Carburated IR Intake Manifold

[blykins]

I would try it using just the thickness of the spacer as the plenum for that first 15% throttle. I think the air will find it's way in. At part throttle there won't need to be much airflow and at full throttle it should act as an IR but with a little mixing.

 I noticed when I had a carb base plate screw fall through my 390 that several spark plugs were smashed flat and evidence of the screw marks in several cylinders. The F427 has a divided upper and lower plane of the intake. One screw , but it damaged five cylinders? Three on the upper plane and two on the lower...hmmmm. There is only a small notch (for 3 barrel carb) on the intake otherwise upper and  lower planes are divided. Somehow that screw went into a cylinder, bounced back out the intake valve and got sucked into another cylinder by way of that 1/2 by 1" notch under the carb multiple times.

When I worked for Valvoline, we had a Cup engine on the dyno.  Retainer broke at a little over 9000 rpm.  That intake valve ended up on the opposite side of the engine. 

[frnkeore]

I'll be gone a week, to a tractor pull & show, If there are any other questions, I'll respond, when I get back.

[cleandan]

If you set this up for individual runner I am wondering how you will adjust each butterfly of the carb to adapt to the specific cylinder needs it is feeding?

I once spent a lot of time trying to dial in an 8-stack injected system.
This system consisted of basically 4 two throat throttle bodies with each two throat being hard linked to each other, meaning no real adjustability of the butterfly between the paired throttle body outside of literally bending the throttle shaft.

I could adjust fuel and air independently between each throttle bore, but the 2 butterflies were on a common shaft and worked together.

This resulted in an engine that ran pretty good overall, but was never quite right because I was unable to specifically adjust for each cylinders needs. The closest I could get was a nice compromise between the paired throttle body.

[cammerfe]

Dan---

That also applies to Weber carbs. My experience is that with fiddling, you'll get close. FI does a better job.

KS