Hello all, are the piston pin heights close enough to use the flat top 4.8 pistons in a 5.3 to get a little bump in compression. I am just curious cuz I have seen info that it would work and give you about 10.5:1 compression, and other people have told me it won't work.

 

i think we have decided it will work im gonna try it whats the worst that could happen??

 

I'm pretty sure that the wrist pins have different heights . . .

 

some say the do some say they are the same i will know soon im gonna buy a set put them in a 5.3 with scat rods stock 5.3 crank with all new bearings and a cam
the motor i pull out of my truck will get 4.8 crank 4.8 rods with upgraded rod bolts 5.3 dished pistons and some 317s or 035s get that compression way down there
put a turbo or two on it and run her till she blows
why u ask????
just because i can

 

Hey guys I checked out MotTec Inc and did some math, just let me know if I am going down the right path.
4.8 stroke 3.27"/5.3 stroke 3.622" | Difference=0.352"
4.8 rod 6.278"/5.3 rod 6.098" | Difference=0.18"
The change in crank throw that the rods have to make up would be =.176"
So in my mind the pin height between the 4.8 and 5.3 is 0.004" 4 thou doesn't seem like the much of a difference. At least I think that my engine math is somewhat correct.

 

4 thousanths higher up or lower??

 

Instead of going threw all that why don't you just have the heads milled, run a thinner gasket??? Just curious, that seems like alot to go threw just for a comp bump...

John

 

or change the pistons and mill some 243's to like 59 cc

 

I am building the motor from scratch so its no problem as long as its a simple piston swap.

 

im puttin milled 243s and 4.8 pistons muahahahahaha