stupid sticky lifters
Printable View
stupid sticky lifters
Something doesn't sound right, when u say the rockers have about 40 thou play, hmmmm. The rocker tip should be flush against the valve tip, no play up and down. It'll have a little if u wiggle the tip back and forth. When a stock rocker is tightened, it touches the valve tip and pushrod then it tightens a little more;
Compressing against the two, no lash.
The lifters are actually preloaded, no lash. Now if Ur compressing the lifter/plunger and the lifter is bled down, there may appear to be lash.
Check push rod length again. Remember, the lifter plunger will push down about or close to 80 thou of preload
I asked Geoff from EPS more than twice about the pushrod length just to be safe. He said with my milled 862's i should run the 7.4's due to the EPS smaller circle base in the cams. I bought the 7.4's and ran them in my stock 862's while my other set was being finished. I never had any loud valvetrain or lifter tick etc... Now with my shaved heads it sounds loud as hell. Im sure with the raised compression and through the LT's the sound is even more magnified. But i thought valvetrain noise was due to the lack of length not too long of a PR. I may order some 7.375s and see how those will do. I figured if i had normal valvetrain noise with the 7.4's on the stock heads then i should drop the PR length the same amount that the new heads were milled.
You're on the right path of thinking, I'm just saying, there is NO valve lash on the rockers/valves, as you tighten them, you're preloading the lifter.
Gotta agree with allen, also when you assembled the valvetrain did you rotate the motor over before final torque of the rockers? The way you're describing the noise just seems like there's something wrong.
Allen you are correct. My rockers only showed lash when you pressed them, the rockers were touching the valve though.
David- the lifters were soaked overnight in like 15w40 or something. It was some thick rotella oil that my buddy had. We did however turn the motor over manually a few times to preload the lifters etc. Im just going to take it easy on it and order some 7.375s this weekend. Or see if i can swap my 7.4's with someone for the ones i need
No need to change parts if that isn't the problem. Throwing money at is isn't always the best thing to do.
Geoff told me to use 7.425 pushrods with stock height heads. So with my heads milled .030 I figured I'd be fine using a set of 7.4s I already had. Might have to second guess that.
if theres play in the rockers wouldnt you need a longer PR?? or am i reading this wrong?
Thats what i was told by Geoff at EPS. He said to run 7.4's on my milled .030 heads. I didn't feel like buying PR's twice so i put them in. They worked fine with the stock heads. They are extra loud now with the milled heads, i guess the valves are finally opening all the way. HahaQuote:
Originally Posted by Frenchy
Thats my guess but supposedly you want a small amount of clearence for the oil to make it up and out of the PR thus providing lubrication. Plus With about .50 thousandths of play the PR moves so quickly that it causes the cam to become a solid roller at high RPM's. This is all hear say. Don't quote meQuote:
Originally Posted by sprayedenali
That first statement isn't a good rule to follow, there doesn't need to be a small amount of clearance for the push rod. Meaning you don't run a short push rod to allow oil to lubricate better, the push rod needs to ride against the rocker tip.Quote:
Originally Posted by f4tal
If Ur push rods have .050" of play between the rocker tip and push rod, then something's not right. Collapsed lifters or wrong pushrods.
Also, the tip of the rocker needs to correctly ride on the valve tip. Right in the center.
See thats what i was thinking and believed.
So you think i'll be alright with the 7.4's?! Im guessing its just louder because the valves are actually opening fully now. Plus the compression is higher now. Either way at WOT it is wicked, well the one time i stabbed it so far. And everything checks out on the wideband/aeroforce so i guess i'll just have to get used to it.
F4tal, there's nothing wrong with your pushrods. It's just the cam with that much lift is deffinately going to be a little louder than stock. Trust me Geoff deffinately knows what he's talking about. He tuned my first 5.3. He's one of the best. Seal up those exhaust leaks and it will sound better. Exhaust leaks on headers will fool you on valvetrain noise.
Got the exhaust welded up today! Sounds TONS better and the truck is quiet again. As far as valvetrain goes, I can still tell it is louder than the old setup with the stock heads but I think it will be fine. It is VERY healthy :devil:
the way you were describing the noise in the first post and the tech info you supplied, it sounded like something was wrong, .040" lash, etc etc,
but to comfort you, some valvetrains are louder than others. for example, my gto is a bit on the loud site, but the truck is quiet, both have big cams, and everything is mechanically correct.
congrats on the new power, keep it floored!