New Engine is Knocking

Discussion in ''Da Nailhead' started by KDML, Jun 12, 2014.

  1. gsgtx

    gsgtx Silver Level contributor

    Walt, Doug's rollers are 1.6 ratio from ta-per. installed spring height was 1.6 with coil bind at 1.00. so he has .600 clearance - .521 cam lift and a .030 shim is .551 total. he has .049 before coil bind. it comes down to lifter bleed down, because of the fast ramp cam and small cam lobes of the nail head camshaft for the small cam bearings. the right lifters should cure the problem, like you said then the cam would be the final solution. turned into a big mess, comp sent him different lifters the first time for a Pontiac thinking that was the problem.in post #27 I mention the magnum pro lifters but Doug already ordered the buick lifters. like to see him go right to solid lifters with Toms approval and help.
     
  2. KDML

    KDML Well-Known Member

    I believe we are all on the same page that the noise I am hearing is the valve hitting the seats. I have accepted the fact that with the ramp rate of the cam lobes I will have more noise. However, I am feeling that the noise is louder than what it should be. What I would like to do is figure out if the louder noise is really caused by lifters bleeding down, before I just start throwing more lifters at the problem. So, are there any tests I can run to verify?

    Also, on the thought of running solid lifters. Is it OK to run solids on a cam designed for hydraulic? I thought the lobe profiles were different. Or is the fast ramp design of my cam more comparable to a solid lifter cam anyway? I did a quick search on the concept and found myself on Speed Talk, where there was clearly a difference of opinion on the subject. Some folks are doing it with good success, but some folks indicate it may work, but is not the right answer. I also found a thread on V8 Buick where someone had the same issue with a BBB and solved it by switching to Comp Pro Magnum lifters.

    Thanks
     
  3. wkillgs

    wkillgs Gold Level Contributor

    Is 1.6 the 'advertised' ratio, or has someone actually measured and confirmed it?
    The contact points move around during the lift cycle and ratio will change between mid lift and full lift. You can even vary the ratio a little by using short or long pushrods.
    I'm bringing this up again since the .049" spring coil clearance might actually be zero if the TA rockers/cam/pushrod combo actually produces a higher than advertised ratio.
    With Tom's rockers, I'm getting an extra 0.060"+ of valve lift over what I'd have with 1.6 ratio rockers....that's why I like them.:TU:

    You guys are likely on the right track with the lifter issue, just want to make sure you aren't overlooking another possibility.
     
  4. gsgtx

    gsgtx Silver Level contributor

    Walt, you make a good point, to rule out coil bind can you check clearance with the cam on full lift and put a feeler gauges between the springs? pro mag lifters seem like a cross between reg lifters and solids
     
  5. Babeola

    Babeola Well-Known Member

    The best way to determine coil bind is to remove the spring and squeeze it in a vise until it binds. Then take a measurement with vernier calipers. Add .060" and subtract that total from the installed height to get max lift. You want to be at least .050" away from coil bind and most builders are more comfortable with .060". On the set of springs in our 425 there is .015" difference from the longest to the shortest spring. The shorter springs went to the exhaust valves with slightly more lift.

    I'd use a solid lifter and measure lift at the valve to determine actual rocker arm ratio and lift.

    Cheryl :)
     
  6. KDML

    KDML Well-Known Member

    Finally had some time to check for coil bind today. Here is how I went about it. Please let me know if I did this right

    First I measured for actual lift at the valve spring. I took an old hydraulic lifter and converted it to a solid lifter and installed it into the engine. I lined up the dial indicator on top of the valve spring retainer, while the cam was on the base circle. I spun the motor until the lobe was at max lift. Exhaust lift came out to 0.482; intake came out to 0.500. I divided both those numbers by the lobe lift on the cam card (0.306 for exhaust and 0.316 for intake), which came out to approximately 1.6, which is the rocker ratio on the TA rockers.

    I then pulled one set of valve springs (inner and outer) and placed them in a vise (separately) with the retainer and squeezed them to coil bind. I took the length of the compressed springs and subtracted the thickness of the retainer to obtain the spring coil bind. The outer spring length was 0.971 and the inner spring length was 0.898.

    I then placed the retainer and locks on the valve and measured the installed height between the bottom of the retainer and the spring seat for both the outer and inner spring. The inner spring has a lower spring seat. For the outer spring I left the spring shim in placed. The installed height for the outer spring was 1.576 and the inner spring was 1.641.

    Once I had all the measurements, I subtracted the spring coil bind numbers from the installed height. 0.605 for the outer and 0.743 for the inner. Subtracting the actual lift from those numbers for both intake and exhaust proves there is lots of room before coil bind

    Does this sound correct?

