turning a 5.3 vortec into an LS1

[tdrumm]

A 5.3L can and have been bored out to 5.7L. To do so you would use LS1 pistons and rods. You could also go up to 6.3L by adding a 4.0" stroker rotating assembly. But for the money you'd spend for machine work on the 5.3 block, you could probably pick up a 6.0 block and add in the stroker assembly for 6.6L.

The reason so many LS1 cars run 5.3L heads is not becasue they flow better. Stock for stock LM7 heads flow nearly identical to LS1 heads. It's for the smaller combustion chambers to raise compression. The smaller chamber also means that the head can be ported more without needing to mill them down to regain compression. The L33 5.3L runs the same heads as a LS6, but without the lightweight valves which definately flow better than LS1 heads.

What kind of vehicle are you building this for?

[05ChevySilveradoSS]

Originally Posted by tdrumm

A 5.3L can and have been bored out to 5.7L. To do so you would use LS1 pistons and rods. You could also go up to 6.3L by adding a 4.0" stroker rotating assembly. But for the money you'd spend for machine work on the 5.3 block, you could probably pick up a 6.0 block and add in the stroker assembly for 6.6L.

The reason so many LS1 cars run 5.3L heads is not becasue they flow better. Stock for stock LM7 heads flow nearly identical to LS1 heads. It's for the smaller combustion chambers to raise compression. The smaller chamber also means that the head can be ported more without needing to mill them down to regain compression. The L33 5.3L runs the same heads as a LS6, but without the lightweight valves which definately flow better than LS1 heads.

What kind of vehicle are you building this for?

Oh Im Not Building Anything, Im Just Ranting On Haha, About How Capable This Engine Is. Like I Said I Just Like Telling And Talking to People About The Potential Of This Engine. Oh Check This Out. This Is One Bad 5.3. (All Motor).

This Is One Bad Vedio-----> http://videos.streetfire.net/video/a...38014af9bd.htm

Tell Me What You Think About Some Of Those Vids.

http://videos.streetfire.net/uploaded/Black%20X.htm

[tdrumm]

Originally Posted by 05ChevySilveradoSS

Oh Im Not Building Anything, Im Just Ranting On Haha, About How Capable This Engine Is. Like I Said I Just Like Telling And Talking to People About The Potential Of This Engine. Oh Check This Out. This Is One Bad 5.3. (All Motor).

My question was for the orginal poster, I'd like some more input on his project.

As for the potential of the 5.3, I know it well. Over on performancetrucks.net there are plently of 99-07 trucks in the 12's with N/A 5.3s. My truck has one and only the shortblock is original . It's a fun little truck and a great engine, but if I was going to go through the effort to build a new engine, a 6.6 would be the minumum size. As it is I'm starting to look into a L92 based 427 stroker.

[05ChevySilveradoSS]

Originally Posted by tdrumm

My question was for the orginal poster, I'd like some more input on his project.

As for the potential of the 5.3, I know it well. Over on performancetrucks.net there are plently of 99-07 trucks in the 12's with N/A 5.3s. My truck has one and only the shortblock is original . It's a fun little truck and a great engine, but if I was going to go through the effort to build a new engine, a 6.6 would be the minumum size. As it is I'm starting to look into a L92 based 427 stroker.

Do It Man, Id Like To See How That Goes. Im Thinking About Building Something, But My Wife Doesnt Like That Idea To Well. She Knows How I Am From When Shes Riding With Me In My SS, and GTO Hehe :P Check Out This Vid.

http://videos.streetfire.net/video/8...6100ee0444.htm

[Cphelps]

The 5.3L Heads are a popular head to get ported as an upgrade to an LS1 head because they can be made to add compression ratio. The stock 5.3L head doesnt flow any better than the regular LS1 heads I don't think, unless the current 5.3L gets the LS2 243 casting heads.

[05ChevySilveradoSS]

Originally Posted by Cphelps

The 5.3L Heads are a popular head to get ported as an upgrade to an LS1 head because they can be made to add compression ratio. The stock 5.3L head doesnt flow any better than the regular LS1 heads I don't think, unless the current 5.3L gets the LS2 243 casting heads.

Hehe I Wish They Did :P

[nailhead425]

FYI, one shouldn't bore a production 5.3 block out 3mm. That's alot of bore without a sonic check. I won't use a block that needs more than 1mm of clean-up. It's reduces your chances to rebuild it and it's a big gamble.

Originally Posted by tdrumm

As it is I'm starting to look into a L92 based 427 stroker.

You sir, are on the right track. My next will be L92 based with a 3.8" crank and CNC AFR heads. 6.6L but with a shorter stroke.

[tdrumm]

Originally Posted by 05ChevySilveradoSS

Hehe I Wish They Did :P

They do, the L33s at least.

Nailhead, why not L92 heads with some work done on the exhaust side to bring them up where they should be?

[nailhead425]

Originally Posted by tdrumm

Nailhead, why not L92 heads with some work done on the exhaust side to bring them up where they should be?

Based on what I have seen, the AFRs are a little bit better on the high-speed side (runner floor) and flow a bit better at high-lift.

The L92s are very good and they allow a person to say "production block and heads" when they have a 700hp engine.

The next one is going to be set on "kill".

[05ChevySilveradoSS]

Originally Posted by nailhead425

Based on what I have seen, the AFRs are a little bit better on the high-speed side (runner floor) and flow a bit better at high-lift.

The L92s are very good and they allow a person to say "production block and heads" when they have a 700hp engine.

The next one is going to be set on "kill".

Meaning? Im Courious

[nailhead425]

Meaning, I have to find some old rich yuppie who wants to go fast because I've got 1000hp on the mind.

I can't justify funding that upfront, well to my wife anyway.