Anyone know all the differences? I thought the only difference between them was the heads, but I read in another post that the crank was different. I have an LLY on an engine stand that I have been buying stuff for one piece at a time with the intention of putting it in my 03 and now I'm wondering if I might not be able to without some other mods.:damnit:
Differences between LB7 and LLY bottom end?
- Thread starter Bluemax
- Start date
Somebody has posted the counterweight location is different.
This could be very important if folk are breaking LB7 cranks, but not LLY cranks.
A LiLLY is fully counterweighted, yet externally balanced. This means every crankshaft throw has a counterweight, but more weight is needed so the harmonic balancer and flexplate/flywheel has an offset weight built into them.
I'm really mad at myself for selling the $600 LB7 engine I had.
This could be very important if folk are breaking LB7 cranks, but not LLY cranks.
A LiLLY is fully counterweighted, yet externally balanced. This means every crankshaft throw has a counterweight, but more weight is needed so the harmonic balancer and flexplate/flywheel has an offset weight built into them.
I'm really mad at myself for selling the $600 LB7 engine I had.
Well, I called somebody who has both sitting there.
THEY ARE DIFFERENT!!
That's what I get for believing everything on the internet, I've been told for years they are the same, and I've been repeating it.
Counterweighting is different. Do not swap balancers or flex plates.
THEY ARE DIFFERENT!!
That's what I get for believing everything on the internet, I've been told for years they are the same, and I've been repeating it.
Counterweighting is different. Do not swap balancers or flex plates.
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alright got it, thanks Pat...Im basically just using the entire short block from a 2001 LB7. Ill keep all the parts together with it; balancer, flywheel, flex plate, etc..
when I have the rotating assy balanced at the machine shop, do I need to tell them anything special, other than "its an externally balanced motor"??
ben
when I have the rotating assy balanced at the machine shop, do I need to tell them anything special, other than "its an externally balanced motor"??
ben
still think its advantageous to go with an LLY shortblock? It won't matter to me once I reach that point, I'll still run LB7 heads et. al. but if there is a CLEAR better option for the bottom end, then by all means, I'll try and run it. 
C-ya
C-ya
:damnit::damnit::damnit::damnit::damnit:
I knew a free motor was to good to be true. What would be the advantages and disadvantages to swapping them?
Or for that matter, is the crank the only difference? I'm gonna have the crank out for bearings anyway maybe throw the lb7 crank in it if it's better
I knew a free motor was to good to be true. What would be the advantages and disadvantages to swapping them?
Or for that matter, is the crank the only difference? I'm gonna have the crank out for bearings anyway maybe throw the lb7 crank in it if it's better
Winner! Winner! Chicken :chicken
And here John had my hopes all up :getout: :banging:
I knew that change happened but I thought it happened much earlier. Like early 02. I will go look but I beleive my cranks are fully counter weighted. I thought the different balancer was only 06 LLY and up. Little known tid bit but some 06 LLYs came with LBZ bottomends. i.e pistons and such including balancer. Pat is there any chance that was a 06 LLY?
FWIW the block has changed some to but nothing that effects us. Some LB7s have extra mounting points on them. IIRC this is for the 4500 and up trucks.
I am sticking to my story. Ben come get your dinner!:rofl:
FWIW the block has changed some to but nothing that effects us. Some LB7s have extra mounting points on them. IIRC this is for the 4500 and up trucks.
I am sticking to my story. Ben come get your dinner!:rofl:
It was Dave at BMS who checked for me, and he has LB7/LLY/LBZ rotating assy's there.
I always thought the LB7 was the same.
But it makes you wonder what year the swap was done. Maybe some LB7's ARE just like LLY's.
I know for a fact the LLY is different than the 06+ trucks. You can see it the difference without taking apart the engine. On a LiLLY the counterweight lump on the balancer is about 90 deg. On the LBZ it's way wider, like 150 deg.
I figured you asked Dave.
I went out to the garage after I finish plowing out the in-laws. My 02 crank appears to have full counter weights. My 04 is at balance so I can not look at it right this moment. IIRC the crank was beefed sometime late 01 to early 02. More mass was added but the overall balance was not changed.
What surprised me about the LLY with LBZ bottomend was that it was not a Bosch ECM. It had the Delphi ECM, FICM set-up. Like you said the Balancer is a dead give a way if you are looking for it. But he was not. It was not until the pistons where out and he saw the wristpin bushings that he knew something was up. If you have LBZ pistons you have to have the crank and the rest of the rotator to go with it.
I would be more than happy to take a pick of my 02 crank in the block to show the weights. I have to go to the dealer to pick rings tomorrow. If I remember I will check the balancer part # for a 05 LLY vs. a 02 LB7
I went out to the garage after I finish plowing out the in-laws. My 02 crank appears to have full counter weights. My 04 is at balance so I can not look at it right this moment. IIRC the crank was beefed sometime late 01 to early 02. More mass was added but the overall balance was not changed.
What surprised me about the LLY with LBZ bottomend was that it was not a Bosch ECM. It had the Delphi ECM, FICM set-up. Like you said the Balancer is a dead give a way if you are looking for it. But he was not. It was not until the pistons where out and he saw the wristpin bushings that he knew something was up. If you have LBZ pistons you have to have the crank and the rest of the rotator to go with it.
I would be more than happy to take a pick of my 02 crank in the block to show the weights. I have to go to the dealer to pick rings tomorrow. If I remember I will check the balancer part # for a 05 LLY vs. a 02 LB7
Just because the Cranks are different doenst mean that the balance is. Lets not get our panties in a knot yet. Im more than willing to bet its the same. The LBZ would need more weight due to the beefier rods and the (most likley) lighter pistons .
Nobodies panties are in a knot!:rofl: If it looks like I was argueing I apoligize!
LBZ pistons are actually heavier and have a longer skirt. The skirt is why you must use them with the correct crank. LBZ pistons will most likely hit the counter weight on a LB7/LLY crank at BDC. Your are right about the rods being heavier but I am not sure how much.
As far as I know the all non LBZ cranks are interchangable. They are differences but they will work. But I could be very wrong.
LBZ pistons are actually heavier and have a longer skirt. The skirt is why you must use them with the correct crank. LBZ pistons will most likely hit the counter weight on a LB7/LLY crank at BDC. Your are right about the rods being heavier but I am not sure how much.
As far as I know the all non LBZ cranks are interchangable. They are differences but they will work. But I could be very wrong.
Engines
Johnboy, I have a 03 lb7 that i'd do some swapping on LBZ parts. I would llike to find a lbz bottom end(after rebuild) to put my top end on. Jeff
Johnboy, I have a 03 lb7 that i'd do some swapping on LBZ parts. I would llike to find a lbz bottom end(after rebuild) to put my top end on. Jeff