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  #16 (permalink)  
Old 04-28-2012, 12:05 AM
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Well im going to pull the oil pan and check for spun bearings and loose rod caps. Im hoping all is well and that I don't have a paperweight

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Old 10-04-2012, 04:48 PM
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I have a sbc 383 with the same problem. I've reajusted rockers,and new plugs, but still have tapping noise at 1500 rpms. Noise sounds like in the area of 1 or 2 cylinder any suggestions?
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Old 10-06-2012, 08:27 AM
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Quote:
Originally Posted by ragee517 View Post
Now it has a knocking or pinging like sound above high idle it doies not do it at low idle or at high idle but about 1500 rpm it starts making noise. Oil pressure is above 80 psi at that rpm so its not an issue with oil not being circulated around. could it be my fuel pump going bad. the pump is mechanical and probably has 155,00 miles on it like the stock 305 had.
What weight oil are you using? All you need is a good brand of 10W40 oil and a good oil filter (do not use Fram). Get a stethascope from the auto parts store so you can find out exactly where the ticking is coming from. Why would you install a fuel pump with that many miles on it on a rebuilt motor.

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  #19 (permalink)  
Old 10-06-2012, 08:28 AM
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SBC 350 misfire at idle in gear

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Originally Posted by ragee517 View Post
Timing is around 30 or 50 its not near the mark. Don't know if its helpful but with the vacation advance unhooked it still makes the noise. It sounds like its up front of the block or by the trans. It doesn't always seem to be in the same spot and as soon as I let off the throttle its gone.
Do you have a timing light with a advance dial on it? It makes it easier to check the mechanical advance. Start by setting the initial timing at 12* BTDC with vacuum hose off the distributor and plugged. Reset the idle to 800-900 rpms. Second step is checking the mechanical advance. Have someone rev the motor to 3000 rpms and hold it. Point the timing light at the scale and turn the advance dial until the line on the balancer is on zero. Adjust the distributor until you have the timing light reading at 36*. You may have to buy an advance kit to change springs to get the mechanical advance all in by 3000 rpms. Your timing curve should be 12* BTDC at idle and starting about 800 rpms the mechanical advance should gradually add about 24* at 3000 rpms. Now unplug the vacuum line and connect it to the full time vacuum port on your carburetor. You can check the timing again at idle and should red 50*-52* with the vacuum connected. Here is an article on HEI distributors to read. http://www.crankshaftcoalition.com/w...EI_distributor
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Old 10-07-2012, 06:26 AM
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hey monte

The issue with mine and the rattle that I had was all the rods were tight but not to proper torque specs. So I had to take the oil pan off and tighten all the rods and noise was gone. Not sure if yours is the same problem or not but it sounds similar in what u explain. It only cost 8 dollars to check it out
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Old 10-07-2012, 11:10 AM
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Rods and mains all tight bottom end has allbeen checked. Guess I'll keep looking.
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Old 10-09-2012, 04:21 PM
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tapping noise at 1500 rpms.

