Baja Rooster

iTrader: (1)

Honestly, before I spent a tremendous amount of time on this forum I believed that I would rather buy assembled heads thinking that the manufacturer would do a better job as it's their product and they should know their product. I'm sure just about every other weekend warrior would expect the same.

NDH2O

Here's the pac 1940 specs. If they were set up at 1.950 they should have 194lbs on the seat and actual coil bind does not occur till .800 lift. It sounds like pac is trying to upsell you to better springs that you may or may not need. As long as your oil temps are in check I would have no problem running these springs in a marine endurance application.

PAC-1940 1.555 1.140 Dual 0.747 194 1.950 500 1.300 1.150 0.700 Yes 469 $14.79

fbc25el

When I put my heads together I used Isky 8205 plus. At 1.900 they came out at 155 #. All of the valve measurements came out to within .003 .AFR did a very good job of machine work.

vintage chromoly

iTrader: (3)

And that's my point.
Everything needs to be checked even though advertising would lead you to believe otherwise.
"Bolt on" and "complete kit" have definite advertising appeal, and I bet the aftermarket sells quite a lot of product like that.

Full Force

iTrader: (5)

When my heads were set up after the first problem I'm pretty sure I had around 200 on the seat but when I had everything rechecked right before we did the heads again this time I was averaging 145 on the seat so there's no way you could ever convince me those springs are any good ...

Full Force

iTrader: (5)

I don't see how it's a bad thing to upgrade if the 1940 Spring is advertised as a mild hot rod upgrade spring I wish I would've known that a couple years ago

chancer540

I'm sorry but it sounds like you would of been money ahead, if you would of had a professional shop build your engines.
I guess that's the chances you take when you decide to build while learning along the way.

I'm not brave enough to do that, especially spending that kind of coin on parts that you did.

Plus we all no there's no guarantees with high performing engines with whoever builds them.

Good info though.

F-2 Speedy

iTrader: (6)

Im just hearing the same thing over and over again that's been talked about in other threads, post a link of the springs your using, not the ones you say are junk tell us what your moving forward with, springs, cams, heads, intake,carb, exhaust ect. spring will be here before you know it.

MILD THUNDER

iTrader: (3)

The Pac 1940 spring would indeed have 194lbs of seat pressure, if installed at 1.95. Open pressures would be

680 lift = 515lbs and .120 from CB
650 lift = 500lbs and .150 from CB
630 lift = 490lbs and .170 from CB

I personally wouldn't run a valve spring over .120 from coil bind in an endurance engine that sees sustained higher rpm. Certainly not .170+

if you're gonna run 500+ lbs open pressure, I'd want the heaviest wall 3/8 pushrods , like some .135 wall, some good rocker arms, and some stud girdles.

The best valvespring, isn't gonna be super awesome, if its setup with the wrong hardware, distance from full stack a mile away, excessive spring temps, high oil temps, and so on. You could put a set of $500 "tool room" springs in an engine, and set them up like chit, and they aren't gonna last longer than a set of $150 dollar springs that are setup properly, and kept cool.

I don't think that pac "hot rod" series spring is necessarily a "bad" spring, but it simply isn't the "endurance" spring some were led to believe they were getting when buying these heads. Unfortunately, not to many guys here, really know the lifespan of these components. Every build is different. Unless you build the same exact combo over and over,and do routine teardowns at various intervals, its all an educated guess at what works or what doesn't.

Full Force

iTrader: (5)

Not always the case, I have some. Buddies that have paid shops much more and still been out of the water, some for years and years waiting on "warranty" work... just because you paid an engine builder doesn't mean it's going to come out right in the end. Many people would not take on what I have go through the problems and keep plugging away at it yes I have learned a lot and yes there has been mistakes on my part and others but when things are finalized it should be a pretty nice set of engines and the learning is very valuable for the future