porsche4786 Posted March 27, 2011 Author Share Posted March 27, 2011 (edited) I finally got around to do the oil pressure again....At warm idle it's about 14psi (not sure how accurate the gauge is I have). And at about 3200 RPM it's at 50+psi. But it does still go up to over 60psi at start, then down to about 28-30ish after 5-10 seconds. edit: will probably try a different filter and oil also. Edited March 27, 2011 by porsche4786 Link to comment Share on other sites More sharing options...
porsche4786 Posted March 28, 2011 Author Share Posted March 28, 2011 I finally got around to do the oil pressure again....At warm idle it's about 14psi (not sure how accurate the gauge is I have). And at about 3200 RPM it's at 50+psi. But it does still go up to over 60psi at start, then down to about 28-30ish after 5-10 seconds. edit: will probably try a different filter and oil also. Okay, replaced oil again with new filter (different brand, different store). I was recommended by a mechanic to use straight 30 weight oil. So I thought, what they heck, I'll give anything a shot once. Oil pressure is up to 65 at start, and holds it there for much longer than before, and drops off to about 24-25 at about 750 rpm. Sounds pretty high to me at that rpm. I think the next step is to pull it all back apart and try again. Link to comment Share on other sites More sharing options...
Kingman Posted March 28, 2011 Share Posted March 28, 2011 As a general rule, 10PSI for every 1,000RPM. 24-25PSI is fine at idle as long as it does not exceed around 75PSI at any point when warm. Link to comment Share on other sites More sharing options...
porsche4786 Posted March 31, 2011 Author Share Posted March 31, 2011 Is this movement supposed to be there in the rocker arms? A couple of them move back and fourth and side to side a little. Pretty freely. http://www.youtube.com/watch?v=CygNJK1bqv0 Link to comment Share on other sites More sharing options...
Kingman Posted March 31, 2011 Share Posted March 31, 2011 No. Not supposed to be like that. Link to comment Share on other sites More sharing options...
porsche4786 Posted March 31, 2011 Author Share Posted March 31, 2011 No. Not supposed to be like that. I'm wondering if it was like that before I changed them...I put every bolt back in the exact hole, and rocker arms in the same spot. Link to comment Share on other sites More sharing options...
sewebster Posted March 31, 2011 Share Posted March 31, 2011 Well, you've found the source of your noise! So now you need to figure out what the problem is. If it's assembled correctly, then you want to check: -lifter height? -worn cam lobes? -worn rocker shafts? -worn rocker inner diameter (on the shaft)? -worn rocker pads (where you contact the lifter and valve)? -valve height? Usually I'd say you could find the problem just by eye... comparing good to bad. The FSM has detailed measurement instructions for pretty much everything though.... but things are so loose in your video that you shouldn't need to actually measure... In terms of knowing it is assembled correctly... let me think. You need to have the lifter guide plates fully seated down on the locating pins. You need to have the rocker shafts on the right side (can you even mess this up?) The cutouts in the shafts should be over the cylinder head bolts. You need to correctly torque the rocker shaft bolts, but even just hand tight you likely wouldn't get that much movement. Link to comment Share on other sites More sharing options...
porsche4786 Posted March 31, 2011 Author Share Posted March 31, 2011 Well, you've found the source of your noise! So now you need to figure out what the problem is. If it's assembled correctly, then you want to check: -lifter height? -worn cam lobes? -worn rocker shafts? -worn rocker inner diameter (on the shaft)? -worn rocker pads (where you contact the lifter and valve)? -valve height? Usually I'd say you could find the problem just by eye... comparing good to bad. The FSM has detailed measurement instructions for pretty much everything though.... but things are so loose in your video that you shouldn't need to actually measure... In terms of knowing it is assembled correctly... let me think. You need to have the lifter guide plates fully seated down on the locating pins. You need to have the rocker shafts on the right side (can you even mess this up?) The cutouts in the shafts should be over the cylinder head bolts. You need to correctly torque the rocker shaft bolts, but even just hand tight you likely wouldn't get that much movement. I'm hoping it's something to do with the rocker arms or shafts, because that's easy. You have to disassemble the front of the engine to get cams out and measure them right? Or can you actually fit a micrometer in there? I'll see if I can get around to removing the rocker arms and shafts and mic them tonight. I don't remember seeing a measurement for the rocker arm pads, but I'll give them a good look over. I'll re soak the lifters as well. Link to comment Share on other sites More sharing options...
sewebster Posted March 31, 2011 Share Posted March 31, 2011 (edited) You might be able to measure the cam height in situ, not sure, but small changes are supposed to be taken up by the lifters... I'd think you'd really be looking for fairly serious damage, like the cam looking all ground up. Happened to me when I had stuck lifters, was obvious. Also the bottom of the lifter was chewed up too. I've also had stuck valves, so the valve wasn't all the way up, causing slack in the system. Edit: the lifters would also expand to take up any minor wear in the rocker pads... (don't think there is any spec for those in the FSM). So again I think you're really looking for something pretty major and obvious with looseness like that. That's my take on it anyway. Edited March 31, 2011 by sewebster Link to comment Share on other sites More sharing options...
