Vacuum headaches.. help me out

[timmyadkins]

ive got an 85 monte that I dropped a 383 with a pretty radical camshaft in it. So I'll need an aftermarket canister for the booster. I know that. There is a hose running from the driver side of the frame that I assume comes from the fuel tank. Where do I run that? Here is diagram of how I think this thing goes. Please correct any mistakes you see.

Thanks in advance!

 

[Kwik_Cutty88]

Can you snap some pictures for some more clarification? You're sure the hose you're talking about isn't for the charcoal canister?

 

[timmyadkins]

Yea sure. Standby for a bit and I'll get some

 

[timmyadkins]

The picture where I have my thumb is the hose. I think you're right because isn't the vacuum canister round? There is an option on that to go to carb. Would I run the other hose to my pcv on my carb? Or can I just get rid of the darn thing all together?

 

[Kwik_Cutty88]

Yep, I'm pretty sure that is the hose that will go to your charcoal canister for emissions. From your diagram it looks like you might have everything hooked up correctly. Does your aftermarket canister have a check valve in it? How do your brakes feel? What kind of idle vacuum is it showing on the gauge?

 

[timmyadkins]

I haven't actually started the engine and ran the vehicle yet. I'm just trying to get everything sorted out while I wait on my headers. The aftermarket canister does have a check valve in it. I'm assuming the check valve side of the canister goes to manifold vacuum and other to booster?

 

[Kwik_Cutty88]

You are correct. Your booster should have a check valve on it as well. Depending on the specs of your camshaft having a vacuum canister may not be enough, I know it wasn't for me. It looks like you've got everything sorted out for now and ready to fire. You'll have to see what it's like once you start it up.

 

[timmyadkins]

I've heard that. What did you have to do to have a sufficient amount of vacuum? My cam is rather large 😎. I haven't even ordered the canister yet so I won't be wasting money.

 

[Kwik_Cutty88]

My cam specs are:

I used a Hella UP28 vacuum pump, that my dad grabbed out of a late model GM vehicle. I wired it in with a vacuum switch and the brake pedal switch. That way it will only come on when the brake pedal is depressed, and it sees less than 22" of vacuum in the can. It is enough to supplement the engine vacuum and gives very good brake pedal feel.

 

[timmyadkins]

Outstanding. And you use that in conjunction with the canister?