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-   -   Big Block Vortec heads airflow data...? (https://www.offshoreonly.com/forums/general-q/58797-big-block-vortec-heads-airflow-data.html)

DonMan 09-08-2003 10:13 PM

Big Block Vortec heads airflow data...?
 
I am playing around on my desktop dyno and was wondering if anyone knew the airflow specs on a set of stock Vortec 454 heads?
If not, the specs for large oval-port heads should be close.
THANKS!

cobra marty 09-09-2003 07:05 AM

POOR AT BEST!

Pat McPherson 09-09-2003 08:12 AM

Hey DonMan,

Are you going to put bigger valves in those heads?

Post some numbers if you don't mind.

Madmax 09-09-2003 09:12 AM

Those aren't correct, those #'s indicate they flow worse than stock peanut ports. I'm betting those are the #'s for SMALL block vortec heads.... those would be much more like what a decent small block head would flow.

Pat McPherson 09-09-2003 09:56 AM

Madmax is right, the numbers are likely for small block heads.

The link is good sutphen30, lots of good info, no L-29 heads though.

Donman, you may want to try numbers in between the GM 049 and the WP Merlins.

Are you running numbers for the ZZ502 cam ???

I need to buy that desktop dyno...

DonMan 09-09-2003 08:07 PM


Originally posted by Pat McPherson
Hey DonMan,

Are you going to put bigger valves in those heads?

Post some numbers if you don't mind.

I`m not sure what valves I`m going to run right now, hence the desktop dyno.....
My 454 went kablooey so I`m considering building a 496 shortblock, possibly a 540....
I know these heads aren`t that great, but I already have them and really can`t afford better heads right now. Just hoping to get a little good from them.

DonMan 09-09-2003 08:09 PM


Originally posted by Pat McPherson

Donman, you may want to try numbers in between the GM 049 and the WP Merlins.


Yes, I`ve heard these heads are better than 049`s but not as good as anything aftermarket.

So, OK give me flow numbers for 049 and Merlins.

DonMan 09-09-2003 08:12 PM


Originally posted by Pat McPherson

Are you running numbers for the ZZ502 cam ???


Actually I`m running the numbers using the Crane 168741.
.610/.632 236*/244* 112 LSA

Initially, I`ve seen 537 HP @ 5000
496cid
dual plane
800 cfm

Pat McPherson 09-10-2003 07:06 AM

Hey DonMan,

Sorry to hear you 454 went boom :(

sutphen30 posted a link to the flow numbers from high performance chevy.

Would you mind running the numbers for the ZZ502 cam in a 454?

DonMan 09-10-2003 07:02 PM


Originally posted by DonMan
Actually I`m running the numbers using the Crane 168741.
.610/.632 236*/244* 112 LSA

Initially, I`ve seen 544HP @ 5500
496cid
dual plane
800 cfm
9.75 compression ratio



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