I finally got to hear it (Youtube is blocked at work) I hate to say it but it absolutely sounds like a rod bearing to me. You can still show good oil pressure until it too late. Hope I am wrong but it does not look good to me. Use a couple paint strainers to pour the oil through and see whats in the filter.

 

Well,

I pulled the filter apart and it didn't look too bad. Checked the flex plate looked fine. Pulled the passenger side valve cover and all rockers are tight. Maybe I just need to do a running adjustment.

Thanks for the replies.

Craig

 

Were you able to drain the oil
and pour it through a paint filter
as Eric suggested? Did you not find
any shavings in the filter?

 

You didn't by chance install crossover plugs in your heads, they can make a similar sound when loose. I wouldn't bother trying to reset lifter preload, pull the motor and find the problem..

 

I didn't pour it through a paint filter and didn't find anything in the filter.

crossover plugs? Spark plugs? I am going to try adjusting the valves one more time. I have been talking to my engine builder.

We'll see what happens!

Craig

 

IMO you should not continue to run this engine. Contact the builder let him listen to it. If he is a reputable builder hes gonna want to hear and see it. You should have found something in the oil if it is in fact an internal problem??? Somethings loose. Did you have the crossover plugs installed in the heads or intake? If so how were they installed?

 

i agree, the engine builder should listen to it ...it has a sound like a piston slap, rod, wrist pin to me...but he built so he should be able to rule out some things...get him to listen to it in person

 

What is a crossover plug?

On another note I pulled the valve cover and noticed outlines of the poly locks on it. This could be a the culprit.

Still investigating! Thanks for the advise! I am talking to the builder and he is a reputable guy.

Stay tuned!

Craig

 

You might try thicker or double gaskets.

 

Have you tried running it with the valve covers off to see if it still makes the noise?

- Eric

 

Except that the poly locks don't move, the rockers do.
It might add some vibration/resonance to the whole thing but otherwise wouldn't interfere.

 

A cross over plug = typically an iron caste plug (slug) inserted into the exhaust passage in the center of each head (or only one) to block off the passage. This passage directs hot exhaust gas through a mating passage in the intake manifold under the carb. The intended design is to provide the carb with faster warm up during cold start to activate the choke quicker and to provide better cold temp atomization and drive-ability...more or less.
Typically, and I've experiences this, the extra heat induces a hot start problem whereas the gas boils out of the carb during hot days from excessive heat soak. These slugs of cast will rattle from the exhaust pulses when loose and not installed properly. I welded mine into my intake to eliminate this. Some will weld them into the head.
But from the sound I hear in the vid its likely rod knock either at the pin or the crank.

 

[QUOTE=droldsmorland;696300]IMO you should not continue to run this engine. Contact the builder let him listen to it. If he is a reputable builder hes gonna want to hear and see it. You should have found something in the oil if it is in fact an internal problem??? Somethings loose.

He hasn't come over YET?

 

Make sure the balancer is tight, I had one
fool me with this type of noise. I

 

I would not run it either until the builder started it up himself. Once I had a 500 Caddy that was making noise. Had 100k+ on it and had set for a while, not real long. The big inch Caddy's are known for making noise after setting. Carbon buildup dries out and then when they are restarted it breaks loose and hammers between the piston and head (rather tight clearance.) A dose of ATF or water carefully ingested usually does the trick. Tried the water route. Got it revved up about 2000 and slowly poured the water. Didn't take but about 15 seconds to find out what the problem was. A rod bolt had loosened up. Rod out through the side of the block, broke another and it was a heck of a racket!!. Pulled it down and the offending rod still had the one nut torqued and the other was wherever it was and the cap was 180* from where it should have been. Bent that rod and open and out she came.

 

I'll ask him about the crossover plug but I am with you about the rod knock


[QUOTE=tru-blue 442;696823]I wanted to investigate the valve adjustment again. I noticed the polly locks hitting the pvc passages on the cover. I re-adjusted the valves and doubled the gasket, fired it up and still have the same noise I am afraid i am going to have to pull the engine!

Harmonic balancer? It is tight. The noise sounds like it's coming from the top of the engine.

Thanks for all the input guys!

I'll let you know what I find out.

Craig

 

Yikes! If that is my case than the builder has "some splaning to do!"

 

detonation?

 

Craig, I'm not saying for sure that this is your issue. Obviously I'm no where near it to help diagnose in person. The Caddy thing is just something that happened to me. Anyway, Scotty may be on to something. When the builder gets there and starts it, I would ask him to disconnect the vacuum advance and plug it to see if it is bringing in the advance too early. I don't think it is valvetrain.

