fixn2 Posted February 8, 2011 Share Posted February 8, 2011 Does anyone know why my hydraulic lifters are acting like solid lifters after start-up Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 8, 2011 Share Posted February 8, 2011 Welcome! Too much oil pressure? Adjusted too tight? Give us more information, engine, cam & lifter brand and age. History on the engine. Bruce Quote Link to comment Share on other sites More sharing options...
fixn2 Posted February 8, 2011 Author Share Posted February 8, 2011 complete rebuild small block. new cam and lifters, proper break in. ran fine after break in then later when i started it up again it had a miss to it. I could hear it popping through the carb real lightly. After checking things out i found that some of the valves were not closing all the way. I have never heard of lifters going into a hydraulic lock (if there is such a thing) so i took each one out took them apart and emptied the oil out of them and reassembled the engine. initial startup is fine but after a few minutes the same thing. Oil pressure is about 80 psi Quote Link to comment Share on other sites More sharing options...
fixn2 Posted February 8, 2011 Author Share Posted February 8, 2011 The cam kit is a comp cams extreme energy 268 Quote Link to comment Share on other sites More sharing options...
Chevyss Posted February 8, 2011 Share Posted February 8, 2011 That oil pressure is just a little to high I would think. Anything over 60 is what they've told me it to much. Quote Link to comment Share on other sites More sharing options...
fixn2 Posted February 9, 2011 Author Share Posted February 9, 2011 if the oil pressure is to high how do i tame it down some? if i remember correctly, it's just changing a spring in the oil pump correct? Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted February 9, 2011 Share Posted February 9, 2011 Tell us how you have adjusted your lifters Quote Link to comment Share on other sites More sharing options...
fixn2 Posted February 9, 2011 Author Share Posted February 9, 2011 TDC #1,3,4,8 exhaust #1,2,5,7 intake rotated 360 then did the rest. backed them off and tightened 1 complete turn after zero lash Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 9, 2011 Share Posted February 9, 2011 Too much oil pressure can do this. Be careful that your oil filter doesn't blow out. I have a call into my brother in-law a retired Chevy engineer. This just happened to his 67 Firebird with the OHC 6 cyl after a rebuild. The oil pump blow off valve was sticking. You should see the oil filter! Bruce Quote Link to comment Share on other sites More sharing options...
Heckeng Posted February 9, 2011 Share Posted February 9, 2011 1 full turn is quite a bit, I would only do 1/4 to 1/2 turn for that cam. I would also adjusts them differently. Your method works ok, especially on smaller stock style cams, but once you get cams that are a little larger, you can run into problems because the duration is large enough to hold the valves partially open. That would give you too little lash though which you don't appear to have. What I like to do is either adjust each cylinder separately when it is on the compression stroke and you know the valves are shut. After you get the first valve adjusted, turn the crank over 1/4 turn and adjust the next one in the firing order and so on until you are done. Or, you can adjust them while the engine is running but you have to have them semi-adjusted to do that at all. Â I wouldn't think your oil pressure is causing this, but it sounds like it has happened to others. I've run 75 lbs of pressure with nothing goofy happening. Quote Link to comment Share on other sites More sharing options...
Sam (Bones) Posted February 9, 2011 Share Posted February 9, 2011 too tight! 1/2 usually does it, I've done it with a dial indiator, most lifters want .030 to .050 preload, a half turn usually comes in at .032-.034 on my big block Quote Link to comment Share on other sites More sharing options...
wallaby Posted February 9, 2011 Share Posted February 9, 2011 1 turn is a whole bunch. I have heard the lifters like to be nearly fully extended instead of compressed. Even if they pump up, they can't go far that way. I can't argue with dial-indicator readings, but I've heard that 1/4 turn is enough. Either way, it's a considerable way less than what you have now. Quote Link to comment Share on other sites More sharing options...
black07ss Posted February 9, 2011 Share Posted February 9, 2011 I hope we are being of help. Also to the site Wynn Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 9, 2011 Share Posted February 9, 2011 I aggree with most everyone 1/4 to 1/2 should be all yo need i've always had better luck adusting them running with engine warmed up but be sure and get the caps for the rockers or you will have an oily mess to clean up and remember to remove them when your done too. Welcome to the site. good luck. Quote Link to comment Share on other sites More sharing options...
fixn2 Posted February 9, 2011 Author Share Posted February 9, 2011 Wow, I was not expecting so much response. Thank you everyone for the replies and the welcome. OK even after all the replies my question still remains, is it possible for the hydraulic lock issue and if so I would really appreciate an explanation on how and why. Once again thank everyone for the welcome and your answers. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 9, 2011 Share Posted February 9, 2011 If you have them adjusted to tight the lifters may be partialy collapsed after it warms and everything expands (everything expands when hot even the oil) they could be expanded enough to cause the lock up you are refering to (total collapse) hopefully there not to tight to break something internally. Readjust and try it again if you still have problems check the lifters again and the push rods. Quote Link to comment Share on other sites More sharing options...
wallaby Posted February 10, 2011 Share Posted February 10, 2011 For the most part, they are supposed to lock up. If they were too cushy they wouldn't open the valves. Ideally, they should act like they are solid, but have a little room for expansion so they can maintain a zero lash. When the lifter is at the bottom of it's bore and not trying to open a valve it is receiving oil and filling up. As the camshaft starts to lift the lifter, the lifter rises up and blocks off the passage that was just filling it...this traps the oil in the lifter so it can't go back out the way it came in. A small ammount of oil is lost from the lifter in the process, but it functions as solid as best it can. Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted February 10, 2011 Share Posted February 10, 2011 When you adjust the valves try it this way: Adjust the intake when the exhaust is just beginning to open, adjust the exhaust when the intake is almost closed. Try a 1/4 turn after zero lash. Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 10, 2011 Share Posted February 10, 2011 My brother in-law, the retired Chevy engineer, didn't think the 80 PSI was causing it (although that is a bit high) or the 1 turn. He asked if 80 was a true reading with a good gauge and that it wasn't a 0 - 80 PSI gauge that was maxed out and running even higher. As to the 1/2 turn after zero lash (that I have always used) he said 1/4 or 1/2 or 1 or 2 even 3 turns would work the same on an OEM valve train system. Sorry I couldn't be of more help. The problem he had with his Pontiac OHC 6 (also could happen on a Vega OHC 4 Cyl) can't happen to our Chevy OHV V8 engines (or Ford or Chrysler) because of the valve train design. Quote Link to comment Share on other sites More sharing options...
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