Just what the topic says, I figured you guys should know

 

only matters what it flows with a head attached to it. Flows enough with the stock heads on it.

Bret

 

Please review guidelines for posting on "Advanced Tech"... this belongs on "LT1 Tech".

Moving.....

 

I have done this test on LS1's but not an LT1 yet. I tested a LS1 that flowed 305 at .600 with just a clay 1/2 inch lip and then installed a LS1 intake. I blocked off all of the other cylinders of the intake so all of the air would have to come through the TB hole. I guess to be more precise I could have had a TB installed at WOT but I did not have one at the time. With the LS1 intake it flowed 229 at .600 lift. I installed a Wiiend aluminum LS6 intake and it flowed 253 at .600 lift. I did not have a plastic LS6 intake at the time.

Hopefully in the next couple of weeks I can flow a LT1 head and install an intake and see what kinda # diff. there is.


NightTrain66

 

Do ported LT1 intakes flow around 235cfm @.550?

 

It seems odd to be measuring pressure differentials of an intake manifold with respect to valve lift.

A more controlled experiment would be to measure the pressure drop at each intake port without a throttle body, but with a clay lip.

It would be interesting to note the flow of the LT1, LT4, LS1, LS6 intake manifolds at each port. The short runners of the LTx family are sure to show different behavior from the midlength LSx ports.

On a separate note:
I like the idea of flowing the intake systems as a whole, surprised it isn't talked about more often. In induction design the volumes of the entire system come into play for resonance tuning.

-Christian

 

Christian, with a plenum attached to the intake port, I don't see the point to that. Individual port to TB would be a different issue.

It would be interesting to note the flow of the LT1, LT4, LS1, LS6 intake manifolds at each port. The short runners of the LTx family are sure to show different behavior from the midlength LSx ports.

While relevant, a more important issue would be the reversion or the constant flow reversals in the intake ports of intake manifold with engine operating. Tuning (or timing) the port for this would be a more challenging issue.

On a separate note:
I like the idea of flowing the intake systems as a whole, surprised it isn't talked about more often. In induction design the volumes of the entire system come into play for resonance tuning.

Agreed. For reasons noted above, easier said than done. Checking/measuring with a steady state flow device doesn't simulate actual operation. I believe better to observe intake flow of an actual running setup through a clear intake with a slow motion camera, and forget about the steady state flow readings. Anyone got one handy?

 

wouldn't the different runners also flow differently in relation to where they are on the intake?

I believe it is cylinder 2 that runs leaner than the rest because of this.........would this come into play as well?

 

Wouldn't the different runners also flow differently in relation to where they are on the intake?

I'm certainly no R & D pro by any stretch of the imagination, (to some that be evident ) but from what I can determine, that will vary depending on what rpm we are using as the variable. IOW, cylinder specific flow characteristics will be different at 900 rpm and 6000 rpm. With R & D man hours, I'm confident some progress can be made with plenum air flow 'tweaking'. However, it may be simpler, or rather, be able to achieve more output with given input, with AFR/O2 and EGT readings, to tune individual injector activity, in pcm/ecm software, to different rpm ranges.

This will not guarantee equal torque output for @ cylinder, but will improve the cylinder to cylinder A/F balance.

Geez, what the hell did I just type here?