Hitting a wall at 4200 rpm.

[Cheromaniac]

But then I have read the MP springs are a bit stiff and have wiped some cams out, Has anyone heard of that?

I used the Mopar 5249464 springs in my original stroker build but it was a bad Crane lifter that wiped out a lobe on my Crane cam after 34k miles. The springs weren't to blame at all.

[SkylinesSuck]

I wiped out 2 cams (Crane & Comp) with Mopar springs installed. Not saying that was the reason, but there it is.

[dwg86]

Look for some other retainers that will fit the Jeep valve. I think the Magnum 5.2/5.9 retainers will work. The Mopar Performance retainers are the same size as the 2.2 4 cylinder I think. I can't remember, but I'm sure someone can chime in. Then maybe find a spring that will work with head and retainer. If you end up removing the head, maybe think about some LS valves and springs

[Cherokee77]

Thank you everyone for the info.
For now we are just going to run it the way it is. I will continue to look for a spring that will work, but if he keeps it below 4200 he will be ok.
I will tell you I learned something from all of this for sure. If we do come up with a spring that works I will let you guys know.
Thanks.

[jsawduste]

There are springs that work.

You just need to take the time to do the job correctly. If you cannot afford the downtime then get another head. Prep it and do a head swap. That won`t take long.

Continuing to fatigue the current springs isn't your best option.

[Cherokee77]

Looks like these might work, what do you guys think?
http://crane.carshopinc.com/product_inf ... 0/99833-12

[Cheromaniac]

Yup. Those would work. To ensure that they're installed at the correct height, you'll need to have ~0.060" of material machined from the spring seats.

[Cherokee77]

Thanks Dino, I guess the head is coming off.

[Cheromaniac]

Thanks Dino, I guess the head is coming off.

If you're going to remove the head and have it machined anyway, you might wanna consider swapping in a set of LS1 valves & valve springs instead.

[Cherokee77]

So a bit of a update, we are going to pull the head sooner or later and go the ls route.
We started having another problem the comp was pulling timing like crazy like a light switch. It would be running fine and poof start pulling timing then poof timing would be back. 2 times it would be idling and then as soon as you touched the throttle it would spit, fart, pop. Turn it off then start it back up and it was fine. Then just randomly pull timing again and no power. Well we had some problems when we were indexing the dist in the beginning rotor would not go where it was suppose to, so we settled where it ran the best.
So I tried to reindex one tooth advanced and timing was way advanced, so we went one tooth retarded and no start, so we put it where it was and cut the ears off and adjusted it. All seems ok so far. Only thing I can think of is the comp went through its cycles and wasnt happy with what was going on.
Crossing fingers. Also valves are not floating till 4700 rpm now. Confused.

[Cherokee77]

I would like to update this thread to further help others in the future. After talking with Russ more I went ahead and ordered the mopar springs, and since I was in there I threw in some HS 1.65 rockers.
Problem is solved and she now pulls strong all the way till she shifts.
I did notice a seat of the pants improvement all the way around. Lot more responsive in the midrange also. I did have to add a little bit of fuel.
Thanks to all who responded. And thanks to Russ for the advice and getting me what I needed.

[BaumSquadM24]

Which MOPAR springs did you end up going with then?

[Russ Pottenger]

5249464 Springs
4452032 Retainers
4529218 Locks.

If you're going to pull the cylinder head and do valve work i'd highly recommend to consider doing the Chevy LS valve and spring upgrade. It'll run you about another hundred dollars in parts. Then add machine work and labor costs on top of that, but at least you'll be taking a step forward to cure the asthma condition in our Jeep Strokers, known to be one of the leading killers in power gains. : )