Lazeum Posted May 11, 2013 Share Posted May 11, 2013 I've run the car for 2 minutes. The tapping sound is gone on my car also for now The engine is quiet (it I can say so with Triples & headers) I did not have time to run it for good, I nned to tune ignition first. So far, it is total success It is a Rebello cam with "tight valve lash". It is setup at 0.006" at cam lobe meaning 0.009" at rocker tip, where I'm doing measurement. Quote Link to comment Share on other sites More sharing options...
JCan Posted May 11, 2013 Author Share Posted May 11, 2013 This is great news! On my car the tapping noise continued to become quieter and quieter as time progressed Please keep us informed as to how your car runs after you tune it up. I think we are on to something here! Quote Link to comment Share on other sites More sharing options...
Lazeum Posted May 11, 2013 Share Posted May 11, 2013 Sure, I will but regarding tuning and performance, I'll switch to my Megajolt ignition topic. If some noise occurs or some facts about rockers happen, I'll report here my feedback. Quote Link to comment Share on other sites More sharing options...
Leon Posted May 12, 2013 Share Posted May 12, 2013 Great job Matt (and Jim)! Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 7, 2013 Share Posted July 7, 2013 Any updates for this thread? I have also been hearing excessive valve noise on my fresh motor. This is something I really need to look at. Quote Link to comment Share on other sites More sharing options...
JCan Posted July 8, 2013 Author Share Posted July 8, 2013 Did you replace your lash pads? Are they square like the ones in the pictures in this thread? Remove 2 or 3 rocker arms and take a look at the wear marks where they meet the lash pad (metal U shim ontop of the valve stem) If they are worn in the center and not on the sides, then all you have to do is remove all of your rocker arms and dress the rocker arm such that it touches the lash pad in the center of the pad (file or grind it with a very slight dome). This solved both Mats and my valve noise. Good luck! PS - My daughter is in her second year at Purdue - Go Purdue! Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 8, 2013 Share Posted July 8, 2013 Hey- I'm an IU fan, don't be talking about Purdue- lol My daughter graduated IU The valve noise issue is one of those deals where you think a certain amount should be acceptable being a solid lifter cam. I have looked for exhaust leaks because I have had that experience before. This head was completely reworked with a Schneider cam so lash pads were replaced for sizing. In fact I just cut the top off of a valve cover to do further investigation, but I might pull some rockers first. It seems to be mostly one valve, so maybe it's just not seating correctly. Quote Link to comment Share on other sites More sharing options...
JCan Posted July 8, 2013 Author Share Posted July 8, 2013 okay. you have new lash pads. Did you have your rocker arms (where they seat on the lash pads) reground? If not, Then take a moment, and remove all of your rocker arms, be sure to number both them and lash pads and have them ground. It is simple and will greatly reduce the sound your motor makes. Do you understand where the noise comes from? Basically the plane of the cam is not parallel to the plane on the lash pad made by the two ridges that you did not grind down, this makes it that you can never accurately gap your rocker arms or it forces them to torque as the cam pushes down the valve. get it? take pictures and keep us up to date. Quote Link to comment Share on other sites More sharing options...
JCan Posted July 8, 2013 Author Share Posted July 8, 2013 (edited) if your rocker arm looks like the below picture, remove and regrind them such that they touch only in the center of the lash pad instead of on the sides like the picture Edited July 8, 2013 by JCan Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 8, 2013 Share Posted July 8, 2013 I believe I got it. I know the lash pads were changed for the cam geometry and the new followers cam from the Schneider kit, so who knows what I have- but some ticking noise ! Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 8, 2013 Share Posted July 8, 2013 (edited) For your information, everything still goes well on my side. I've made around 600mi - no problem to report. First check after roughtly 100mi: I had to adjust valce clearance. It had move a little bit (0.015mm at lash pad) . Very consistent wear accross every rocker. Since rocker surface had to be broken in again, it was expected. Last check to control lash pad clearance showed no change or wear. I did not have to adjust anything. Edited July 8, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 8, 2013 Share Posted July 8, 2013 Soooooo- the actual noise is from the fact that the rocker arm is crashing into the lash pad during engine operation---because the valve adjustment is wrong for the reason that the arm comes into contact with the lash pad in the wrong area( the side). That is because certain pads were made differently. So upon doing the feeler gauge adjustment there is no load on the rocker to seat it properly on the lash pad so it is held up by hitting the sides of the lash pad. Under load the rocker crashes past this point and causes noise and improper valve movement or adjustment. So if I adjusted the valve at .010 with an improperly seated pad, the gap might actually be .014 or something like that. So am I understanding this fully ?? Quote Link to comment Share on other sites More sharing options...
JCan Posted July 8, 2013 Author Share Posted July 8, 2013 Yea you have it. Remove your rocker arms and take a fine file to them and get rid of the edges so that it seats ontop of the center of the lash pad. Good luck! Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 9, 2013 Share Posted July 9, 2013 Anyone have a good link for a thread on rocker removal? Ive been searching but... Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 9, 2013 Share Posted July 9, 2013 (edited) With my cam reground, primitive cam diameter is smaller than stock. I just have to get lifters as low as possible to provide enough clearance to remove first lash pad with a magnet pen & then rockers. You need to make sure of course rockers are having clearance against cam (=valve close) If you do not have enough clearance a big screw driver to make a lever between valve and cam shaft could help. I believe I've seen some drawings about it in service manual... Edited July 9, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 9, 2013 Share Posted July 9, 2013 Okay, I got some rockers off. Take a look at the second one I pulled off. Only half the rocker pad touches the lash pad, so it is sitting on there cock eyed I guess. Should I try and dress this somehow so it rides on there square-any recommendations? The others aren't as bad, but I haven't checked them all yet. It seems that my lash pads are the "H" type and it's not a matter of the rocker hitting the high spots on the sides. It's just very uneven wear, which seems worse. Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 9, 2013 Share Posted July 9, 2013 I will add that my cam lobe to rocker wear looks great and very even Quote Link to comment Share on other sites More sharing options...
madkaw Posted July 9, 2013 Share Posted July 9, 2013 So with all rockers inspected, #2 and #10 are both the same with only half the pad in contact with the rocker. Some others show uneven wear, but it is very minor compared to the two I am talking about. Quote Link to comment Share on other sites More sharing options...
Lazeum Posted July 9, 2013 Share Posted July 9, 2013 (edited) I would be tempted to grind the side of the rockers to bring the contact pad in the center. However, I'm not an expert, I would get comments from others prior to do anything. Maybe contact patch is uneven for another reason, you need to understand what could have happened. Some reasons could be: - Valves not perpendicular to rockers/cam (how? valve seats damaged? but I believe head is freshly rebuilt - Valve seat not straight? could machining, if any, have been done wrong) - Rockers already reground with cam pad not parallel to rocker tip area? - Cam lobes not straight? (could that be possible??!?) - lash pads not flat? Besides rockers being reground I don't believe other reasons could be realistic but who knows... Edited July 9, 2013 by Lazeum Quote Link to comment Share on other sites More sharing options...
JCan Posted July 9, 2013 Author Share Posted July 9, 2013 Wow... This is troubling. it is clear that your rocker arms were dressed, however it seems like the guy that did it didnt put the crown i the center of the rocker arm to lash. Maybe his setup was a bit crooked? too many beers? I think all you have to do is put a slight crown in your rocker arms to ensure the wear is in the center. Good luck! Quote Link to comment Share on other sites More sharing options...
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