Thanks, I had the same scenario, but the problem I did the same thing...replaced the gasket and it is still an issue. I am having my VETTE Shop mechanic drive it tonight and he is going to see what he can find. Lifter seems to be at the top of the list. I will continue to keep you all posted.

 

Work on the nitrous kit as well?

 

Were the heads milled at all?
The pushrods may bee too long, but 777 was saying something about trying a longer pushrod?

 

The heads were not milled, so I went with stock pushrods.

 

Some aftermarket cams have a smaller base circle which would require you to run longer pushrods. If the heads were milled you would most likely need to run a smaller pushrod, unless your base circle was smaller and your heads weren't milled much. Also the head gasket plays a rold in this as well, so the best thing to do is good a pushrod length checker.

 

Just got a call and here are a couple of things he is looking into.

He was concerned with my oil pressure (I did not upgrade my Oil Pump), so he is going to remove my oil filter and cut it in half and see if he sees any debris that would lead him to believe that I have a bad oil seal. The reason he believes this could be causes the noise is...the oil pump is not moving oil up to the lifters as needed and causing the lifters to collaspes prematurely and that would be causing the noise that I am having.

He also wants to check the my pushrod lengths to ensure that they are correct and doing the job they are needing to do correctly.

There was a small crack in my header off of the air tubing that connects to my air system, but said that would not be causing the noise that we are hearing, but may lead to issues later, so I am seeing a header upgrade.

Will keep you guys posted.

Micah

 

small crack in header + exhaust sounding leak = I think you just answered your own problem. I dont know how a crack in the header would not cause the sound? It is also in a place where they are known to crack and leak. I would take it to an exhaust shop, have them seal up the crack real quick (less than 20 min job for them with the stick), and see if that fixes it. It would all make sense because the crack is probably small enough that it takes load (which equals more exhuast pressure) to make the sound and you said that the sound only happens when under load. I doubt its your oil pump because I know plenty of people who still run their stock oil pump because they had low miles on them and they work just fine. Hope you work it out.

 

Well, there is a sell/gasket where the feeding tube connects to the Oil Pump and if that is damaged that is not good, so if I have to, I will replace it and keep telling myself, I should have done it in the first place.

Micah

 

I have tapping noises and all that coming from under my hood.. alot of it is normal. the header crack, that's a problem, at least get that welded up, that can only help the situation. As for pushrod lenth, well depending on who you talk to, you will get a differnet answer about what is right and what's wrong from just about every person you talk to. I knwo of people that were running heads that had a TON of milling, and wee still on stock lenth pushrods.. I'm talking they had teh car together with a cam, etc.etc, and pulled the heads and had a ton cut off them and put back together, no pushrod lenth change and had no issues.... but there's so many factors as to why I dont' even want to try to comtemplate it.

If you are having oil preeusre issues that is a whole differnet issue as well, tha can cause all kinds of differnent things. What is teh pressure at idle when teh car is warmed up, what are you running for oil? I have seen cars see 40 psi and some with 60 psi on a factory gauge at idle. Are you going off an aftermarket guage or the factory one, because that factory guage could just be wrong.

 

Having a pushrod that is too long won't make noise. Give it some time and see if he's not having problems. Not noise problems but motor problems. Lifters will crap out and your camshaft will be worn. Plus the valves will stay open and you will have crappy compression.

 

Well, it is really bad, they checked my filter and nothing really noticeable, they checked my magnetic tip and found pieces of my CRANE Double Roller Timing Chain on it and the real concern is...what damages has it done to my crank, the front of my motor, etc.

 

Is the timing chain is coming apart or was it not shimmed out enough to have the clearance that a double roller is supposed to have?

 

Myself and CRANE are both interested to find out. If anyone wants to help out, please stop by. It was spaced out far enough, the link that came off just looks like it would have been a manufacture defect, it looks really weak.

Micah
(843)245-8624

 

Well, I solved my problem today. The retailer that sold me the stuff changed their mind about the size of the pushrods- 7.350. This was about 5 seconds after I told them that I preloaded about 3 1/2 turns to get to 22ft lbs. At first I was skeptical about going with the smaller pushrods- because of the group speak on this forum that was going on in this thread. Now I'd have to look back in my previous posts but, I don't believe that I mentioned that the factory LS6 243 castings that were CNC'd were also milled and the valves were shorter than stock on a virgin 98 block. Geometry wise going smaller makes sense in this case because the preload reveales it all. Normally the common practice for preloading as I understand it is to tighten the rocker bolt hand (socket with extention-no wratchet)tight, then reference how many qtr turns it takes to get to 22 ft. lbs. I have a cal'd torque wrench. With the new shorter pushrods it only took a 1/2 turn- perfect. I believe that the longer pushrod was compressing the roller in the lifter thus, when at lower rpms it was acting like a solid lifter. At the higher sustained rpm's the inequity would result in the lifters bleeding down and then the tapping noise that would subside after you gave them a chance to pump back up after a 5 min idle. At any rate I changed them out tonight and voila, no more tapping at sustained rpms. What really dissapointed me was the thing about the shop that I ordered the stuff from. I discussed my needs / goals with them and they just shot gunned the parts to me. I am sure that if I was to parce together these parts individually I could have gotten the whole thing cheaper with the extra expense being my time and research into the whole geomtry thing. This should serve as a friendly reminder to all those seeking a deal like this that some things you just are better off doing yourself.

 

Doc,

Glad that you found your problem, I ordered a pushrod length checker and I am going to check my lengths too. If I recall correctly, I had to make more turns than necessary to get the 22 lbs too, so this may also be a problem. I will soon find out. Thanks for the info, however, I do have a timing caining falling apart and I need that fixed...and I am doing that this weekend (tearing the front end apart), come on up if you are bored. I am only 4 hours from Jacksonville, FL...(843)245-8624

Micah