454 TBI flow and 454 cam specks

[Walter Sherwin]

>> Cam specs for a late model L19 TBI 454 were roughly as follows:  192/203
@
>> .050" duration, .398/.430" lift @ 1.7:1 rocker ratio, 111 degrees lobe
>> separation, and tiny valve areas.
>
>Wow, that is tiny.  It is a roller cam though, right?



Nope, BBC's did not go roller until 1996 when the GEN VI multi-port version
was released.



>
>> How much can the 454  2" TBI support?......275 Hp at near the stock fuel
>> pressure........ 425+ Hp if reworked for increased fuel pressure.
>
>I have seen these 454s run low 15s/high 14s in their trucks with a few
>things, like open K&N filter, Chip, Slicks, headers, etc.  I don't think
>that my 400 would run any more then 360 HP.



A stock 91-93 454SS, with 4L80E & 4.10 gears will consistently run 15.4 all
day.  Mid 13's with cam, porting, headers, intake tract reworks, and more
fuel pressure.  If you are planning on 360'ish HP at 5000'ish RPM with your
powerplant, then you are going to require about 15-18 psig of fuel pressure
at your TBI unit, as opposed to the factory 10-11 psig setting.   One real
easy way to do this is to purchase a new 18 psig regulator/meter cover
assembly from GM, under P/N 17113186.  It is cheap, and will bolt in place
of your stock unit, to give a factory looking conversion.  Of course you
will have to then also go into the code and cut back both the idle fuel and
the low to midrange open loop fuel to prevent overly rich operation under
these conditions.



>
>Is there any way to get rid of the EGR valve with the TBI system.  I have a
>Performer Intake for my 400, but it is a non-EGR one.  Thanks.




Yup, simply go into the TBI software that you choose to run, and defeat the
EGR function so that EGR is never commanded active (ie: defeat it based on
temp, TPS, etc.).  If you choose one of the more common TBI boxes then there
are a ton of references in the archives as to exactly how to do this, and
where the addresses are.  TBI fuel will work with a conventional carb
"Performer" manifold, but works better with a good TBI manifold built
expressly for that purpose.  Edelbrock have a number of good TBI manifold
selections that you may want to peruse.


Walt.