I am wanting to know if you can get a ls1 stroked out to a 427. I have seen a couple people with ls1 427 and I want to know how they do it? The costs, pros and cons, everything I need to know please. Any info appreciated. Thanks

 

That would be a LS3, LS7 or LSX Bowtie block. LINK You can actually go 454 CID.

 

I've heard of people calling the lq4 a iron ls1. With lq4 it is possible but not recommended.

 

You have to get it resleeved to do so.

You can speak to Steve at Race Engineering (sponsor), he co-developed the sleeves with Darton.

 

The block needs Darton MID liners installed 4.125" bore and a 4" stroke crank for 427". You can build a 454 as well, 4.185" bore 4.125" stroke assuming this is an actual LS1 block and not a later model LS6.

Steve

 

Nope, it is an actual ls1 block. Whats a good estimate to resleeve?

 

Better off buying a new different block - unless for some reason the LS1 block is a must!

 

I want to do same thing.

It's about $2600 to sleeve your LS1 block out to 4.125"

Or you can get a bare LS7 for $3200.

I am leaning more towards resleaaving my LS1, so I don't have to mess with the GenIV/GenIII conversion stuff (reluctor, cam sensor, knock sensors, etc). But I haven't researched enough yet to know if there is a REALLY good reason to use a newer block vs. a current LS1.

 

From what I have HEARD a sleeved 427 LS1 has thicker walls than a LS7 block so considering that you are better off going that route.... Looking for input to confirm this????

 

I am pretty sure they are not thicker, but they are stronger. Different alloys.

 

The LS7 block is dry sleeved with gray cast iron liners with 35,000 psi tensile strength at best. I resleeve these blocks with both dry and wet MID liners on an ongoing basis because the stock liners and the block itself will crack if there is any detonation at all. Many guys have me sleeve their blocks before they crack saving a lot of grief. Darton sleeve material is centrifugally cast ductile iron with a tensile strength approaching 120,000 psi. So there is a vast difference in strength in materials. The same exact material is used in top fuel and funny car sleeves made by Darton.

The stock LS7 dry liner has a wall thickness of .0775" @ 4.125" bore. The dry Darton Seal Tight liners I use in Gen IV blocks LS2 LS3 LS7, etc. have a wall thickness of .100" @ 4.125" bore. So not only are the sleeves stronger, they are thicker as well allowing a max. bore normally aspirated of 4.185".

The wet MID sleeve, (the only way to large bore on the LS1) is different in that it does not rely on the block to support the sleeve. The wall thickness of the MID sleeve @ 4.125" bore is .237". Similar sleeves in tractor pull engines with 4.875" bores with only .1875" wall thickness will take over 125 lbs. of boost. Four banger Honda and Ecotec engines are making 1450 to the wheels using MID sleeves.

Since the MID sleeve does not rely on the block for support, the bores stay much rounder in service than any dry sleeved block whether one of my resleeves or any after market block. Westec conducted some dyno testing a few years back and found the LS1 MID block had less blow by than any engine they ever ran on their dyno.

Max. bore size on the LS1 block is 4.200" with the MID sleeves. Most guys opt for 454" 4.185" bore, 4.125" stroke. You can go to 4.25" on stroke but I don't recommend doing so unless the engine is strictly race. Longevity will suffer as the stroke length is increased regardless.

Below find a photo of an LS1 MID prior to decking and a Gen IV MID sleeve. The LS1 MID sleeve is identical save for the seating depth.

Steve

 

So a sleeved LS1 is a little cheaper, stronger, and you don't have to worry about the gen III to IV conversion...

What is the down side? Why aren't more doing this? Or are they and I just don't know?

 

Yeah that was a ton of valuable info. Thanks for posting.

 

In for ^^^ that question to be ansewered.

 

First, no one knows how many blocks are being done for one. I do quite a few LS series blocks. I do many more import blocks for drag and road racing applications however.

The LS business has been increasing of late because a lot of guys have figured out that sleeved blocks are reliable and will take a lot more abuse than a stock block.

That said, there are two reasons, cost being the first, that more guys aren't using this approach. It is cheaper (not better) to build a 427 using an LS3 block with 4.060" bore and 4.125" stroke or slightly larger bore and 4.1" stroke. The stroke is longer and the stock sleeves are weaker and shorter in this combo than I what you end up with a sleeved block.

Second, a lot of guys got burned with sleeved blocks in the past by shops that had no clue what they were doing. I replaced several of these blocks ruined by other shops years ago at no charge to help the guys out and show there was nothing wrong with the design, the installation was the issue.

Further, I do a lot of MID blocks other than the LS series. Ford GT40 aluminum block is another American manufacture I have done many of. These blocks have been built up to 2,200 hp with turbo and methanol. I also MID sleeve the Dodge 6.1 iron hemi blocks. I have a couple of those on the way in now for a customer building to 2,000 hp. I have wet and dry sleeves of my own manufacture for the Dodge Viper as well. I have over fifty blocks out there. You do not want to race one against of those cars! I can get the cubes out to 535 inches on those.

The other blocks, besides the Ecotec, are all import. Honda by far being the most popular. You can get a thousand horsepower to the wheels out of 1800 cc's with the MID sleeves. The larger 2.4 liter engines are making 1,450, same as the Ecotec.

A certain 2.3 liter Volvo road race team (I can't mention the team) Randy Probst drives, just won an SCCA Pro series championship using my MID sleeved blocks. Smallest engine in the class, running against Vettes and other high horsepower cars.

I am one of the patent holders of Darton's line of MID sleeves by the way. I do all the block R&D regarding sleeve dimensioning. These MID blocks work out great if the installation is done properly.

Steve

 

So what are the limitations of the LS6 block? And why can you not go as big with it?

I have a 2002 so I guess there's a chance I have an LS6 block.

 

If you got to sleave it...RUN AWAY!.....DONT DO IT...NOTHING BUT PROBLEMS SOONER OR LATER!

 

Why do you say that?

 

If your going say something like that, tell me why. Do you have a bad experience or what?

 

Someone had a bad experience... Seems like guys are making more power with them.