The carbs aren't modified except for a new check valve as opposed to the original one and aftermarket air cleaners. This is how the carbs came out of the factory boxes. This has been a drag car since the early 60s. The original owner purchased a ton of parts in the 60s that he included when he sold the car in 2013 including a brand new tri power setup. The secondaries work with the factory vacuum tank but not long enough to get down the quarter mile. Vacuum bleeds off through the slide valve too quickly. Yes it's dumb to try to make this work for drag racing but I can't help but try. I can easily hide another vacuum tank under the dash or in the trunk and tee the hose so I am also using the factory vac tank. There are plenty of tri power cars with mechanical linkage and for good reason. I just like to be different.Small rod to hold the outer carbs open would work and look much better. No point to vacuum carbs that are modified incorrectly.
Perhaps there is a ruptured diaphram on carbs?The tank holds vacuum for a long time when the engine is shut off so the check valve is working. It is leaking down quickly from somewhere at wide open throttle, either through the slide valve or the pod at the front. It seems like the system should hold the carbs wide open until you let off the gas and allow the slide valve to return to the top.
There is a hose running from the slide valve to the top of the front carb. I'm not sure what this one does. The other hose from the slide valve activates the pod at the front. I will get a vacuum gauge on there to see what is happening.
Yes, I just used a new brass check valve. Image attached. It holds vacuum in the tank for a long time after the engine is shut off. With all the vacuum in the big air tank I rigged up, it is easy to hear and feel where all the vacuum is bleeding off when the throttle is held wide open with engine off. It is leaking right out the side of the slide valve on the side of the center carb where the 2 screws hold it on to the mounting plate. With the big air tank for a vacuum source, It takes about 40 seconds for the vacuum to bleed off and secondaries to close. I have no idea if it is normal for the slide valve to leak vacuum or not.I would still like to see a picture of the check valve on the rear of the center carb base. You said the check valve had been replaced.
I will take the slide valve and see what is going on with that. I hope to only need 12.5-13 seconds once this is working properly.The slide valve should not leak.
But I would hope you could run quicker than a 40 second pass.
Sorry I couldn't get any closer to the back of the center carb with my phone to show the check valve. That part of the system is doing its job.Can't tell anything from your picture.
Now that's what i'am talkin aboutI will take the slide valve and see what is going on with that. I hope to only need 12.5-13 seconds once this is working properly.
There really is no way to seal the slide valve.Any chance you could seal the outside of that valve.
You may be right but I will get a better view than I did when I was racing with a single 2 barrel.You better put high test in that tank if you want a better look at the tail lights
I just ran that one on two two barrelsYou may be right but I will get a better view than I did when I was racing with a single 2 barrel.
Yeah Right,,,James!!!!!!!I just ran that one on two two barrels