496 dyno disappointed

[grumpyvette]

Just had my motor built for my 70 SS, feeling a lil disappointed after seeing the dyno. Anyone think this has more in it or are the heads restricting it.

Scat forged roatating assembly
Mahle forged pistons
Compression 10.5:1
Brodix race rite 270 ovals
Comp hyd. Roller 11-444-8
Rpm air gap
F.A.S.T. Ez efi 2.0 1000hp system
2" primary dyno headers

What do you guys think? This the best it can be or should I try a different cam.

http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=447&sb=2
Jimmyrigs, I have to ask a few questions,peak torque generally closely matches peak air flow, and fuel delivery, peak efficiency

do you have dyno sheet showing,
plenum vacuum?
exhaust back pressure?
pictures of the spark plugs?
ignition advance curve?
fuel/air ratio?
and yes fuel air ratio at each rpm level?
fuel pressure art each rpm level?
whats the valve spring load rates and clearance limitations
(yes I know Brodix race rite 270 ovals, good for .600 lift)
http://www.jegs.com/i/Brodix/158/2061006/10002/-1?parentProductId=755729#moreDetails
but at times what is printed on the box , and what is in it,and reality don,t match
I don,t think its the cam, unless its not installed correctly
and a dyno torque curve print out is at times useful?
you generally don,t see a combo like that max out torque at about 4600rpm, so I'm thinking the fuel map needs work or theres a air flow restriction at some point, frequently related to a restrictive exhaust or lack of effective cylinder scavenging

http://garage.grumpysperformance.co...ers-and-yeah-thinking-it-through-helps.15137/

 

[philly]

i think theres something wrong in the tune there... because the sum of those parts seems to lend itself to alot more power... maybe the air-gap intake should be port matched to the heads also

 

[johnnmo]

I'd have to ask about cam position, ( is it straight up/ adv/retarded?)are the valve springs for a hyd. roller? And, why 10.5 compression? ( with aluminum heads Id go 1 point higher)
It looks like the power came off very fast after 5,000 which makes me think VSprings.

 

[Grumpy]

Id also suggest you test a decent single plane intake on those oval port heads, preferably with a 2" open carb spacer , if hood clearance in that application allows it,
as it can and frequently will provide a significant boost in airflow over the dual plane, and a 496 BBC with only 270 cc runners can at times show a marked improvement swapping to the single-plane intake.
Id suggest
https://www.summitracing.com/parts/wnd-7620/overview/