Join Date: Mar 2003
Location: Spokane WA
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Re: Valves stuck open after PT lifters and Pope Shims
with a V8 and adjustible rockers and hydraulic lash adjusters you run 1/2 turbo on the base circle on say a Chevy and with ridged roller rockers on any engine you run base circle and a 1/4 turn. This gets you away from lifter float, but not spring float.
Glad to see there is a lot of commen sense on this forum. Un like the rice forum that bases every thing off opinion of about 3 people. First off the valve train weight is hugely important, HUGE. The Comp Beehives require 30% less spring rate than a normal spring out right. Then the steel retainer weighs less than the Ti stock size retainer. Then 85% of the spring weight is moving on a double spring with dampener, vs 80% with a Beehive that is also a single spring without a dampener. How can this not be seen from the space shuttle as better?
The PTs have the design changed in a few spots. As I said before your stock lifter has the oil enter real low on the lifter, leaving a big upper gap for air to get trapped. The PT lifter has the oil hole near the top, almost scary how high they have it. So all oil is going to enter and leave where air is going to want to go. The plunger and spring and so on is basically the same, the old Neon lifter and the 2.2 lifters used the same guts. I have always been pissy with Mopar as to why we can't have the new design for the 2.2 out right...
Then price comes in, no brainer
then comes up the high RPM S60 lifters. These I haven't taken appart so I have to go off the Mopar description. They don't use engine oil,,,,,,, They are a sealed unit so they must be basically a pressure shock absorber. Why don't they use engine oil? Because the crap is filled with air!!!!! LMAO, and Mopar knows it.
interchange. This has been an issue. All cars older than the PT like the breeze and any 2.0 DOHC engine all came with the old design. I called them PTs because if it has a PT it has the right lifter. A 2.4 DOHC Stratus or Neon isn't going to have them in older junk yard rigs. Truth be known the followers are better in the PT as well, I would run the lifters and the followers in a 2.0 DOHC Neon.
As far as RPM range. If you have the big turbo, big F4 cam, big shorter runner big plenum intake on you 2.2 with a big valve head. Best plan for 7,500 RPM. Now that many don't listen to old folks barking that the 1 piece is as good as a 2 piece in a race car. The world of flow has changed, the RPM range rules have changed. Shadow is the first to really show up and not be called a liar, that's how long we've been in the dark.
Today with our really high 1.89 rocker ratio, windage air filling oil systems, better roller cams and stock cheap followers. We all need to do as much as we can for RPM use when building a 8v now. Reducing weight on the follower and reducing the spring pressure. Then having a lifter that keeps the follower planted so it doesn't slap on the lobe. It is all about making the followers live at 7,000 RPM now, then rest of the parts are out there.
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