: Air Intake for 307



Big_Blue
03-02-05, 09:20 AM
I have already added the one inch carb spacer for my quad jet carb and working on the exhaust(Magnaflow Cat and dual Mufflers) if I can get the mechanic to figure out the routing of the exhaust. But I wanted to know if you guys know a nice way to get more air into my carb sort of like ram air or cold air induction into my 1986 FWB.


Also I wanted to say since I added the carb spacer to the car I have noticed that I am getting more exhaust fumes into my car threw the vents. Has anyone else have this problem??

90Brougham350
03-02-05, 11:44 AM
Vents, like, air vents? You definately need to figure out why, it's very dangerous to have exhaust coming into the vehicle. As for getting more air in, buy an open element cleaner. Edelbrock makes one with a chrome plated base and top for about 40 bucks, and then the replacement filters are the cheap 14x3 units you see at every auto parts store, or you can buy the K&N for around 50 and keep it forever.

Brian

Big_Blue
03-02-05, 01:44 PM
I thought about gettting that open air one but I was confused on the PCV valve and the return line under the standard element( the one from the exhaust man) are they capped with a smaller filter ?

N0DIH
03-02-05, 01:45 PM
Do you have Engine Code Y or 9?

The Y is the 140 hp 307
The 9 is the 180 hp 307 (from the 442)

Many "9" engines found their way into Cadillacs so the rumor goes.

You can make a factory looking dual snorkel air cleaner if you can find another one to cut the snorkel off of. I did it and hardly anyone ever knew it wasn't factory. I also ducted it to under the bumper ram air. Worked good for me. It was an Olds 350 in a 85 Cutlass that previously had a 307 "Y" engine.

Tom

Big_Blue
03-02-05, 04:17 PM
Do you have Engine Code Y or 9?

What place in the vin tells me if its a 9 or Y?


thank you guys for responding

Also to 90Brougham350 (member.php?u=20067) I belive its the Char canister that may be old and in need of replacement. Reading the manual has lead me to belive that it purpose is to clean the air and when failing it allows exhaust fumes possibly into the air vents

90Brougham350
03-02-05, 04:39 PM
Hmmm, I don't know a whole lot about emissions, but I always thought the charcoal canister was designed to put fuel vapor into the carburetor, I don't think GM would design a product that would allow exhaust fumes into the cabin of the vehicle, to me that sounds like lawsuits up the ass. I believe the PCV valve either goes through a 3/8th inch vacuum tube either to the front of the carburetor or to that strage little canister deal infront of the carburetor, either way, that shouldn't touch the air cleaner (but I might be wrong), and the crankcase ventilation pipe that runs from the valve cleaner into the side of the air cleaner, I think you should just be able to put a breather on top of that. As for the stove pipe hot air duct that runs from the exhaust manifold to the air cleaner neck, you would be alright without that if you live in a warmer area, but you would still be alright without it even in Ralph's neck of the woods, it's not that important. Hope this helps a little.

Brian

Big_Blue
03-02-05, 06:22 PM
my pcv pipe leaves the valve cover and goes right into the air element.

90Brougham350
03-02-05, 06:26 PM
That's not too hard then, the Edelbrock open element has a fitting on the bottom that comes with the unit, you can chose to install it or not, you just drill out a hole and screw the little piece on and then you can "plumb" hoses and lines into the air cleaner.

Brian

Night Wolf
03-02-05, 06:42 PM
the air cleaner is NOT the restriction on the 307

you can have the biggest air cleaner in the world on the 307, but that will not let down the fact it is still sipping thru a straw... the ports on the heads are just too small. IIRC from my reading, if you want to do anything to a 307 to get power, get the heads ported at a machine shop. but the only thing an open element air filter on an otherwise stock 307 will do, is look cool and make lots of noise.

I put a 14" Edelbrock open element on my 425, and I took had the breather valve problem... installing the stuff they gave me was too much work... had to drill it out, cut the metal away, find your own house and a fitting... then it is more difficult to remove the whole assembly...

so I bought a small 3.5" breather filter... that didn't fit as the inlet was 1 1/4" or so.... so I went to Advance Auto, and they have a section of APC stuff (yeah... the stuff for ricers) and I bought their small breather.... this time it was too small of an inlet, so what I did was I got a long piece of duct tape, but ripped it in half down the middle and kept wrapping it around until it got a snug fit, then I just pushed it on the hole.

it is chrome and, when new had a red filter (look like a K&N) but now form use with oil splashing around, it is black... still, far better then an open hole for stuff to get int he enigne and oil to slatter everywhere.

I have a picture of it, but not on the computer yet, I am just starting to get my stuff back on from a reformat

Katshot
03-02-05, 10:37 PM
I seem to remember back in the day, that a hot-chip made a HUGE difference in the 307. Have you done any programming mods?

