HOTSIX

Hey guys - I'm relatively new to the LS engine. Im looking at building a 5.3 truck motor or buying an LS1 outright. It would be dropped in an S10 truck conversion.

I understand the basic difference is that the 5.3 truck motor is an LS style engine and has an iron block - LM7 etc compared to the aluminium LS1. They seem pretty cheap at the yards running around 700-1000 or so.

My question is can I buy one of these LM7 5.3 truck motors and bolt an LS6 intake on it, throw an LS6 cam in it, have the computer programmed to work and go? Is all of this stuff easily just swapped onto this motor?

What kind of HP could I expect if the above is possible?

Like everyone else I'm trying to keep the cost down and if its possible to do the above I could avoid spending $2000 plus on a used LS1....

remauto1187

iTrader: (1)

Im doing the same thing right now. If you are buying a 5.3L and going to totally have it rebuilt you might as well take it to the 5.7L bore since you are going to have to bore it for oversize anyway and would have to buy o/s pistons as well. Get the 5.7L pistons and technically have a LS1 iron block. Crank and rods are the same in a 4.8/5.3/5.7l so you can reuse the lower end of a 5.3L! LS1/LS6 will bolt right up to the 5.3L. I am going with the LS6 intake but mine is going in a vette. Your 5.3L is going to have the truck heads on it which will limit you! buy some salvage yard 243/799 heads which are LS6 heads. The truck heads will not have the 2" valves, they are smaller.

Enjoy!

NemeSS

iTrader: (127)

Just get a basic 5.3 instead of boring to 5.7 displacement. I use to machine and assemble engines and IMO it's more cost effective to invest in a 6.0 iron block if u get into building it up. Just run it from jy with parts u mentioned. They all work. Ls6 intake bolts on. Ls6 cam works. Etc.
Don't worry about valve sizes the 5.3 heads are enuff at this level.

remauto1187

iTrader: (1)

Because if he/I wanted to spend the EXTRA money on a 6.0L we would have.
And once again....engine will have to be bored so why not get the extra cubes of the 5.7L since we will have to buy pistons anyway for the same cost. Heads are going to have to be ran through anyway so might as well make it what originally came on a 5.7L instead of the smaller intake size of the 5.3L.

My target is 350hp and anything above is gravy.

NemeSS

iTrader: (127)

You build ur engine any way you want. You obviously have never built one of these engines before. Most of your information is incorrect. It takes more than just bore and use 5.7 bore pistons. And since when are the 4.8 and 5.3 rods and crank the same???

HOTSIX

Thx a lot fellas.

I'm hoping to just get hold of an engine that I wont have to open up - one that is in decent shape and without a huge amount of miles on the ticker. That way I really keep cost down. Just swap out intake, cam, injectors for the LS6 stuff and go.

I figure the 5.3 is a near 300 hp engine stock anyway so the LS6 intake and cam should really wake it up and be more then enough for my S10.

Trouble on the LS6 heads is they're pretty scarce up here Ont. Canada from what I can tell so far - and those that have 'um want way too much for something that may have had way too much abuse.

I figure even with those parts I should be able to make some decent power.

NemeSS

iTrader: (127)

That's a good starting point. Use those parts on a 5.3. Although the scr of a 5.3 is usually 9.4:1 depend on yr u end up with. The 243/799 heads engines have higher scr but usually cost more than 706/862 heads engines.

remauto1187

iTrader: (1)

Found that the 4.8L is indeed a shorter stroke.
But...

The 5.7 L shares little other than similar displacement, external dimensions, and rod bearings, with its predecessor. It is an all-aluminium 5,665 cc (5.665 L; 345.7 cu in) pushrod engine with a bore of 3.898 in (99 mm) and a stroke of 3.62 in (91.9 mm).

The Vortec 5300 is a V8 truck engine. It is a stroked (by 9 mm) version of the Vortec 4800 and replaced the 5700 L31. Power output is 285-300 hp (223-239 kW) and torque is 335 lb·ft (454 N·m) to 350 lb·ft (475 N·m). Displacement is 5.3 L (5,328 cc (325.1 cu in)) from 96.01 mm bore and 92.00 mm stroke.

Stroke is close enough for me.

