LT-5 Head Air Flow #
 

Hi All,
Does anyone have a link or know what CFM the stock LT-5 heads flow at? Thanks you

Re: LT-5 Head Air Flow #
 

I have them somewhere if i find them i will post them for you.
May i ask why you want them?

They mean nothing unless you test on same flow bench.

Pete

Re: LT-5 Head Air Flow #
 

Copy from Corvette Forun
"Here's something that was posted on the ZR-1 Net by Greg Van Deventer:

Here's some intake numbers from a stock 1990 cylinder head tested @ 28" H2O
on a stock 3.900" liner with secondary port throttle assembly and clay
radius...

Lift CFM
.1 92.78
.2 167.97
.3 222.01
.4 246.84
.45 256.86
.5 263.44"

Re: LT-5 Head Air Flow #
 

Thank you for the posting. No problem, Just curious how they flow in comparison to other heads LT-1, L-31, Lt-4, LS1 etc.

Re: LT-5 Head Air Flow #
 

new LS stuff is way better but it's not all about "raw cfm" flow quality, tumble, mix, detonation reistance and of course flow velocity make the LT5 work pretty good depite the rather low bench numbers

a good set of ported heads will sneak up on 340 cfm and support well over 700 ponies

above that you are a bit flow bound.

FYI the out of the box new LS7 heads flow 370+ which stomps the living crap out of our heads but of course a 4 valve head has many other advantages such as lighter valves, less valve shrouding, low tension springs

and pete is right, flow benches like dynos don't tell the whole story

Re: LT-5 Head Air Flow #
 

I wouldn't pay the final attention to max. cfm numbers.
There are other important things to consider. A 700 HP LT5 perform different and better than a 370 cfm flowing LS7.

We brought a C6 Z06 on the same car weight like a C4 ZR-1 and did some acceleration tests. The LS7 pulled in spite of its 427 cui pretty modest.

Re: LT-5 Head Air Flow #
 

Of course you are right Sam. The motor spends most of its time in the mid lift flow area. Max flow is visited very briefly.