From what I have been reading, these springs don't require any machining... But I am confused on how you guys actually got these springs to go over the valve seals without interference.... Do you guys not use the valve seals at all and use O-rings instead with these springs, or is the inner spring big enough to where it just slips over the valve seal? If someone can clarify this for me, I would really appreciate it. Thanks.

 

You have to remove the valve seal and remove the spring cup. Put in your shims or new cups for proper installed height. Reinstall the valve seal. Then the springs will go over them. You only need to remove the seals to get the old cups off, since the inner diameter of it wont clear the seal.

 

so no machining is required? plus these springs are good to ~.700 lift?

 

No machining.

Lift depends ultimately on installed height, but if installed as suggested, yes .700.

 

what would be a good seat pressure & spring height on stock heads with a cam like, oh, the 847

 

about 135 on the seat and 340 open just guessing. the 847 doesnt have very steep ramps there 62 degrees so it not a very agressive open and close. it not near as hard on the valve train as a EX grind.

 

I've got a set of k800s for sale for 40 bucks shipped. They have 2k on them.
If interested pm me.
Kory

 

The 847 calls for Closed 115 LBS and Open 336 LBS

The K-800 springs are
Installed Height 1.850
Seat Pressure At Installed Height (lbs) 165
Coil Bind Height 1.085
Open Height 1.150
Open Pressure (lbs) 495

So.... find the spring rate, and your needed installed height and go from there. I would actually recommend running a little more pressure than Crane reccomends

 

well with those pressures you could never run stock lifters.

those are more than enough presures for that cam it only has 62 degree ramps the ex grind have a 52 degree ramps and the 987s are enough for the ex grinds.

 

you wouldnt want stock lifters with a high RPM cam like the 847 anyways. definitely want to go with comp r's

 

Find the spring rate: (495-165) / (1.850-1.150) = (330)/(.700)=471 lb/in

Find the difference in installed height: 1.900-1.850 = .050 inches

Calculate load change for .050 travel : .050 in. * 471 lb/in = 23.5 lb, so seat load @ 1.900 = 165 - 23.5 or 141 lb.

You can do the same again for 1.95, which is pretty close to where mine were installed (on stock lifters)

Your turn: what do you get for 1.95 installed height?

 

I recomend going with the comp r's I have the k-motion and I have broken two of them on a cc306! I called k-motion to see what the deal was and they said these should not be on a daily driven car since most people jump in their cars and start driving hard right away and they never warm up! But both of mine broke while driving regular and after a long drive home from work. I won't ever buy them again Another friend of mine in Missouri had some on a 8 sec. vega and broke a couple! Again k-motion came up with some reason as to why they failed and wouldn't replace them. In my car the first one went about 6 months after I installed them with the cam. The second one went about 2 years after the instal.

 

423.9 open and 148.5 closed

but i was under the understanding that 400 i the limit for stock lifters.

 

You got messed up somewhere in your math...

(495-165) / (1.850-1.150) = (330)/(.700)=471 lb/in

Find the difference in installed height: 1.950-1.850 = .1 inches

Calculate load change for .10 travel : .10 in. * 471 lb/in = 47.1 lb, so seat load @ 1.950 = 165 - 47.1 or 117.9 lb closed.

Then for open you have (cam lift x spring rate) 471 x .595 (exhaust) = 280lbs + closed (117.9) = 398lbs open.

Not sure what the limit is on stock lifters, mine were just fine. I wouldnt guess there is an "exact" number that they fail at.