Vintage trap door air cleaner

[Huicho417]

I recently purchased and restored an original vintage 340 vacuum actuated trap door air cleaner. Looks great but compared to the open cleaner I purchased from summit is way too restrictive. I put it on to got to a show and have been running it for about a month now. Car has a faint smell of fuel and smokes a little when I accelerate hard from stop. I do have it connected to the manifold vac port on carb and the trap doors are functioning as they should.

There is a 2.5” round port under the snorkel that I can add a tube and route for fresh air intake. Would that help?

 

[oldkimmer]

I sure u need to dial in your tune. If u truly have a 318 that air cleaner will never be too restrictive. Kim

 

[71gtx471]

I doubt the air cleaner has anything to do with fuel order & slight eng. smoking, obviously the door is naturally open w/o vacuum applied & that's the way I would run it w/o vacuum applied, the purpose of the trap door & snorkel flap where emission related for quicker eng. warm up when closed which we really aren't concerned about plus you live in TX.

 

[RR Fan Dan]

That hose connection on the bottom is for cold starts. There would have been a connection at your stock exhaust manifold to run a hose from the air cleaner too. On cold starts the flappers close off air from entering the snorkel and allow hot air from the exhaust to flow into the air cleaner to warm up the carb. When the car is warm the flappers open back up to seal off the hot air and allow cool ram air from the snorkel into the carb. The flappers fail in the open position so if you remove vacuum it is always in the cold air mode. You said you routed the vacuum hose to the base of your carb. Did you change the configuration of your PCV vacuum when you did this? That may be why the new smell of gas.

 

[71gtx471]

The beginning of pollution controls EPA dictating, get the choke & eng. warmed up sooner brings the emissions down chokes open & high idles off.