    Thanks
    Doug
     
  7. Babeola

    Babeola Well-Known Member

    Coil bind ruled out. I would keep your numbers handy in case you change springs at some point. Do you have valve seals, and is there enough travel between the seals and retainers?

    The stock spring installation heights are 1.60" and 1.69". Why are yours short? Have you run a straight edge across the valve stems to see if they are consistent in height? The normal height of the valve stem is 1.54" above the valve cover surface (according to the manual).


    Some more fun things to check - Cheryl :)
     
  8. wkillgs

    wkillgs Gold Level Contributor

    Now I feel bad for making Doug go to the trouble of checking! Well, it did have to be checked as a possible cause. Now at least we all know what the true ratio of the TA rockers is...
    I take it your valve lash was near zero while you checked the lift, correct?
    As suggested, check the retainer/seal/guide clearance next. Easy to do if you substitute some lightweight hardware store springs for the valve springs. Put dial indicator on retainer, go to max lift, then push valve down till it stops to measure clearance.
     
  9. 66larkgs

    66larkgs paul 66gs turbo nailhead

    Doug , How many miles or hours did you run it with this noise? have you driven it and if so have you been babying it or beating it up?
     
  10. KDML

    KDML Well-Known Member

    Cheryl, I only have seals on the intake valves. Distance between lowest point of retainer and top of valve seal is 0.550; with 0.500 lift on intake, that gives .050 cushion. Not sure why installation heights appear low. I has previously run a straight edge across valve stems when I was finding different measurements for pushrod length and they all appeared to be the same

    Walt, no worries on going through the exercise to check for coil bind. I don't look at these challenges as a problem - only a chance to learn more

    The engine has probably a little over 1 hour on it, as I needed to break in the cam and then I had to break in the second set of lifters. I have been fairly gentle only bringing up the rpm to break in speed. I have not been able to drive it as it is still in pieces.

    Next step will be to install comp cams pro magnum lifter as previously suggested. I already have them. Going to need to check for pushrod length again as they look like the pushrod cup is lower in the lifter then with the previously lifters I have used.

    Thanks
     
  11. gsgtx

    gsgtx Silver Level contributor

    the new lifters are .040 deeper but don't forget you only have to have 4-8 thousand preload so you should be fine. as for the height is that because of the .030 shim that makes it lower?
     
    Last edited: Aug 10, 2014
  12. KDML

    KDML Well-Known Member

    Finally got around to installing the comp pro magnum lifters this week. Got it all back together and ran it this morning. Noise is still there. Here are a few more videos for your viewing enjoyment. I even took one under the car where I can still hear the noise. Also, brought up the rpm which did nothing but push a lot of oil through the valve cover gaskets. In fact there is so much oil on the top of the heads it is overwhelming the gaskets most of the time (see pics after I shut it down). Yes, the valve train is noisy, I can hear it under this noise, but this does not sound right. Oil pressure is still good, but I did notice after I raised the rpm and brought the engine down to very low idle I was at 10lbs, which is the lowest I have seen. Gave it a little gas and pressure went back up to 20. At this point I don't know what to do next. Maybe install the original rockers and pushrods and see what changes or maybe go back to doing bodywork and leave the engine for next year.

    http://vid1175.photobucket.com/albums/r639/kdml1/Mobile Uploads/IMG_1229_zpsabbd81c0.mp4
    http://vid1175.photobucket.com/albums/r639/kdml1/Mobile Uploads/IMG_1228_zps70fb613c.mp4
    http://vid1175.photobucket.com/albums/r639/kdml1/Mobile Uploads/IMG_1227_zps1f322f59.mp4

    valve cover leaking1.jpg
     

    Attached Files:

  13. telriv

    telriv Well-Known Member

    I hope you have been numbering the "Used" lifters you have removed just in case you want to install them again. As I remove each lifter I spray some Brakleen on it & wrap with a piece of tape. #1 cyl. exhaust would be #1. #1 cyl. intake would be #2 & so on until #7 exhaust which would be #8. For #2 cyl. exhaust it would be #9 & intake would be #10 until the end #8 cyl. exhaust which would end up at #16.
    That oil pressure @10lbs. hot idle sounds "kinda" low. 20lbs. is definitely low at anything above 1400 or so RPM's. Should be closer to 35-40.
    You also need to find out WHY SO MUCH oil is being pumped to the heads/rockers. Originally it was pretty dry.
    Just my thoughts.


    Tom T.
     
  14. KDML

    KDML Well-Known Member

    Yes, I have been using the boxes to identify where the lifters where. I wonder if all of the oil on the top of the motor is causing the noise - too much oil on top not enough down below.
     
  15. DigDugMd

    DigDugMd Member

    Is it possible the rocker shafts are upside down? ie oil holes pointing up instead of down?
     

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