Differences between LS3 427 stroker and LS7
Differences between LS3 427 stroker and LS7 Aside from the dry sump vs wet sump, and the different OE internal parts, can anyone explain to me what the main differences are between an LS3 that has been sleeved bored and stroked to 427CI and a LS7 which is also a 427CI engine?
More specifically I'm trying to figure out why some folks shy away from the LS3 427 build? Is it just because of the re sleeving thing? Is the OE sleeving in the LS7 more durable? Or is the block stronger???
LS7s are quite a bit more money to work on. Just trying to figure out why?
More specifically I'm trying to figure out why some folks shy away from the LS3 427 build? Is it just because of the re sleeving thing? Is the OE sleeving in the LS7 more durable? Or is the block stronger???
LS7s are quite a bit more money to work on. Just trying to figure out why?
The big difference between the LS7 and LS3 in relation to what your question is the bore and length of the cylinder. The LS7 has a 4.125 bore so you need is a 4" stroke to get to a 427. The LS7 is the only OEM block with a longer cylinder so a 4" stroke is not an issue. The LS3 has just over a 4" bore so a 4" stroke gets to a 416". A 4" stroke or longer has had issue because it comes out so far out the bottom of the cylinder (piston rock). There has been advancements in piston design to help minimize these issues. More than a 4" stroke is just asking for problems on an LS3.
More specifically I'm trying to figure out why some folks shy away from the LS3 427 build? Is it just because of the re sleeving thing? Is the OE sleeving in the LS7 more durable? Or is the block stronger???
LS7s are quite a bit more money to work on. Just trying to figure out why?
LS7s are quite a bit more money to work on. Just trying to figure out why?
Usually a 427ci LS3 is done with a longer stroke crank in a stock sleeve block. Most people are scared of that much stroke or they want to run a power added and want to extra thickness a piston can be designed with for a 4" stroke.
Been running a LS7 block for 8 years and no issues.
Just have to make sure your tune up is right.
I am not sure I can call the sleeves fragile. Not any more than pistons.
Not it a big fan of going over 4 inch stroke. Piston speed puts an exponential load on things.
Just have to make sure your tune up is right.
I am not sure I can call the sleeves fragile. Not any more than pistons.
Not it a big fan of going over 4 inch stroke. Piston speed puts an exponential load on things.
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From: Coast of San Mateo County Between Pacifica & HMB
Aside from the dry sump vs wet sump, and the different OE internal parts, can anyone explain to me what the main differences are between an LS3 that has been sleeved bored and stroked to 427CI and a LS7 which is also a 427CI engine?
More specifically I'm trying to figure out why some folks shy away from the LS3 427 build? Is it just because of the re sleeving thing? Is the OE sleeving in the LS7 more durable? Or is the block stronger???
LS7s are quite a bit more money to work on. Just trying to figure out why?
More specifically I'm trying to figure out why some folks shy away from the LS3 427 build? Is it just because of the re sleeving thing? Is the OE sleeving in the LS7 more durable? Or is the block stronger???
LS7s are quite a bit more money to work on. Just trying to figure out why?
VS a LS7 Block (due to better material, thicker & longer sleeves)
and you can Bore to 4.155" with Power Adders or 4.185" NA VS
4.130" at best with the LS7 factory sleeves.
Definitely RED the way to go with factory blocks IMO.
As mentioned earlier most 427" LS3s are 4.100-4.125" Strokes
Not what I would do for a number of reasons.
The RED sleeves are like 5.8 inches long while the LS3 I think is like 5.6 inches and the stock LS7 is like 5.9 inches in length. RHS block is like 5.87 inches long and their tall deck is like 6.35 inches.
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Verdad Gallardo When I compare block specs, deck height, main bore, cam bore location and cyl bore spacing all the OE LS blocks are the same.
Why is the LS7 is able to have the 4.125 bore and the others can't? Are the sleeves thicker?
I see some after market blocks have taller deck heights.
Would a taller deck height make it possible to use the longer stroke?
Why is the LS7 is able to have the 4.125 bore and the others can't? Are the sleeves thicker?
I see some after market blocks have taller deck heights.
Would a taller deck height make it possible to use the longer stroke?
Taller deck height allows you to use a longer rod in every configuration.
A quick google shows a tall deck rotating assembly with a 6.460" rod length! 4.250" stroke.
That's a 1.520 ratio. Stock LS7 is 1.516 ratio.
A 427 LS3 is a 1.49 rod ratio, but without aftermarket sleeves it really does not support the piston well at BDC.
A quick google shows a tall deck rotating assembly with a 6.460" rod length! 4.250" stroke.
That's a 1.520 ratio. Stock LS7 is 1.516 ratio.
A 427 LS3 is a 1.49 rod ratio, but without aftermarket sleeves it really does not support the piston well at BDC.
When I compare block specs, deck height, main bore, cam bore location and cyl bore spacing all the OE LS blocks are the same.
Why is the LS7 is able to have the 4.125 bore and the others can't? Are the sleeves thicker?
I see some after market blocks have taller deck heights.
Would a taller deck height make it possible to use the longer stroke?
Why is the LS7 is able to have the 4.125 bore and the others can't? Are the sleeves thicker?
I see some after market blocks have taller deck heights.
Would a taller deck height make it possible to use the longer stroke?
Tall decks will allow more stroke, but tall deck blocks are not all created equal. Some have longer cylinders than others and some have raised cam tunnels to clear the rods better. Right now, the biggest LS I've ever heard of was 523ci with an RHS tall deck. It made 700whp with ported OEM LS7 heads and a FAST intake.
You can still put a lot of stroke into a standard deck block with stock sleeves if you have a competent engine builder. A 4.100" crank isn't really that much and 4.250" is starting to be more common. You just end up with pistons with thinner crowns which become less tolerant of boost & nitrous.
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Joined: May 2009
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From: over dere
Not sure. This was the first I've heard of it. And the 3/4 ton engine is still 6.0 based
10 Second Club
Joined: May 2009
Posts: 3,427
Likes: 226
From: over dere