Intake valves hit pistons

[YerDugliness]

Just curious here.....there's no way to tell without pulling the rod/pistons, but is there any chance the pistons were installed backwards? It's hard to tell from the photos if there are different valve reliefs on each side of the piston, but it does look like each side holds a larger relief for the intake valve.

Probably not an issue.......but just a thought.

Cheers from Dugly

[PoppyMod]

I would suggest these pistons for both current and future applications. Especially, if you upgrade to TWs. Also, always, always check PVC at overlap. This is the only time, you'll have a collision, short of a grossly negligent build.

[Woodz428]

Originally Posted by madmaxx

There is no such thing as an "anti- pump" up lifter.
.

I agree with your adjustment regimen, but regardless of whether they really are "anti-pump up", I am pretty sure there are/were several companies that marketed them under that description. Never bought any( I don't recall, but I've been building engines since the 60s and may have at some point) but I do the lifter adjustment as a precaution on all engines with hydraulic lifters.

[madmaxx]

Dont need a rest here. It is you that do not understand the physics of how a hydraulic lifter operates. The only motive force to pump up a lifter is your oil pressure, even at 60 psig (lb per square inch) oil pressure the force imposed by the oil on the lifter plunger is 40lbf (lbf). The only way a lifter can pump up is if the valve train looses control, an example would be the lifter leaves lobe due to harmonics or launches off the peak. At that point there is no spring pressure applied to the lifter and the lifter pumps up. During normal operation it is not possible for 40lbf imposed on the lifter plunger to over come 150lbf seat sprng pressure, not to mention 350lbf open spring pressures.

A way to prevent damage to your pistons due to valve float is to set the lash on the lifter at zero. This does not prevent the valve from floating but does prevent the lifter from "pumping up" since it travel is limited, hence the reason for the cir-clip instead of the wire retainer. If you are going to run against the retainer you are better off with a circlip the wire retainer which will pop out, not necessarly break.

I do not beleive you can buy a Rhoades hydraulic roller lifter.

Originally Posted by RICK LAKE

madmaxx. Hey Max give your voice a rest. You have no idea about some things. There are anti pump up lifters. If you took the time to read and talk to tech people you would know this. Poor info again. Yes some of the tech people are not the shapest in some companies, but when you are paided 10-12.00 per hour, don't expect an engineer every time. Talking to KCR, Bylins, Barry R. for info is a plus, BUT they don't make a living off FREE info. It doesn't pay the bills. Rhodes used to make bleed down lifters for high lift camshafts to raise the vacuum in a motor and Cranes sell anti pump lifters with a different bleed orfice inside. It has damn little to do with the clip that holds the lifter togeather. A machined "C" clip is better than the wire chip that are on most lifters. There is a different between normal driving and racing. Rick L.

[madmaxx]

Oh, by the way Crane suggest you set their anti pump up lifters at .005 preload, that is about as close to zero as you can get. If they have such special orficing then why not .020" to .030" like other set ups. Seams like they are selling crap you are buying. They also use the circ-clip instead of wire retainer.

[madmaxx]

132lb seat pressue with that profile, what is open pressure?. If you have less than 400lbs do what you like but I would not set the preload past 1/4 turn on the rocker adjustment. Unless you are using beehive springs and titanium retainers YOU WILL FLOAT THE VALVES ABOVE 5500 RPM'S. You could set the lash to zero but then you will just hammer your cam to pieces and not know it until extensive damage is done. I agree heavy spring pressure wear components, better wear than hammering when the lifter leaves the lobe and smashes down onto the back side. The real solution is a reasonable cam and spring pressures, if you want more power there is no replacement for displacement. Get a larger engine.

Originally Posted by CobraV8

I know that mentioned gentlemen have an excellent reputation, but I already gathered all the parts over the last months, and I live on the other side of the pond so everything is a little more complicated (shipping etc).
I bought only brand name parts from well known companies however (Comp Cams and Lunati), so I hope to be on the safe side.

The springs recommended by Comp are 132lbs seated. I know these are a bit on the soft side for the camshaft, but heavier springs also tend to cause problems like collapsing the lifters and raised stress levels for all valve train parts. If the solution was that simple, the stiffest spring available would just be used for every application.

One thing I don't understand is why so called "rev kits" aren't used more widely on these engines. These very simple and cheap devices place springs on the lifters, effectively eliminating the inertia caused by the lifter's weight.

People spend lots of money for titanium retainers, beehive springs and ultra-light rockers in order to lighten the valve train. The use of a rev kit to cancel out the lifters weight seems uncommon however. Some are available for Chevys, however I only found one for Fords made by Price Motorsports, and this one is available only for 9.5" deck height blocks.

For hydraulic roller cams with link bar retrofit lifters such a kit would be very beneficial, as these lifters are really heavy.

Maybe I'll fab up my own rev kit, I'll do some calculations for the springs required for my lifter's weights.