Valve train noise increases after 224 .581 cam install
#1
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So I have about 1,500 miles on motor after cam install. Initially with the cam in and when I was installing the rocker arms back in I noticed there was not any free play at all at the rockers, I figured the lifters will bleed out a little after driving and rockers will be loose. The motor at first did not have any ticking or valve train noise except the typical sewing mechine sound at idle. After about 300 mi. I took a 800mi. round trip with it and on the way back I started to notice more and more valve noise. It is not damaging sounding at all but definitely louder then when the motor first started running. I pulled the valve cover off and now I have valve clearance, not free play but just enough so the rockers can wiggle back and forth. I pulled the oil filter to check and no sign of metal and the magnet on the oil drain plug is as clean as it can be. Is what I am experienceing normal? the motor runs great other then valve train noise around 1,900 rpm.
#2
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You gotta retorque those rockers. They should not have any lateral freeplay. And if you want to eliminate a lot of valvetrain noise, make sure they have the proper pre-load on them when you retorque. Loosen all the bolts then tighten them down just enough to where you can't wiggle the rockers back and forth with your fingers. Then it should only take ~1.5 turns past that to get to the 22 ft/lb of torque needed on them.
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That is what we did with mine. A slightly longer pushrod quieted down the valvetrain noise noticably. I still have some but that is to be expected because the XER lobes that I have are quite agressive.
Originally Posted by PREDATOR-Z
I reduced my noise with 7.425 p-rods. Not gone completely but really reduced over 7.40's
#7
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I see. I did retorque them but it seems like the lifter will bleed and I can wiggle them again in about 30sec. I am still using stock P rods, but I don't understand why it took over 1,000 mi. for them to start making noise.
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stock push rods? That may be just enough cam to bend those by itself. I am running the same cam with TSP hardened pushrods and it is fine. Check those stock pushrods for bending....
#10
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Originally Posted by 02sierraz71_5.3
how did you account for the smaller base circle of the cam?
do you still have the stock length pushrods?
do you still have the stock length pushrods?
Comp cams sells the longer pushrods - sponsor Thunder Racing has some in the 7.425 length and others.
Last edited by Grimes; 11-14-2005 at 11:37 PM.
#11
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Originally Posted by Grimes
The lifters take up the slack. But I am interested what the actual reduction in base circle is exactly.
Comp cams sells the longer pushrods - sponsor Thunder Racing has some in the 7.425 length and others.
Comp cams sells the longer pushrods - sponsor Thunder Racing has some in the 7.425 length and others.
This is relatively easy on unmilled stock heads, stock gasket setups, but get more complicated as you factor in thinner gaskets, milled heads, longer/shorter valves, different lifters etc...
Most poeple do not want to mess with calculations but if you establish an excell sheet with formulas it becomes a snap.
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Very interesting indeed! Anyone have a copy of a spreadsheet like the one mentioned? I'm going to be doing a 224/228 .581/.588 on a 113 in my car soon (Cartek 2X) and would like to know the exact length of the pushrod that I need to use before I go just ordering up a set of hardened 7.4's.
#13
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Well at this point it is not getting any louder, may be 7.425 rods are what I need... but wouldn't the hydraulic lifters fill up to make up the extra clearance from the smaller base circle?
#14
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Originally Posted by mazdized
Well at this point it is not getting any louder, may be 7.425 rods are what I need... but wouldn't the hydraulic lifters fill up to make up the extra clearance from the smaller base circle?
But factor in lifter bleeding, type and weight of oil used, etc...
That is why the sewing machine effect is more pronounced at low rpm than at higher ones.
Basically the mission is to get tighter preload.
#17
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Did you change your oil??
I am haveing the same problem.. It showed up after about 800 miles when I switched to Mobile 1 synthetic.
I also think it is a bad lifter but not sure how to check the lifters..
I am haveing the same problem.. It showed up after about 800 miles when I switched to Mobile 1 synthetic.
I also think it is a bad lifter but not sure how to check the lifters..
#20