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Originally Posted by Monte84 View Post
I have a sbc 383 with the same problem. I've reajusted rockers,and new plugs, but still have tapping noise at 1500 rpms. Noise sounds like in the area of 1 or 2 cylinder any suggestions?
Is this a new rebuilt engine, if not how many miles is on it. Did you check the rod bearings on #1 and #2 with plastic guage after hearing the tapping noise? It could be a wrist pin or piston slap. I remember the first time I rebuilt a 383 I took my block in to the machine shop and told them to check the block and bore it if needed. They told me It was fine just needed honing. I had just rebuilt this motor as a 350 and read about the 383 in a magazine. It ran fine with no tapping noise. I had the 400 crank turned and the block prepped by the machine shop. I had the old TRW 11.1 pistons. I even had my heads shave to give me more compression. Well when I got it running the first thing I heard was a faint tapping noise coming from the passenger side. I pulled the oil pan first checked all the bearings one at a time and retorqued. Rods were not hitting the bottom of the cylinders or oil pan rail. ??? I drove it a couple of times but the tapping was getting on my nerves. I pulled the heads and no valves were hitting, so I pulled the motor and disassembled it to take the block and pistons back to the machine shop. I knew the guy that waited on me and told him what was happening. He called the next day told me that # 2 cylinder and piston were out of round. Well what happened to checking the block to see if it needed boring. Ended up putting a sleeve in that cylinder and new piston. Sorry about the long story!!!
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Old 10-09-2012, 05:59 PM
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I had short block done by local machine shop {wham race engines} have not pulled heads yet double checking cheaper fixes first. Engine has about 200 miles on build-up. Noise started within last 5 miles checked all lifters,pushrods,rockers,accesories,transmission,f uel pump,fuel pump rod,distributor,valve springs, and headers.
Pulled engine and did a visual look at bottom end did not see any problems took oil and filter back to machine shop to have builder look at filter and check oil. The owner cut filter open and said filter looked normal for first filter and oil (second oil change) looked normal except running rich, probably from alot of idle time looking for problem.
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Old 10-09-2012, 06:13 PM
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Quote:
Originally Posted by Monte84 View Post
I had short block done by local machine shop {wham race engines} have not pulled heads yet double checking cheaper fixes first. Engine has about 200 miles on build-up. Noise started within last 5 miles checked all lifters,pushrods,rockers,accesories,transmission,f uel pump,fuel pump rod,distributor,valve springs, and headers.
Pulled engine and did a visual look at bottom end did not see any problems took oil and filter back to machine shop to have builder look at filter and check oil. The owner cut filter open and said filter looked normal for first filter and oil (second oil change) looked normal except running rich, probably from alot of idle time looking for problem.
First, get a handle on the total timing and the advance curve. Start by making a temporary timing tape so you can see what the total timing is w/o a dial back light. Advance curve info here. You need to do this regardless if it's the problem or not. Not knowing what you have for total timing can cost you an engine.

Then be sure it's not an accessory like the alternator, fan clutch, or power steering pump, etc. Even an exhaust header leak can sound just like a knock- I mean JUST like one, and it's fooled experienced guys, too.

You can use a mechanic stethoscope to listen for where the sound is coming from. If you do not have one, use a length of rubber fuel line. Hold one end to your ear and use the other end to touch around the heads, accessories, etc. to see if you can isolate the noise. BTW, do NOT use a screwdriver held to the side of your head. One slip and that screwdriver can end up sunk into your brain.
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Old 10-09-2012, 10:19 PM
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I'm going back to the beginning here and assuming you set valve lash at initial start up? That's kinda what I understood you were saying anyway, and if thats the case I'm betting you hurt the cam right off the bat, and now your going to find a loose, or several loose rockers due to a lobe on the way out. If it was started, brought up to operating temp to set lash by your method, then proceeded to cam break in, my moneys on hurt cam.
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Old 10-10-2012, 07:05 PM
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Initial timing set at 14 and mechanical set at 20 all in by 2650 tapping/ticking noise comes and goes with no pattern to temp but at random at 1500 rpm. removed all accesories and unbolted torque convertor but can not isolate noise.
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Old 10-10-2012, 07:58 PM
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Quote:
Originally Posted by Monte84 View Post
Initial timing set at 14 and mechanical set at 20 all in by 2650 tapping/ticking noise comes and goes with no pattern to temp but at random at 1500 rpm. removed all accesories and unbolted torque convertor but can not isolate noise.
6 degrees mech advance only? Or 20 mech giving you 34 total? Either way, clarify your cam break in exactly, as based on your earlier posts it still sounds to me like that might not have gone 100% right and I think u hurt the cam .....I did exactly this with a comp thmpr a couple years ago, turned out to be a positive as I went with a "real" cam afterwords....
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  #28 (permalink)  
Old 10-14-2012, 04:40 PM
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yea a lifter tap will have a much faster tapping rate than a rob or main bearing... If its a quick tap, its likely a bad lifter that won't hold pressure, when called on of a cam lob on the way out.
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Old 10-17-2012, 06:30 PM
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Pulled cam and measured lobe and no wear.
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