need help building a 5.3
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 55
Likes: 0
From: Concord, North Carolina
need help building a 5.3 I would like to build a good engine for my jeep. (It has a stock 5.3 now) I have a 5.3 and a 4.8 engine in the garage. I also have some LS1 pistons & rods. I have heard if I use my 4.8 rods, a 4.00 crank, and bore the block for the LS1 pistons I will have a 383 block. Has anyone tried this? Will it work?
Thanks in advance & Merry Christmas.
Thanks in advance & Merry Christmas.
The block would need to be bored to a 3.905 with a 4'' stroke to be a 383. So in that case you can't use a stock LS1 piston because they are only 3.898. Also, you said it's a stock 5.3, then asked if you could use your 4.8 rods? 5.3's have dished pistons and 4.8's have flat tops. Might want to see what you're working with first. Good luck!
Thread Starter
Staging Lane
Joined: Oct 2006
Posts: 55
Likes: 0
From: Concord, North Carolina
The block would need to be bored to a 3.905 with a 4'' stroke to be a 383. So in that case you can't use a stock LS1 piston because they are only 3.898. Also, you said it's a stock 5.3, then asked if you could use your 4.8 rods? 5.3's have dished pistons and 4.8's have flat tops. Might want to see what you're working with first. Good luck!
I have these 2 engines and hoped to use as many parts as I can to make a good LS engine. The reason I asked about using the 4.8 rods is because I've read that you need 6.2 rods when using the 4.00" crank in a 383. The 4.8 has the 6.2 rods, right?
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
Ultimately, you need to optimize your component geometry to meet your target piston deck height (height of piston at TDC relative to block deck surface, this is a negative value for piston "out of the hole"), which is a variable in determining your static compression ratio. There are 4 variables in determining your piston deck height:
A. stroke/2
B. rod length
C. piston compression height
D. height of block deck surface to centerline of crank bores, after any extra surface machining.
A + B + C + (piston deck height) = D
You could possibly use 6.2 rods, depending on your piston compression height, etc. Do the math and find the right combination to achieve your target piston deck height.
