Strange situation with power block/720 on MK2

Just got a power block and 720 plenum installed on my MK2. Went smooth no leaks after but my power is way down.

Seems to be making more power at 110 bar than it did at 160. This is the first impact I've played with that doesn't have the return spring in the plenum. I've even tried it with no return spring at all only pressure keeping the valve shut. Seems very timid.

New spring, 6 gram hammer weight, new hammer. Even tried an 8 gram hammer weight I have it's no better.

C1 is bottomed out around 5mm of reveal, I'm stumped. Seems to be an insanely short dwell.
 
When you shoot do you hear the plenum refilling?
No, but I've been checking the reg gauge and its stable.
Isn’t the valve seal larger? If so that will have more surface to close the valve faster. Only thing I could think would be a heavier weight to over come that. You might also want the softer return spring at the front valve adjuster

I've tried both a heavier hammer weight and the weight it came with (that is heavier than my previous) And currently running no return spring.
 
Interesting. How heavy is the hammer? I think you’d want something around 14gram
Haha the tungsten one is 11 I think. It came with a 6 gram and I tried with a 8 gram also.

Did the valve housing come already installed in the block. If it’s somehow not indexed properly, you might be getting restricted flow which would equal the short dwell you believe you detected. And also would cause the gun to take a big enough gulp of air in order to hear the plenum refill.

No it was all in pieces, I'll pull it apart tomorrow and check it out. I'm familiar with how it goes together with the flat and set screw that goes from the rear block to the valve house. Valve house is flush with the rear block, the pin tip isn't flush with the valve house but maybe that's normal with this setup? Thanks for your input b
 
Ok I guess I got it, maybe this spring is weaker than my previous one. I compared it with my shorty and both on max with similar preload on the HST this one the angle is further back on the cocking handle before I'm hitting spring tension.

Turned up the preload and it's pounding even at the 110 bar on the reg. Might swap out the hammer springs tomorrow.
 
The Valve poppet size (when sitting on the cone) that drives the distance how far the 2mm Valve Rod pin will stick out on the hole. Only if the poppet wears out the pin can get flush with the outside wall.
I don't have the new Power Block but I can imagine the airpath holes are larger=unresticted. I did machining on my Rear Blocks and that unleashed soo much power that a rubber ball in the Valve Adjuster is a must. Guess how I know?