SBC 350 top end noise

[eodbeast]

I have a top end tick that I can't find the cause of. Brand new Lunati cam (10120701), lifters and matching springs installed two weeks ago. No retainer/guide clearance issues, no coil bind, no retainer/rocker arm interference no rocker arm/valve cover contact, no collapsed lifters. Pulling 30 psi oil pressure at idle and 45-50 at cruise.

Valves have been adjusted 1/2 turn past zero lash, both static and while running with no difference. Replaced old stamped rocker arms with brand new OEM replacements and that took only a slight bit of the noise away...at least for a little while. I'm running Vortec heads on an older block. The same noise was there with the old stock heads, thought changing things out would quiet it down. Eliminated all belt driven accessories (alternator, water pump and power steering).

I'm at a loss and it's driving me nuts. Been turning wrenches on SBCs for 25+ years and have never had one stump me like this. Any ideas?

Here is a short video of what it sounds like.
http://youtu.be/B99cClzos1c

[Slammed84]

Sounds like you've covered the majority of possible causes.
Is it both sides? Seemed louder on the passenger side in the vid.

Wiped cam lobe? Bad cam break in? Something in the distributor? 30 psi seems low to me for oil pressure but its well within the safe range. Maybe connection between distributor and oil pump?

Unfortunately sounds like you might have to really do some digging. That would drive me nuckin futs.

[Jake Wade]

Did you install the self aligning style rockers?

[eodbeast]

Originally Posted by Jake Wade

Did you install the self aligning style rockers?

I did. It took few tries at Advance Auto to get a complete set that were all self aligning. It seemed to help for a short while, but the underlying tick is still there.

[Jake Wade]

My bet is the noise is the nature of the beast with the aggressive lobe designs of the VooDoo/Extreme/etc.

Some aluminum valve covers amplify this.

[eodbeast]

Originally Posted by Jake Wade

My bet is the noise is the nature of the beast with the aggressive lobe designs of the VooDoo/Extreme/etc.

Some aluminum valve covers amplify this.

I've almost resigned to that possibility, but I've seen far more radical cams that don't make half this noise. And this isn't but one step up from their baseline in the VooDoo line; .454 lift/213 duration intake, .468 lift and 220 duration exhaust.

Using some old stamped valve covers I picked up at the bone yard.

[Slammed84]

Originally Posted by eodbeast

I did. It took few tries at Advance Auto to get a complete set that were all self aligning. It seemed to help for a short while, but the underlying tick is still there.

I dont think you're supposed to run self aligners and guide plates together. Just one or the other.

[eodbeast]

It seems slightly louder on the passenger side to me as well. Break in went perfect, no issues at all. Truck runs like a scalded dog. All the rocker arms have been measured for travel and match the lift specs of the cam.

No metal particles in the oil, that was the first thing I checked. The reason for the new cam was 6 wiped lobes on the original because of the oil I was using. Found out the hard way that these old flat tappet cams don't like the lack of ZDDP in their bath.

I was thinking possibly distributor too, (it is an Accel after all) but nothing indicating that as the cause when I put the stethoscope to it. As a matter of fact, neither the stethoscope or a length of hose to the ear has helped pinpoint the source. Even replaced the header gaskets to eliminate that as a possibility.

I hate not being able to solve this problem, but may have to start collecting the pieces to put the 355 block on the engine stand together to have a little more peace of mind. This old 84 K10 is going to be my daily driver soon and don't want to have to concern myself with reliability issues. The engine is the only thing that I have not completely rebuilt on this truck. Everything but the rods and pistons have been replaced at some point in the last year as I got parts together.

[Slammed84]

If hes running guides he shouldn't need the self aligning rockers arms. As long as there is adequate pushrod clearance.

[Slammed84]

Did you make sure the pushrods were the correct length? If you reused the old ones the tips of the rockers might be sliding off the valvestem?

Im trying to think outside the box here, I know its not likely but stranger things have happened.

I just got done tightening one rocker arm on my buddies vortec crate engine we installed a couple years ago. It was number 8 exhaust. We didnt touch the rockers during installation and everything looked perfect under the cover. Just that one rocker was loose, the nut just decided to back off that day. ???

[eodbeast]

Originally Posted by Slammed84

Did you make sure the pushrods were the correct length? If you reused the old ones the tips of the rockers might be sliding off the valvestem?

Im trying to think outside the box here, I know its not likely but stranger things have happened.

I just got done tightening one rocker arm on my buddies vortec crate engine we installed a couple years ago. It was number 8 exhaust. We didnt touch the rockers during installation and everything looked perfect under the cover. Just that one rocker was loose, the nut just decided to back off that day. ???

Forgot to add pushrods to the list of brand new items with the cam swap. Everything I read said 7.8" pushrods when using Vortec heads with non-roller blocks. If I'm mistaken, please point me in the right direction. I would love for it to be that simple a fix.

