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Discussion Starter #1
Did my first chassis dyno today, it was awesome. Made 345 HP and 365 Tq at the wheels. Temp was 77F, humidity was 49%. I need to change jets to get my fuel curve in line. Engine specs:

1972 454 0.030 over block
049 heads with 2.19I and 1.88E valves, 1.7 crane roller rockers, no port work, 116cc chambers
KB pistons with -12cc dome for ~9.2:1 CR
Lunati SFT #40299, 241, 249 @0.050, .590I, .610E lift, 112 LSA
Edelbrock air gap performer intake
BG Mighty Demon 850 carb
Summit electronic dist, MSD 6A, 18 initial, 38 total advance by 2800rpm
700R4 trans
4:10 gear, 28" tires

The shop suggested moving up two sizes for primary and secondary jets. Any thoughts? Thanks.
 

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Boldly procrastrinating
66 El Camino 57 Chevy pickup 2004 Tahoe
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looks pretty good.

does look a little lean, you have a large carb anf the air velocity through it is probably not that great. notice how it richens up a little as the RPM goes up. I'd go up 1 size all around and recheck.

You might be better off with a 750 though.
 

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RPM drops off a bit early for a FT of that size. It should continue the curve into the 6's range. Maybe not enough spring pressure.

A little pocket port work with those bigger valves would help.

Still very repectable numbers.
 

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The oversized valves in those heads are a waste without some work on the ports. A little more compression wouldn't be bad. Did you measure the combustion chamber volumes yourself? Unless those heads have been surfaced quite a bit, I doubt the chambers are 116cc and consequently I'll bet your compression ratio is less than you think.

Any idea what your quench or dynamic compression ratios are?
 

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The oversized valves in those heads are a waste without some work on the ports. A little more compression wouldn't be bad. Did you measure the combustion chamber volumes yourself? Unless those heads have been surfaced quite a bit, I doubt the chambers are 116cc and consequently I'll bet your compression ratio is less than you think.

Any idea what your quench or dynamic compression ratios are?
I agree, it does no good to put bigger valves in without the supporting bowl work. If the bowls are still the same size as they were with the smaller valves and now the bigger valve is impeading flow into the combustion chamber because the shrouding is worse, you'll make less power. A good bowl port and make sure the valves are unshrouded and they will make a good chunk of additioanl power.

X2 on the compression. That cam, IMO, needs at least static 10-1 comp.
 

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Discussion Starter #6
Thanks for the great input. I bought the shortblock and heads already done. UDHarold helped me with the cam. Future plans (and cash) are for good aluminum heads, and higher compression ratio~10.5:1. I cc'd the heads myself and the cylinders averaged right at 116cc's. I plan on tuning, more dyno, and the track in September. The car is very fun to drive.
 

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my numbers were 485 torque. 395 hp. the only difference is i run brodix rr heads cam is lunti too 231 242 575 595 750 holley performer intake shorty headers 1 3/4 pipes 454 60 over pistons trw 23cc 10 to1 compression its a torque monster
 
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