Any ideas dual snorkle 307 cold air? Is tge second snorkle controlled to open? Pics on how anyone has successfully plumbed?? Thnx
Dual Snorkel cold Air Ideas
- Thread starter Chenz62
- Start date
There's so much garbage in the way stuffed under the hood on an Olds G-body that they didn't want to re-design stuff so the engine could have an extra snorkel on the passenger side that was useful. That's why it's 180 out and shorter. Because that's the only place they could fit it, not the best place for it.
The stock 307, when running, closes both flappers to outside air when cold (below 86 F). Engine vacuum is plumbed through the thermac and then to the flapper actuators. The thermac is the temperature controller. If it senses 86 F, it'll start to open to bleed off vacuum to the flappers. The flappers are now in regulating mode. Once temperature gets warmer, and reaches 131 F, vacuum is fully bled off and the valves are fully open. The small snorkel near the HVAC box doesn't care really, but the driver side snorkel attached to the heat stove tube draws air through the heat stove initially, as exhaust heat warms up the air entering the air cleaner from the bottom of the flapper. This air temp is what the thermac looks at. Don't worry, it's a controlled vacuum leak through a tiny port. Just like the hot air choke. It's designed to allow the carb and CCC to adjust mixture if needed to make up for that slight extra air ingestion. It's sorta worked that way on Oldsmobiles since the advent of emissions controls came into play on Oldsmobiles (and other GM cars) somewhere around 1968 I think.
The bi-metallic thermac is mounted to the air cleaner base. It senses temperature rise, it will start to open the vacuum port to bleed air into the vacuum line to the flappers. If vacuum drops to 4.5" Hg, the flappers will start to open. If it further drops to 1.5" Hg, they'll be fully open.
You will do yourself better if you get a dual snorkel air cleaner off a Camaro or something similar to move those air cleaner snorkels toward the front. Of course, that means you can't leave it stock. Some emissions stuff and maybe A/C junk will have to move. It's going to be tough to get that second Olds air cleaner snorkel plumbed to where it looks like it was supposed to be there.
The stock 307, when running, closes both flappers to outside air when cold (below 86 F). Engine vacuum is plumbed through the thermac and then to the flapper actuators. The thermac is the temperature controller. If it senses 86 F, it'll start to open to bleed off vacuum to the flappers. The flappers are now in regulating mode. Once temperature gets warmer, and reaches 131 F, vacuum is fully bled off and the valves are fully open. The small snorkel near the HVAC box doesn't care really, but the driver side snorkel attached to the heat stove tube draws air through the heat stove initially, as exhaust heat warms up the air entering the air cleaner from the bottom of the flapper. This air temp is what the thermac looks at. Don't worry, it's a controlled vacuum leak through a tiny port. Just like the hot air choke. It's designed to allow the carb and CCC to adjust mixture if needed to make up for that slight extra air ingestion. It's sorta worked that way on Oldsmobiles since the advent of emissions controls came into play on Oldsmobiles (and other GM cars) somewhere around 1968 I think.
The bi-metallic thermac is mounted to the air cleaner base. It senses temperature rise, it will start to open the vacuum port to bleed air into the vacuum line to the flappers. If vacuum drops to 4.5" Hg, the flappers will start to open. If it further drops to 1.5" Hg, they'll be fully open.
You will do yourself better if you get a dual snorkel air cleaner off a Camaro or something similar to move those air cleaner snorkels toward the front. Of course, that means you can't leave it stock. Some emissions stuff and maybe A/C junk will have to move. It's going to be tough to get that second Olds air cleaner snorkel plumbed to where it looks like it was supposed to be there.
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