Lifter, piston slap, bottom end, general aggressive valvetrain, other?
11-25-2011, 09:51 PM
#1
Safety Car
Thread Starter
Lifter, piston slap, bottom end, general aggressive valvetrain, other?
Figured I'd get some input from the knowledgeable people on here. Sorry to make you look at some Ferd chit.
347 SBF stroker with AFR 165s, custom cam, Pro-systems carb etc. etc. in a Panoz. Trying to help my father nut/bolt the car and it was making more noise than I generally like.
Shortblock was purchase used and completely rebuilt by a very reputable shop. Car ran good this spring but cracked a valvespring at VIR in July. Heads were gone through and freshened up. Then in October it chucked the water pump pulley coming out of Hog's Pen.
The noise really sounds like it's coming from the center of the engine. Initially I thought it was more from the front, but after running it with both VCs off I'm not so sure. I put each piston to TDC and checked the pushrods and rocker arm adjustment and found no indications of a weak or collapsed lifter.
Thoughts? General noise from an aggressvie aftermarket valvetrain? Bottom end issue?
347 SBF stroker with AFR 165s, custom cam, Pro-systems carb etc. etc. in a Panoz. Trying to help my father nut/bolt the car and it was making more noise than I generally like.
Shortblock was purchase used and completely rebuilt by a very reputable shop. Car ran good this spring but cracked a valvespring at VIR in July. Heads were gone through and freshened up. Then in October it chucked the water pump pulley coming out of Hog's Pen.
The noise really sounds like it's coming from the center of the engine. Initially I thought it was more from the front, but after running it with both VCs off I'm not so sure. I put each piston to TDC and checked the pushrods and rocker arm adjustment and found no indications of a weak or collapsed lifter.
Thoughts? General noise from an aggressvie aftermarket valvetrain? Bottom end issue?
11-26-2011, 12:57 AM
#3
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I would try a stethoscope with the metal part removed. Basically plastic tubes with the ear pieces. Had a noise similar to that started at a autocross last year. Looked hi and low at the valve train.. Ended up being a header gasket blown in the back where you couldn't see it. Good luck..
11-26-2011, 12:59 AM
#4
Safety Car
Did you verify pushrod length/lifter pre-load? That is the usual culprit for noise w/hydraulic lifters.
Check mfg's suggestion vs what others have run.
Is there much geometry change w/the new heads (think throughout from lifter to rocker)?
Sounds like valvetrain from here, but hard to tell. Anyone else w/that motor & components have similar issues?
Check mfg's suggestion vs what others have run.
Is there much geometry change w/the new heads (think throughout from lifter to rocker)?
Sounds like valvetrain from here, but hard to tell. Anyone else w/that motor & components have similar issues?
11-26-2011, 06:56 AM
#5
I just installed a set of Crane Cams 1.8 ratio rockers together with new lifters. During first startup, when the lifers needed to be pumped, they sounded roughly like this. Only for about 5 minutes though.
Fred
Fred
11-26-2011, 08:11 AM
#6
Safety Car
Thread Starter
Pushrods and lifter pre-load have all been checked... no evidence of anything off there. No indications of a weak/soft lifter.
Going to test it and start unplugging plug wires to see if I can isolate the cylinder.
The heads have been on it since I built up the original 5.0. Don't remember a noise like this with that setup.
Going to test it and start unplugging plug wires to see if I can isolate the cylinder.
The heads have been on it since I built up the original 5.0. Don't remember a noise like this with that setup.
Last edited by travisnd; 11-26-2011 at 08:13 AM.
11-26-2011, 11:06 AM
#7
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My vote would be for a header gasket leak. I would check the gaskets carefully, a very small blowout can make a lot of noise. Use a stethescope to try to isolate further.
11-26-2011, 11:54 AM
#8
Melting Slicks
Sounds like a bottom end issue to me. Lifters and valvetrain have a higher pitched ticking noise in my experience. That sounds like a more substantial clacking noise. Rod bearing?
