Anyone ever tried or thought of putting longer 4.8 rods with the 5.3 stroke? I know it would mean raising deck height somehow and using longer push rods but you would have the advantage of a more balanced engine and less piston slap.. Just a thought

 

It wouldn't work on an Iron block for 1 thing.

You can't just raise the deck on a Iron block. There is no way to maintain cylinder roundness through a spacer with out putting sleeves through it. Not to mention welding an Iron spacer to an Iron block...

On an aluminum block, ERL does this type of work for strokers and large bore displacement. But, the cost of machining a spacer and new sleeves are cost prohibitive to maintain the small bore and use factory parts.

On a factory height block, You would need custom made pistons.

 

Well now I know.. Figured maybe with custom pistons and a really thick head gasket it might be worth it but hell these ls engines can already turn plenty of rpms and hold up to stupid power I guess it would just be pissing in the wind. Thanks for the input though

 

You think too much.. You could have some custom pistons made but it would put your wrist pin up into the oil ring and consume a lot of oil.

 

Ok so I'm looking at another thread where the guy wants to take and use the 4.8 crank with the 5.3 rods and looking at the numbers he has and adding them up as if I were to be using the 5.3 stroke with the 4.8 rods if my calculations are correct it would only put my piston .17 out of the hole further than factory .008 which would mean if you could get a head gasket that's .17 thicker than factory it would work no?

 

If 4.8 rods = 6.276
And 5.3 rods = 6.098
Then 6.276-6.098=.178

Ok so almost .18 but does that not seem possible without having to sleeve cylinders and weld in a deck spacer?

 

You would need a head Gasket nearly .230 thick. That's pretty close to 1/4 inch...

Since the pistons are already up, out of the hole at TDC by approximately .008 The additional stroke would likely bring the top ring near the top of the hole or possibly out on a standard block.

 

Yeah, even with a thicker head gasket to allow for the piston to not hit the head, you are not taking into consideration that the top ring may be higher than the deck at TDC. Obviously you can't rely on your nearly 1/4" thick head gasket to act as a "cylinder extender" and keep the top ring tight on the piston.

About the only thing you can do that has been proven with factory 4.8/5.3 parts is to install the flat top 4.8 pistons on a 5.3 rotating assembly. This gives you roughly 1/2 point higher compression 5.3 for no added cost but some 4.8 pistons (which are cheap) and pressing out and in the wrist pins if you dont have a press to do it yourself.