Quote:
Originally Posted by americanmusc1e
have to done any testing to confirm that putting a bolt in the secondary linkage is actually an improvement?
The vacuum secondaries open on demand from airflow. If they aren't opening then you might not have enough airflow to really need them. Holley's secondary spring kit is more what you need. I'd bet that it's faster with that bolt taken out.
https://www.holley.com/products/fuel...ts/parts/20-13 |
I have the kit and ran the lightest spring there is. Pull the graph and look at it. Most of those springs actually limit the carb and the motor never sees the 750 CFM. One actually causes the secondaries to basically never open!
As for testing. Butt dyno and an independant passanger. Most testing is done knowing how the truck runs on a certain section of roads. Forcing the secondaries open does cause a bog/lean spot at their tip in but it does recover from it. This happens because you can't get the blades 100% synced. There is no accelerator pump on the rear of a 3310 (except the original factory carb). As for the after effect acceleration is quicker through the RPMs and speed increased on a given section of road. Oddly fuel milage went up also on the interstate by 2 MPG also. I am not trying to figure that out. AFRs stayed constant but I am sure it has to do with the volume and not the mixture. All this was originally done as a test and it worked. Now I just need to get a new carb because this one is pushed as far as it can be. Life just got in the way of dropping the coin. It works so hot rod parts are last on the budget. Bank note, food and broken parts come first. This month gave way for a broken header that needed replaced. The replacement will be a quick fuel ss 830DP.