porsche4786 Posted March 31, 2011 Author Share Posted March 31, 2011 You might be able to measure the cam height in situ, not sure, but small changes are supposed to be taken up by the lifters... I'd think you'd really be looking for fairly serious damage, like the cam looking all ground up. Happened to me when I had stuck lifters, was obvious. Also the bottom of the lifter was chewed up too. I've also had stuck valves, so the valve wasn't all the way up, causing slack in the system. Edit: the lifters would also expand to take up any minor wear in the rocker pads... (don't think there is any spec for those in the FSM). So again I think you're really looking for something pretty major and obvious with looseness like that. That's my take on it anyway. Or maybe (when I take it apart) it will be one of those things that is just WAYY too obvious to see/take the time to look at. I did see a fairly worn looking spot on the drivers side cam, you could feel a slight wear on the cam (which, if you can feel it, it's probably too much). But that's by far the worst spot I've seen. And that isn't the only place noise is coming from. The lifters themselves (old ones) look ok, didn't see obvious highly worn spots. Link to comment Share on other sites More sharing options...
porsche4786 Posted April 1, 2011 Author Share Posted April 1, 2011 Ok...while my hands aren't oily I snapped a couple photos of the lower set of rocker arms (I don't know if they are exhaust or intake). The long arm pad of the rocker arm is very worn compared to the lifter pad side. The valve ends also have markings to match the rocker arm pads. I haven't pulled the upper set yet. The rocker arms and shaft mic'd fine. Link to comment Share on other sites More sharing options...
porsche4786 Posted April 1, 2011 Author Share Posted April 1, 2011 Ok, pulled lifters, 3 out of the 6 are rounded now, not flat.....what causes this? No oil? The cam looks to be fine, but I can't get my micrometers in there. Link to comment Share on other sites More sharing options...
sewebster Posted April 1, 2011 Share Posted April 1, 2011 The rockers don't look fantastic, for sure, but they don't seem worn enough to cause the motion in your video? Do the three worn lifters correspond to the rockers that were loose? Pics of lifters? Compare height to good ones? Link to comment Share on other sites More sharing options...
JamesRich Posted April 1, 2011 Share Posted April 1, 2011 The slack in the video is just because the lifters are collapsed. If they were pumped up they would take out the slack. The rockers don't look good but probably don't have as much to do with the noise as the lifters. The rocker pad when new has a slight angle on them so that it rotates the valve a little each time it opens it. This keeps wear on the valve face and seat even. From that last pic you can tell the valve hasn't been rotating so I would say you need new rockers. The toe of the cam has this angle too to keep the lifter rotating also for even wear. The lifters must have collapsed because of the low oil pressure problem you were having and probably galled up inside now. If the bottom of the lifters are concaved you need a new cam also. Now is a good time for Jim Wolf cams, just make sure you are getting oil to the heads. James Link to comment Share on other sites More sharing options...
porsche4786 Posted April 1, 2011 Author Share Posted April 1, 2011 The rockers don't look fantastic, for sure, but they don't seem worn enough to cause the motion in your video? Do the three worn lifters correspond to the rockers that were loose? Pics of lifters? Compare height to good ones? I'll have to double check, but I'm pretty sure yes they do. Because there were two worn lifters on one far side, the middle two were fine, the other end has one fine and one bad. I was also wondering if a rocker arm shaft, if not perfectly straight, could cause extra wear on the lifters. Or if the shafts were not torqued down properly. The slack in the video is just because the lifters are collapsed. If they were pumped up they would take out the slack. The rockers don't look good but probably don't have as much to do with the noise as the lifters. The rocker pad when new has a slight angle on them so that it rotates the valve a little each time it opens it. This keeps wear on the valve face and seat even. From that last pic you can tell the valve hasn't been rotating so I would say you need new rockers. The toe of the cam has this angle too to keep the lifter rotating also for even wear. The lifters must have collapsed because of the low oil pressure problem you were having and probably galled up inside now. If the bottom of the lifters are concaved you need a new cam also. Now is a good time for Jim Wolf cams, just make sure you are getting oil to the heads. James I turned the engine over a little and one of the lifters pushed up and took the slack out. So yeah, you're right. I did notice the angle on the cam. How does the cam cause the lifters to get caved in like that? I thought it would be due to not enough oil getting there? As I understand, the cam is a stronger steel than the lifters. Too bad you can't write off a loss on your car in your taxes..... I've spent probably double what I paid for it a little over a year ago... Link to comment Share on other sites More sharing options...
sewebster Posted April 1, 2011 Share Posted April 1, 2011 While the lifters can "pump up" with oil and take out some slack, if all your components are in "like new" condition then there is no slack even with the engine off (for any cam position). I'm not sure on what exactly the lifters and cams are made of, but I think if you have significant wear on the lifter bottoms then the cams are going to be toast too unfortunately. Link to comment Share on other sites More sharing options...