I suppose car craft and god knows whom else that have built the 5.3L into 5.7L engines dont know what they are doing either, huh?

And no...i haven't built a lsx motor before. But i can like most otheres here, read!...now gen 1's..i have done more than you got fingers and toes. So how many ls engines have you done since we are attacking personal experience statistics?

NemeSS

iTrader: (127)

Ok dude
I've only actually machined and built the 5.3 to displace 5.7 before so I think I have some insight about it. You failed to comprehend the info I was giving to the op. Which is first hand hands on exp. Not something I read somewhere. It takes more than just boring the block and bolting in the 5.3 crank,rods and ls1 pistons. Have built more than enuff sbc and ls motors to know when I see bunk info.

remauto1187

iTrader: (1)

I usually can tell when someone is full of themselves and they tend to argue how something is wrong but fail to provide a more correct answer.


It takes more than boring and bolting in the 5.3l crank and rods.... ??? SAY WHAT? Did they invent more internals in the lsx that only you know about? Seriously? Dude?

5.3L rods, crank and ls1 pistons yield 347ci. Im definitey not the first one to do it.

parks450

iTrader: (17)

4.8L motor:
293 CI
3.780" Bore (same as 5.3L)
3.27" stroke
290 HP'
Rod Length 6.278" powdered metal cracked cap design

5.3L
325 CI
3.780" Bore ( same as 4.8l)
rod length 6.098" ( same as LS1) powdered metal cracked cap design
3.622" stroke ( same as LS1)
270-330 HP depending on year.

LS1 Motor
3.898" bore
3.622" stroke (same as 5.3L)
6.098" rod length (same as 5.3L) powdered metal cracked cap design
305-350 HP depending on year.

I have a 5.3L that i bored out to 3.898 ls1 crank which is the same as a 5.3L and mahle ls1 pistons mild cam headers and 799 heads off the aluminum 5.3s which are same as 243s except for they dont have the lightweight valves, and a pro-products 96mm intake, and guess what nemess????? its 347CI, dam near identical to a ls1, except for small ****.

NemeSS

iTrader: (127)

Ok dude
Build whatever u want. Not here to argue. Good luck with your build.

speedtigger

iTrader: (16)

I don't know if a 5.3 block has thick enough cylinder walls to bore it to accept 5.7 pistons or not. But, I suspect that the 5.7 pistons will weigh more than the 5.3 pistons, so don't forget to have the rotating assembly rebalanced.

NemeSS

iTrader: (127)

Shhh... Just move along tigger.
:wink:

parks450

iTrader: (17)

not here to argue either but dont beat on someone elses thread if you dont have your ducks in a row. i was scarred to bore it that much believe me but numerous shops like teexas speed and performance said it was no problem, they do it all the time, the walls on the 5.3 are pretty thick believe it or not.

NemeSS

iTrader: (127)

Sigh
Never said it was a problem to do have this done. Just mentioned that it takes a few more steps than just boring the block from 3.78 to 3.897 or 3.905. For overbore pistons. I'm not here to argue with you either. It appears you did not read all I wrote. Again good luck with yalls builds

remauto1187

iTrader: (1)

Like i said....you are full of yourself.

You still haven't put out the top secret imaginary information that you are holding on so tightly too.

pistons, rods, bore, crank all determine CI displacement. Of course the head gasket, heads and any machine work on the head/block will play a minor role in the end result.

Put up or SHUTUP!

garygnu

do your research HOTSIX ,get a 5.3 with the good heeds and add a good cam and a ls6 intake .this wil make some usable power.

remauto1187

iTrader: (1)

Hey welcome to the discussion! So what cam are you running in your (according to NemeSS) "imaginary" motor? I am going to be running mine in a 85 vette and would like some mild loping at the stoplight but dont want to get too crazy with it. The car is going to be a daily driver and i want the engine to live a long dependable life. The vette will probably never be on a track so i dont need a drag engine. I plan on going with some 799 heads too since it seems alot of people including junkyards dont know what they are which keeps their price down.
Do you have any experience comments, warnings, heads up, shortcuts, etc. about our builds?

NemeSS

iTrader: (127)

Op
I apologize for any inconvenience I may have caused in your thread. Moving along