Secondary Rod Question

[Bigb206]

I bought a 17057253 carb off of eBay, it came with CV secondary which seems to be the correct rods, however it appears that the rods are bottoming out on the factory plug before sealing that silver disc, is this normal?

Also, if anyone could tell me if I would have to increase the Jets or idle tube size. This will be going in a 72 cutlass 455 manual, 12mmg vacuum, 9.5:1 compression, cam lobe separation 110, @50 230/236

Thank you!

[omaha]

no they should not bottom out. some investigation is in order. check for bent hanger, bad cam or maybe improperly installed plugs. Last one is a long shot but all should be looked at. jet and rod combo you can figure out with the recipes in the book.

[Bigb206]

That was with me manually holding the rod, perhaps using the hanger would make it not bottom out? I'll try and report back.

[Cliff Ruggles]

Those are excellent carburetors for what you are doing.  It will need recalibrated to be happy on that engine. 

I would install one of our kits in it, with HP pump and high flow N/S assembly, small float, and jets/metering rods, PP spring. 

It will also need a few tweaks to the idle system, and for sure convert it to electric choke during the rebuild......Cliff

[Bigb206]

Thank you, I will call you guys this week to order the kit!

[Cliff Ruggles]

Sounds great, make sure to have all of the engine specs close by when you order, specifically the CID, cam, and true static compression ratio....tks....Cliff

[Bigb206]

Even with the hanger they were barely touching the plug, would it be ok to slightly ground down the top on the rod so the rod and disc make a complete seal.

One other question I have...I ordered my kit on Tuesday, while waiting for the kit to arrive I wanted to do the modifications. I noticed that the the previous owner must have drilled this out air bleeds in the airhorn, they are approx 0.065, Will this be a problem?

[Cliff Ruggles]

The MAB"s in the airhorn should be very close to .070" on that carb number......Cliff

[Bigb206]

Cliff,

I received the kit and have a few question. With my specs above and this carb (which doesn't have the holes drilled for bypass air in the base plate), would you recommend drilling the base plate or throttle plates? Also, which PP spring would you recommend.

If it matters, I'm using recipe #2 in the book.
 

[77cruiser]

Drill for bypass air. Are all the other channels there for it?

[Bigb206]

Drill for bypass air. Are all the other channels there for it?

Thanks....yes everything is there but the baseplate. One question about that. I have a spare base plate (for another carb)  has the holes drilled all the way through the base plate. In the book it shows drilling a hole from the bore to that hole...is that necessary, or will a hole all the way through the base plate be sufficient?

[77cruiser]

I'd put them in the factory location.