I have searched and read countless posts but I haven’t fully found my answer. I have a 69 skylark I restored a few years ago. It has a Buick 350 that was a 2 barrel when I got it. I have since been running a poston s divider but I have never been fully satisfied with how it runs. With a edelbrock 750 1407 performer, 1/2” holly 4 hole spacer, hei distributor, long tube headers, shift kit in the th350 and 3.26 posi rear end. It never has had the punch off the line I thought it would and I was leaning towards a higher stall torque converter which I am still planning to do. But then I got reading about the s divider and I am wondering if it’s worth keeping. The t a manifold is a little pricey for me new. I have the intake off to do some engine bay cleanup. It was milled down .750 by poston but I was wondering if milling it down further would help. Or any other tricks that can be done. I am wondering if it’s worth any modding or if I should look for a t a or even a oem cast manifold. Sorry for the long post but you guys have never let me down in the past. Thanks.
I have never really heard great things about the S divider intake. From what I have read, it seems to like a spacer, and I see you are using one. You have headers and decent gearing, so it really should perform. I don't like the Edelbrock/Carter AFB clone carburetors. I think the Quadrajet is a much better carburetor. My main complaint about them is the secondary counter weighted air valve, it isn't adjustable. I had that same carburetor on my first Buick along with a TA 350 intake. I always had a huge lag in secondary actuation, it was like a bog. Once the secondaries opened fully, the car pulled the way I wanted it to. Part of my problem was my 2.56 gears. I think if you want that type of carburetor, you are much better off with the AVS models. They have a spring loaded adjustable air valve on the secondary side, like a Q-jet. My advice is to get a Q-jet built for your engine combination. There are 2 guys here on V8 that offer that service. http://www.everyday-performance.com/ Ken (techg8) http://v8buick.com/index.php?forums/everyday-performance-llc.172/ https://quadrajetpower.com/ Mark (carmantx) The other thing I would look at is your ignition timing. See where your mechanical advance is all in. See if you can get it all in by 2500-3000 RPM. That can make a big difference. See my Power Timing thread, http://v8buick.com/index.php?threads/power-timing-your-buick-v8.63475/ As far as a converter, you can't go wrong with one of these 9.5" converters. http://v8buick.com/index.php?threads/tsp-9-5-street-strip-converters-lifetime-warrantee.147066/ You get what you pay for with converters. Spend the extra money to have one built for your car. Off the shelf converters are a crap shoot. Jim knows Buick engines.
I had a feeling the Q-jet topic would come up. I will look into them. As far as the manifold should I just leave the s divider alone and see if changing other things could help? I chased this problem all summer last year. Tuning. Having a shop tune it etc... and I was never real happy with it. If I keep the poston can I weld the 2 egr exhaust ports shut to keep hot exhaust gas out and stop it from dead ending? And I will have to ask my buddy when timing is all in. I can’t remember but 3000 comes to mind for some reason. I can’t for the life of me remember.
If you floor it from a dead stop, does it leisurely take off, and then all of a sudden start to pull harder? Can you feel the secondaries kick in. Didn't know the S Divider had EGR provisions. A block off plate should suffice I would think.
It takes off pretty leisurely and takes a bit for the secondaries to open. I know it’s not going to be unbelievably fast but I think it should take off a little quicker. From a stop if I floor it I can’t spin the tires. With a brake stand I can get them to spin for a little. My thought was the factory converter is holding me back. But it could be the intake and carb as well. I believe the intake has the egr provisions. I bought it cheap from a guy that had it on a SBB in a Jeep.
Possibly, but it also heats the bottom of the plenum, it's an exhaust cross over. I would block that off at the heads.
Ok. What’s the best way to block it off? I was going to just tig the manifold ports shut with some plate
Also am I better off to look for a different intake or would switching to a q jet be money better spent? My timing is all in by 2500 by the way based off of your post.
Look inside the center ports in the heads. Most people block the round holes with cup plugs. If you can tig the intake closed, just make sure it's thick enough to prevent it from burning through. Not sure. Like I said, I never read stellar things about that intake. The S divider thing never really proved itself. The Q-jet is a vastly superior carburetor IMO. They get a bad rap because people take them off engines they were calibrated for, and then expect them to run right on a completely different engine. If you have one built for YOUR engine, you'll be much better off. 2500 is great.
Alright. Well I guess I will put the edelbrock carb up for sale and get a q jet. Now as far as the intake should I try and run what I have or sell it and look for a t/a or a cast manifold? And is there a good benefit to plugging the crossover ports? Im not trying to build a drag car or anything crazy just something that is fun and runs a bit better than it does now. I think the day I drove it home with the 2 barrel it seemed like it had more off the line pep than it does now haha.
A little more converter will help. I would get a decent Quadrajet also. the 69 2 barrel engine had 8.2 compression from the factory. Having heads milled some can bump compression up and get more low end torque if your really looking to get some kick. But can cause bolt alignment of intake issues or need for shorter pushrods if it becomes excessive. There’s always give and take. You may not be getting full 4 barrel with the 2 barrel accelerator cable. Don’t forget it needs to travel more. I would keep the intake, since you already have it. Block crossover if you can.
Ok thanks. Someday down the road I would like to pull the motor and do a full build. But for now I just want to enjoy the car. So some freeze plugs seem to be the way most people plug the heads. I have a friend who is a pro tig welder that could tig the ports in the intake for me if that works too. So keep the intake, get a 4 barrel throttle cable, a q jet carb and then torque converter. It’s never easy or cheap.
Blocking the crossover will keep the intake cooler. The only downside to it is if you drive the car in cold weather, especially cold humid weather. The carburetor could ice up under certain conditions. The aluminum intake conducts heat faster than cast iron, so it will get warm faster. The torque converter will be a big difference as well. That 9.5" converter will be about 12-15 lbs lighter than the stock one. That's weight off the crank. You won't know it is there until you step on it.
Ok great. I don’t drive the car in cold weather. Really just on nice days. And I will have to save up for that converter. I was looking at the jegs 10” 2300-2700 stall that was much cheaper. But off the shelf and not built to the car. So I think I’ll put the manifold back on after plugging up the crossover. Then get a q jet for what I have done to the car. I’ll save my pennies after that for the torque converter. Thank you for all the help so far. This forum is the best I have ever been a part of.
That converter will make a big difference. There is no comparison to be made with the Jegs converter. Jim has lots of experience with Buick engines. It will be perfect from the get go. Probably burn rubber for the first time.
I believe there was, but also the throttle bracket that attaches to the intake is different. It's a simple thing for you to get someone to hold the gas pedal floored, engine off of course, and then see if the throttle on the carburetor will open more by hand. Then you'll know if you aren't getting full throttle. I would check that first rather than assuming you have a problem.
I think the cable will work but I took this from a previous post about converting from 2 to 4 barrel on a 350 (http://www.v8buick.com/index.php?threads/350-2-barrel-to-4-barrel-swap.261247/) FYI the 45 degree throttle cable bracket is correct for a four barrel setup The straight up one was the two barrel bracket. Be sure to check that the secondary throttle blades are wide open when the pedal is floored. More often than not, they wont be. another FYI is that you can bend the gas pedal bar to get some more throttle opening at WOT if you need to. I'm pretty sure you're going to have to adjust things to get full throttle.
It’s been a bit since I checked that and it’s all apart now but I think it went wide open no problem. Just didn’t have any power off the line.
