Originally Posted by F-2 Speedy

make sure you use the ARP assembly lube when reassembling the engine and proper torque sequence on the heads

Originally Posted by PQ290Enticer

Installed height for both are: 1.920 and 155lbs
Open ht is 1.370 and 340 lbs
bind is 1.187 and 550lbs.
I have no idea what this means. It's on the build sheet.

Originally Posted by PQ290Enticer

Installed height for both are: 1.920 and 155lbs
Open ht is 1.370 and 340 lbs
bind is 1.187 and 550lbs.
I have no idea what this means. It's on the build sheet.

Originally Posted by Unlimited jd

in my opinion that’s a bit light for 5500+ rpm. Rather see at least 420-450 open.

Originally Posted by PQ290Enticer

540Fever, Yup. I missed almost 2 full season's working on these engines between cash flow and everything backordered. Now finally done and It seems everyone thinks I have 2 expensive grenades ready to go off at any time. Obviously it would be beyond terrible if they do grenade but I can't chase something based on opinions of people that had no hand in them at all. Ultimately I'm going with the guys that built and dyno'd these engines. Neither see's a problem with the printout's or the way they performed. If you boat on the Grand River or Lake Michigan and see me getting towed in, be sure to wave and tell me you told me so.

Originally Posted by SB

His cam lift is just .550” vs the .610” to .632” or more we typically see on bbc builds. So maybe that makes the open look lower than normal ? Time for some math for a look see.

“To calculate a valve spring rate, subtract the seat pressure from the open pressure, then divide by the lift.”
OR JUST LOOK ON PAC's WEBSITE

So, plugging in the provided #’s:
340lb (open) - 155 lbs (seat) = 185lbs
1.92” seat - 1.370” open = .550” lift
185lbs/.550in = 336.4 lbs/in spring rate

Did i do math right ? 336 rate is low. As example The popularly used Isky 8005A is 400lbs/in.

Originally Posted by Rookie

https://www.racingsprings.com/index....ing-11334.html

Install height = 194lb
Spring rate is 469lb/in (PAC website)
469*.550 = 258lb
258lb + 194lb = 452lbs open
Those are close to the Comp 933's I run.

Originally Posted by SB

i missed the pac # then. What is it ?

edit in: Okay, from your link PAC-1940.