oil pan but believe that al L-82's had the windage tray.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
he was also told, but couldn't confirm, that when St. Louis would run low on L-48s, it's possible some L-82s were installed, while all paper-work read L-48, again, to keep production fluid.
My '79 Z28 came with an engine designated LM-1, but I believe it is identical to the L-48 in almost all aspects
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 971
From: Tennessee/Rhode Island
Not sure about the oil pan but believe that al L-82's had the windage tray.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
There were major differences in the roatting assemblies between L-48 and L-82.
- All L-82's were 4 bolt main with forged crank, pink rods (rods shotpeened for strength) and forged flattop pistons. Good basis for a buildup.
- The L-48's had cast crank, cast dished pistons, and normal rods. Some L-48's got a 4 bolt block but only when they ran out of 2 bolts. Basically standard GM car engine.
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
Although not directly related to the bottom end, the L-82 also had the higher torque starter from the big block and got the corresponding larger amp battery.
Just to add to the above: L-82 flat tops were 6cc relief volume, and mine cmae from teh factory with .015" thick steel shim head gaskets to give a perfect .040 quench.
Just to add to the above: L-82 flat tops were 6cc relief volume, and mine cmae from teh factory with .015" thick steel shim head gaskets to give a perfect .040 quench.
