Got a ? for the LT1 gurus
08-02-2008, 08:34 AM
#1
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Got a ? for the LT1 gurus I'm looking for a rotating assembly for a 93 Lt1 but am unsure of what will fit as far as cranks. I'm looking at (starts with a J and sounds like kegs)(not a sponsor) and they list assemblies from Eagle internally or externally balanced for Gm 350's with either a 3.480 or a 3.750 stroke.
My main ? is is there a differnece in the standard 350 crank and an LT based crank?
The engine I have spun a bearing on #8. I'm sure it can be machined.010 over but would rather just get an assembly. It's going to be a DD but would like to strengthen the bottom end slightly. I plan on going with the LT4 cam kit also upon rebuild.
Any help would be highly appreciated!
My main ? is is there a differnece in the standard 350 crank and an LT based crank?
The engine I have spun a bearing on #8. I'm sure it can be machined.010 over but would rather just get an assembly. It's going to be a DD but would like to strengthen the bottom end slightly. I plan on going with the LT4 cam kit also upon rebuild.
Any help would be highly appreciated!
08-02-2008, 09:23 AM
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The lt1 crank is a 1 piece rear main seal and is internally balanced. The lt1 pistons are also lighter. If all your plains are is for a hot cam i would just use freshened up stock stuff.
08-02-2008, 09:39 AM
#3
The LT1 crank has a one-piece main seal and is balanced externally at the flexplate and internally at the damper. If you switch to full internal balance, you'll need a different flexplate (or flywheel). For the application you describe, the crank you have should be more than adequate.
08-02-2008, 09:59 AM
#4
Eagle stuff is well known for dimensional issues. Scat is slightly more expensive but in the longrun often cheaper because the quality control is better.
The stock crank is better than the $200 aftermarket crap too so I would probably reuse it before buying a cast rotating assembly.
The stock crank is better than the $200 aftermarket crap too so I would probably reuse it before buying a cast rotating assembly.
08-02-2008, 02:33 PM
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The LT1 crank has a one-piece main seal and is balanced externally at the flexplate and internally at the damper. If you switch to full internal balance, you'll need a different flexplate (or flywheel). For the application you describe, the crank you have should be more than adequate.
Most people go to an internal balanced "rear" with thier performance rebuilds and a new flex-plate. The front is always internal with an LT and uses a dampner, not a balancer.
WD
08-02-2008, 05:17 PM
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So if I were to go with a new crank I would have to have my flywheel balanced to the crank? Eagle kits say they come with a new flexplate but the trans is an M6?
If the stock crank is more than adequate to for small mods I'll go that route and save a few $$$. I can get a reman crank kit from Oreilly's for about $250through my shop. I'll order the kit and see what it looks like before using it though!
If the stock crank is more than adequate to for small mods I'll go that route and save a few $$$. I can get a reman crank kit from Oreilly's for about $250through my shop. I'll order the kit and see what it looks like before using it though!
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08-03-2008, 07:48 PM
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You dont have to balance the flywheel to the crank, Just get the flywheel neutrally balanced. That is if you are going to go the internally balanced route.
Yes the stock LT1 crank is a pretty decent piece.
Yes the stock LT1 crank is a pretty decent piece.
08-03-2008, 11:21 PM
#9
Theoretically, if you buy a remanufactured crank kit, your flywheel should match the balance. The operative word is "theoretically." I would strongly advise rebalancing the internal rotating assembly as a unit with the flywheel you intend to use.
Also, if the bottom end got hot enough to spin a rod bearing you would be well advised to have the mains touched up with an align-hone before the cylinders are honed for new rings.
I don't think I could put anything inside my motor, particularly something labeled "remanufactured" without double-checking EVERYTHING. All the crank bearing journals should be checked with a micrometer and clearances confirmed with a bore gauge. A mistake on the part of the crank grinder as small as .001" could be enough to screw up everything. If you have questions about the checking procedure, PM me and I'll walk you through it. For a few bucks you can get all the equipment you need to do it right.
For the cost of a balance job and the time spent verifying clearances you might save hundreds or even thousands of dollars.
Good luck with the project.
c
Also, if the bottom end got hot enough to spin a rod bearing you would be well advised to have the mains touched up with an align-hone before the cylinders are honed for new rings.
I don't think I could put anything inside my motor, particularly something labeled "remanufactured" without double-checking EVERYTHING. All the crank bearing journals should be checked with a micrometer and clearances confirmed with a bore gauge. A mistake on the part of the crank grinder as small as .001" could be enough to screw up everything. If you have questions about the checking procedure, PM me and I'll walk you through it. For a few bucks you can get all the equipment you need to do it right.
For the cost of a balance job and the time spent verifying clearances you might save hundreds or even thousands of dollars.
Good luck with the project.
c
