Putting in this BBC solid roller cam in this 13-1 468 & although the cam card says open spring pressure 490 & closed 160 that just seems a little weak to me.
Cam is 262/272, 300/310, 708/708 on a 110 installing it on a 108.
That spring pressure just seems a little weak to me, what's your thoughts or advice

seems lot weak. While who;e other animal I had Hemi get don to 180 seat once and kept knocking blower off at 8800 every trip down track.

I would thibnk 240 on seat as minimum. That said I do not go along with lots of folks want a ton of seat preessure. I know some that look for 450 plus. WHY? I raN 280 WITH 9500 shifts and 45lbs boost. Amlmlost nobody twist bbc that high and diffently not bracket racers.

If average parts and nothiong sup[id heavy I see no reason to go over 280 seat new and no less than about 240 on used springs. JMO for what it worth,

We had a 496 we threw together a few years back, used everything. Good stuff but used.

Long story short, been a great engine and never missed a beat. Ran it just short of 300 passes. Went to rebuild it this off season and found out we had about 140-160 on the seat

It had 990 steel heads and a lunati 722 lift 272/280 solid roller and always went 7k easily.

No signs of valve float and the lifters still feel tight.

Depending on how aggressive the ramps on the cam, the weight of valves and retainers, plus the operating range of the engine dictate spring rate for that cam.
990 heads will be out of steam by 7K unless they have had great port work done to them, so I would venture a guess your RPM range will be limited to that.
With out knowing the cam brand and such at least call the manufacture and express your concerns.

Yes I agree that the spring pressure is a bit light from what I would run.

on our sbc's we run Pac1225 springs at 250@2.000 and 762 open 1.200 on a similar cams a little more lift and duration to 8k plus and never an issue your specs seem low to me spend the $$ on Pac springs it is worth it.

What lifter raise is the 300 duration at? If it is the standard 0.020" then that cam has a 38 Minor intensity (300 - 262) which is not that aggressive.

Stan

Similar engine and cam, my springs are 200# on the seat, 575# open.

quote:

Originally posted by HR3377:
on our sbc's we run Pac1225 springs at 250@2.000 and 762 open 1.200 on a similar cams a little more lift and duration to 8k plus and never an issue your specs seem low to me spend the $$ on Pac springs it is worth it.

For me, I'll never run PAC again. Had valve train issues for several years, made the switch to PSI, virtually same spring but different frequency, and most of the issues disappeared. There was a huge issue with PAC a couple of years back, Cost Bob Book over $25k.. I'd hope that whatever their issue was it's fixed, but I'm sticking with PSI regardless.....

PAC Is the only spring I have ran for the past 15 years from simple bracket engine to blown TD. Never ever have had any issues or even broke one

Never broken one? Obviously not tryingh hard enough.LOL Can nogt tghink of mush of anything I can say I have not broken at least one of.

quote:

Originally posted by Big Steve:
PAC Is the only spring I have ran for the past 15 years from simple bracket engine to blown TD. Never ever have had any issues or even broke one

I had valve springs breaking, and signs of valves going crazy. Tips of the springs were breaking all the time and you could see the locks scrubbing on the valve stems. When I changed to the PSI, pretty much stopped all of that. I had other issues going on as well, but not valve spring related. New stuff is all PSI and will remain that way. PAC lost a customer in me because of that...