L92 Crank in LS2 Block, Budget Build?
05-29-2008, 12:19 PM
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L92 Crank in LS2 Block, Budget Build? I have a brand new LS2 block that I am looking to pull together into a very budget friendly, street driven combination. I had originally intended to re-sleeve this block as a spare to another engine, but plans have changed and I am looking to build this up for a performance cruiser (69 Camaro convert). In addition to the block, I have a nice sheet metal intake for the LS3/L92 type heads that will be used also. The price of the L92 crank is very attractive, using this, with a set of forged pistions and modest set of aftermarket rods should handle anything I throw at this combo.
The question I have is for a rotating assembly. I have read repeatedly that the crank on the L92 engines is a cast unit, not a forged, but that's okay. The stroke is 3.622", and I have found an off-shelf piston solution from Mahle that will work with an aftermarket set of 6.125" rods, so using these and a set of used rods is also in the plan. So, the main question is if the L92 crank will support this configuration.
Will it fit into the LS2 block without any needs to modify either the crank or block? I know that the L92 has VVT, but will a stock style/LS2 timing chain setup work with it? Any issues with the reluctor wheel (58x is fine, I don't have a controller yet anyway)? Will a standard style accessory drive work with it? LS2 covers, etc? Oil pump?
Completely appreciate any direct experience and feedback, thanks in advance.
Mark
The question I have is for a rotating assembly. I have read repeatedly that the crank on the L92 engines is a cast unit, not a forged, but that's okay. The stroke is 3.622", and I have found an off-shelf piston solution from Mahle that will work with an aftermarket set of 6.125" rods, so using these and a set of used rods is also in the plan. So, the main question is if the L92 crank will support this configuration.
Will it fit into the LS2 block without any needs to modify either the crank or block? I know that the L92 has VVT, but will a stock style/LS2 timing chain setup work with it? Any issues with the reluctor wheel (58x is fine, I don't have a controller yet anyway)? Will a standard style accessory drive work with it? LS2 covers, etc? Oil pump?
Completely appreciate any direct experience and feedback, thanks in advance.
Mark
05-29-2008, 09:16 PM
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05-29-2008, 09:42 PM
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I don't think there's really any difference in the LS1, LS6, LS2, LS3, L92, or L76 cranks besides reluctor wheels. They're all cast nodular iron. Some may have radiused journals but I doubt it. Correct me if I'm wrong. I'd love to know the difference if there is. The LS7 is a 4.00" Forged Steel one with a different snout.
05-29-2008, 09:57 PM
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The truck motors are a different story though. The 4.8's use shorter cranks and the 5.3's had differences in flange widths and 6.0 LQ4 and LQ9 cranks I wouldn't fool with because there are differences in balance.
05-30-2008, 08:09 AM
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LS2 and L76 might be the same balance.
L92 and LS3 might be the same balance.
05-30-2008, 12:47 PM
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Thanks guys, I hadn't thought too much about using an LS2 crank, as I understood that they are a lot more expensive than the L92 units (they build a LOT more trucks than they do Corvettes). Couldn't find the part number for the LS2 unit, but I had looked in the past and recall it was about $600 new, which is too close to the price of a stroker that I hadn't given it any further thought. A take out might be a good idea unless I have to have it turned, not sure what the factory heat treat is, and of course, it's more money. That's why the L92 looked so attractive: new piece, cheap. SD lists a host of parts for the L92, such as a keyway, crank sprocket, bolt, etc on their website which implies to me that these are unique to the L92.
A full parts breakdown/exploded view would be SO helpful for these types of questions, but I haven't been able to find such info for either the LS2 or L92. There are some great part number lists on this forum, but it's not all-inclusive. Tough for a guy like me building his first Gen IV.
Thanks, maybe easiest to find a take-out LS2 crank from a stroker conversion. Got one handy?!
Mark
A full parts breakdown/exploded view would be SO helpful for these types of questions, but I haven't been able to find such info for either the LS2 or L92. There are some great part number lists on this forum, but it's not all-inclusive. Tough for a guy like me building his first Gen IV.
Thanks, maybe easiest to find a take-out LS2 crank from a stroker conversion. Got one handy?!
Mark
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05-30-2008, 03:36 PM
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I wonder if the cranks for each displacement are actually the same even though they have different casting numbers. It doesn't make sense to me for GM to make 2 different nodular cast iron cranks for the same displacement motors.
05-30-2008, 11:48 PM
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Originally Posted by Mean 69
The question I have is for a rotating assembly. I have read repeatedly that the crank on the L92 engines is a cast unit, not a forged, but that's okay.
Some Gen IV Vortec engines use aluminum cylinder blocks, which offer reduced mass – an attribute that supports improved vehicle weight distribution and slightly improved fuel economy. The aluminum blocks are virtually identical to their iron counterparts, including a deep skirt design that incorporates cross-bolted main bearing caps and a structural oil pan. All engines, except the 6.2L L92, use a proven iron crankshaft design and highly durable reciprocating components. The high-performance 6.2L L92 uses a forged steel crankshaft.
05-31-2008, 02:11 AM
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That's old news. Unfortunately it's wrong. At the last moment GM changed their mind and production engines got cast iron cranks instead. Remember...the LS7 was supposed to get Forged pistons. Looks like the GM bean counters did some last minute cost cutting on the L92.
