4.8 with 5.3 pistons anyone done it
#1
4.8 with 5.3 pistons anyone done it
Has anyone ever done this if so what was the results looking to build this motor out of leftovers from building a cast iron l33 i have all leftover parts to use 5.3 pistons in the 4.8. Would this make a good turbo motor?
#4
The point is it would be an extra motor built out of spare parts that would also be turbo charged so the lower compression wouldn't hurt I wouldn't think but that's just my thoughts looking for reasons why this won't work and if anybody has ever done this what the outcome was
#5
TECH Fanatic
The pistons are interchangeable since the rod lengths maintain the factory compression height with the different stroke cranks.
Just remember that you lose compression with the shorter stroke, so if your 5.3 pistons are dished, you are going to have even less compression than a comparable LM7. Out of boost, the engine will be a dog.
Just remember that you lose compression with the shorter stroke, so if your 5.3 pistons are dished, you are going to have even less compression than a comparable LM7. Out of boost, the engine will be a dog.
#6
Teching In
iTrader: (1)
Using the 5.3 piston would be a great way to get the motor Turbo ready. The smaller stroke of the 4.8 will also compliment the turbo idea. Remember the rod length for the 4.8 is longer than the 5.3 so you will need to verify PTV if you use the either rod. You would then just need to decide on what heads to use. The 317 will have a lower compression than a 243/799, but there are places out there that has all the specs for all the different heads. If it were my motor I would want larger chambers and larger runners to promote lower compression and better flow numbers.
Last edited by 68Poncho; 04-15-2016 at 03:14 PM.
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#10
TECH Addict
iTrader: (15)
We've discussed this quite a few times but I think we come down to balancing throwing the budget off. Last time we were talking 5.7 pistons and rods in a bored 5.3. Would we run into the same issues here? That is, it'll fit but unless you invest in proper balancing at a machine shop, it would rattle your teeth out?
#11
TECH Senior Member
iTrader: (26)
haha i just recently put a motor together with gen 4 4.8 slugs, gen 4 5.3 rods and a gen 3 5.3 crank. right after we were talking about and iron 5.7 i decided to try an iron L33
the floater 4.8 slugs were 425-430g compared to the 415-440g 5.3 press-fit slugs
i did not weight the rods or the wrist pins.
i'm guessing it'll rattle like crazy. or maybe not?
the floater 4.8 slugs were 425-430g compared to the 415-440g 5.3 press-fit slugs
i did not weight the rods or the wrist pins.
i'm guessing it'll rattle like crazy. or maybe not?
#14
Restricted User
#15
TECH Addict
iTrader: (15)
The short stroke of the 4.8 crank is what is referred to I believe. Turbo is a little out of my wheelhouse(but have my project 4.8 ready when my wallet is ready) but I believe the (longer?) piston dwell time is what makes the 4.8 so good for boost. Hot Rod mag did a project with a 5.3 that was stock bottom end, even had some rust in a cylinder. Made something like 1100 horsepower without it blowing up and THEN discovered it was actually a 4.8 all along! After reading that I hit Craigslist for a 4.8 the next day. You know, because I'm stupid and don't have enough junk in my garage already. ;-)
#16
Restricted User
The short stroke of the 4.8 crank is what is referred to I believe. Turbo is a little out of my wheelhouse(but have my project 4.8 ready when my wallet is ready) but I believe the (longer?) piston dwell time is what makes the 4.8 so good for boost. Hot Rod mag did a project with a 5.3 that was stock bottom end, even had some rust in a cylinder. Made something like 1100 horsepower without it blowing up and THEN discovered it was actually a 4.8 all along! After reading that I hit Craigslist for a 4.8 the next day. You know, because I'm stupid and don't have enough junk in my garage already. ;-)