LSX / Supra classification

[yarp]

how do you know its a 4.8 and not a 5.3?  They're exactly the same on the outside?

Well I am trusting the technician who rebuilt the engine. It has flat top pistons.

I also have no reason to believe he'd lie to me about the smallest, least desire-able engine available.

Why? Am I stepping on someones 4.8l toes?

[Stan Back]

I had flat-top pistons in a Model A, but I don't think it was a 4.8.

[ronnieroadster]

I had flat-top pistons in a Model A, but I don't think it was a 4.8.

  Stan I think the Model A was four cylinders not 4.8! Wait is that cylinders or? 

[redhotracing]

You're not stepping on toes, I think Dave was probably
asking just to make sure. Seeing as every iron LS looks
exactly the same from the outside... I've driven to quite
a few junkyards and CL leads for a "6.0" only to find a
5.3 or 4.8 awaiting me.

[greenjunk]

how do you know its a 4.8 and not a 5.3?  They're exactly the same on the outside?

Well I am trusting the technician who rebuilt the engine. It has flat top pistons.

I also have no reason to believe he'd lie to me about the smallest, least desire-able engine available.

Why? Am I stepping on someones 4.8l toes?

Heh, funny.  You got a a long way to go before you step on my toes...

All jokes aside.  I was asking because a 4.8l is actually a 5.3 block with a shorter stroke.  The block is even cast with the 5.3L designation on it.  The only way to tell is to measure the stroke. If you're not 100% sure you should run in the next engine class up.  As far as not desirable, i think you might be a little confused....   

[yarp]

Heh, funny.  You got a a long way to go before you step on my toes...

I didn't mean you, but you're right. I don't even have a rookie license yet so I'm pretty sure if I did step on you, you wouldn't feel it.

All jokes aside.  I was asking because a 4.8l is actually a 5.3 block with a shorter stroke.  The block is even cast with the 5.3L designation on it.  The only way to tell is to measure the stroke. If you're not 100% sure you should run in the next engine class up.  As far as not desirable, i think you might be a little confused....   

It came out of an 01 Silverado as did the 4l60e I'm using. The engine was disassembled inspected cleaned and rebuilt by someone I trust. He had a hell of a time selling it because it was small, and automatic. Everyone out there on the street or strip wants big inch power. I traded a pile of SBC parts and cars for this pre-swapped supra just so I could have my first LSX. I didn't give a hoot that it was a 4.8 cause I wanted one anyway for the short stroke. It's dead stock other than a corvette pan and intake. base E85 tune. I'm not really a supra fanboy so it won't bother me a nights sleep to start stripping and welding on a rust free car. I'm busting my ass to try and pass tech in May and rookie up. I'm positive its a 4.8l but doesn't impound have a way of testing displacement if it becomes an issue?

[Stan Back]

I think those flat-top pistons are a clue.

[yarp]

I've driven to quite
a few junkyards and CL leads for a "6.0" only to find a
5.3 or 4.8 awaiting me.

See?

Whats so wrong with a 4.8?

Especially an old tired girl that I got all liquored up on the cheap stuff. (I even used my kroger plus card , race gas , hah! , I fart in your general direction)
She wants to spin her guts out for a last hurrah.
I feel obliged to ride her.

[redhotracing]

Nothing wrong with a 4.8... They make great D motors for little money.
We opted for a 6.0 to be at the top of C class limits, that's all. A 4.8 with
turbos should make good power. 800+whp with good parts.

[greenjunk]

^^^ This

[yarp]

I have no idea what that means.

[redhotracing]

I have no idea what that means.

He was agreeing with my previous statement that the 4.8 is a good starting point
for a D class motor. You can make good power with them. Obviously the lack of CI
will limit potential, and even with the shorter stroke from the factory you still won't
want to spin in past 6,500RPM, really 6,000 unless the springs have been upgraded.
That's the beauty of power adders- big power without having to spin (break) parts.
We built and tuned our combo to make peak power below the "danger zone" of LS
motors, which is realistically 7,000RPM without spending too much money. We run
the cast OEM crank and make over 1,000 hp & tq. No point in spinning it too high.
Dave, Mike and I have broken a lot of parts over the past 10 years, and we are
merely trying to help guide you in a direction that will (hopefully) allow you to go
fast without breaking the bank.

[greenjunk]

^^^^ This.    But my motor still turns 9200+ rpm

[redhotracing]

^^^^ This.    But my motor still turns 9200+ rpm

Your motor is a mutant beast of epic proportions, Dave. When springs and push rods cost
more money than my entire engine, I hope the things spins to the moon 

[greenjunk]

your enigine was only $1500?