Thread: XPZ Cam 130 lb spring longevity as daily?

I have a XPZ Cam with the 3/8 pushrods I'm going to run in my 98 Regal. Currently my heads have 90lb LS6 springs on heads I ported. Will the 90lb springs work at all without destroying something and just give me a performance loss or are the 130lb springs required? If I run the 130lb springs, how long should I expect they'll last before having to replace them so I don't end up with a broken spring. The Regal will be daily driven. I'll also be using the stock rockers with the JP Performance Double Roller chain. If I need the 130lb springs, which brand should I get? I know there were some failures on one the brands 105 springs.

you need 130s for that cam.

they'll last.

get crow

Do you know how long or many miles the crow cam 130 lbs have lasted in our cars? Anyone get 20k or 50k yet running them with an XPZ or similar cam?

dd'ing them. im not sure, if you arent always ragging on it, with the double roller im sure you could go 50k

I'm surprised no one suggested reading up on the JP failures. A couple years back it was an issue, not sure if it still is etc. May have been more the deflection of people not machining the crank gear..but there was talk about Jp vs rollmaster and definately ensure the crank gear is right.

130# Crowe should be fine to daily. Doesn't the XPZ require different pushrods and Stage 3 heads for clearance?

he has the 3/8...OR option i have no clue on

I have those sitting in my garage on Bill Stewarts XPZ.

Originally Posted by BillBoost37

I'm surprised no one suggested reading up on the JP failures. A couple years back it was an issue, not sure if it still is etc. May have been more the deflection of people not machining the crank gear..but there was talk about Jp vs rollmaster and definately ensure the crank gear is right.

130# Crowe should be fine to daily. Doesn't the XPZ require different pushrods and Stage 3 heads for clearance?

The JP failures I read a while ago were 99% install error, but heard about the crank gear also. I think it was Blueguy91 that said it was mostly install errors. Somewhere on here I read the JP sets were supposed to have been fixed. I assume you mean the crank gear doesn't line up with the other gear so it had to be machined so the chain lines up?

I have the 3/8 pushrods (six of each 7.05 and 7.10 I think). The heads they noted port and polished required. Not sure what you mean about clearance.

the chamfer on the gear needs machined to match that of the stock gear..nothing a minute on a lathe doesn't fix

My heads have 130lb crows. Previous owner said he's put 20K on them. I see no issues with them. He also had a cam a little bigger than the XPZ.
And no go on the JP. Get a rollmaster

Just an FYI too guys. When your rollmaster gets stretched, Cloyes makes a chain that works on the rollmaster gears. I forget the PN but I'll dig it up.

Originally Posted by deangtp

IM Daily driving an XPZ/130 car. Only about 2k miles on it though. I had a JP with an XP cam and 105's. That thing stretched out big time. Im now rolling with a rollmaster.

Was it a single or dual JP chain? How many miles did you have on it with the XP and 105's? Do you stomp on it often? And so, are you saying the JP chain itself is weaker than the rollmaster? There is a bit of price difference between the 2, but I assumed it was because of the past failures with the JP's they had to make themselves more attractive. I currently own a single rollmaster with about 5 minutes of run time and a brand new double JP.

The JP chains suck. They stretch fast and some have snapped

Originally Posted by darkhorizon

The JP failures were due to the wrong gear being used for the wrong chain... they just did not mesh correctly and it was obvoius.... I have used the old JP chains without problems for tons of miles. A stock chain would be a fine choice behind the XPZ and 130s too... they are highly underrated for some reason.

Does the chamfer on the gear need to be machined to match that of the stock gear still then on the JP double set? I bought my JP double roller set at the beginning of this year so it's not that old. Still in the box. I've heard of people running the stock chain with 130s on here too. The JP Double should still be stronger and better than the stock though right? Think Blueguy91 on here said the Rollmaster failed on him so seems to be issues with both sets. Don't want to buy another set since I have the JP double, but will if I have to.

Originally Posted by darkhorizon

The JP failures were due to the wrong gear being used for the wrong chain... they just did not mesh correctly and it was obvoius.... I have used the old JP chains without problems for tons of miles.

A stock chain would be a fine choice behind the XPZ and 130s too... they are highly underrated for some reason.

I wouldn't trust a stock chain with that cam and 130s...