melsie68

iTrader: (8)

Assuming your LS7 heads have 70cc chambers and pistons have -12cc dish you are at approximately 11.2:1 static compression ratio with a .040 head gasket and .000 deck height. There is no way possible to mill those heads an achieve 14:1. In order to keep the shortblock the same you will need a 50cc combustion chamber to get 14:1. In order to take off 20cc you would be milling approximately .100 off the deck surface of those heads and that just isn't happening. You would need a different cylinder head with small chambers like a C5R, or have extensive welding and re-shaping of the LS7 chambers or you would have to run dome pistons. Good luck. I suggest you run it as is and keep life simple. I seriously doubt the added compression ratio would be worth the trouble especially where you are talking about a driver.

PUNISHER TA

iTrader: (13)

Yea, that is what I didnt know, I need to compute that, and see how much compression I can get.

venom ws7

iTrader: (13)

Mill the heads to 57cc and get the thinest heads gasket you can get ... LOL
I think you'll be close to 13:1

14:1 will be impossible to get with your pistons.

Stang's Bane

iTrader: (22)

i vote just leave it alone.

PUNISHER TA

iTrader: (13)

Im leaning that way. It would cost me $1500+ just to build my fuel system... then Id need a twin disc for the new power... then my 10 bolt would probably explode...

but minimally, it would be another 3k.. which i just dont have. I just wanna drive her.

kyles2000z

iTrader: (8)

I vote everyone quit whining about the 10 bolt. I have many friends making BIG power and running well at the track with the 10 bolts. One friend is making 715 in a 6 SPEEED, cutting 1.6s.....it's fine. Another is cutting 1.4s, VERY close to 1.3s.....and his 10 bolt is fine too!

SlickVert

iTrader: (5)

You will need to up grade the fuel system to run e85 regardless of the compression. e85 requires about 30% to 40% more fuel @WOT. It does make more power. It is all a trade off.
Bob

Advanced Induction

iTrader: (2)

If you have untouched GM LS7 heads, then having the port work addressed is worthwhile. With a 454 shortblock from a good builder like HKE you should be able to manage to get close to 700rwhp with moderate compression. If you're looking for higher compression then you'd want a different piston. Of course, if you combine both then we can manage over 700rwhp. However, I wouldn't be inclined to recommend you daily drive a 14:1 setup unless it would be fed a known fuel as opposed to an unknown blend of pump fuel.

A really good LS7 head and a proper HR will meet your goal without making fuel type an issue.

Haans249

iTrader: (24)

KISS. If you're going to be putting 30K miles a year on this motor, par down your expectations. You would need a serious setup to get 700rwhp out of a 454 with what you're talking, 600rwhp is more feasible, but would still be difficult given your top-end and intake choice. Listen, you can always swap heads/intake/cam in the future if you find that you don't like the combination and run higher compression, sheetmetal, larger cam if you want. Just get the dang thing on the road already and see how you like it! haha.

Get to it!

Beaflag VonRathburg

iTrader: (176)

+1, If you keep changing your mind you'll never get it finished. Ask the 8 different sets of heads, 3 blocks, 3 cranks, 3 sets of rods, and 4 sets of pistons I've had how that works.

Stage7

iTrader: (1)

What do you consider moderate compression in order to reach near 700rwhp with your heads?

ramairws6

iTrader: (33)

That's kinda what i was wondering also.......

Advanced Induction

iTrader: (2)

The 482 that made 69Xrwhp with our 280cc GM LS7's and HR was at 11.6:1 if I recall correctly. The cam we provided was relatively small to retain reliability w/ stock rockers & run a normal HR dual spring. It managed over 500rwtq by 3k rpm & made peak power below 6500. It would have been impressive with some compression & upgraded valve train.

I've got a pile of test data we collected when we developed our re-cnc'd LS7. If I get some time I'll make a thread w/ dyno data, 3rd party results, pics, and video if we took any. Hope that helps.

-Phil

Stage7

iTrader: (1)

Thanks for the info. What intake was on the 482? Do you do LG Motorsports heads as well? I remember they did a 482 with insane #s. Is this the same motor you are referencing? Any other examples? If you can find the time to post some of the results you mentioned, it would be very helpful! Thanks

Stage7

iTrader: (1)

sorry for the thread hijack.

Advanced Induction

iTrader: (2)

The 482 I'm referencing that made ~690rwhp ran our 280cc re-cnc'd LS7, a grind we did for that particular application, and a GM LS7 manifold w/ some porting. We work with just about anyone who wants a professional racing quality part, whether it be a one off head, or a version of an existing head specifically for them. PM/email if you like, hate to take the guy's thread completely off on a tangent.

venom ws7

iTrader: (13)

The car that LG Build was 500ci not 482ci..

Advanced Induction

iTrader: (2)

The particular engine that made ~690rwhp was 481.Xcid.

http://www.advancedinduction.com/Dyn...tedIntDyno.jpg

Zbinkley

What does 14.1 do to your egt's?? sorry if thats a dumb question but im a bit of a newb.

blackonblacksls

iTrader: (1)

Wcch can angle.mill ls7 heads to.53 cc. I just spoke with then about it yesterday.