anth0nycurtis

Hey Everyone,

So right I have an 86 Z28 with a 350 in it, it has an edlebrock intake and a holley double pumper 600cfm carb on it. The Carb is in dire need of a rebuild and is spitting gas out the vaccum nozzle at the top of the carb. My question is do you think the Holley is worth the rebuild or should I move to something new? If so what are your opinions on the edlebrock 1405?

Thanks in advance!

Edwardgp

That tube at the top spitting gas, I believe is the float bowl vent and something might be stuck in the needle and seat causing the bowl to fill up to much and over flow [maybe but not for sure] IMO they are a good carb. worth fixing up.

anth0nycurtis

I've been told that they are great carbs, unfortunately the car sat for a couple years before I picked her up and the carb is seeping gas from various seals around the carb so I've been babying it till I can afford to rebuild or replace it. There is also steam coming from that tube as well which someone told me is a vaccum leak inside the carb. Do you think the steam may be from that same issue you're describing?

Edwardgp

It could be gas vapor that you are seeing. I think I would do a rebuild before she burns up [IMO]

anth0nycurtis

Yeah I think it was gas vapor, I adjusted the mix and it stopped spitting gas and the vapor stopped as well. I hadn't touched the mixture screws since I bought it knowing that the carb was on the todo list. one of the screws was nearly completely backed out while the other was almost all the way in. I think I'll go ahead and rebuild this carb, since the mixture is right now it's performing a lot better and no more bogging.

I'll admit I'm still a bit torn as to weather I should just put the 1405 on there, I mean it is a daily driver but I do enjoy a clean engine bay and this carb is just dull and worn out in appearance either that or I could but another Holley on it.

TreeFiddy

Perfect opportunity for you to learn about carb internals. Holley's are big and dumb - easy to pull apart / put together, and the parts are cheap. Always best to be in the know about what you've got.

If it ends up being un-salvageable for some reason (unlikely), you're not out much and at least you learned something.

Get a Holley book or do some basic research online about your particular carb. Then grab a gasket kit and a bunch of carb soak. Pull it all down, soak it all overnight, and reconstruct. You'll be surprised at the difference in both performance and looks.

Start by reading the Holley tuning sticky at the top of this forum; good advise for selecting internal parts like jets, power valves etc, and general tuning.

anth0nycurtis

Thanks for all the advice, I'm gonna check out the part # on my carb today and see if I can get the rebuild kit, this thread has inspired me to go for it. I've rebuilt smaller carbs on smaller engines but nothing automotive so I have the general concept behind it but I know it's way different. I'm looking forward to it! Any advice you can share before I get elbow deep?

TreeFiddy

Clear yourself a largish CLEAN work area, so you can lay out the various major bodies along with associated parts as you dis-assemble.

As with anything you're unfamiliar with, get yr phone/camera and take lots of pics as you dis-assemble. Get a bunch of zip-lock bags to hold the various screws and fittings, package logically and label them.

Do you have a source of compressed air for blowing out crap from the various little passages in the main + throttle bodies, and metering block(s)?

On re-assembly, be careful not to over-tighten the screws that hold the various parts onto the main body. It's very easy to strip threads, then you have to get into helicoils or tapping oversized replacements. Indeed, you might find the odd one stripped already as you pull it apart.

What kind of carb is this - mechanical or vac secondaries? Do you know the model number or List number?

Edit: Sorry, just realised you already said 600 dp.