Harleyhound

I'm not sure if I'm starting my posts off by being in the right place as I'm new to the forum, so someone set me on the right track if I'm off.

I have a 152 CID motor that has inadequate compression release volume for cold starting. They're the 10mm variety but just won't let enough compression out. I can take them completely out and the motor fires just fine but that's not really a solution, rather a clear test of their inadequacy. I've read the posts about whether they're necessary or not and how much they help but that's not my issue. I can install adaptors to change to 12mm threaded ones but I'm not sure that would increase volume release.

Sooo, my question is, is there anyone on here that has physically tested different brands of compression releases to determine which ones have the largest volume release? All information and opinions are welcome.