427 LSx or LS7?

[tyoneal]

Hello:

I just read an article on, "How to build a 427 LSx".

Not a bad read, however it only makes 550 hp. Not bad, but an LS7 can easily make that with a little bit if effort.

When it came down to discuss the price of he LSx, it said about $12,000!

Who would build one of these when you can have a Aluminum Block 427 for the same price as an iron block 427?

Did this cross anyone else's mind?

Ty

[Stuart Adams]

Cam, headers puts the LS7 at around 600 hp if I recall. Scott, Jody?

[JUSTANOVA]

Dont forget the added costs of the dry sump parts that aren't included in the crate engine price on the ls7

[James OLC]

In my opinion (and depending on your application), naturally aspirated the LS7 is a better choice while the LSx would have an advantage if you were going forced induction. The LS7 has some other advantages, especially with respect to rotating mass which is nice as well. Equipping the dry sump in not that great an expense - Tyler at ATS has all the pieces available for that and the cost is really quiet reasonable; packaging is slightly more complex - you wind up with a lot going on under the hood.

I am biased here though, our LS7 is at Katech right now.:thumbsup:

[TravisB]

not sure who built the 427 LSx but 550 is mild for one of those. Considering for bascially no extra money you can build more cubes with an LSx up to almost 500ci I believe. There are several companies out there building 427-440ci LSx engines that make well into the 600hp range up to 700hp in some cases depending on cam and heads. Durability of the LSx block has to be better than the aluminum block.

[tyoneal]

The LSx Block you can make more horsepower with forced induction. The limit is 2500 hp on the block. Here is a company that sells the short block. http://texas-speed.com/shop/item.asp?itemid=709
I believe Devious has LSX block in it.

Jeff

http://www.kodakgallery.com/67rscamaro
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I guess it's application oriented.

I like the PT/Road Race type build. 600 RWHP would be at the very top of needed. The weight difference would be a much higher selling point for me. 2500 hp is cool, but I bet the aluminum block could handle enough boost to get to 600 RWHP without breathing hard.

From my perspective the LSx 427/550hp build for $12,000 seems silly.

I'm sure there will be a few folks build 2500 hp cars with one, but I bet we don't find many on this site.

Ty

[tyoneal]

not sure who built the 427 LSx but 550 is mild for one of those. Considering for bascially no extra money you can build more cubes with an LSx up to almost 500ci I believe. There are several companies out there building 427-440ci LSx engines that make well into the 600hp range up to 700hp in some cases depending on cam and heads. Durability of the LSx block has to be better than the aluminum block.
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I think it was the new PHR, or Super Chevy. You'll see it advertised at the very top.

Ty

[jeff s]

Dont forget the added costs of the dry sump parts that aren't included in the crate engine price on the ls7
The only dry sump parts needed on an LS7 is the oil tank, hose adaptor for pan, and hoses, oil pump is internal and included.
Add an aftermarket dry sump to a LS2, see what that costs!

The article was SC, and it was an LSx built with a stock LS7 cam and components. Basically an iron LS7. It'd be good for a bunch of NOS.
Only reason to do it. IMO.
We have dyno tested 650 and 700 na packages available for LS7, includes upgrade rod bolts, chamfering the rod caps for the bigger radius on the bolts. headwork, cam, MAF, intake. Also 1000+ LS7 twin turbo. We've done over 30 LS7's this year. (Haven't done a single LS1 or LS2 this year.) No need for the iron block up to 1200 hp or so in my experience. THe LS7 has a longer cylinder wall, that is better for strokers, we did one with a +.25 stroke. The tall deck LSx is best for a stroker, but I'm not sure if that one is really available yet either.
We've had an LSX iron block for months for a magazine article, waiting for GM to release the heads with extra bolts, not available yet. And the bolt pattern is different than the World Products LSX.

[rocketman]

Stock Z06's are in the 530-540hp range bone stock.There are a bunch of dyno pulls to back this on the net. I would do a 454 LSX and spray it.

[victionone]

I had to make the same decision and went with a LS7. The GM crate LS7 was a few thousand dollars cheaper btw. The LSX has a few extra cubes and is bulletproof. I don't plan to make 1000+ hp and the 454 LSX's aren't making any more power than a 427 LS7. The LS7 has a lighter rotating assembly, aluminum block, dry sump, and was cheaper.

[TravisB]

I don't plan to make 1000+ hp and the 454 LSX's aren't making any more power than a 427 LS7.

that depends on who builds the 454 LSx....

[68protouring454]

I had to make the same decision and went with a LS7. The GM crate LS7 was a few thousand dollars cheaper btw. The LSX has a few extra cubes and is bulletproof. I don't plan to make 1000+ hp and the 454 LSX's aren't making any more power than a 427 LS7. The LS7 has a lighter rotating assembly, aluminum block, dry sump, and was cheaper.
are you serious? not making any more power??? on the edge of street driving, 11-1 lsx with a serious cam in it will see 700 hp easily n/a for 1/2 the price of a built ls7, and the ability to go bigger if something bad happens

[trapin]

My official "canned response" to this type of thread is; If money is not an option, go with what your heart tells you. If money IS an option, forego the "wants" in favor of the "needs".

To me I've always viewed the LSX block as something for the drag racing community. 2500 horse power? That's drag racing country. If you plan to have your face in the sky for the first 60 feet, then do the LSX engine. For a Pro-Touring car, weight is the big consideration, and for that I would do the LS7. Short on money? Then a warmed over LS3.