 

I believe detonation can only happen under load.

 

Now here is a story its a long shot but it happened to me. 1st time I had built a 350 and at idle it shook since it had a pretty rowdy cam . The engine mount was loose so the header would actually hit the frame. I failed to notice that and thought it was rod knock until I had my dad lift the side up with a pry bar the noise went away and viola rod knock fixed lol. Another time I had a bad alternator that sounded like faint rod knock. I pulled the belts and ran the engine with no accessories noise went away and I replaced the alt. At this point have it looked at but I have had my share of scares.

 

I wondered it it was detonation too. Now that I think about it I have the vacuum advance hooked up but the distributor is to be run without it. I wonder if that would cause it to detonate?

Craig

 

It is not detonation. It is something tapping period. As mentioned over and over it sounds like its in the rotating assembly. I know you don't want to and I don't blame you but the motor needs to come out and apart whether you or your builder does it.

 

X2 on what gearheads said. Don't **** away your investment at this point get the builder to handle it.

 

Yeah, but wouldn't that just be a whole lot easier I think I'm going to fire it up one last time tomorrow. (I'd do it tonight but I have a pain in the *** neighbor!)

Wish me luck!

Craig

 

Unless you see something obvious outside the engine the could be causing it I would not do it. What if that one more time is all it takes to make what ever it is let go.

 

I would go back over the valve adjustment. IMO 1/2 turn past zero lash is too much assuming hyd roller. I think you may have some lifters bottomed out. Zero lash then no more than a quarter turn is my experience. If you can find a way to do it running without making a big mess that would work but I haven't found a clip that will sit on an aluminum roller rocker & never came up w/ a cut open valve cover that contained the oil decently in the absence of clips.

If the locks are touching valve covers it is going to introduce or magnify noise. Add spacers or thicken up your gaskets to ensure clearance. With a/c + stock engine the spacer is probably not the answer.

 

The more you mess with it
the farther away from your
warranty you get.
Unless he is on board with what you are doing.
Just something to think about.

 

I agree with you but did you listen to the whole video? The noises it made at the end just don't sound like valvetrain to me. I know we are all trying to help from a distance and could all be wrong but I would rather he be mad at me I was wrong and he had to do a little labor and buy some gaskets than tell him to run the valves one more time and he has a catastophic failure in his driveway.

 

I'd never be mad at any of you! I am on board with the engine builder. He will take the engine back and fix it if need be. Just want to rule out everything else.

Thanks everyone for your advise. We'll figure this out!

Craig

 

Epic fail of rebuild.
JMHO. Best of luck with it.

 

Well we are narrowing in on the problem. The builder came over Saturday and listened to the engine and looked at the eminence of the oil filter. He believes it isn't a bearing. The problem seems to be the Poly locks hitting the valve cover where the pcv chamber is. There are marks on it with a indentation of the poly locks. We shaved the poly locks down .050 and I am in the process of installing them and putting her back together!

Stay tuned!

Craig

 

I think I mentioned the poly locks "touching" the valve covers would add to the resonance.
And FYI, Comp makes a shorter poly lock for about $25.00.

 

Now you tell me!

Thanks!

Craig

 

Poly locks do not move. The rocker moves. I dont think thats your problem. Sounds like a bad rod bearing, or maybe a bad piston pin.

 

As someone stated before. Run it without the valve covers on. Just to test.

 

There are other problems with this engine than just the real obvious.

 

Sure sounded like the top end to me. I'm just surprised that with that deep an indentation from the poly locks that the VC rail isn't bent from pulling them down that far onto the poly lock? Could always try 2x gaskets also or just remove the baffles.

 

That's my take on it also. But so far we've been over ruled about 50 to 2.

Studs & poly locks do move a bit and when in contact with a valve cover they also will transmit other sounds into the valve cover which magnifies them like a loud speaker.

 

"That's my take on it also. But so far we've been over ruled about 50 to 2."

Well I've heard a bad rod personally and that sound isn't it. The fact there is nothing in the oil reinforces that. You're right Smitty it transfers the sound and will tend to magnify it. A stethoscope on that VC or any other suspect place would have confirmed the location instead of this guessing game.

Just for speculative purposes are those rocker studs 5/16 to 3/8 conversion or straight 3/8 or 7/16 throughout? In other words you re-tapped the heads.