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#41
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Stock rods? Rod side clearance? Piston pins. Press fit or float?
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#42
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I agree with several posts here that suggest getting your engine builder in the loop right away. Since he is local, that is a huge plus compared to removal and shipping out of town. I am sorry to say this, but it probably isn't going to fix itself. So be prepared to remove the engine again and it will need to be opened up. The way the engine was set-up isn't a recipe for a nice quiet street engine IMO. Bearing clearance is loose, about where I would set-up a mild race engine. The piston to wall clearance is almost double what the manufacturer recommends. Not sure why it was put together that way.
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The Following 2 Users Say Thank You to mgarblik For This Useful Post: | ||
#43
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.0015 side clearance Floating pins |
#44
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#45
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I don`t think the bearings are shot because of the good oil pressure. I don`t like the .005 piston clearance. But, my 5.3L LS motor has a piston slap when cold. You can hear it up top till it runs for a while. Yours sounds fine up top. 8 pistons slapping would be loud but, should quiet down once warmed up. What I don`t know is the piston pin clearance in the rods. If the exhaust ain`t leaking, it might be time to get that builder to fix that thing.
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#46
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My daily *****box Chevy Lumina with the 3.1 raps LOUD at cold start but when fully warm it's quiet. |
#47
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Are those stock rocker studs and stock length pushrods? And, has the heads or the block been milled?
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#48
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"Dirt and grit" in an oil filter from a freshly rebuilt engine spells trouble. It's not unusual to see a little silver glitter from rings & such wearing in but "dirt and grit" is completely unacceptable. I can't understand how people can stay in business building engines when they are as sloppy and dumb as this "engine builder" seems to have been. Really sorry to read this. IME, there are not that many "engine builders" who actually do good work and I'm super picky about who I trust to do it.
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---------------------------- '72 Formula 400 Lucerne Blue, Blue Deluxe interior - My first car! '73 Firebird 350/4-speed Black on Black, mix & match. |
#49
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IMO oil pressure is not the end all.Oil flow is more important at low RPMs like 2000 when breaking in a FTC.Really heavy oil can show high oil pressure but might be hurting the film cooling and lubricating bearings.I have never been a big fan of heavy oil.FWIW,Tom
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#50
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yes, yes and no.
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#51
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Subsequent oil changes will tell the whole story. Check the oil and filter until satisfied you are seeing clean oil. I set my crankshaft clearances to the high side of stock tolerances and piston clearance (SpeedPro forged) to dead center of Mfr clearances and the motor is free of mechanical noises. The prior build was loose as a goose and the pistons (reused Venolia pistons from the prior owner's build w light honing) slapped and sounded like a diesel when cold.
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Triple Black 1971 GTO |
#52
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Just because the heads and or block have not been milled does not mean the base circle of the Cam your running is the same as a stocker!
Any change will make a need for different lenght push Rods depending on how you set the lifter preload. Since it seems your running stock rocker studs you then have no way to make the needed adjustment which could be done atleast a little bit if you had adjustable set up of straight rocker studs and poly locks. Valvetrain issue come in two forms it seems, noisy when cold, or noisy when hot unless something is way far out of wack, and then it's noisy all the time!
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
#53
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My opinion, FWIW, is that there is no issue with the valvetrain of this engine. The issue is that it was assembled with clearances that were too large and is loose enough to be noisy. May run forever like that.....may not. I like to build mine on the low side of the spec, not at or past the top side. Why rebuild an engine to worn-out specs?
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Jeff |
#54
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#55
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The .005 piston to wall is very strange to me. I was somewhat concerned about my 461 build at .006 and called Butler to run past what I did since I bought my pistons from them. Talked to David Butler and he told me they run .005 on street strip engines will filled blocks. Your engine is defiantly not one of these. In my case .006 is right where I want to be in a 700HP build with 11-1 and open headers with filled block.
One poster had the idea of getting some Race Tec pistons with a custom dia so you can get the clearance you want without re boring the block. Expensive and a pain to do it all over. But it would tighten things up for sure. You could run some coated bearings and that would get you .0005 tighter on the bearing clearance. Your machinist has some explaining to do. Thing is, this engine is a textbook case of rebuilt cast rods and good ol cast Silvolite pistons at .0015 and run it. Completely stock engine with stock cam. Full floating forged pistons with matching H beam rods are overkill. Even H beams with pressed pins and TRWs @ .0035 would be better. Sometimes overthinking things works against you. More of a chance for miscommunication. I hope it all works out for you. Might be best off to just run it, you have good pistons and rods. It should quit down when fully warmed up. |
#56
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Odd thing is, the opposite is true.........
When cold it's a bit noisy but not bad, as it starts to warm it slowly gets progressively louder to what you hear in the vid. Thats at full operating temp which is 195. |
#57
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If that is really true then it wouldn't seem to me to be a piston clearance issue. Aluminum expands considerably more than cast iron. Excessive piston clearance almost always quiets down after an engine comes up to temp.
Granted the "hole" will also expand as temps rise in the block, but the aluminum piston will expand more. |
#58
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Or maybe the clearance is beyond the .005 who knows, but it's obvious something isn't right. If not the pistons then another issue. Eventually it will be disassembled and inspected to find out what is wrong. |
#59
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Warm engine noises, in our experience, are usually bearing-related or lifter-related.
As previously stated, really thick oil will give you an indication of where to look.
Lifters that get loud when heated up will usually be noticeably quieter. Bearing noise sometimes goes completely away with thick oil. And, also stated previously, bearing problems can sometimes be identified by holding your hand against the oil pan with the engine running. If that engine were mine, the 'engine builder' would be helping me take it out and take it apart, right there in my garage, so we could document with photos EXACTLY what is found. I wouldn't run it any more than necessary. Tell him to bring his good micrometers and his reading glasses. Good luck! |
#60
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He's aware of the issue and hasn't offered to do anything, other than insist the pistons are not the problem.
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