Lifters...curious discovery
#1
928 Engine Re-Re-Rebuild Specialist
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Lifters...curious discovery
My heads are back on and torqued to spec. I put the lifters back in and I notice that some of them are a little "springy" and can be pushed slightly down with thumb pressure. Others won't go down even if I push hard with my thumb, even after I rotate the crank. The cams are not installed, so all the valves are closed.
Is this normal?
Is this normal?
#3
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I just moved them from the old heads to the new ones and wiped off the oil that was all over the outside. Am I supposed to somehow fill them with oil?
#4
Gluteus Maximus
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Well, there's differing theories on what to do with hydraulic lifters. Some people say you should let them soak in oil overnight, some don't. Some people think you need to bleed the air out, some don't. And then there's the whole preload issue.
To be honest, most of the engines I've ever torn apart have had solid lifters (old Fords and new motorcycles), so I'm sure someone else is in a better position to answer your question. But it's my understanding that with hydraulic lifters it doesn't really matter so much what you do. That's part of the reason why they're used, cause they don't need the fine adjustment (and periodic readjustments) that solid lifters do.
To be honest, most of the engines I've ever torn apart have had solid lifters (old Fords and new motorcycles), so I'm sure someone else is in a better position to answer your question. But it's my understanding that with hydraulic lifters it doesn't really matter so much what you do. That's part of the reason why they're used, cause they don't need the fine adjustment (and periodic readjustments) that solid lifters do.
#5
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I've looked in the archives, and it seems that the lifters that can be depressed may need to be replaced. Yes/no?
#6
Drifting
Don't forget that they have 2 to 5 bar oil pressure in them when they are working. As far as I'm aware the only replace recommendation in the WSM is after engine failure (i.e. no oil pressure rather than cam belt failure) as they are likely to have metal particles in them that can't be flushed out.
#7
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So now I'm confused. Do I just leave them alone and continue rebuilding....or do I need to pull them out and do something to them??
I'm getting good at running into out-of-the-ordinary problems. I hope someone's out there learning from all this.
I'm getting good at running into out-of-the-ordinary problems. I hope someone's out there learning from all this.
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#8
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I recently had the cam towers off to replace all gaskets & seals. I just put th elifters back as i had taken them out. Yes, they are springy but I assume this is because therr is no oil pressure. Hope I am right.
#9
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Well some of mine are springy, some aren't. The lifters were out of the heads for about a month before I put them back in. One set (passenger side) went back in the same locations, the others (driver's side) were mixed up and put back in at random locations. I wiped off the oil that was all over them and slid them back in.
#10
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I replaced the ones that were 'springy', I did leave them in oil overnight and then depressed while submerged in oil but mine did not harden up.
Just an FYI, when you start your engine up it is going to sound like a diesel until those lifters are purged, scared the crap out of me ....
Chris
Just an FYI, when you start your engine up it is going to sound like a diesel until those lifters are purged, scared the crap out of me ....
Chris
#11
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Originally Posted by Chris
I replaced the ones that were 'springy', I did leave them in oil overnight and then depressed while submerged in oil but mine did not harden up.
Just an FYI, when you start your engine up it is going to sound like a diesel until those lifters are purged, scared the crap out of me ....
Chris
Just an FYI, when you start your engine up it is going to sound like a diesel until those lifters are purged, scared the crap out of me ....
Chris
I'll pull the springy ones, dip them in a container of oil and press them. Hopefully they'll suck in some oil.
#13
soaking and pumping them while they're submerged didn't work for me. I actually used a hypodermic to inject oil into that tiny little feed hole. This was after I had flushed them to try to remove the contaminents associated with a bearing failure so mine were completely empty. I've had no problem with them but then again these are in a 944 race motor.
#14
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Some people test them by filling them with air via a rubber tipped blow gun and a compressor. If the valve works well they should stay firm after that, I'm told. I have not tried it. This might clear any debris out of the valve so it might fix a lifter that does not pump up too.
-Joel.
-Joel.
#15
Drifting
Originally Posted by Chris
Just an FYI, when you start your engine up it is going to sound like a diesel until those lifters are purged, scared the crap out of me ....
Chris
Chris