I was just picking up my my block from the machine shop and a worker said that the 4.8 rods and the 5.3 rods are the same. Is this true because I always thought they were different.

 

Kindly tell the worker he is full of it.
4.8 rod length- 6.275"
5.3 (and all but LS7) -6.098"
.173" difference

 

They are not the same because they use a different crank.

4.8 is the only one that has different rods. All the others are the same as each other.

 

4.8= 3.780 bore, 3.480 stroke crank, 6.275 rod and a 1.255 CH piston
5.3= 3.780 bore, 3.622 stroke crank, 6.098 rod and a 1.331 CH piston
5.7= 3.898 bore, 3.622 stroke crank, 6.098 rod and a 1.331 CH piston
6.0= 4.000 bore, 3.622 stroke crank, 6.098 rod and a 1.331 CH piston
6.2= 4.065 bore, 3.622 stroke crank, 6.098 rod and a 1.331 CH piston
7.0= 4.125 bore, 4.000 stroke crank, 6.067 rod and a 1.173 CH piston

All LS engines share a 9.240 deck height.

 

For some dumb reason I always thought the LS7 had a higher deck height.... that's what I get for thinking.... lol

 

4.8 and 5.3 use the same CH for the piston.

 

I don't claim to know all there is to know about LS engines but let me apply the math here to the stock 5.3 combination.

3.622 divided by 2=1.811

1.811+6.098=7.909

9.240-7.909=1.331

I could be wrong and a 1.255 CH piston was used which put it down in the hole about .076 below the deck. Doesn't make sense to me as your giving up compression so I'm calling

 

Awesome. Now apply that math to the 4.8, but use the correct stroke of 3.268.

 

Wrong #s on the 4.8 crank so I stand corrected.

 

Are those 4.8 rods a good choice for making a stroker? What would happen if you put the 4.8 crank and rods in a LS1?

 

4.8 rods are good only for a DEstroker, since they are longer. When you stroke an engine, the rods get shorter

 

So as to avoid any more confusion, it should be mentioned that when you keep the piston compression height the same, the rods should be shorter when you increase the stroke in an engine. However, in reality, the rods are actually longer and the piston compression height is usually lowered when you go from a stock 3.622" stroke to a 4" stroke rotating assembly.

 

Back in the day, when you stroked an engine you always went to a shorter rod so you could keep stock pistons.
The compression heights of 5.3 and 4.8 pistons are the same. That's why you can use 4.8 pistons to gain compression in a 5.3 because they are flat tops (4.8) vs dished (5.3).

 

Must work, because some of the 5.3s like L33s have 4.8 pistons.

 

I know you can put 4.8 pistons in a 5.3 so they have to be the same compression height in order to do that. My error was thinking the 4.8 stroke was 3.480 throw crank which is not the case.

 

So the additional stroke is from a longer throw crank?

 

How ELSE would a piston move further up and down in a cylinder????
Unless you're being REALLY facetious.....

 

Well, I thought it was a combo of longer throw crank and longer rods since the wrist pin normally sits higher in the piston on LS stroker setups.

 

Rod length has nothing to do with stroke.

 

Thanks, I wasn't aware of that.