[Va68goat]

Here are a couple more pictures that may help.

[redhawk44]

Originally Posted by grivera

Seems the front crank journal and crank timing gear would affect the depth of the balancer rather than the length of the snub- I believe the balancer sleeve buts up against the face of the gear. That being said, I assume the short appearing crank snub is an optical illusion as it’s a factory 455 crankshaft. If so, the balancer dimensions may be off.

I thought about that too.

[Scott Stoneburg]

Looking at these marks. I can't tell from the pics if the paint has been knocked off. Is this ground in there to miss something or has something been hitting and made its own clearance?

[scott70]

Looks like a romac balancer. I had the same problem when I used one of those years ago. I clearanced it and used if for a while but eventually ditched it for a ati reminding myself not to buy a romac again.

[shoebox1.1]

I sure hope this noise gets found soon and the owner can report some fun outings with the car! I’m invested in the story lol. Hours reading all this!! Good luck brother

[mgarblik]

Looks like that area between the timing case and the aftermarket balancer needs a little attention. Once the real problem is discovered and corrected, I would carefully trim the timing cover a little and/or the the oil pan lip just to make sure you have .060"+ clearance at the tightest pinch point. Of course verify the thrust bearing and crankshaft end play are OK, which I imagine they are. These are all typical fit issues we have to deal with on every build nowdays. None of the aftermarket parts really "fit" like the factory stuff. From what I understand the only factory part in this entire front assembly is the crankshaft. The crankshaft timing gear can have slight tolerance issues, the balancer, the timing cover and the oil pan. If each of these parts was off just .010" of an inch, you have contact when it's all put together. A scraping, sheet metal sound, possibly. A knocking sound, I don't think so. However, 1300+ posts have been wrong so far, including at least 10 by me. 45 years of building Pontiac V-8 engines, this is in the top 10 of weird ones.

[gtospieg]

If you look at your second pic in your latest post you will see that the front seal(for the harmonic balancer) is not fully seated(it is crooked and probably not creating a good seal)...this could be the source of your leak.

[Va68goat]

Scott Stoneburg,
Paul clearenced the timing chain cover and I'm not sure if thats his work or if those are marks from the balancer. I don't see any marks on the balancer so I'm sure that was done when he was making the proper clearance.

scott70,
I think Paul has had success with these balancers. He suggested it to me when he was building the motor.

shoebox1.1,
I'm hopeful to have a little drive time before the season ends. I think there are a lot of people that would love to see this thread end...myself included. I know I've learned a lot and a lot of guys here have contributed a lot of time and thought. I owe a burnout video when this get resolved!

mgarblik,
Great information! I hate to be on your top ten list for something like this...hahaha! This has been disappointing but I'm not discouraged yet. I'm positive this will get resolved soon.

gtospieg,
We'll check that out tomorrow. Good eye!

[64speed]

Originally Posted by TedRamAirII

$43 at Summit, I though you were a Summit Man? LOL. I bought one at a swap meet, $10.. Its a must have tool!

But you gotta pay shipping. Shipping is free from JEGS if you buy thru amazon

[64speed]

Originally Posted by Sirrotica

I agree, My LS2 in my GTO has had piston slap since I bought it new in 2006, and now has 140,000 miles on it. It sounds nothing like piston slap. Piston slap also varies with ambient temperature. At below 32 degrees mine makes tons of noise until it warms the internals up, and when up to operating temps you can just barely hear it at idle. LS engines are pretty well known for it, it seems to hurt nothing as proven by making 140,000 miles with no issues.

This engine (to my knowledge) has no change in the rapping noise based on engine temps, so clearance issues are kind of eliminated, as cold oil, more oil pressure at start up, and shrunken parts cold seem to make no difference in the noise.

I wish I knew what the noise was, but worrying about piston slap is, IMO, chasing a wish. As many Stratostreak engines as I'd laid my hands on in 50 years time, I've never had one making that noise, with the symptoms this engine has, and the noise seems centered on the distributor area, (by all accounts of the people that have worked on it). Which pretty much leaves out piston slap because there are no pistons in the distributor area.

In one of the early videos when the car was on a lift, and the phone/camera was being moved around under the car, to me the noise is in the rear of the engine near the rear of the pan around the flywheel area. It however does not sound like a cracked flexplate, and has proven that changing it made zero difference. I said before the flexplate was changed that I thought changing the flexplate would not fix it, and it didn't. I believe it's in the distributor oil pump area, but I can't think of what it is, and I've thought about it a good bit.

