Hydraulic lifter problem??

[bmodracer]

I believe I am having lifter bleed down problems. I'm trying to chase down a problem with not being able to get any RPM after the engine warms up to temp. Although it sounds like a carb problem, the engine acts like it is getting way too much fuel but I have tried different carbs and fuel pumps along with everything else from bumper to bumper of the car with the same result. Here is why I think the lifters are the problem. As I was checking and adjusting valves when the engine was warm / hot, I opened the intake valve just past max lift to check my exhaust...looked over and could visually see the intake closing by itself. I've never seen that before and I've ran hydraulic lifters for the past 15 years. I'm wondering if the lifters are collapsing and not opening up the valves all of the way at speed and temp.
Can anyone shed some light on this?
LUNATI 71817G-16 LIFTER
COMP 941-16 SPRINGS
20W-50 VR1 OIL
Thanks!!

[LRtireCHANGER]

Are you sure the lifters are not tightened down too far? If they are too tight, the valves will stay open at higher revs, which will cause power loss and limited revs. The best way to set hydraulic lifters is to set them one at a time, kinda like you would set a solid. To do this, get a cylinder to top dead center, which will ensure both valves are closed and that the lifters are on the heel of the cam. Then tighten down the rocker while spinning the push rod with your other hand. When you feel the pushrod start to drag a little bit, go another quarter of a round, and thats it. Then you do the other valve on that cylinder the same way. Then get the next cylinder to top dead center, and repeat.

[Lizardracing]

Are you sure the lifters are not tightened down too far? If they are too tight, the valves will stay open at higher revs, which will cause power loss and limited revs. The best way to set hydraulic lifters is to set them one at a time, kinda like you would set a solid. To do this, get a cylinder to top dead center, which will ensure both valves are closed and that the lifters are on the heel of the cam. Then tighten down the rocker while spinning the push rod with your other hand. When you feel the pushrod start to drag a little bit, go another quarter of a round, and thats it. Then you do the other valve on that cylinder the same way. Then get the next cylinder to top dead center, and repeat.

Wiggling the pushrod up and down is better for a new guy because it's easier to feel than the spinning method. If you have poly locks gently turning the poly until it seats is an easy way to do it. Actually way easier than the swedged stock type nuts.

You could have a bad lifter but oil pressure is keeps them pumped up so without the engine running

[bmodracer]

I've tried from zero to 1/2 turn pre-load. The only reason I am thinking this is because this I have these exact lifters in 2 different motors and both are acting the same way. I've never noticed the valve closing before when the motor wasn't running but that's not to say that they didn't.

[LRtireCHANGER]

Regardless of what u pay for lifters, most these days are made offshore. The quality of most of what is available is suspect, and this includes much of the "name brand" lifters. If I had two sets that were suspect, I would call a real cam company like Bullet, because they stand a better chance of knowing what is quaility and what is junk.

[RCJ]

You might try going to brad penn.Even tho it is a 50wieght like your valvoline it is on the thicker end of the range.I have heard of people finding more hp with thicker oil on hydraulic lifter motors.

[dave41]

check for excess clearance on lifter bore , check ball in lifter after pump up .

[Krooser]

I believe these are the remaining flat tappet lifter manufacturers in the US. Most name brand cam companies buy from one of the three... the era of bad import lifters is pretty much over unless you buy on ebay or strictly on price.

http://johnsonlifters.com/Products/HydraulicFlatTappetLifters.aspx

http://www.hylift-johnson.com/our-company/

http://www.sealedpowervintage.com/product/valvetrain-parts/

[CCHIEF]

hylift-johnson is the gold standard in production lifters. Rhoads vmax is a modified hyliftJ and an excellent racing lifter

[bmodracer]

I broke down and bought a set of Johnson's. problem solved.
Thanks!!

[Krooser]

good deal...