[Jake Wade]

Maybe I missed it but, I don't see where he said he is using guide plates.

[eodbeast]

Originally Posted by Jake Wade

Maybe I missed it but, I don't see where he said he is using guide plates.

No guide plates, just self-aligning rockers.

[Jake Wade]

Is it oiling up top? 6 flat lobes can leave ALOT of debris in an engine.

[Slammed84]

Originally Posted by Jake Wade

Maybe I missed it but, I don't see where he said he is using guide plates.

My bad, I saw guides and thought guide plates. Didn't think about valve guides.

[Slammed84]

Originally Posted by eodbeast

Forgot to add pushrods to the list of brand new items with the cam swap. Everything I read said 7.8" pushrods when using Vortec heads with non-roller blocks. If I'm mistaken, please point me in the right direction. I would love for it to be that simple a fix.

Well they would have to be pretty damn long or short to actually be sliding off the edges of the valvespring. But with no other solid leads it wouldn't hurt to check. You can clean off the tip of the valve stem and rocker. Put a good coat of Sharpie ink on the valvestem and reinstall the rocker. Turn it over a few times and see where the rocker tip is making contact.

[Jake Wade]

What lifters? I rarely use flat tappets anymore but, when I do, I use the GM hard face lifters from Chevrolet Performance.

You are going to have valvetrain noise with the VooDoo line of cams, yours does seem extreme on the video.

[eodbeast]

Originally Posted by Jake Wade

What lifters? I rarely use flat tappets anymore but, when I do, I use the GM hard face lifters from Chevrolet Performance.

You are going to have valvetrain noise with the VooDoo line of cams, yours does seem extreme on the video.

Lunati p/n 71817PR-16...they came as part of the cam kit. I would prefer to be using rollers myself and I think I might bite the bullet and pick up a retrofit roller kit and save myself the worry.

[eodbeast]

Originally Posted by Slammed84

Well they would have to be pretty damn long or short to actually be sliding off the edges of the valvespring. But with no other solid leads it wouldn't hurt to check. You can clean off the tip of the valve stem and rocker. Put a good coat of Sharpie ink on the valvestem and reinstall the rocker. Turn it over a few times and see where the rocker tip is making contact.

Hadn't tried that yet. They appear to be centered laterally, at least visually. I'll try that out tomorrow or Wednesday when I get a chance just to verify.

[jjzepplin]

Subbed

[77 350 Shorty Wide]

Good Morning, I'll chime in on this a bit. Have you determined if it is cam or crank rpm based. If cam rpm... have you listened to the fuel pump yet? They have been known to make sounds like this. If it's crank rpm based... When does the ticking start, cold, hot, when revving up or winding down? This should lead to whether it maybe a piston or rod sound. Well just trying to help. Seems to me if it was there before all the work was done and it's still there, the fix would be something entirely separate not yet addressed.

All have a great day, God bless, Terry

[eodbeast]

Originally Posted by 77 350 Shorty Wide

Good Morning, I'll chime in on this a bit. Have you determined if it is cam or crank rpm based. If cam rpm... have you listened to the fuel pump yet? They have been known to make sounds like this. If it's crank rpm based... When does the ticking start, cold, hot, when revving up or winding down? This should lead to whether it maybe a piston or rod sound. Well just trying to help. Seems to me if it was there before all the work was done and it's still there, the fix would be something entirely separate not yet addressed.

All have a great day, God bless, Terry

Thanks Terry. It is cam based. Fuel pump and pushrod are brand new. That was one of my first suspects. As I mentioned earlier, the only parts not new in this engine are the rods and pistons. I'm not hearing any typical wrist pin double tap and piston slap tends to have almost a bell ringing sound to it. This is definitely top end, but just can't isolate it.

The more I think about it, I didn't put new cam bearings in when I did the swap. Did everything with the block still in the truck. I had an old Ford T-bird years ago with a 400 that had a similar but more subdued sound both before and after a cam swap. Turned out that one had a bad cam bearing in the rear journal.

[Slammed84]

Pop them valve covers and do some diggin. You might have to start taking rockers off, checking pushrods and lifters. If you got a bad lobe then you'll have a bad lifter.

I am starting to agree with Shorty Wide in the above post. If it was making the noise before the swap then you might have something goin on in the bottom end.

[eodbeast]

Originally Posted by Slammed84

Pop them valve covers and do some diggin. You might have to start taking rockers off, checking pushrods and lifters. If you got a bad lobe then you'll have a bad lifter.

I am starting to agree with Shorty Wide in the above post. If it was making the noise before the swap then you might have something goin on in the bottom end.

The only top end component not replaced was the cam bearings. Had something similar in an old Ford I had. Engine's gotta be yanked to change them out and if I'm pulling it, I'll be building up the 355 block I have to throw back in it...with ALL new parts.

[Jake Wade]

I'm sure your cam bearings don't look the best but, your oil pressure would be low if clearance was excessive.