y-man

I ordered a short block from an engine builder who will remain nameless. Numberous problems throughout (another story) I didn't provide a block but instead got a new one. I noticed when assembling the rest of the motor that on the back of the block, just covered by the flywheel the following casting mark:

I checked my old block and it said '5.7L' so I'm wondering now if I got a 5.3L block (which I thought were iron blocks) instead of the LS1 block I was suppose to or is this just coincidence. On the other side was another casting number but I'm not sure if it tells me anything more.

Can anyone clear this up please?
Thanks!
Matt

PREDATOR-Z

6.0 liters are iron blocks. This is a 5.3 liters .

JoeyGC5

iTrader: (24)

What displacement are you suppose to be at? Check your bore size and rough check the piston stroke also

427

iTrader: (3)

That would be a SSR block.I think they come in the Trailblazer EXT also.


Kurt

StickSS

Hi: I was wondering about this block also? Did you check the bore yet? Maybe the 5.3 aluminum block just has thicker sleves and can be bored out to 3.905 like an iron block motor? Anyone know about this? Thanks

goober35

iTrader: (1)

Iron blocks dont have sleves. He got a 5.3 iron block. Witch sucks for him because it can be bored to a 5.7 but the walls are to thin to do anything.

cyphur

iTrader: (10)

Matt, was that builder local? Thats pretty messed up.

madpwr1

iTrader: (3)

that sucks, hope you get it worked out ... at least you seem to be a lot more calm bout this then i would be ... i'd take that motor straight to his office and drop it right on his desk and demand every cent back with my lawyer on the phone.

strokedls1

iTrader: (1)

That is an iron block. They are thick enough to bore out to 3.900 and still be ok to use. They came with real thick sleeves. However, if you ordered an all. block that is unexceptable. I would take legal action also if they won't exchange the block.

y-man

The block looks exactly like my AL 5.7L block sitting on the garage floor next to it. It can't be an iron block because it's too light (less than 200#). I meassured the bore and it was the same as my old stock 5.7L (as near as I could tell) and there are sleeves in it. Like I said, the only thing different I could tell was the casting of '5.3L' underneath where the flywheel covers. I never got a chance to check the stroke on it. Is that were the difference in displacement would be? This motor was built with forged rods, forged, low compression pistons for a turbo application.

Oh, the engine builder.... 3 guesses and the hints are 3 letter name and they're from Canada....do I need to go any further?

madpwr1 I'm pissed as can be. This is just the latest in the nightmare I've gone through with this motor. I still don't have a build sheet to tell me what's suppose to be in the motor (even after calling everyday for 3 weeks straight). Hell, I can't even get them to tell me the grind on the cam they installed. I kick myself everyday for going with them, but I guess that's what life is. Learn from your mistakes...

Matt

Slowhawk

iTrader: (12)

Looks ike an iron block to me too but the simple magnet test would answer all questions.I thought 5.3's were made in aluminum now too?

technical

Is it a 5.3HO block? The Silverado's have an option for a 310hp Al/sleeved engine.

y-man

Good suggestion about the magnet test. I'm on travel this week for business, but I'll do it this weekend when I get back.

How would you tell if it's a 5.3HO block? Would that casting number (see original picture) tell me that?

Where is the difference in displacement between the 5.3 and 5.7 at? Bore, stroke, or a combination of both?

technical

5.3 bore (inc. HO) 3.78
5.7 bore 3.90

Both have the same stroke. The HO motor is Al vs. the standard truck motor which is Fe.

y-man

Sorry it has taken me so long to get back, but I did the magnet check and the block is definitely Al. If it is the HO 5.3L, could they have possibly bored it out to 3.90 to give me the same displacement or is that too much for that block? How much difference in hp am I looking at?

Does that also mean that if it was bored to 3.90, I have no hope of ever boring it out larger than that?

Thanks
Matt

Keith

A ruler would let you know for sure.
-almost 4" if is has been taken to 3.9"
-almost 3.75" if it is still stock.

I'll agree with Kurt on this one. Aluminum block 5.3L

smask04C5

iTrader: (1)

The block you have is a 5.3L Aluminum block used in LM4/LM7/L59 truck applications. Standard bore is 3.779 as compared to LS1 3.898, both shared same stroke crank of 3.622. This block in standard form displaced 325 ci, and CAN NOT be bored to 5.7 specs

MattG

smask04c5, where do you get such information that a 5.3L block cannot be bored to the same specs as a 5.7L? Have any hard information to back that up?

To the best of my knowledge, the 5.3L block is exact same block as a 2001+ 5.7L block other than the size of the bore. The same oem sleeves are used and are just bored larger for the 5.7 than the 5.3. I dont feel there is anything wrong with boring a 5.3L block to 5.7L specs.

technical

Unless you want to use it.

Beast96Z

iTrader: (21)

Most factory sleeves can only accept a .010 over bore at most. A 5.3 block would be no where near 5.7 specs in this case. I'd say file a complaint. This "place" is supposed to be up and running in a new "customer oriented" location. I'd see if they would live up to there word.