LS6 Block vs. LS1 Block for a 383 Stroker...
LS6 Block vs. LS1 Block for a 383 Stroker... 
12-31-2003, 05:31 PM
#2
Staging Lane
Join Date: Nov 2001
Location: Sydney, Australia
Posts: 68
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by Jimmyz
project. Is it worth the extra $500 to purchase a never run surplus LS6 block vs. just using a LS1 block? I've been told it is and can be worth 10+rwhp by using the LS6 block. Opinions?
What you're after more so in the LS6 block is it's strength over the standard LS1 block. It is definitely more sturdy as a whole.
12-31-2003, 05:54 PM
#3
I'm probably shooting myself in the foot with this but here is my honest opinion. Friend of mine that builds engine and I had this discussion on Christmas Eve and the answer was...
Yes and No because it really depends on how high your going to rev.
Yes, if you going to spin the motor into the high RPM's where the bay to bay ventilation will show improvements. A high reving motor will benefit. Say a solid roller going to ~7,000 rpm or 7,500 would really shine with the LS6 block.
No, if the motor won't be rev'd high. If the engine is only rev'd to say ~ 6,000 rpm the ventilation will be worth much.
Likewise, I no longer accept the argument LS6 block is stronger than the LS1 block for our typical applications. The open windows for winding the motor up basically are holes that weaken the structure. There was a thread a while back where Steve or Racing Engine Steve and Scott Turvey (sp) the owner of Gen III explained in detail why in many applications the LS1 block is actually better than the LS6 block.
Yes and No because it really depends on how high your going to rev.
Yes, if you going to spin the motor into the high RPM's where the bay to bay ventilation will show improvements. A high reving motor will benefit. Say a solid roller going to ~7,000 rpm or 7,500 would really shine with the LS6 block.
No, if the motor won't be rev'd high. If the engine is only rev'd to say ~ 6,000 rpm the ventilation will be worth much.
Likewise, I no longer accept the argument LS6 block is stronger than the LS1 block for our typical applications. The open windows for winding the motor up basically are holes that weaken the structure. There was a thread a while back where Steve or Racing Engine Steve and Scott Turvey (sp) the owner of Gen III explained in detail why in many applications the LS1 block is actually better than the LS6 block.
12-31-2003, 06:14 PM
#4
Staging Lane
Join Date: Nov 2001
Location: Sydney, Australia
Posts: 68
Likes: 0
Received 0 Likes
on
0 Posts
yes...Hi RPM is where you are going to pick up any power at all as this is where the added ventilation staves off pumping loss.
I was under the impression from discussions and articles in GMHP magazine that a combination of the casting process(slightly thicker walls) and slightly different metalurgy of materials(superior grade aluminium alloy) used in Nemak gave the LS6 more strength.
I'm open minded to other opinions though...perhaps it depends on the was the engine is used.Just curious why GM would supply an 'up-spec' block if it was in some way weaker.
The LS1 block can be made very tough by fitting the New Darton MID sleeves. They add a great deal of upper deck strength. but these puppies aren't cheap and generally only considered when going with a 'big bore' option.
I was under the impression from discussions and articles in GMHP magazine that a combination of the casting process(slightly thicker walls) and slightly different metalurgy of materials(superior grade aluminium alloy) used in Nemak gave the LS6 more strength.
I'm open minded to other opinions though...perhaps it depends on the was the engine is used.Just curious why GM would supply an 'up-spec' block if it was in some way weaker.
The LS1 block can be made very tough by fitting the New Darton MID sleeves. They add a great deal of upper deck strength. but these puppies aren't cheap and generally only considered when going with a 'big bore' option.
Last edited by 8POTS; 12-31-2003 at 06:23 PM.
12-31-2003, 09:52 PM
#6
Darton says they like the LS1 block for resleeving more than the LS6 because of the bay windows as the removed material (in the LS6) is area that would be better used for securing the sleeves.
Also, a couple of different sponsors have said the difference in HP between the LS1 and LS6 blocks is hardly noticeable (under 7,000 RPM).
The material (aluminum from which they are cast) and the wall thicknesses are the same. While one is pressure cast (LS6) and the other is gravity cast (LS1), that’s really splitting hairs. The only main difference between LS1 and LS6 is the windows. Its safe to say if one will fail (main structure), then the other one would.
Also, a couple of different sponsors have said the difference in HP between the LS1 and LS6 blocks is hardly noticeable (under 7,000 RPM).
The material (aluminum from which they are cast) and the wall thicknesses are the same. While one is pressure cast (LS6) and the other is gravity cast (LS1), that’s really splitting hairs. The only main difference between LS1 and LS6 is the windows. Its safe to say if one will fail (main structure), then the other one would.