porsche4786 Posted April 1, 2011 Author Share Posted April 1, 2011 While the lifters can "pump up" with oil and take out some slack, if all your components are in "like new" condition then there is no slack even with the engine off (for any cam position). I'm not sure on what exactly the lifters and cams are made of, but I think if you have significant wear on the lifter bottoms then the cams are going to be toast too unfortunately. The old lifters that I took out didn't have a rounded bottom, they were all very flat by feeling them. These new ones are very obviously rounded, I'll try and get a photo when I get home from work. Just weird that the old ones were fine, but all the sudden the new ones are junk. Link to comment Share on other sites More sharing options...
sewebster Posted April 1, 2011 Share Posted April 1, 2011 The old lifters that I took out didn't have a rounded bottom, they were all very flat by feeling them. These new ones are very obviously rounded, I'll try and get a photo when I get home from work. Just weird that the old ones were fine, but all the sudden the new ones are junk. Maybe you had the same problem I did. Oversize lifters seizing in the guide plate. I had to buy three sets of lifters before I got ones that weren't too big. Mic them! Link to comment Share on other sites More sharing options...
porsche4786 Posted April 1, 2011 Author Share Posted April 1, 2011 (edited) Maybe you had the same problem I did. Oversize lifters seizing in the guide plate. I had to buy three sets of lifters before I got ones that weren't too big. Mic them! Maybe I'll just throw a rotary in it and be done with it I'm getting antsy to get home and start looking more into the lifters themselves...I did buy the cheapest ones rockauto had.....Next time I'll make sure I get made in USA. edit: I still have the old lifters. What would happen if I tried a couple of those in place of the bad ones? I don't know which of them came from where though... Edited April 1, 2011 by porsche4786 Link to comment Share on other sites More sharing options...
sewebster Posted April 1, 2011 Share Posted April 1, 2011 Maybe I'll just throw a rotary in it and be done with it I'm getting antsy to get home and start looking more into the lifters themselves...I did buy the cheapest ones rockauto had.....Next time I'll make sure I get made in USA. edit: I still have the old lifters. What would happen if I tried a couple of those in place of the bad ones? I don't know which of them came from where though... Well, I started by buying the most expensive ones RockAuto had, and still got screwed... Old lifters would probably still work, but if your cams are ruined then you still need to replace those. The lifters I got that were eventually good were Clevite brand I think. I had problems with Sealed Power and Beck Arnley. Link to comment Share on other sites More sharing options...
porsche4786 Posted April 2, 2011 Author Share Posted April 2, 2011 (edited) Well, I started by buying the most expensive ones RockAuto had, and still got screwed... Old lifters would probably still work, but if your cams are ruined then you still need to replace those. The lifters I got that were eventually good were Clevite brand I think. I had problems with Sealed Power and Beck Arnley. Okay...here's some photos of what the ruined lifters look like, they are pretty much all the same. The scratches on the bottom of the lifter are pretty hard to feel with your hand. I tried to get a descent shot of the cam lobes, but was having trouble with the light reflecting too much off the steel. I double checked the old lifters, and they are all flat as far as I can feel. edit: They all seem to be pretty darn close to .628'' Edited April 2, 2011 by porsche4786 Link to comment Share on other sites More sharing options...
sewebster Posted April 2, 2011 Share Posted April 2, 2011 Looks like those lifters and that cam is toast. Looks exactly like what happened to me with oversize lifters. The spec is 0.6278 to 0.6282. Mine were like 0.629 if I recall correctly. Measure again, very carefully with a mic that is good to tenths? Link to comment Share on other sites More sharing options...
porsche4786 Posted April 2, 2011 Author Share Posted April 2, 2011 Looks like those lifters and that cam is toast. Looks exactly like what happened to me with oversize lifters. The spec is 0.6278 to 0.6282. Mine were like 0.629 if I recall correctly. Measure again, very carefully with a mic that is good to tenths? Pretty much .680'' exactly, unless I tighten it down on the lifter. Then it is slightly under .680. But mine only show me .XXX, after that you are guessing. Mine are not digital. I wish! Link to comment Share on other sites More sharing options...
sewebster Posted April 2, 2011 Share Posted April 2, 2011 I assume you mean .628 since .68 wouldn't even fit in the guide plate. There are certainly mechanical micrometers that read to tenths, the last digit is on a vernier scale. Anyway, could be some other seizing problem I guess... is the guide plate hole way oversize? The damage looks like the lifter is not going up when it is supposed to and is grinding against the cam lobe... Link to comment Share on other sites More sharing options...
Chriskaw440 Posted August 18, 2011 Share Posted August 18, 2011 did I hear the word ROTARY on here? I used to own 3 RX-7s.....all first generations... '81 '82 and '84 (84 GSL) I autocrossed one for a while, and restored all of them myself.....I miss my rotaries! SO easy to work on....and the 4 barrel carbs were cool too I had one of my new lifters get toasted like that too...I bought new ones...fitted each one to each lifter plate hole where there was no resistance been ok ever since but I still get some noise at start up when cold and a little when under load but oh well....thanks to the economy I cant afford to get all new lifter stuff like lifters, plate, rocker arm sets etc etc. Still runs great....I just turn up the sub woofer. Wish my wife didn't make me sell my last RX-7....it even had Recaro seats and they all had racing exhaust. Link to comment Share on other sites More sharing options...
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