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Discussion Starter #1
Hi gentlemen,
This site is the most impressive site as far as the technical prowess of your community out of all the forums I belong to. I have learned so very much from reading the posts here.......my compliments to you all.
Well as my post says I am about to pull the trigger on a LSA TT build and I am shooting for 1100+rwhp hopefully at 20 psi max (below that would be great) . After reading all the post regarding TT /Supercharged engine builds I am now questioning using the LSA block/heads for the build. I see several builds using the LSA platform that are running here on this forum at 1100 rwhp and on several other forums also. But I have seen a couple posts that make me question the LSA platform choice. It was Duck's post that jumped out at me.

I would highly appreciate all input as I make my final decisions. Here is Duck's post I referred to:

"The ability to handle the extra Boost / HP comes from both
the extra bolts / fasteners as well as the thicker deck.

To put things in perspective; let's look at this
from a historical perspective:

---------------------------------------------------
---------------------------------------------------

GM had an LS3 and they wanted to increase the
HP by something more than +100 HP.

The block and heads were both aluminum and
the heads were held down with an 'effective'
4-bolts per cylinder.

---------------------------------------------------

So GM changed the materials of both the block and
the heads, made the cylinder head deck thicker and
added the Supercharger and called the package the LSA.

While the better quality aluminum and thicker deck
did add ridgitiy to the engine package, this package
still used the effective 4-bolts per cylinder to
fasten the heads to the block.

This engine was warranted by GM for 556 HP
---------------------------------------------------

GM decided to offer a complete line of High
Performance engines / engine parts via their
GMPP performance division for the LS engine series.

They call it the LSX rather than the more common
denotation for the entire LS engine series which is LSx.

But when you look at the LSX mark the X is larger
then the rest of the letters, so I write it as lsX.

The lsX B-15 is warranted for 900 HP and people
from GM have stated in writing that the engine
in NA form is good for 1500+ HP with a 4.200” bore.

The block is a Cast Iron / Nodular Iron Block
and the heads are, as I understand, it the same
high quality 356-T6 aluminum found in the LSA Heads.

They also come with the same thicker deck as well as an
equivalent 6-Bolts to fasten each cylinder to the block.

So once again GM has added ridgitiy to the engine package.

---------------------------------------------------

Why worry about rigidity at the cylinder head to
engine block interface?

It stops 'Ballooning"!

When the cylinder head to block interface balloon's
one can lose head gaskets and / or ring seal.

Regarding blocks overall;
If blocks are not sufficiently ridgid, this can lead to poor ring seal.

Loosing ring seal can lead to destructive self-detonation
because of the loss of ring seal, as even a small amount
of oil in the cylinder, greatly reduces your octane.

Better materials, thicker decks as well as additional
cylinder head fasteners holds everything together
with very high rigidity that helps stop the ballooning.

Higher quality fasteners such as larger diameter
bolts or studs can also additionally help.

Cheers,
The Duck"
 

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Premium Member
Joined
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4,343 Posts
Hi gentlemen,
This site is the most impressive site as far as the technical prowess of your community out of all the forums I belong to. I have learned so very much from reading the posts here.......my compliments to you all.
Well as my post says I am about to pull the trigger on a LSA TT build and I am shooting for 1100+rwhp hopefully at 20 psi max (below that would be great) . After reading all the post regarding TT /Supercharged engine builds I am now questioning using the LSA block/heads for the build. I see several builds using the LSA platform that are running here on this forum at 1100 rwhp and on several other forums also. But I have seen a couple posts that make me question the LSA platform choice. It was Duck's post that jumped out at me.

I would highly appreciate all input as I make my final decisions. Here is Duck's post I referred to:

"The ability to handle the extra Boost / HP comes from both
the extra bolts / fasteners as well as the thicker deck.

To put things in perspective; let's look at this
from a historical perspective:

---------------------------------------------------
---------------------------------------------------

GM had an LS3 and they wanted to increase the
HP by something more than +100 HP.

The block and heads were both aluminum and
the heads were held down with an 'effective'
4-bolts per cylinder.

---------------------------------------------------

So GM changed the materials of both the block and
the heads, made the cylinder head deck thicker and
added the Supercharger and called the package the LSA.

While the better quality aluminum and thicker deck
did add ridgitiy to the engine package, this package
still used the effective 4-bolts per cylinder to
fasten the heads to the block.

This engine was warranted by GM for 556 HP
---------------------------------------------------

GM decided to offer a complete line of High
Performance engines / engine parts via their
GMPP performance division for the LS engine series.

