Stupid question to most of you...

I've always thought the LS1 was a 346, but then I keep reading all over from places like MTI and LGM that they have 347 kits. Is the 347 just a rebuilt, bored out 346, or is the LS1 really a 347? This is really bothering me...

 

a 0.005 over bore stock stroke ls1 is a 347

 

That's what I thought (well, not exactly 0.005). Thanks!

 

I can't remember if the stroke is 3.62" or 3.625" (3.625" = 3 5/8", makes more sense ) but regardless, even at 3.625" (and a 3.9" bore), the total displacement is 346.431 cu. in., which rounds down to 346. With a .005" overbore, then it's 347.320 cu. in..

 

This is very interesting for me actually... The local track has a "100mph club", and on their website they list all the people that have made it this season. All the LS1 cars they list claim to have a 347. I always thought that was a little odd...

http://www.beaversprings.com/100mphclub.html

Now keep in mind this is in a rinky dink redneck town. Unfortunately it's the closest track to State College... not to mention it's 17 feet uphill

 

pretty sure stock it is a 345.5 wich is a 346.

 

how do you figure...... 345.5 IS 345.5......

 

Using basic mathematical theory which we all learned in elementary school... when you have a decimal between .1 and .4 tenths, you round down. When you have a decimal between .5 and .9 tenths, you round up. So 345.5 is rounded up to 346. Unless i'm missing something

Then again, three-hundred and forty-five & a half is technically just that, 345.5 cubic inches. But a Z28 is technically rated at 310hp, but who said that was true either

 

Like I said in my above post, I'm not 100% sure if the stroke is 3.62" or 3.625", but if it's only 3.62", then the engine would be 345.953 cu. in..

 

I know the LS1 is 346 c.i., but the quick reference guide in my instruction manual says it's 350 c.i., why is that?

 

Marketing. 350 is a well known engine w/a great following. Thats the same reason GM said a 402 was a 396.

 

That's what I figured.

 

3.62 and he is correct

 

346 per gm...

 

Plus 5.7 L is a 350 which the reason why it is a well known engine is the fact that it has been a very reliable small block since 67.. Even go to Mortec,

12550592...350...97-up...crossbolted block, Gen.III, "LS1", aluminum
12559378...350...99-up...crossbolted block, Gen.III, "LS1", aluminum
12559846...350...98-up...crossbolted block, Gen.III, "LS1", aluminum
12560621...350...98-up...crossbolted block, Gen.III, "LS1", aluminum
12560629...350...99......crossbolted block, Gen.III, "LS1", aluminum
12561168...350...01-up...crossbolted block, Gen.III, "LS1", aluminum
12562174...350...98-up...crossbolted block, Gen.III, "LS1", aluminum

This is for the LS1 over at Mortec's site, so instead of calling it for example 4.8, 5.3, 6.0 for the Truck/SUV Small blocks, GM decided to say the LS1 was 5.7.. I think the LS1 is a cross between the 1958 - 1965 348 Small Block and 350 Small Block.. Plus how many complaints would GM have recieved if they would have dropped the 350 from their current engines which is why the LS1 is listed as a 5.7 L block which will translate to a 350 CI block eventhough LS1 is actually 346...

This is just my opinion though..

Charlie