Don Terrill’s Speed-Talk

just what is your desired usage

just wondering if you use the equalizer caps for the vacuum secondarys

Most heads i have done for customers tell them to increase jetting 20 to 30%. each holley jet size is about 4.5% increase.
with a power valve in the curcuit might play with the jetting to figure how much to open the PV fuel feed.

look at the flow testing in my brodix IK heads for sale

flow testing several SBF dual planes found the lower plane on average flowed better than the upper plane. figure its due to port entry angle is more on center with the port center line. i usually cut down the divider wall to some point and havent had much issue with having to stagger jet. Some issue...

You want to block off the runners not being flow tested. It acts like there is an infinite plenum. A running engine is stealing flow from other runners. closing up the runners not being flowed gives a closer idea as to what actually happens in the engine not perfect but a lot closer.

The shop i worked for designed the 18x chevy heads ports and their porting programs for Brodix. Shop is in Westland Mi.

if one used calcs to figure HP based on cylinder head flow vs flow sucking with the intake mounted, the intake mounted to the head flow will be more accurate.

Blow through would flow figures would be way off

champhering the throttle blade is what i have done in situations were its needed to uncover the proper amount of the transfer slot.

Charlie, I tried the same thing as you several years ago on 3 or 4 intakes and made notes on each test. Then I turned them around with the air being pulled in as it normally would be. Every test in the blow through method gave higher numbers. I think this is due to the way the air acts at the runne...

looking at the pic tape looks like it maybe sucking not blowing. The bench i used could reverse the flow usually suck flowing intake side head or intake, blow through on the exhaust.

IF you are doing blow through instead of sucking myself would never do that.
Also because of pushrod locations the left side of the intake needs to be worked different than the right side.

holley 390 carbs in chrome and air cleaner. air cleaner can be set to use on many center to center distances.
550 + shipping. i use modified versions of these on my 302

Having adjustable/ jet able orfaces of air and fuel in all circuits works out the best. Most have no idea other than changing a main jet as to how to tune a carb. Main jet is a cruse jet most dot know that. Just changing the main jet might do well at the drags but street and and road race not so ho...

Having adjustable/ jet able orfaces of air and fuel in all circuits works out the best. Most have no idea other than changing a main jet as to how to tune a carb. Main jet is a cruse jet most dot know that. Just changing the main jet might do well at the drags but street and and road race not so hot...