That's just what supertech call their heavy duty spring. Should be a good spring. I guess you could compare to the cost of JWT but I think the supertech can handle more pressure. JWT are probably your cheapest option at the moment though (without checking prices I can't be 100%, but probably cheap as from coz) and will suit standard factory retainers.
Do we all realise that some cams are designed for use with solid lifters only? Could that be part of the problem in the original installation? Lift & bas circle diameter have little to do with it, cam profiles are different between solid & hydraulic lifter profiled cams even for the exact same duration & lift. (as far as I know in any case - happy to learn though if someone knows better)
yes it could be, Rich said someone told him this could be the case. How could I find out? Rich didn't know and Tighe didn't tell him when he bought them It would seem strange that a cam thats not massive would be designed for solid lifters though
I guess it depends on the intended purpose of the cams, maybe they are for high revving engines but with moderate lift etc to promote low down torque offsetting lag from huge turbos? No sense in having mental big cams if the car wont pull until 6K or something I would just contact the manufacturer & ask, no harm in that - if they can be contacted easily enough.
Will contact Tighe tomorrow if I get the chance. for now here are the specs of the springs used Part No. O.D. I.D. Seat Pres. Open Pres. Coil Bind. V.S.I. SHIM PS 25109 1.090 .775 1.415:65 1.065:175 .850 (none) What do people think of those springs? any apparent problems?
lift and base circle have a lot to do with contact wear surface and stress area since the Z32 camshafts are offset on each lifter bore. My main question is this...what valve spring are you guys running on the solid lifter setups? All springs out on the market currently (that are supposidely designed for the solid lifter application) are severely lacking in spring pressure both at seat and open pressures. I've gotten feedback from several individuals when crunching numbers and asking why so little on spring load their response was overhead valve weight...this of course is an incorrect assumption and theory.
A couple of here - at least three that I can think of. Mad Mike, Mike C & a chap with VG30DE in a jet boat Spring rates I'm not sure I haven't asked. Mad Mikes eng has the Tomei style cam followers that are extremely light in comparison to stock boat anchors, the jet boat eng has custom hand made ones that are (supposedly) lighter again. Lets not forget factors like the very small valves (in comparison to the big old V8s) that therefore require less spring pressure to operate EFFICIENTLY. I would tend to follow the advice & recommendations of manufacturers such as Tomei & Ferrea, Nismo etc. They most likely have tested their designs over thousands of hours & kept changing until near perfect - why ignore all that hard work & research? The point Re base circle & lift was that they are independent (to a degree) to a cam being for solid lifters or hydraulic lifters & that it is the profile that dictates type of follower. OBVIOUSLY cam design changes other factors but then we weren't talking about "contact wear surface and stress area" were we?
at the rate in which these engines are turning now the valve springs go into float situations much sooner than what Tomei or anyone else that makes a mechanical spring setup than expected. No matter what size valve the engine has when you go to a mechanical style lifter application and have direct engagement of cam to valve actuation, you need to have a spring that has enough control to ensure harmonics are with held and kept to a minimum not to mention collapsing under coil bind issues. You will ALWAYS require more spring pressure with a solid setup than with a hydraulic setup. Much of the harmonics and exerted pressures are consumed by the hydraulic unit there within allowing to have better control with a lighter functioning spring. Valve springs manufactured for these setups were designed years ago when the market and advancement of HP production weren't as good as they are now. With the abundance of increased RPM and pressures we see now in the engines running the valve springs suggest just will not keep up. my statement in correlation to solid camshafts about contact wear surface and stress area was to give a point in an issue the Z32 has that is inherently an issue we haven't been able to justifiably resolve without having an excessive cost in an alternative. That directly has a connection with the base circle comments made previously.
No one was asking for a fricken lecture on harmonics & engine design man If you are so full of information why didn't you ask if they were sure they had the correct camshafts for the application in the first place? That is after all one of the obvious questions. Why did you wait till someone else asked & then start trying to bluff your way into looking intelligent by taking us completely off topic? Come on man the engines are twenty years old :rofl: there's F all that's new about any of this. Are you trying to say Jun never revved the speed record car beyond 7K rpm or something? :rofl::bash: Guys have been beating on these engines from day one & the gear has been developed to do as required the whole time. Issue: cams were in eng but had issues with Hyd "followers pumping up" Things to check: Correct type of cam (hyd or solid followers) Spring rates matched to cams etc (also massive boost could cause trouble here but not common) Did removing the cams & fitting alternative resolve the issue with no signs of the lifter trouble?
You're right I'm slightly out of line there. I intended to be only a little bit rude so I apologise for some of that. I would attempt to justify my post but that will take us further off topic & result in me being a hypocrite.
Good (sort of) that shows the cams were the issue & hopefully not some other unusual side issue. Can we get a picture of the lobes so we can see the actual cam profile?
I called up Tighe just then, they said that they are a hydrolic lifter cam and you can tell from the spec sheet because it says valve lash is 0.000 He also said that the issue that Rich was experiencing would be due to incorrect (too soft) springs
They are stock regrinds with the VTC release valve removed and blocked with a bolt, unless they have rethreaded the end of the cam, you should be able to refit the release valves and retain VTC.
Just remove the valves form the old cams. There is a circlip that retains them, remove the circlip and use a large flat blade screw driver to unscrew them. They are usually quite tight, you may need to use an impact driver to lossenthem off.
