Thread: carb set up

Tweet

Don't know what carbs your set up for 3 bolt or Rochester, but it sounds like 2 things are happening, your over-carbed at wide open throttle (WOT) and your end carbs are coming in to fast. If it was me, the first thing I would do is slow down the opening and limit the amount of opening of the secondary carbs. For what it's worth, this is the way I set up a Tri-Power.

This is a picture of my SBC tri-power linkage. I have run this set up on a 307, mild 327 and a 383 stoker (It's currently residing on a 350 LT1). Once I've got it to the point it will idle and run, I set the adjuster on the end of the top piece of linkage to start opening the end carbs at a certain speed so I can comfortably cruse on the center carb only. I usually use 80 MPH on a flat stretch of road as the tip in point (the interstate speed where I am is 75 MPH).

On the 307 and 327 I used the upper hole in the front carb linkage because it caused the end carbs to open slower and in that case the end carbs would not completely go to WOT. The total CFM at WOT with all 3 carbs is around 900+ CFM which was entirely to much for a small CID (which I think is the problem your having). It could be slowed/limited even more if I had moved the linkage higher on the front carb or lower on the center carb.

ON the 383, I used the lower hole which opened the end carbs faster and wider (but still short of WOT). I think you'll find that for your 305 the end carbs will not need to be open very far (with the center at WOT) for it to be effective anything else is just over-kill.