roller rocker
- Thread starter viz79
- Start date
- Status
If it is a hydrolic cam there should be preload on the lifter even when the valve is closed, so the push rod shouldnt spin. My roller rockers will move just a bit when the valves are closed but the push rod doesnt spin because it is preloaded. hope that helps
with a new engine yer supposed to check the valve lash afer 500 miles to make sure the rocker nut hasnt backed off. so re-lash the valvesin the proper sequence. after 500 more miles check it again and it should be fine.
what u meen beermonkey by the rocker nut?
after re-lashing the valve is a good idea to make sure my problem is fix to put some stud girdle or it doesn't change anything
btw my cam is a xe 294h by compcams and my heads are 210 alluminium 64cc procomp 2.02/1.6.
thanks
after re-lashing the valve is a good idea to make sure my problem is fix to put some stud girdle or it doesn't change anything
btw my cam is a xe 294h by compcams and my heads are 210 alluminium 64cc procomp 2.02/1.6.
thanks
You shouldn't need a stud girdle with a cam that size.
I've found it easier to adjust a hydraulic cam (both roller and flat tappet) with the engine running. It's messy as ever unless you can find an old valve cover that will clear your rockers. Cut the covers in half so the adjusting nut is exposed but the oil holes on the end of the rocker is still covered to deflect the oil back into the engine.
With the engine running and warmed up, back off the rocker you're adjusting slowly until it starts clacking a bit. Then slowly, tighten until it quits clacking and then tighten 1/4 - 1/2 turn more. When you start hearing the clacking sound, there is no preload on the lifter. When the clacking is starting to disappear you are starting to put the preload on the lifter. The 1/4 - 1/2 turn is the needed preload for the lifter. Only do one rocker at a time.
The oil pressure is what keeps the lifter pumped up and that is the self adjusting nature. Unless your rocker nut is losing adjustment or the cam losing the lobe or lifter collapsing, the adjustment shouldn't be needed on a constant basis. After a rebuild, it's just to make sure everything is wearing in and adjusted correctly. After 500 - 1000 miles, no other adjustment should be necessary. If it keeps losing it's adjustment, you have problems. If you have a cam lobe wearing down, then the gap between the lobe and lifter gets farther apart and that's why the constant adjustment is needed. After it wears some more, it'll need adjusted again. That happens until there is no more lobe to wear out and you have enough metal filings in your engine to eat your bearings. That's how and why my 350 became a 383. The metal filing ate the bearings and crank so rather than getting my crank reground, I just bought a stroker crank. And a hyd roller cam so it wouldn't happen again.
Modern oils don't have the needed additive for flat tappet lifters anymore so an oil additive with ZDDP is needed.
I'm not trying to scare you. Just trying to warn you what to look for. If someone other than yourself built the engine and the lifters are not staying adjusted after 500 - 1000 miles, take it back so they can inspect the engine to see what is wrong.
I've found it easier to adjust a hydraulic cam (both roller and flat tappet) with the engine running. It's messy as ever unless you can find an old valve cover that will clear your rockers. Cut the covers in half so the adjusting nut is exposed but the oil holes on the end of the rocker is still covered to deflect the oil back into the engine.
With the engine running and warmed up, back off the rocker you're adjusting slowly until it starts clacking a bit. Then slowly, tighten until it quits clacking and then tighten 1/4 - 1/2 turn more. When you start hearing the clacking sound, there is no preload on the lifter. When the clacking is starting to disappear you are starting to put the preload on the lifter. The 1/4 - 1/2 turn is the needed preload for the lifter. Only do one rocker at a time.
The oil pressure is what keeps the lifter pumped up and that is the self adjusting nature. Unless your rocker nut is losing adjustment or the cam losing the lobe or lifter collapsing, the adjustment shouldn't be needed on a constant basis. After a rebuild, it's just to make sure everything is wearing in and adjusted correctly. After 500 - 1000 miles, no other adjustment should be necessary. If it keeps losing it's adjustment, you have problems. If you have a cam lobe wearing down, then the gap between the lobe and lifter gets farther apart and that's why the constant adjustment is needed. After it wears some more, it'll need adjusted again. That happens until there is no more lobe to wear out and you have enough metal filings in your engine to eat your bearings. That's how and why my 350 became a 383. The metal filing ate the bearings and crank so rather than getting my crank reground, I just bought a stroker crank. And a hyd roller cam so it wouldn't happen again.
Modern oils don't have the needed additive for flat tappet lifters anymore so an oil additive with ZDDP is needed.
I'm not trying to scare you. Just trying to warn you what to look for. If someone other than yourself built the engine and the lifters are not staying adjusted after 500 - 1000 miles, take it back so they can inspect the engine to see what is wrong.
Most oil's that you can buy today don't have enough ZDDP in it. You have to buy an additive to supplement your oil. Oil for diesels (such as Rotella 15-40) used to have it in it, but I've heard they are dropping it, too. Besides, 15-40 is a bit thick for a street engine unless you have some wide bearing clearances or operate in extreme conditions.
ZDDP is the additive that prevents excessive wear on the flat tappet cam/lifter. Since all modern engines now use roller lifters, the oil companies have reduced/removed the additive. Here's a tech page from Comp Cams on the subject.
http://www.compcams.com/Base/pdf/FlatTa ... lletin.pdf
I'm not positive, but I think it has to be added at each oil change, not just a one time treatment. I'm running a roller cam so I haven't really kept up on the subject.
Edit: Found another article: http://www.zddplus.com/
I'd also recommend doing a search on *ZDDP Additives* to learn what are myths and facts.
ZDDP is the additive that prevents excessive wear on the flat tappet cam/lifter. Since all modern engines now use roller lifters, the oil companies have reduced/removed the additive. Here's a tech page from Comp Cams on the subject.
http://www.compcams.com/Base/pdf/FlatTa ... lletin.pdf
I'm not positive, but I think it has to be added at each oil change, not just a one time treatment. I'm running a roller cam so I haven't really kept up on the subject.
Edit: Found another article: http://www.zddplus.com/
I'd also recommend doing a search on *ZDDP Additives* to learn what are myths and facts.
I am using AMSoil... many of their oils are made with our old engines in mind, with zinc and other additives.
I would also recommend Mobil1
I think 10w30 is a good way to go... 15w40 may be to exessive, and 5w30 may be too thin.
I would also recommend Mobil1
I think 10w30 is a good way to go... 15w40 may be to exessive, and 5w30 may be too thin.
- Status
Similar threads
