427 LSx or LS7?
 

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

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

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

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:

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 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

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I think it was the new PHR, or Super Chevy. You'll see it advertised at the very top.

Ty

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.

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.

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.