[rocketman]

There isn't that much wieght differnce in the two blocks, maybe 50 pounds

[victionone]

are you serious? not making any more power??? on the edge of street driving, 11-1 lsx with a serious cam in it will see 700 hp easily n/a for 1/2 the price of a built ls7, and the ability to go bigger if something bad happens

I apoligize. I meant to say not much more power than a LS7. The two 454 LSX dynos I have seen both dynoed under 600 rwhp. SW made 571rwhp on his LS7 with a cam. I know there are a lot of variables, and there is no doulbt a bigger cubed LSX will make more power. No arguement here.

I got a few estimates for a LSX build and they all ranged from $14-15k depending on components. This price includes injectors, rails, tb, coils, sensors, etc. Basically everything a crate GM LS7 would include. A GM crate LS7 can be had for under 12k and also includes a flywheel and clutch btw. ;) A build with a LS7 block would cost $700 more since a LS7 block is about $700 more than a LSX block. I don't see how it can double the total cost.

[jeff s]

There isn't that much wieght differnce in the two blocks, maybe 50 pounds

It's actually well over 100 lbs heavier.

[rocketman]

I didn't have a Ls1 block to weigh it doesn't seem that much heavier, but I found where it's a 105 pds heavier

[James OLC]

for what it's worth:

http://www.ls1tech.com/forums/showthread.php?p=8356237#post8356237

[tyoneal]

for what it's worth:

http://www.ls1tech.com/forums/showthread.php?p=8356237#post8356237
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I guess for now, that takes care of that.

I hope they get things settled, for everyone wanting one.

TY

[trapin]

I have a friend that builds engines, Chris Uratchko is his name. He owns Uratchko Racing Engines here in Michigan. We've talked about that block in the past and I remember him telling me his disdain for it. That was the first I heard that they were made in China. Interesting that this now comes out. I'll have to show him this thread.

[rocketman]

I have a friend that builds engines, Chris Uratchko is his name. He owns Uratchko Racing Engines here in Michigan. We've talked about that block in the past and I remember him telling me his disdain for it. That was the first I heard that they were made in China. Interesting that this now comes out. I'll have to show him this thread.



The cast in New Zealand, there are few blocks, cranks, rods, etc cast in the states. Donovan is th eonly block I know of cast in the states, brodix might also. But the Ls1, LS2, LS7 blocks are all cast side the states

[awr68]

Good topic guys!! I've often wondered what would be more cost effective a built LS2 like rupp's/parson's or a cammed LS7 like Scotts?

[victionone]

Good topic guys!! I've often wondered what would be more cost effective a built LS2 like rupp's/parson's or a cammed LS7 like Scotts?

The GM crate LS3's will be rolling out soon and cost less than half the price of LS7's. Defintely more cost effective. Worked stock heads and a cam should get you 500rwhp easily. LG claims their cam can get you there with stock heads.

[awr68]

good info thanks!

[Spiffav8]

That is good info. Any idea on the price?

[jeff s]

The GM crate LS3's will be rolling out soon and cost less than half the price of LS7's. Defintely more cost effective. Worked stock heads and a cam should get you 500rwhp easily. LG claims their cam can get you there with stock heads.
LOL, Yea, they'll be available soon, just like the 6 bolt GM heads and the stand alone ecu and harness for LS7.

[victionone]

LOL, Yea, they'll be available soon, just like the 6 bolt GM heads and the stand alone ecu and harness for LS7.

Seriously. The LSX blocks can really use those heads. :yes:

The standard LS3's are already available but in short supply. GMPP's LS376/480 and LS276/520 are another story tho. GM says early 2008 but we'll see.

GMpartsdirect has the crate LS3 for $4680 but shipping is $1000 plus a $300 core charge.

[jeff s]

Seriously. The LSX blocks can really use those heads. :yes:
The standard LS3's are already available but in short supply. GMPP's LS376/480 and LS276/520 are another story tho. GM says early 2008 but we'll see.
GMpartsdirect has the crate LS3 for $4680 but shipping is $1000 plus a $300 core charge.
THe LSX is designed for the extra bolts, the block's been out a year, but no GM heads yet (you can use stock type heads, but then there's no advantage of using the heavy block since the heads will lift at 20# boost without the extra bolts)
The LS3 you talk about is a replacement long block for someone who already has a LS3 vette. No intake injectors coils, etc. Where are you gonna come up with a core? Try ordering one, my guess you need to give them a VIN # too, in order to actually recieve one.
On my own stuff I used an LS2 and have an LS3 block for another project.
However all my LS customers this year wanted an LS7s.
If you're paying a shop labor, it's still cheaper to get 650 na hp out of an LS7.
Thanks
Jeff

[deuce_454]

If you're paying a shop labor, it's still cheaper to get 650 na hp out of an LS7.
Thanks
Jeff

just out of curiosity... (partly fueled by the realisation that i cant ever run the single turbo setup (that you sold me) legally in this country) how much is the 650 hp ls7 with everything required to install it (less headers and fuelpump..) ???

[awr68]

Jeff I respect you and all your knowledge and possible insider knowledge...but why would they advertise this already if they only plan on selling long blocks? They are showing all three LS3 options including the coil packs and intake.http://www.gmperformanceparts.com/Parts/showcase_detail.jsp?engine=2
I feel that the LS7 is king but some guys need an option and this LS3 in just that...if it ever is available. ;)