Project GatTagO

iTrader: (7)

Does anyone know if GM scribed numbers on the respective connecting rods. I just pulled the pan on my LS6 to replace it with an F-body pan. I have to swap pans in order to fit my RX7. I noticed that all my connecting rods were numbered with the cylinder numbers. Can anyone that has had their pan off confirm this?

Thanks,
Andrew

Plum Crazy Rob

iTrader: (3)

On a 98 mine were NOT.

I'd be curious to see more replies to this - wondering if your engine has been apart (I assume that's why you asked...)

2001 Pewter WS6

iTrader: (43)

On my 2001 they weren't numbered
either...

J-Rod

That would tell me the engine has been apart, and the shop that pulled it apart numbered the Rods and pistons.

Project GatTagO

iTrader: (7)

This engine is brand new and has never been run. From what I can figure out, its a pre-production LS6. The intake manifold has a sticker on it that says prototype part. The heads are very odd. The casting number is 799, and they look like LS6 heads with a distinctly "D" shape exhaust port. The connecting rods were numbered, which leads me to believe that the engine was blueprinted. The exhaust manifolds carry a production Corvette LS1 manifold part number, but have "D" shaped port that match perfectly to the heads.

Andrew

robertbartsch

weird...why would someone blueprint a brand new engine?

Project GatTagO

iTrader: (7)

The same reason you would blueprint a rebuild engine. To make sure that all the tolerences are right on the money.

Andrew

robertbartsch

CatTago:
Yeh, I figured that too, but it seems like an expensive and unnecessary step, particularly if the motor is new and is under full warranty...

robertbartsch

Is it possible that this is a "newer not new" engine returned to GM under warranty and they tore it apart, fixed the bad stuff and then re-sold it as a new engine?

...BMW did this stuff in the 1990's and got sued becasue they did not disclose it to buyers...

robertbartsch

If it was my motor, I would be asking some serious questions about why it was torn apart as evidenced by the numbered rods

...if a new engine's rods are not numbered, something is rotten in Denmark!!!!

Demand an explaination; you may have paid for a new engine but only received a used rebuild motor!

robertbartsch

While your at it, you might as well take the heads off and inspect the bores...

This sounds like a classic case of mis-representation.

Who did you buy the "new" engine from?

robertbartsch

Do not install this engine and start it until you have solved this puzzle....

It sounds incredibly suspecious to me!!!!!

BIG PD

pretty sure ls6 motors have numbered rods. besides when i do motor rebuilds using the stock rods...i sure as hell don't carve numbers into the rods. i just use a piece of masking tape and a black marker.

robertbartsch

Not sure here. I read an article about the production of LS1/LS6 engines in a magazine... It implied there are VERY similar ....nothing was said about different rods, numbered rods or special assembly for LS6 engines,...

Did GM sell this engine as new?

Project GatTagO

iTrader: (7)

I did not get this engine from GM. So please don't anyone think that GM is up to something fishy. The more I dig into this the more I think that its just a hand assembled preproduction engine.

Andrew

robertbartsch

Really? Interesting...do u think it has been on an engine dyno?

L-EATER

iTrader: (2)

Where did you get it? Sounds like you might have one off GM test mule.

robertbartsch

Sounds cool; I wonder if it has any speed parts the General may have been testing....is it like a certified engine for street use? ...all this is very misterious...

What application will it be used in?

J-Rod

Interesting. Where did you come up with a pre-production ls6 mule.

Big PD - As for stamping your rods. Most machine shops use a method that won't fall off when it goes through caustic vat. Putting tape on your rods is fine for someone at home, but tape comes loose. A stamp never goes away unless you stamp over it. That is why we stamp thae ammount that has been milled off the heads into the head. The ammount milled off the deck of a block, the connecting rod numbers, the ammount the mains and the rods have bben ground into the crank, etc...

That way there is no question of how things are. It is a generally accepted best practice.

Project GatTagO

iTrader: (7)

All this talk makes me want to pull the valve covers and check the valve lift. I have a dial indicator, so it should be fairly easy. Anyone know the specs of a 2001 LS6 cam?

This is going into an 87 RX7, backed by a T56.

Here is a pic of the intake:

Intake

Here is a pic of the exhaust ports. They sure look like LS6 heads, but the casting number on the head is 799.

Exhaust ports

Andrew