P487-6062 Springs

[Mickcollinsb16b]

Hello JeepStrokers Forum. New guy here without a stroker yet. In the process of doing a 4.0/4.2 swap. Gonna stroke it next year but want to get it running in this stock form. Some questions on springs. Want to cam it this summer but for right now just need it to fire it up and get through emissions first so I need to keep the stock 4.2 cam for a few months. I had planned on running the p524-9464 but seems that they have been discontinued. So I went with these P487-6065. I'm a little nervous on how these aggressive springs are gonna react with the cam. Maybe some seat pressure numbers if anyone knows them. My set up is - JohnsonHylift lifters bumping SmithBros pushrods(haven't measured or ordered yet but will use them) pushing YellaTerra RollerRockers opening 5249875/5249880 valves to feed a slightly hi-comp 4.0/4.2(.030 shaved off head and using 452-9242 HG). Do you guys think I will destroy the cam? Thx a lot in advance and any advice is welcome!

[Mickcollinsb16b]

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[jsawduste]

I answered that over in JF.

For special folks here it is again. 110-115 on the seat/ ~245 @ .500 lift.

Measuring the pressure at installed height and then at .500 is the best way. Even if you have the spring specs.

The latest set from Bennie was speced to install at 1.7 and ended up at damn near 1.8 maybe a bit (old age and CRS) more to bring the seat pressure down. This was on a 7120 casting. 112 on the seat and 245 @ .500 were the final numbers. Brad Penn 10W-30 and a happy cam.

[Mickcollinsb16b]

Thx. Will look into the Brad Penn oil. Never heard of it and 10-30 seems light for the 4.2 buttom but that is what my wife uses in her '01 XJ 4.0. I'll look into it.