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Tapping noise from valvetrain - problem solved!

This is a discussion on Tapping noise from valvetrain - problem solved! within the Internal Engine forums, part of the LSx Technical Help Section category; I shattered the ring and pinion as soon as I drove onto the highway after having my upgrades and stuff ...

  1. #21
    Member chieftransam's Avatar
    Join Date
    Nov 2006

    2001 Pontiac Trans Am M6

    I shattered the ring and pinion as soon as I drove onto the highway after having my upgrades and stuff installed. I took off in first easy and then got on and slammed it in second and boom there went the 10 bolt. At the time I was excited but very ticked So at the time I just had them rebuild it because I didn't have the $$$ for a 12 bolt or 9". I'd like to buy a set of fuel rail covers but that's not a top priority for me right now.

    On the 13.2 run I had my stock tires on...I can't seem to think which brand they were at the time but right now I have the eagle f1 gs-d3's. I'm going to slide on the m/t's on for the track this weekend if I have enough miles on her by then.

    I have a brand new set of bmr sfc's (black tubular) just sitting at my house. I would love to have the ws6 hood or a raptor hood myself.

    I haven't thought about adding more oil to see if it would go away....hmm... I'll check into that.

  2. #22
    Veteran Firebirdjones's Avatar
    Join Date
    May 2006
    Quote Originally Posted by DaddySS View Post
    In my last post on the tapping noise coming form the engine, I was having trouble locating the source of the noise. It was intermittent, had a kind of cycle where it would come and go, sometimes very loud, sometimes not and sometimes it sounded more like a rattling noise than I steady tap.

    The lifters, cam and heads had about 5k miles on them so I didn’t suspect lifters but it sure sounded like it.

    Well I began to open it up to locate the source and when I got the cam out it all started to make sense. (See the link to the photos below).

    The cam was apparently one of the bad F13 cams and had several lobes that were badly damaged and lifters had also been chewed up.

    My major concern now was how much damage this shower of crumbling metal from the cam and lifters had caused to the engine itself. I opened up the oil pump and the gears had some damage so I knew that would need to be fixed but the pump is before the filter, so I was hopeful that the filter had trapped most of the metal before it did too much harm. I looked as closely as I could at the cam bearings and they seemed be OK.

    I proceeded to take off the heads to replace the lifters. I had the heads milled .018 while they were off – should have done that the first time round and got a Cometic .040 to give me a 63cc chamber, 10.8 SCR and 8.28 DCR and a quench of .033 (conferred and agreed this plan with AFR).

    I had done a leak down and compression test prior to starting the work so I had a good baseline and didn’t expect to find much in the way of problems in the cylinder bores.

    Took care of the pump and replaced the cam with the milder of the AFR recommended cams – 220 224 581 581 114 +4 (also conferred and agreed with AFR to give me more torque down low and a milder setup overall), degreed the cam in (it was right on the money) and buttoned up the front. Lifters were replaced with Comp OEs and new lifter trays were installed as well.

    I replaced the double springs that came with the AFR heads with Comp 918s to reduce the load on the valve train and take advantage of the beehive technology. Buttoned up the rest torqueing everything to spec and took special care in the deck prep and cleaning of the bolt holes. Replaced the 7.350 pushrods with 7.400s for a preload of about 65 to 80.

    I cranked it over with the PCM/IGN fuse removed for three 5 second spins and the oil pressure came up strong on the third spin. Hooked it back up and she started right up and found idle in about 15 seconds. No leaks (I was really worried with the Cometics) and she runs really strong.

    The valvetrain is really quiet now – no more tapping and very little sewing machine sound – almost stock sounding!

    The torque is really excellent with this new set up, it keeps spinning the tires even on mild acceleration from stops. Mileage is way up, and drivability is much improved.

    I need to get it retuned now but if the way it runs now is any indication, I should be in good shape.

    Futral was contacted about this as soon as I saw the cam and they offered only a replacement cam even though there is a known problem with this run of F13s. So no compensation for the lifters, oil pump, gasket sets, or labor even though in my view they are liable for the damage done by their defective part.

    I know many of you that had this problem were satisfied that Futral offered to make good on the cam but I am not, and will not do business with Futral or Camotion again. It would have cost them very little to make a client happy but instead they chose the absolute minimum – their choice to make because I am not going to incur legal expenses for this small amount – but my choice too, I won’t do business with you if I am not valued as a customer.

    This not to say Futral or Camotion have bad products, or that they necessarily have bad service, just that in this instance I think they did not treat me right and they no longer have me as a client.

    Anyway, it really runs and sounds good now so I am really happy that I was able to locate the tapping, get it all done myself and have it turn out this well (800 miles on it so far and no problems), will get it tuned next week.
    This sounds exactly what I went through with my chevelle, although you neglected to mention what spring pressures were on those double springs from AFR you pulled off. I would be leary of AFR's.

    I run AFR heads on my chevelle, and AFR also did the custom camshaft through Comp Cams. After dyno time, installed the engine and all was well. Although there was more lifter noise than should have been on such a mild hydraulic roller,,,much like you described. Car ran fine and dynoed fine though. The cam sounded more like a solid roller.

    Well,,,,,after being in the car for about a year and putting about 6,000 miles on it,,,a lobe was wiped off the camshaft and several others scored,,,with ruined rollers as well.

    After calling around to AFR and Comp,,,I found that AFR installed "SOLID ROLLER" valve springs with WAY too much spring pressure,,,even after AFR had Comp custom grind a HYDRAULIC roller for the car and knowing what was going in, (it was even in the damn paperwork),,,they sent me a set of heads with the wrong spring setup.

    Anyway,,,,it explained the lifter noise it had,,,,simply too much spring pressure was collapsing the lifters, the excessive pressure (630 lbs. over the nose, 310 lbs. at the seat) eventually wore down a couple of lobes since at the time,,,,Comp Cams hydraulic rollers were made from soft cast iron.

    Anyway, after finding who to blame,,,,AFR did nothing to fix the problem and were absolutely no help at all. Comp Cams custom ground another hydraulic roller camshaft,,,(which by the way are now all billet steel cores) and sent the correct springs, (400 lbs. over the nose a 260 lbs. at the seat) as well as a new set of roller lifters. Did I mention that 10 of the AFR springs were broken as well???? The springs they setup the heads with were for a huge solid roller up to .750 lift with incredible pressures, those tend to not like extended rpm street use,,,, create tons of heat,,,, and generally break as a result. Funny though the car never skipped a beat.

    Well $2,500 later, the engine is now very quiet with no lifter noise at all, and running strong.

    I would be interested in seeing if those springs you had DaddySS are indeed the wrong spring pressures. Something to look into,,,as your situation sounds frightenly much like mine, and the camshaft company was not to blame at all in my case.

    You didn't mention if your camshaft core was cast iron or billet steel. I am guessing softer cast iron.
    I was glad to hear that Comp Cam switched to billet steel cores for all hydraulic rollers now, same core they already used for the solid rollers.
    Last edited by Firebirdjones; 02-25-2008 at 11:09 AM.

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