Knocking, after cam install, ADVISE PLEASE
04-20-2006, 10:05 AM
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Knocking, after cam install, ADVISE PLEASE This past weekend I installed a buddies cam. He went with the MS3 and patriot gold springs. Its a forged shortblock with 2cc reliefs, fwiw. This is about my 6th cam install in an LS1 and I have never heard this bad of a noise after an install. My first thoughts were slop in the valve train into the lifters. So I pulled the valve covers and checked all the rocker alignment and tension. It was fine. After a long weekend I tore back into it last night to make sure it wasnt the front of the engine. I also in stalled a double roller timing chain. Spacers were in, it was dot to dot, no visible wear on anything, so I closed it back up after we spun the engine over a few times to make sure with the cover off. Again no problems anywhere in the front. I dont know if knocking is the exact right way to describe the sound, more of a really loud ticking. Car had no audible issues before the install. Stock rockers, lifters, and hardened 7.40 pushrods with 853 heads milled .015. Tonight I am going to run a compression test to see if there are any issues in one or more cylinders (why not?) Then I will take the rockers back off, remove pushrods and spin the engine over and try to reset the lifters. Can any of you think of something I am missing here? Also, I need to point out that we used pen magnets to hold a few lifters that were trying to fall. Homeboy decided to pull one of them alittle too hard and broke the end off ON TOP OF THE LIFTER. I had to pull that head and decided to pull the other as well, since it would save us time on a few things, and I wanted to inspect the combustion chambers anyways. We didnt have new gaskets or head bolts and had to reuse the mls gaskets. There is not any steam or visible loss of water from the exhaust, again fwiw. I am close to be stumped. Ideas?
Brandon
Brandon
04-20-2006, 10:10 AM
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How long was the engine running? Might have just had to let the lifters fully pump up. Mine took about 5 to 10 minutes over about 3 restarts before they quieted down, although those were new lifters. Your plungeers may be extended further than normal, so the lifters still may have needed to fill up a little.
04-20-2006, 10:16 AM
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We let it run a total of about 15 minutes over 4 restarts. Oil pressure was fine, and that should have been plenty, I would think anyways......
Brandon
Brandon
04-20-2006, 10:37 AM
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I did not degree the cam and never have. Dont have an adjustable timing gear and just went dot to dot. Dont know how to check lifter preload, and for that matter have never had an issue with it. Maybe I do now.
Brandon
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04-20-2006, 10:53 AM
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1) What kind year of car?
2) Easy preload method with heads on, pull spark plug on #1, use a ziptie, or something rigid enough but not abrasive, bring #1 piston to Top Dead Center, TDC, by sticking the ziptie in the spark plug hole just enough so that when you are turning the crank your buddy can hold/feel the piston hit the ziptie. At that point you should hand tighten the rocker with socket/ no extension. When it is hand tight, with a calibrated torque wrench count how many turns it takes you to get to 22ft. lbs. Generally you are looking for 1/2 to 1 turn. With stock rockers, 228/228 .588/588 114 cam, PRC LS6 Heads, hardened 7.4 pushrods, on a stock bottom end 98Z I got 3 1/2 turns preload -way too much. I changed to 7.35 pr's. 90% of the tapping noise went away. I resolved the other 10% with timing adjustments with EFI Live.
3) What kind of tuning?
2) Easy preload method with heads on, pull spark plug on #1, use a ziptie, or something rigid enough but not abrasive, bring #1 piston to Top Dead Center, TDC, by sticking the ziptie in the spark plug hole just enough so that when you are turning the crank your buddy can hold/feel the piston hit the ziptie. At that point you should hand tighten the rocker with socket/ no extension. When it is hand tight, with a calibrated torque wrench count how many turns it takes you to get to 22ft. lbs. Generally you are looking for 1/2 to 1 turn. With stock rockers, 228/228 .588/588 114 cam, PRC LS6 Heads, hardened 7.4 pushrods, on a stock bottom end 98Z I got 3 1/2 turns preload -way too much. I changed to 7.35 pr's. 90% of the tapping noise went away. I resolved the other 10% with timing adjustments with EFI Live.
3) What kind of tuning?
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04-20-2006, 11:24 AM
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Originally Posted by Doc
1) What kind year of car?
2) Easy preload method with heads on, pull spark plug on #1, use a ziptie, or something rigid enough but not abrasive, bring #1 piston to Top Dead Center, TDC, by sticking the ziptie in the spark plug hole just enough so that when you are turning the crank your buddy can hold/feel the piston hit the ziptie. At that point you should hand tighten the rocker with socket/ no extension. When it is hand tight, with a calibrated torque wrench count how many turns it takes you to get to 22ft. lbs. Generally you are looking for 1/2 to 1 turn. With stock rockers, 228/228 .588/588 114 cam, PRC LS6 Heads, hardened 7.4 pushrods, on a stock bottom end 98Z I got 3 1/2 turns preload -way too much. I changed to 7.35 pr's. 90% of the tapping noise went away. I resolved the other 10% with timing adjustments with EFI Live.
3) What kind of tuning?
2) Easy preload method with heads on, pull spark plug on #1, use a ziptie, or something rigid enough but not abrasive, bring #1 piston to Top Dead Center, TDC, by sticking the ziptie in the spark plug hole just enough so that when you are turning the crank your buddy can hold/feel the piston hit the ziptie. At that point you should hand tighten the rocker with socket/ no extension. When it is hand tight, with a calibrated torque wrench count how many turns it takes you to get to 22ft. lbs. Generally you are looking for 1/2 to 1 turn. With stock rockers, 228/228 .588/588 114 cam, PRC LS6 Heads, hardened 7.4 pushrods, on a stock bottom end 98Z I got 3 1/2 turns preload -way too much. I changed to 7.35 pr's. 90% of the tapping noise went away. I resolved the other 10% with timing adjustments with EFI Live.
3) What kind of tuning?
Good info. Its a 98 car, with a forged 2001 engine, I believe. Probably has around 15,000 miles on it. It is an old tune that was meant for the 224/.570 cam in it. But this is a serious metallic sound. I have to wonder if the MS3 and this setup would be more suited for 7.35 pushrods? The guys from TSP said the base circle of the cam and .015 off would be right with 7.4s.
04-20-2006, 12:11 PM
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If I could do it all over again I would not go with "should be" type answers. Either it will work with the setup or not. The only real way to do it is to buy a calibrated pushrod checker to be 100% sure otherwise have supreme confidence the shop you are dealing with has proven the exact same setup they are selling you. I wouldn't rule out timing just because of the "metallic" sound. You did say oil pressure was good. Haven't changed the filter/oil yet eh? If nothing scary in there...tuning. Specifically, timing too far advanced.