They call it the LSX rather than the more common
denotation for the entire LS engine series which is LSx.

But when you look at the LSX mark the X is larger
then the rest of the letters, so I write it as lsX.

The lsX B-15 is warranted for 900 HP and people
from GM have stated in writing that the engine
in NA form is good for 1500+ HP with a 4.200” bore.

The block is a Cast Iron / Nodular Iron Block
and the heads are, as I understand, it the same
high quality 356-T6 aluminum found in the LSA Heads.

They also come with the same thicker deck as well as an
equivalent 6-Bolts to fasten each cylinder to the block.

So once again GM has added ridgitiy to the engine package.

---------------------------------------------------

Why worry about rigidity at the cylinder head to
engine block interface?

It stops 'Ballooning"!

When the cylinder head to block interface balloon's
one can lose head gaskets and / or ring seal.

Regarding blocks overall;
If blocks are not sufficiently ridgid, this can lead to poor ring seal.

Loosing ring seal can lead to destructive self-detonation
because of the loss of ring seal, as even a small amount
of oil in the cylinder, greatly reduces your octane.

Better materials, thicker decks as well as additional
cylinder head fasteners holds everything together
with very high rigidity that helps stop the ballooning.

Higher quality fasteners such as larger diameter
bolts or studs can also additionally help.

Cheers,
The Duck"
If you have any specific questions don't hesitate to ask..:D

Cheers
 

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31 Posts
Discussion Starter #3
Hi Duck,
Thank you for your reply. My main concern is the ballooning effect you were talking about..... on the LSA block. Plus there was a post saying that the LSA block has a tendency of "going out of round" above the 700 rwhp mark?

So is the LSA block a good choice for my build target of 1100+rwhp? Obviously the engine will not live there, but will for some 1/4 mile 9 sec track runs. It will be a 80/20 between street and track and @ 700-800 on the street.

Will the LSA live here? I do not want to throw good money after bad......
 

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There are a fair amount of TT LS3 cars making over 1k rwhp in Corvettes, Camaros, trucks, etc. Block failures aren't very common. 6 bolt heads are nice, but with studs and moderate boost levels, I don't think I would want to incur the weight penalty of the iron block for a street car that sees occasional passes at the drag strip. For a dedicated drag race car, where you can offset the weight with reduction efforts, it makes more sense.
 

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Discussion Starter #5
Hey Unavowed.......that is good to hear. I did not know what the frequency rate is of LSA block failures that have been in high HP heavy cars were. I have heard of water jacket area failures issues on stock LS3 blocks tho, but not to much on the LSA since it is much stronger aluminum.
Richard at WCCH believes the LSA head should not have a issue at that hp level. Richard said the only stronger metallurgy head is ALL PRO.....at a much higher price.
 

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Hey, I’m the only one here allowed to speak directly to Richard!



Just kidding. Enjoy the build.


Sent from my iPhone using Tapatalk
 

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If you are buying a block I'd go with the lsX at that power level. I was on the fence around 700-800hp but I already had a good lsa core so I couldn't justify the lsX. If I had no core I'd buy the b15-lsX.

It all comes down to what life you expect to get, can you run an lsa? Yes, will it last as long as an lsx? Probably not if all things are equal.

Is 100lb worth the better block strength. What if you want more power? (We all say we don't but we all know we do). And at that level the 6 bolt heads will be a big plus.
 

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Hey, I’m the only one here allowed to speak directly to Richard!



Just kidding. Enjoy the build.


Sent from my iPhone using Tapatalk
Bahahha when I read he spoke with Richard I thought to myself "ohhh someone under cutting karch here comes the ban stick" (kidding of course)
 

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4,343 Posts
I am hoping that those who are posting are not suggesting that any
of the thinly sleeved aluminum blocks from GM are 'Better or even as Good'
as the 'LsX Iron Block'

If so please pull yourself up to your keyboard and explain?

RD
 

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6,496 Posts
I am hoping that those who are posting are not suggesting that any
of the thinly sleeved aluminum blocks from GM are 'Better or even as Good'
as the 'LsX Iron Block'

If so please pull yourself up to your keyboard and explain?

RD
Better as in lighter and less expensive or better as in heavier and more expensive?
 

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No one would argue that. But is the juice worth the squeeze to the OP?
Unavowed,
Your car runs some impressive numbers..:cool:

If you don't mind; who tunes it?

Cheers,
Bruce
 

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To all;
No trick question; just a simple one many should, I am sure, be able to answer.

Why do some cars require 'Catch Cans'?
Why do some cars require multiple 'Catch Cans'?

Cheers
 
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