Jeep Strokers

Didn't see this covered yet but according to Edelbrock Tech here are the stock Valve Spring numbers shipped on the 50169 head:
Seat press= 100
Installed Height= 1.710
Open Pressure = 260
Coil Bind = 1.120
How do these numbers look to all the cam guru's in the house?

I`d run it, little stiff on the open but livable

Spring loads look like they're in the ballpark... Any news in what the head will cost bare?

I don't understand what open pressure is. Is that pressure at what lift? or spring rate?

The 100 pounds at seat is good.
0.590" bind - 0.040" safety = 0.550" lift max is good.

6TIME wrote:Spring loads look like they're in the ballpark... Any news in what the head will cost bare?

Summit=~1200

jeepxj3 wrote:I don't understand what open pressure is. Is that pressure at what lift? or spring rate?

The 100 pounds at seat is good.
0.590" bind - 0.040" safety = 0.550" lift max is good.

I think he said pressure at 1.310" lift is 260.

Dangit! I forgot to ask about what kind of rocker hardware these will need.

jsawduste wrote:I`d run it, little stiff on the open but livable

What he said! I figured open load was measured at .500" not 260 @ .400". If this is true... they're pretty stout for any daily driver with smallish cam profiles.

So if it is, 100 pounds at 1.710" and 260 at 1.310" (0.400" lift) that is 160/.4 = 400 pounds per inch, that's too much I think. That would be 300 pounds at 0.500" lift.

The springs were already discussed on page 2. 400 is a bit high.

nicpaige wrote:

jeepxj3 wrote:I don't understand what open pressure is. Is that pressure at what lift? or spring rate?

The 100 pounds at seat is good.
0.590" bind - 0.040" safety = 0.550" lift max is good.

I think he said pressure at 1.310" lift is 260.

Dangit! I forgot to ask about what kind of rocker hardware these will need.

X a number of others, too high with the new info..

Like to shoot for around 110 on the seat and 245 ish @ .500

X2. I'm running about 90 seat and 250 open with LS beehives. Works excellent.

Has anyone successfully installed a knock-sensor yet? Just Curious. I've always wanted to. Correct me if I'm wrong, but weren't they omitted on the OBD2 engines as well? As I understand it, Chrysler found that cold-start/ winter weather operation would produce just-enough piston rattle/ slap to trigger the sensor and pull timing unnecessarily on a standard 4.0. Reason I ask, is to do any productive research on timing maps with this new head it'd be real nice to find where the timing advance limits are on a given setup without having to rely on audible knock. From my experiences with turbo engines (and some carbureted), I've learned that damaging detonation can occur at less than audible levels, especially if allowed to occur over long periods. It'd be a great help for guys looking for reassurance when trying to run 87octane, and obviously a benefit to higher state-of-tune setups. Any way to run a sensor and turn down the sensitivity threshold, yet still provide useful info?? I'd love to have one in-place for some honest dyno time to dial-in all the ignition advance I can and still avoid damage. In some of the motorcycle engines i've played with, forged pistons have proven far more resistant to detonation damage than the aluminum combustion chamber. Just low-level, transitional-throttle knock over a long period but it took a lot of welding & machining to repair all the pitting in that chamber! I've experienced knock in my current stroker tune with ambient temperature extremes and heat-soak, but the only truly vulnerable components are the top-rings/ring-lands and spark plugs. The insulators would get pocked/porous but thankfully no ring damage so far. Basically, Al is generally less durable in this regard to cast-iron and I'd just want to be extra sure that I wasn't detonating on a new aluminum head, even at subtle levels.

PseudoSport wrote:I sent Edelbrock and email asking for some more details. They said pricing will be about $1300-1500 depending on where you buy it from and that they hope to ship it out by 12/1/2014. Also here are the specs for the springs that come with the head.

1st Load: 100 lbs @ 1.710" Installed Height
2nd Load: 260 lbs @ 1.310" (.400" Lift) 400 lbs/inch
Coil Bind: 1.120" (.540" Max Lift Recommended)
Outside Diameter: 1.250
Inside Diameter: 0.750
Replacement P/N 5814

A better option spring might be-
P/N 5813
1st Load: 80 lbs @ 1.700" Installed Height
2nd Load: 200 lbs @ 1.225" (.475" Lift) 252 lbs/inch
Coil Bind: 1.150" (.510" Max Lift Recommended)
Outside Diameter: 1.222
Inside Diameter: 0.875

Well it seems my head will not be shipped until the 12th of March now. I figured this would happen.

Wasn't that the ship date listed?