Ida Venturies

[neil68]

Looking for some info:

I'm running some IDA's with 42 mm vents and I'm thinking that these are probably too large for my motor .

Specs are:  2017 cc, CB oval-ports 42 x 37 with Scat manifolds, Engle FK8/1.4's, 9.6:1 CR, 1 5/8\" header.

Motor makes 130 HP at the wheels with fan belt on, so I'm thinking maybe 150-160 at the flywheel without fan belt?

Tranny is a Rancho 4.125/3.78/2.26/1.48/1.04 (this is what Sam recommended) with 23.5\" tall BF Goodrich Drag Radials.

So far, my best 1/4-mile is 14.493 seconds at 3,700 ft altitude (high 13's at sea level, maybe?).  Top speed is 94.24 MPH.

Any personal experiences on whether other vent sizes such as 40 or 37 mm might help improve air flow?  I'm not sure what is even available these days.

Thanks

[dannyboy]

every motor is different, but with the vent size the same as the intake valve, you might find you get a very soggy bottom end.... from what ive read vent sizes should be ballpark 2-4mm smaller than the intake valve. when i ran 42mm intakes my motor really liked the 40mm vents, it didnt sacrifice too much bottom, but definatly had way more pull in the mid-high rpm range versus the stock 37mm vents. when i went to 44mm valves i didnt notice too much of a power difference until i swapped the 40mm vents up to 42mm vents.
 

[neil68]

I guess I should just step up and build a 2332 cc with 44 x 37 wedgeports and be done with it