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Edelbrock 1409 question

A

Act Three

Contributing Member
Sorry to go back over old stuff.

I bought a pair of 1409s to replace the Quadrajets on my Chrysler 360s. I know I'm supposed to drill out that blocked port between the idle jets using a 5/16" drill and then tap it for the PVC fitting. Got that.

But when I look at the underside of the carb, it appears that to get PVC vacuum, I'd also have to drill out that blocked port between and just above the primaries. Is that true? If so, how big a hole should drill in there? You can see the port I'm talking about if this photo loads.

Edelbrock 1409 underside.jpg

Thanks

Bill
 
You also have to drill upwards until the two holes meet. An 1/8 " drill bit is large enough. Scary thing to do with a brand new $$$ carb, but necessary.

I can't believe Edelbrock STILL does not provide a PCV fitting hole after all this time! Hell, the street version of this same carb has two: one for PCV, the other (in back) for power brakes.

Jeff
 
Here's an update to my post regarding the 1409 carbs and the PCV port.

My old Chrysler intakes are spread bores and the 1409 is a square bore carb so I had to also buy the Edelbrock 1296 adapter. I didn't think of that until I looked at the manifold again. When I got the 1296 adapter (a nicely machined piece of aluminum that came with the right gaskets) I noticed that the datasheet mentioned, "These adapters have a 1/4" NPT hole in the back, which can be drilled if an additional vacuum source is needed."

The hole was certainly there, nicely threaded, but it was located directly between the two secondaries. Drilling straight in wouldn't get me anywhere. I called Edelbrock (great customer service) and got a guy on the phone who knew exactly what I was talking about. He told me to drill a 1/8" hole at an angle, avoiding the threads, into one of the secondary ports. He said that the 1/8" hole would easily evacuate the crankcase gasses in a marine engine.

I had a hose barb fitting that I added and I think we are finished with this project for now. Won't know how they run until spring but for now, at least I can mount the carbs and connect everything.

Bill
 
.."When I got the 1296 adapter (a nicely machined piece of aluminum that came with the right gaskets) I noticed that the datasheet mentioned, "These adapters have a 1/4" NPT hole in the back, which can be drilled if an additional vacuum source is needed."

The hole was certainly there, nicely threaded, but it was located directly between the two secondaries. Drilling straight in wouldn't get me anywhere."

Unbelievable! When will those people at Edelbrock wake up!

Rant over.

Jeff
 
fastjeff said:
You also have to drill upwards until the two holes meet. An 1/8 " drill bit is large enough. Scary thing to do with a brand new $$$ carb, but necessary.

I can't believe Edelbrock STILL does not provide a PCV fitting hole after all this time! Hell, the street version of this same carb has two: one for PCV, the other (in back) for power brakes.

Jeff
Click to expand...

I took mine to a machine shop because I was too scared of ruining my new carbs (even though I've drilled and tapped a thousand different things). I think I paid about $45 for the whole job. Worth every penny for the peace of mind.
 
Not too brave, eh! I understand

Let's hope the Edelbrock supervisor gets a lump of coal in his stocking for putting us all through this nonsense.

Jeff
 
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