The engine is quiet (NO ticking noise) when it first starts up and is cold. You can hear a slight ticking noise when it gets to 180* BUT when it gets to 200* (operating temperature) this is what you hear..... What causes that? and right now, I'm using 20w Mobil 1 synthetic oil....would changing the oil to regular 10W30 with high zinc + STP Oil Treatment eliminate the noise? The engine was recently rebuilt from the original 350 to a 383 stroker with NEW lifters, roller rockers and new drive train. We've heard the same noise thinking it was one of the lifters going bad (even though they were brand new)...so replaced them all with new lifters....same noise! We have adjusted the valves several times. She runs GREAT with A LOT of pick up and go! According to the NEW Holley Sniper screen she's idling at 700-750 and the A/F ratio is 13.9 to 14.2. The guy who rebuilt the engine is a 20-year engine rebuilder for a custom automobile remodeler / restorer here locally. He's stumped!! HELP!!

 

Are you absolutely sure it is not a leaking exhaust gasket? I would guess that they would get quieter as they warm up. The exhaust gaskets can leak and the sound is similar to yours.

I might suggest that you check to be sure that all of the push-rods are allowing the oil get up to the Roller rockers. I had a 427 high compression engine built and it started tapping very soon after breaking it in.. It became obvious when the roller rocker started turning black. I don't know how the plugged push-rod made it past myself and the builder working together. My engine builder had CAN AM Racing experience and he didn't catch it. I cut a Big Block valve cover so I could see and adjust the valves without making that big of a mess.

The only difference is my ticking started 15-25 miles after installation and startup of a new engine. Your ticking sounds similar to what I had. I was lucky as all I did was put in a new Rocker arm and Push-rod and all was better. You might want to check to be sure the cam has not damaged a lobe. I keep hearing about the problem with cams getting wiped out during break-in.

20 weight oil is awful thick oil for a startup. I was taught that the oil grade is based on the bearing gaps. I think I have 5w15 Driven Oil which is expensive but the engine performs well with it. I know that my main bearings were set on the tight side. Big Block Chevrolet engines are not fond of High Pressure oil pumps so I changed the spring in the Moroso oil pump. Your engine builder should know what oil to use on that sweet engine of yours.

I am also a big believer in a magnet stuck to the oil filter to catch anything. Cheap insurance for a 10k engine.

 

The oil you are using, I don't know of any straight 20 wt mobile one. So is it 20w-50 or 5w-20 or 0w-20? That will make a big difference is what were talking about. Is this a flat tappet engine? If so you need to run a higher zinc oil. At least a good 1000ppm.
If you put in new lifters on a broke-in flat tappet cam then you got problems there too.
If it is a roller lifter engine your suggested 10w-30 would run fine in it.

 

Sounds like an exhaust leak...I would use a stethoscope to find the source.

 

You're right...5w20 Mobil 1

 

We used a stethoscope and isolated the noise to the center valves on the driver's side.

 

Are you using a flat tappet camshaft.

 

Don't know but I will find out.....

 

oil too thin.
may or may not quit collapsing with 10/30
10/40 20/50.
In your hot area, at least 40wt

 

Thanks! Hope changing the oil will fix it. Going to do that today....

 

Please be absolutely sure you have the ZINC the new engine might need if it has a standard camshaft and lifter. This is critical in a new engine with all the problems associated with camshafts today.

I wish you the very best in eliminating the ticking sound! I also hope it is something simple!

 

*** UPDATE ***** UPDATE ***** UPDATE**** Changed oil to 10W30 Lucas Hot Rod Oil with high zinc + I added 1 QT of the Lucas Oil Stabilizer. After driving around town for about 45 minutes , I took her up on the Interstate (in this heat), ran it up to 3,000 - 3,300 RPM's (85- 90 mph) for about 20 minutes....temp 205* On the way home, whenever I would stop at a red light (window down), I would listen for any ticking noise bouncing off the car next to me and THERE WAS NONE!!! There were still no ticking noise after I pulled her into the garage and kept the engine running.
YEA!!! I think the 5W20 synthetic was TOO THIN and the hydraulic lifters collapsed. Even though I just had the original engine bored & stroked (383 stroker) she's still 'Old School" and doesn't like change.

 

Good news, did you notice a change in oil pressure.

 

Did not notice any difference in oil pressure...at 35-45mph she read 45-55 psi BUT when I had her at 3500 rpm (90mph) she pegged out at 80 psi. My engine builder said he put a high pressure pump in when he rebuilt it.

 

I'm glad your issue is not more serious, did you find out if you have a flat tappet cam?

The reason for the quote is, and I mean no disrespect to you, I am surprised the builder was stumped with out suggesting an oil change and/or at least asking what you were running in it...maybe cut the filter open to check for metal.. that kind of thing...

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Why do I feel the heavier oil is hiding the issue? I have someone you trust pull that valve ocver and check all the valves and rockers. My 2 cents.

 

Vetteguy75,

If you have the std stamped rocker arms, you can purchase steel clips that block the pushrods from spraying oil everywhere. Sold in sets of 8.
Then insert a narrow piece of cardboard between the valve cover ledge and the valve springs. Start it up, let it idle and observe.
Button up that valve cover, then do the other bank.

If something in the valvetrain is amiss, it will be noted quickly when the VC is removed and idling.

Sometimes:
Broken valve spring.
Excessive lash. (loose rocker nut)
Loose rocker stud.
Bent pushrod.
Faulty rocker-arm ball.

 

Thanks but the rockers are Edelbrock roller rockers.

 

I'll find out tomorrow what kind of cam I have....

 

It's a roller cam (Comp Roller cam)