adams2003

I am currently having a 454 built for my 03 Silverado SS that should be done within the next 2 weeks. Just wondering what you guys think I can make HP wise AT THE CRANK. Here's the updated build list.

-LSX BLOCK
-4.185" Bore
-4.125" Stroke Callies Crank
-Custom CP pistons with a reverse dome (mirror of ls7 chamber) 13cc dish
-Callies rods
-WCCH exhaust ported ls7 heads
-Jeremy formato ported ls7 intake
-Comp Cam 244/254 .612/.596 lift, 114 lsa.
-11.06:1 SCR
-8.5 DCR

Quickin

675-680

adams2003

Really....I was hoping to break the 700 mark.

Katech_Jason

iTrader: (19)

Quicken is more realistic. 1.49hp/ci

vs. 1.54hp/ci

Doc99SS

iTrader: (2)

ideal CFM @ 6,000RPM is: (454/1728) x (6000RPM/2) = 788 ideal CFM
It is generally accepted that it takes 1.3 CFM to make 1.0 Hp....

Therefore, a 454 should make about 606 engine Hp.... Pretty low isnt it. This stuff came out of a book that I have on Chevy engine design.

The 1.3 CFM to make 1.0 Hp is really for Gen 1 engines. So the above math may not hold well for LSx engines, which seem more efficient than Gen 1 engines.

However, the above formula worked out very close for my head/cam/etc LS1 Camaro SS.

BTW: I am contemplating building a LSx 440 motor, and I expect to pull about 500 RWHp @ 6000RPM which would be about 585 Hp @ the flywheel.

Patrick G

iTrader: (14)

To break 700, you'll need more compression or a bigger cam. I'd vote for more compression.

Also, it's pretty common knowledge that for most street strip motors, 2.2 hp per cfm is the formula to use. Pro Stockers approach 2.4 hp per cfm, but we're not anywhere in that league.

98Z28MASS

iTrader: (6)

I have to agree with everyone else and say low to mid 600's with that cam and compression. Get the compression up over 11:1 and have a slightly more aggressive cam and you will be getting close. Out of curiosity, what type of exhaust are you going to be running?

supersub

iTrader: (25)

Are you still planning on the A4,what stall speed is planned?with the current duration any weight reductions put in to place?.very curious.awsome build up by the way.good chioce on heads LS7 is the way.

H82BL8

I'm not sure of his actual internals, but here is Reggie Jacksons build that states he made 641 HP & 611 TQ. This was with Warren Johnson helping him build it according to the article. Can't imagine there was much left in it with Warren helping, but we also don't know what they were trying to accomplish either. I'd take the 641 HP!

tcr98taws6

My LSX 454 with 11.8 compression, Trickflow 235's, ported FAST and an aggressive camshaft put 624RWHP, so +10% with the M6 would be 686 at the flywheel.

adams2003

My engine builder told me that he expects around 700 so I guess we will have to wait and see. Supposevely with the Reverse dome pistons we are going with (exact replica of the ls7 chambers) its supposed to maximize quench and reduce compression loss. So it should act like a much higher cr motor than the numbers say.

adams2003

The motor is going into my 2003 AWD silverado SS. It will be a 3200 stall in my 4L65.

Quickin

Wow, thats encouraging to hear. I'll be using the ETP CV heads and ETP sheet metal intake and a pretty aggressive cam with 11.5:1 cr...sounds like I should easily go about 650-660 RWHP. And geez, I think I'm gonna sell the LSX block I have and go with a tall deck to do a 481ci instead of 454ci. Another ~35 hp right there.

Whats your cam specs?


.

Old SStroker

I agree 700 fw is reasonable for this buildup and that more compression would help get there. No comment on the cam.

FWIW, NHRA Pro Stocks are 200++ hp above your 2.4 hp/CI. A 1450 hp @ 9500 500 cube PS makes 800 lb-ft (@9500) or 1.60 lb-ft/cube and 2.9 hp/cube!

2.2hp/cube would be just shy of 1000 NA fwhp on a 454. That's a long way from 700 and I think that might be a stretch for LS7 heads with any intake.

If it made that power @ 7500, the BMEP would be about 232psi or 1.59 lb-ft/cubic inch @ power peak rpm. That's also a stretch. To achieve that kind of BMEP, the LS7 headed engine would need to be a lot smaller.

My $.02

adams2003

What size headers do you guys think i will need to run with this setup?

Old SStroker

Diameter or length? Both count in headers...and in some other things.

Length of the primaries depends on what you are trying to do with them. The intake tract length is going to determine where the intake ramming peaks are (rpm points), and where the troughs (torque holes) are. You could use the primary length to tune to fill in the holes.

Diameter is probably related more to power output. If you get to 700+ fwhp, smaller than 1-7/8 will probably hurt you. Not everyone agrees with that. They are worried about "losing low end torque with big primaries." I suggest if you do them and the valve timing correctly, you will have a net gain over 1-3/4 primaries. Get the parts for 700 fw first, however. Choose headers last.

adams2003

Well i am kinda limited to what i can use because I have a awd silverado ss. But I was talking about primary size. Anything I go with will be custom and probably expensive so im trying to figure out what will be the best route without having to experiment.

adams2003

New Update

We changed the pistons at the last second to up the CR a little. Here's an updated build list.

-LSX BLOCK
-4.185" Bore
-4.125" Stroke Callies Crank
-Custom CP pistons with a reverse dome (mirror of ls7 chamber) 13cc dish
-Callies rods
-WCCH exhaust ported ls7 heads
-Jeremy formato ported ls7 intake
-Comp Cam 244/254 .612/.596 lift, 114 lsa.
-11.06:1 SCR
-8.5 DCR

OKcruising

Me thinks you'll fry your '65E in very very short order.

How bad is it limited for 1 7/8ths? It's been a while since I've gone under the hood of a Silvy (though I'm tossing around a SSS build up similar to yours or gone boosted)

Old SStroker

Even good 427 inch LS7 engines get stronger with 1-7/8 primaries. How much power are you willing to leave on the table with 1-3/4's? 30? 50? more?