Lsx iron block
08-09-2009, 10:48 PM
#41
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....was there a budget in mind for this build? That would help with the discussion topic i think...for reference, i've got ~$11K in receipts for my 454 and it still needs an intake and water pump...
08-10-2009, 12:08 AM
#42
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I've ran trick flow 245's and seen similar cars to mine with less ci make more power with LS7 style heads on the same dyno *shrug*
The all pros beat out the ETP heads, but theyre also more expensive.
I think the LSX heads will be somewhere in the middle without the huge pricetag. I havnt looked into them though, are they out yet?
08-10-2009, 01:49 AM
#44
All pros are in the lead now, and I'm willing to bet they will continue to lead over the LSX heads, too.
I've ran trick flow 245's and seen similar cars to mine with less ci make more power with LS7 style heads on the same dyno *shrug*
The all pros beat out the ETP heads, but theyre also more expensive.
I think the LSX heads will be somewhere in the middle without the huge pricetag. I havnt looked into them though, are they out yet?
I've ran trick flow 245's and seen similar cars to mine with less ci make more power with LS7 style heads on the same dyno *shrug*
The all pros beat out the ETP heads, but theyre also more expensive.
I think the LSX heads will be somewhere in the middle without the huge pricetag. I havnt looked into them though, are they out yet?
I'll hit him up with another pm.
.
08-10-2009, 02:20 PM
#46
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I know nothing of their new ports, so I can't say. I wish I'd have gone ls7 on my 454 from the beginning. ETP or all pro wouldn't have mattered to me.
Im interested to see on a high CI motor (440 + ci) what the ls7 fast will do over a stock ls7 with a set of nice heads
I know a guy here running stock ls7 heads on his c6z He went from a stock ls7 intake to a ported fast ls7 and so far picked up 15rw on back to back testing.
08-10-2009, 05:23 PM
#47
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The "older" all pro heads have been proven to make more power then the etp ls7 heads.
I know nothing of their new ports, so I can't say. I wish I'd have gone ls7 on my 454 from the beginning. ETP or all pro wouldn't have mattered to me.
Im interested to see on a high CI motor (440 + ci) what the ls7 fast will do over a stock ls7 with a set of nice heads
I know a guy here running stock ls7 heads on his c6z He went from a stock ls7 intake to a ported fast ls7 and so far picked up 15rw on back to back testing.
I know nothing of their new ports, so I can't say. I wish I'd have gone ls7 on my 454 from the beginning. ETP or all pro wouldn't have mattered to me.
Im interested to see on a high CI motor (440 + ci) what the ls7 fast will do over a stock ls7 with a set of nice heads
I know a guy here running stock ls7 heads on his c6z He went from a stock ls7 intake to a ported fast ls7 and so far picked up 15rw on back to back testing.
08-13-2009, 12:39 PM
#49
I was wanting to know this answer too, because GM says you can go up to 4.25 inch bore on the LSx. I did my final project in my IC engines class (as a senior in mechanical engineering) on finding the limit of the LSx block with a 4.25 inch bore using the Finite Element Analysis program ANSYS. I modeled the engine with 11:1 compression ratio, 4.25 inch bores, 4.5 inch stroke with the 4.4 inch bore spacing and pump gas. The LSx block uses 15% stronger iron than regular production iron blocks and has siamese bores. I did my analysis kinda like ERL did with the darton sleeves in a LS2 block with a 600 shot of nitrous except I did a boosted application, the link to their analysis is here:
http://www.erlperformance.com/images...eve_Design.pdf
I started out without boost, and the stresses were so freakin small I wanted to find some sort of limit. Using 1 atmosphere increments (14.696 psi) I got up to 105lbs of boost before I reached the wall displacement that they saw and wasnt even close to the yield stress of the block. I never got my report back after graduation but ended up with a B+ in the class and only had a B- test average so Im assuming I did it right and thats why I got the higher grade, or he curved, or felt bad, I dont know. I know that my experiment had to be a little off using pump gas on a boosted 11:1 motor, but I think it shows why GM engineers say 4.25 inch bore is safe on a LSx block.
http://www.erlperformance.com/images...eve_Design.pdf
I started out without boost, and the stresses were so freakin small I wanted to find some sort of limit. Using 1 atmosphere increments (14.696 psi) I got up to 105lbs of boost before I reached the wall displacement that they saw and wasnt even close to the yield stress of the block. I never got my report back after graduation but ended up with a B+ in the class and only had a B- test average so Im assuming I did it right and thats why I got the higher grade, or he curved, or felt bad, I dont know. I know that my experiment had to be a little off using pump gas on a boosted 11:1 motor, but I think it shows why GM engineers say 4.25 inch bore is safe on a LSx block.