The only hint I have seen is the oil pump driveshaft is rubbed shiney only on one side, but unless the pilot hole that engages the top of the oil pump drive was off center when made it could make a noise hitting the cast lug in the block. I think that all those components have been replaced though in doing diagnosis elimination, so doubtful there would be 2 driveshafts made incorrectly If the shaft is off center it may be what caused the lower distributor bushing to fail also, but that is entirely conjecture on other peoples diagnosis during this problem.

Maybe the new guy will bring more insight into the mystery noise, I hope for everyone involved this ends soon.

My 356000 mile 5.3 has had piston slap from day one and still runs like a top. I think it’s time to bite the bullet and pull it out and tear it down. Either that or run it till it blows. It seems to me by now there is no easy fix

[Va68goat]

64speed,
Paul doesn't think the knocking noise is piston slap and neither do my buddies that have been working on my engine. I think through the process of elimination, it's pretty safe to bet that this is internal / mechanical. The tech is coming over to do a few things today. I know he plans on checking out the balancer and possibly put a little more clearance on the timing chain cover. I'm not hopeful about the balancer being the source of the knock because when he was here last time he used his mechanics stethoscope and did not get a signature at the balancer / timing chain cover area.

[grivera]

Originally Posted by gtospieg

If you look at your second pic in your latest post you will see that the front seal(for the harmonic balancer) is not fully seated(it is crooked and probably not creating a good seal)...this could be the source of your leak.

Not sure about the seal on Joe's engine but the one I installed on my #'s matching engine looks the same as it bottomed out in the timing cover before the edge reached the surface. Mine is a reproduction timing cover so not sure if the dimensions are off or the seal is too "deep." It did not affect the seal's performance.

[chiphead]

Ditto on the front seal. Usually it bottoms before the lip perfectly hits the timing cover. Never had a problem with a major leak there. It's common to have some oil residue or a slow drip, because the timing chain throws a lot of oil against the pan lip and the front seal. The galley plug mod (if done) adds oil being thrown off the chain as it runs.

Not exactly on topic, but: Is the Romac that good of a balancer? Why not use a SFI-rated balancer that doesn't require so many modifications?

[Va68goat]

chiphead,
Paul requested this balancer during the build so I bought it and sent it to him. I imagine he's had success with it or he wouldn't have suggested it. I'm not betting this is the source of the knock though. There were no witness marks on the balancer. I think we've tested everything we could possibly test at this point. I don't know what the tech is going to be doing after looking at the balancer but it may be time to break down this motor.....Again! The knocking noise has been consistent for almost 2 years now.

[chiphead]

Every builder has a couple of go-to recipes of parts that he's familiar with and worked for him on previous builds. I'm sure the Romac falls into that category.
Paul K recommended the Pro-Race brand 64275 because he's had good results with it. I installed it on the 434 I just built. It clears everything and fits the stock '69-newer pulleys without having to re-drill the holes. Downside it's more expensive than similar balancers.

Often it's not a better/worse thing, just personal preference. Several guys swear by the Romac, they just do the modifications to make it fit. Some of the less expensive, easier to install SFI-rated balancers have come apart at speed, so it's not an area to skimp on if you're going to run it hard.

[Va68goat]

Interesting stuff...I hope to be able to run it hard one day. For now, I'll just setting for running. As I said before, we don't think it's the source of the knock but we definitely need to clean it up a little.

[gtofreek]

Originally Posted by Va68goat

chiphead,
Paul requested this balancer during the build so I bought it and sent it to him. I imagine he's had success with it or he wouldn't have suggested it. I'm not betting this is the source of the knock though. There were no witness marks on the balancer. I think we've tested everything we could possibly test at this point. I don't know what the tech is going to be doing after looking at the balancer but it may be time to break down this motor.....Again! The knocking noise has been consistent for almost 2 years now.

Just for the record, I did not suggest this balancer. I have never used one before and will never use one again. It was with the group of parts you sent me.

[Va68goat]

For the record, I didn't even know what a harmonic balancer was before I had this motor built. That balancer wasn't on the previous motor so it wasn't sent with the heads. It was ordered from Butlers.

Sent from my SM-G955U using Tapatalk

[ponjohn]

Originally Posted by Va68goat

For the record, I didn't even know what a harmonic balancer was before I had this motor built. That balancer wasn't on the previous motor so it wasn't sent with the heads. It was ordered from Butlers.

Sent from my SM-G955U using Tapatalk

Who paid for it and provided the shipping address?

[Mike Davis]

Nothing wrong with the Romac balancers. I have had one on a few different engines turning 7200RPM time and time again.
And the Romac's are SFI approved.