5.3 motor buildup
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TECH Apprentice
Joined: Oct 2003
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From: Florida
5.3 motor buildup I have a 5.3 that I am going to rebuild and had planned on going all out, but now I think because of budget restraints I am going to cut back on a some things. What stock parts can I use to obtain 400hp? I had planned on arp bolts, stock ls6 crank, stock connecting rods, patriot heads, and a TR 224 or larger cam. The only aftermarket parts would be forged pistons and the arp fasteners. I may run nitrous later on down the road. What are the other stock components good until? Such as the connecting rods? I want to get away as cheap as possible but still have a quality motor. If anyone could help or offer some cheaper alternatives to aftermarket parts please let me know.
TECH Fanatic
Joined: Apr 2003
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From: Albuquerque, NM
Originally Posted by benpimpin1
I have a 5.3 that I am going to rebuild and had planned on going all out, but now I think because of budget restraints I am going to cut back on a some things. What stock parts can I use to obtain 400hp? I had planned on arp bolts, stock ls6 crank, stock connecting rods, patriot heads, and a TR 224 or larger cam. The only aftermarket parts would be forged pistons and the arp fasteners. I may run nitrous later on down the road. What are the other stock components good until? Such as the connecting rods? I want to get away as cheap as possible but still have a quality motor. If anyone could help or offer some cheaper alternatives to aftermarket parts please let me know.
I am on the back side of a 5.3 buildup right now. I went a little different in the fact that I bored out the 5.3 block to the 5.7 slug size of 3.900". This opens up a LOT more piston/rod/head options for you. I had the block sonic checked afterward and there was plenty of meat left ( min is 0.150 period, my block min was 0.250 ). The machine work was around $350 using deck jigs. Normally the bore work is cheaper but they had to remove a lot of material since the 5.3 bore is 3.78". FYI, the crank/rods are identical on the LS1/LS6/5.3-LM7 motors. You already have a LS6 crank! I have verified the part #'s match. The stock bottom ends are pretty much good up to 500hp, including the rods. The big weak link is the oiling system as some oil pumps do not flow very well. You can get a good ported and blueprinted pump for around $150 that will take care of ya well.
I bought an awesome manual on Ebay for the LS1/LS6 motors. I will look up a thread and post it soon if interested. It has just about everything you need to know including tolerances, torque specs, and suggested modifications. Goes for about $20 shipped.
Patriot heads and a mild cam will put you right up there at 400hp, probably at the rear wheels! Eagle has also just come out with a stroker kit that will definitely get you up there and boost the torque numbers, really good for those heavy trucks. They are running around $2300 shipped, much more affordable than the Lunati ones at $4000.
Sorry about the length, drop me a line if you want more info. I'll post the manual info soon.
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From: Florida
I am definately interested, I had planned on doing the bore at 3.900" but hadn't heard anyone really that had done it, I am glad that it has been done so I wil also plan on doing the bore now. I also checked out the eagle crank, looked to be about half price of the lunatis, I think just the crank is around $800 as compared to the lunati being around $2000, I think the $4000 price of the lunati was for the whole rotating assembly. I have also seen the callies crank on ebay brand new for around $1500. Im not sure how far along you are on your build but I am definatley interested. If you could send me some more info and post some pics that would be great. I had almost given up hope on my poor little motor and was looking into 6.0's.
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From: Albuquerque, NM
Just looked on Ebay, could not find the manual. If nothing else I'll ship it to ya.
The block is ready to be picked up at the machine shop. I still need to pick up some bearings and gaskets but otherwise I expect to assemble and install by the end of the month. I'll take some pics soon of the block and sonic test slip and post them. I'll also take some pics of the assemble and install.
Parts I am installing are #241 heads, 02 Z06 cam and springs, new lifters, roller timing chain, ported oil pump, and new gaskets. I may go for the Eagle 373 stroker kit if the wife lets me use the tax refund!
Thanks for the interest, I'll definitely keep you updated on progress.
The block is ready to be picked up at the machine shop. I still need to pick up some bearings and gaskets but otherwise I expect to assemble and install by the end of the month. I'll take some pics soon of the block and sonic test slip and post them. I'll also take some pics of the assemble and install.
Parts I am installing are #241 heads, 02 Z06 cam and springs, new lifters, roller timing chain, ported oil pump, and new gaskets. I may go for the Eagle 373 stroker kit if the wife lets me use the tax refund!
Thanks for the interest, I'll definitely keep you updated on progress.
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From: Florida
Sounds great, wish I was that far along. Im still deciding what route I want to go then i am going to start buying all my parts so they are ready to ge when I have it machined. Are you installing ported heads or stock? And why are you going with the zo6 cam? I was looking at something like a TR 224 and was told that I would have much better gains with that over a z06 one. Just wondering if there was any reason. Thanks Ben.
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Joined: Nov 2002
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From: Los Angeles
I just had my 5.3 rebuilt because I blew up #7. I went with stock sized pistons though. My engine builder called around and no one had off the shelf pistons for the 5.3, so we had to get them custom made. I went with Ross because that's what he preffered and because they were local. It took almost a month and a half to get them custom made because they never made them before. If you're looking to go the quick route, you should give them a call since they already have the specs now. I also went with Eagle H-beam rods.
In hindsight, I wish I went with the 3.9 bore. I didn't know it was possible.
In hindsight, I wish I went with the 3.9 bore. I didn't know it was possible.
