After I filmed the second video I went back to stock jetting and a smaller pump nozzle. And the car is worse. Good news is that the Edelbrock is back to its stock settings for when I go to put it on my chevy k20. I do not think fuel pressure has ever been an issue. Cuz when I'm in second gear and just flooring it keeps up fine I feel. The car definitely ran its best when I was three stages rich on the primaries and secondaries.
That is the exact carburetor that I have saved to my wishlist on summits website. Do you think they make annular boosters for it?
Well I'm definitely planning on getting the stall I just want to get one built by Jim that is built to last. And I live in southeast Iowa. I would love to try a 750 double pumper. I have a couple of buddies that run double pumpers but they would have to take them off their vehicles. One of them is a 850 manual secondary and one is a 750 vacuum secondary.
I'm not a fan of vacuum secondary carbs. Tried that 20 yrs ago. Annulars are not necessary, the dbl pumpers mostly have the standard downlegs anyways. My spare 750 has downlegs and didn't miss a beat when I ran it.
you should do some reading on annular boosters compared to downleg boosters each one of those have a different application and do things a little different. I can't think of what they are on the top of my head but I know it is one of my Holley books just been a while since I read them. I would not use a vac secondary carb they suck too. I see the car just does not want to get up and go Dang Q-Jet would probably work better. I see you also have 1 3/4 headers so you have a little more on the exhaust primary tubes. Those headers do ask for a little more and will give you more in the upper rpm range. You are set up for more power in future so don't worry, and yeah I got to agree the carb just seems to suck. If you can I would try your buddies carb off his car the 850 one you should be ok with it. I can tell you what jets belong in it for stock if you get the list number off the airhorn on top of carb. You will at least find out if the carb or the engine is slowing you down. I wonder if the cam is in it's correct spot. It might need advanced 1 degree. Have you tried to put a vac gauge on the carb (One that sucks air) when idling. Would like to see where that is at. I got to tell you where you are at has snow out so I would figure it is about 30 out maybe. I imagine with that much cold on the intake and the incoming air that you will need a boatload of gas to get it going. That carb will probably work ok (that's all I can give it) in the summer time. I bet the cam I am using would have worked better in your car and it is bigger
I was able to adjust the idle screws to get about 14-15 hg of vacuum around 850 rpm. I know the cold weather is hurting me. But really how much is the question. It's a 650 cfm. Im certain after reading all of your guy's comments about needing a double pumper that it should definitely help. The cam was degreed to 109.5 lobe sep by the machinist that did my heads. Larry suggested checking the fuel pressure. The car performed much better 3 stages rich following edelbrock tuning chart. Which is the farthest the kit lets me go. Anything past that would be me literally just experimenting with rods and jets from bigger carburetors like 750 800cfm calibration kits. I'm done with it.
Part of why I was so excited about annular. The low speed torque it makes with a bigger cam and single plane.
I wonder who is buying these China copys and if they are even worth the 2 hundy.? https://www.ebay.com/itm/NEW-850-CF...BBEV2bDemotion&_trksid=p2332490.c101103.m3021
I know this has been suggested before but you seem to keep ignoring the advice, get a afr gauge on it. Your flying blind without it & just guessing.... Not sure if you have asked if any members are close to you that could give you a hand with tuning, but in order to tune properly an afr gauge is Absolutely needed.
The plan is to get one eventually but five other people that run a built 350 with a single-plane intake all run 750 double Pumper. I'm running a 650 avs2 edelbrock and I'm certain that I'm getting a lean flat spot when I hammer it. If I use the largest accelerator pump nozzle and the air valve tightened way Beyond Factory recommended specs I get noticeably better performance. I never made a video of when I had the carb jetted three stages rich. But it ran way better than the two videos that I posted on this thread. Pulled fast and hard to 90mph was very impressive. I could not tune out the lean flat spot though. Double pumper has to help me here.
Got an off topic question. You encouraged me to use the composite intake gaskets. When I ordered them Ta said most guys use the. 040 thickness so that's what I used. I had a large gap at my end seals dang near 3/8 of an inch. It's not leaking oil or anything but if alignment is bad enough could I have internal vacuum leaks? I get around 14 to 15 hg at 850 rpm. Could I have good vacuum and still possibly have a leak?
A quick sanity check for a vacuum leak is to cover the carb with your hand (air cleaner off) while the car is idling. If the engine dies right away then you don't have a vacuum leak. If the engine runs with your hand over the carb blocking all of the intake air then you have a vacuum leak somewhere that is letting in all that extra air. Easy and cheap way to check! I'm really rooting for you to get your Skylark where you want it! I know that feeling of disappointment every time you floor the gas pedal, my car used to ping pretty back from worn rings before I decided on my current build.
14-15 is decent considering a bigger cam. You may be able to get more but I would not think much more.
Hey man thanks for the suggestion. my car died instantly when I blocked the carburetor with my hand. I think I can roll out vacuum Leaks.
Is your carb an avs2 or avs original. Seems like they had to improve it, maybe cause it didn't perform... https://journal.classiccars.com/201...rburetor-designed-for-exceptional-smoothness/