Scottie in Alabama
03-02-05, 11:55 PM
I seem to remember back in the day, that a hot-chip made a HUGE difference in the 307. Have you done any programming mods?

Do Tell, what do I need to do? Where can I get a chip?

N0DIH
03-03-05, 02:53 AM
Do Tell, what do I need to do? Where can I get a chip?

If you are looking for power, don't waste $ on a chip. Do the low buck or free stuff here first.

1. Adv timing to the point of detonation with the highest octane you can afford. Most chips only tweak high end timing, so adj timing does all they do anyway. None touch part throttle fuel. The carb handles WOT fuel.

2. Adjust 4BBLs to open fully. 307's are pretty restricted. Don't worry about giving it too much air, they are still vacuum limited, so you will only get what it can take. This will allow for the full 800 CFM. ALL 307's were 800 CFM carbs, but they were restricted to around 570 to 620 cfm from the factory.

3. Loosen 4BBL's to open faster, if they bog, then tighten back up a little. This takes some time and some driving. These are pretty tight from the factory.

4. Install a 180 thermostat. Don't believe anyone who tells you that this will keep the car from going into closed loop. They do not understand this ECM. The high performance type, like from Robertshaw, Autozone carries this for around $6, don't waste $ at Summit for $12.

5. Disconnect vacuum lines from carb to air cleaner and plug off. This will force cooler air in carb and aircleaner.

6. Dual snorkel mod, and route to ram air under front bumper. This one actually helped my Cutlass a lot. The reason for dual over single is additional air when used with ram air, w/o ram air no benefit.

7. Do not suck up underhood air for any reason. Too hot.

8. Get a set of Torque Plus intake gaskets (if they are still made), this helps atomize the fuel air mix.

9. Restrict or block off the exhuast crossover in the intake. Will likely hurt mileage and drivability in the winter. If you are adventurous, weld up the intake crossover and plumb for hot water, then block the water in the summer.

10. Head swap, get a set of early 70's #5 Olds 350 heads. Keep CC to 64 or a little less. More will hurt compression. Std 350 heads after 74 were 67 cc. For more reasonable heads, get a set of 81 to 84 307 heads and Aluminum intake. Same cc, better airflow. If money isn't an object, toss in some 455 valves (2.07/1.7x). Pocket port the heads for sure, don't hurt velocity, you need it.

11. Check exhaust manifolds, if you have tubular steel, find some cast, if they are cast, they are decent, not great, but decent. Better than tubular steel ones. I think most B/D had the cast. Cast are mandatory for item 10 above. Custom duals can be done. Get exhaust manifold block off from the Diesel Olds 5.7 cars to plug up extra hold from crossover on the pass side manifold. Rumor is all Diesel stuff went to Detroit Diesel. So they may be hard to find. There is enough room in a G Body to make dual exuasts down one side so you don't have to screw with the crossmember.

12. Shim distributor to take up slack. This can be difficult without binding the distributor up. Check with Mon(ey)dello. I think 0.050" clearance is normal, most are much much more. This gives timing accuracy. Take your cap off and turn the rotor, does it turn left to right at all? It shouldn't in a good distributor.

13. Cam Swap, get a VIN code 9 cam. This has .440 lift, far more than stock "Y" cam. But it will hurt lower end torque a bit. This cam was std with 3.73 geared cars (442's). These were 180 hp cams in a 307 with 7A heads.

14. Richen secondaries to around 0.86 to 0.88v as read on the O2 Sensor at WOT. You will need an assortment of metering rods to do this. Edelbrock sells them now new. Else, scrounge junkyards. Look for lowest letter secondary metering rod hangar. I have seen the "A" hangar on the 1986 4.3L V6 AstroVan's. Or you can redrill a hangar that is farther along in the alphabet. This only controls the rate at which the secondaries go rich.

15. Set up carb precisely as the factory Service Manual documents. Be precise as possible, this will enhance overall drivability.

16. If the car starts cold then dies immediately, then restarts fine, replace the primary vacuum break (the one on the front), 95% of the junkyard cars I have seen have this part bad. This has 2 functions, choke pulloff (to open choke slightly when cold to allow engine to breathe) and controls the opening rate of the 4BBLs. The 403 Olds from the T/A vacuum break has a slightly faster rate. Check the 442 Olds (1985-1987 307 "9"). Ask parts store to let you play with them and look for the fastest opening one. Despress fully and count seconds till returned. Faster is better. Cars to look at, any 77-79 403 Olds car (Check 88/98/Toro and T/A, and also check 75-76 455 Cutlass. Makes sure they are same mounting, most were. Must be a M4M carb, not the 4MV. The M4M's started in 75, these had the taller primary metering rods over the 4MV series.

17. My 307 had the timing factory average so high it was firiing on the edge of the HEI cap contacts. I cut off the index mark on the cap and reindexed the cap 3/16". Helped drivability and idle quality when you adv the timing. Else it will be starting to fire off the edge of the contacts of the cap. Make sure you mark the cap to distributor base first then remove index notch, then resinstall one notch thickness backwards (centering the rotor contact on the cap)

18. Olds rocker arm Fulcrums wear fairly fast (I think these are the same rockers as the Cad 4.1 to 4.9). Replace them if they are noisy. This will quiet the engine down as well as stabiltize the valve train. Not to bad cost at NAPA. But Ford 302 Rockers can be made to work very easily if you want rollers.

Tom

Scottie in Alabama
03-03-05, 07:52 PM
Thanks replying, but that's a bit much Tom. Don't have that much free time or know how.

Big_Blue
03-04-05, 06:30 AM
But my question is this .... How can I tell what car I have by the Vin? I know the lettering 9 and Y but which place on the Vin are they.

I have free access to a junkyard with I say has a good stock of American cars. I am in the process now with the dual air element and routing of the pipes. I also learned the more angles in my air duct the more restrictive on air it is. I am trying to make a sort of Air box where the current battery is. Moving the battery to the passenger side with the canister being relocated along with another small item. I'm gonna present a box with air to dual cones air filters. Praying that water can find its way back with the bottom of the air box or I should say the the front drivers well side being a sort of water strainer. I havent gotten it all figured 100 percent yet. I have made rough rough scetches of my projects so far

I know someone is gonna say why not change the motor but I dont want long periods of down time plus I am totally in love with my caddy and I MUST DRIVE her Daily or every other day. :)

:halo:* Personal Note *:halo:

I feel that any caddy has a good motor in it just some arent racing standards but I feel that old caddys pack a punch and can still keep up with currrent big body cars if given the right things. I am not gonna do the most expensive stuff to my car because I do this has a hobby alone only getting help and detailed insight from what I read, hear and researched. I paid 350 bucks for this car(81k orignal miles) on a deal that came out of nowhere for something I always wanted. I re did the interior myself (Headliner,visors and rear seats) I have re done the suspension (shocks,springs,grease fitting). Change most things on the motor along with the brakes, Brake Lines and bearings, Seals and Gaskets. I can honestly say the only real problem that I saw was the clutch on the fan had to much resistance and kept car temp too high which was changed. I also undrecoated my car to prevent more rust after carefully sanding down or trying to remove what I could off the bottom. The car didnt need that much work but the comfort of mind that I dont have to worrry if it was done by prior owner but it was done by me. If I can get enough urge to take some body work on I will start removing the small rust spots on the bottom of the doors and front fendors since the preson prior to me had welps not really dents cause dont have scratching or sharp corners on them. Get them out and prepare for the paint job search


I just need this car to last 10 or 15 more years and when that time is done I may want more years of of it.

N0DIH
03-04-05, 08:21 PM
The Olds 307 is one of the most reliable engines from GM. Take care of it, and it will last a very long time. Mine was at 186K miles when I dropped a screw down the carb. It was terminal then. (I dropped in a 77 Olds 350 after that) But upon teardown, it looked fantastic inside. Yes, BBob, it ran synthetic most of its life, and even some of the cross hatching on the cylinders was still present, bearings look excellent. As a matter of fact the transmission, the lowly THM200C, is still in the car, unrebuilt, untouched. The car (85 Cutlass) has around 270 to 280K miles on it. And it is still driving, and has survived 1 teenager (who didn't beat on it much), and 1 who has it now who is trying to everything on the cheap, I hope it survives it...

Take care of it, don't beat on it and do the proper maintenance and it will take good care of you. Mine did.

Get a FSM, get to know what GM recommends and at what time.

Tom

Scottie in Alabama
03-05-05, 01:27 AM
The Olds 307 is one of the most reliable engines from GM. Take care of it, and it will last a very long time. Mine was at 186K miles when I dropped a screw down the carb. It was terminal then. (I dropped in a 77 Olds 350 after that) But upon teardown, it looked fantastic inside. Yes, BBob, it ran synthetic most of its life, and even some of the cross hatching on the cylinders was still present, bearings look excellent. As a matter of fact the transmission, the lowly THM200C, is still in the car, unrebuilt, untouched. The car (85 Cutlass) has around 270 to 280K miles on it. And it is still driving, and has survived 1 teenager (who didn't beat on it much), and 1 who has it now who is trying to everything on the cheap, I hope it survives it...

Take care of it, don't beat on it and do the proper maintenance and it will take good care of you. Mine did.

Get a FSM, get to know what GM recommends and at what time.


Tom


Off subject, but what part of Wisconsin are you in? I grew up in Racine and still have some family there.

N0DIH
03-05-05, 09:53 PM
A little farm town of 1600 people, Darien. About 60 miles west of Racine, just a couple miles southwest of Highway 50 where it ends in Delavan.

Tom