[grivera]

Originally Posted by 72LuxuryLeMansLa.

Cap and Coil should be swapped just for due diligence!

I think Mike R (HWYSTR455) tried a different coil during a different testing session- Mike ? Also, Joe used a different dizzy/wires and posted the video.

Originally Posted by 455GRIN

No way, don't run that motor it has issues.

This is why the oil filter needs to be dissected - at this point if it's eating itself it will be immediately evident

[HWYSTR455]

Originally Posted by grivera

I think Mike R (HWYSTR455) tried a different coil during a different testing session- Mike ? ....

I did have a known good coil with me when I went over, but didn't try it. When I made initial adjustments, and bypassed the ignition 12v wire, I felt the knock had somewhat subsided, but admit the idle was at 1000 rpm, and was more unnoticeable.

In the latest vids, you can see the vacuum gauge swinging while it's missing. I believe that is a key factor, the miss coincides with the knock.

I still don't understand why someone would bother checking total timing and not initial, and the one time it cranked it cranked slow. I still say in that vid the initial timing is too high, but don't believe that's what's making it knock. There is some type of ignition or valve/valvetrain issue to cause a consistent miss like that. Some type of abnormal combustion, which could certainly cause an audible knock like what's being experienced.

EDIT: I'm glad to see a number of tests were done that eliminated several questions/possible causes, that narrows it down more.

.

[Formulajones]

Originally Posted by HWYSTR455

I still don't understand why someone would bother checking total timing and not initial,
.

Since this thread has swung all over the place I can't determine who that refers to. But in a nutshell, when an engine is run on the dyno, total timing is really the only thing you're concerned with, to find the spot where the engine makes best power. The rest of it is up to the end user to determine what the car likes best because there are way too many variables that will change the requirements, none of which can be found on an engine dyno.

You'll have to change initial timing to suit the car by modifying the breaker plate, the rate of the curve will likely need to be slowed down a bit, and the vacuum advance adds more to the equation after everything else is nailed down. None of that has been posted that I can find. This stuff has to be done once in the car. If it's still an MSD distributor this stuff is very simple to do once put in service, and they even provide a chart to follow.

There really isn't enough information provided here on the users end that I can find that can determine a cause for anything one way or another. I haven't seen any timing numbers posted, I have seen compression test numbers posted or how the test was done. Just saying they are low doesn't tell anyone anything. Is there a post here somewhere with this information that I am missing??

And Paul is well aware of the rod issues when it comes to cranks with BBC rod journals and aftermarket rods in these Pontiacs. It's been a problem in the aftermarket for quite some time. That area has been addressed so you guys are going after a dead end there.

[HWYSTR455]

When I set initial timing, I set it at 12, and that was at idle. Paul specifically mentioned to me directly that the 18 degree black bushing was in place. The note with the engine stated to ensure max timing was no more than 34 degrees. That was determined on the dyno. And agree with your comments, no way you can determine a curve on a dyno, HAS to be in the car and by trial.

In the one vid, I noticed they were holding the RPM around 3-3500, and setting the timing. That's where my comments are directed. IMO, that's pointless, and can cause initial to be off (EDIT: for example, if total doesn't come in until 4k). On the second vid, when cranking, it struggled, hence my thoughts of it being too advanced. (initial)

Vacuum can has been plugged this entire time.

BBC rod journals are actually smaller, so there would be more likely to be an issue using a factory crank/stroke. Or at least that's my line of thought. (correct me if I'm off there)

Clay, in that second pic in your last post, you can see the counterweights on the crank have been clearanced, that appears to be an aftermarket crank, in the previous post, those clearanced areas are not present. I suspect it's possible on that second post, that clearanced crank was ment to be used with 6.70 rods. That may have been the issue there. But just guessing it's a possibility.

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[chiphead]

Originally Posted by Formulajones

And Paul is well aware of the rod issues when it comes to cranks with BBC rod journals and aftermarket rods in these Pontiacs. It's been a problem in the aftermarket for quite some time. That area has been addressed so you guys are going after a dead end there.

How do you know this has been addressed in this build? Have you been inside this engine? Do you have documentation of the parts used and clearances in question in this engine?

The shop that built the engine may be aware of proper clearances required, but are these clearances DOCUMENTED anywhere for this build? Typically you want at least .060" between the bottom of the piston and the crank counterweight. Autotec pistons want at least .050" side clearance between rod small end and pin boss of piston.

I had to have my aftermarket rods narrowed .045" on the small end to clear my autotec pistons. Eagle 6.8" rods and Scat 4" forged 3" main crank. Mine are BBC rods, and the rod offset isn't perfect when rods are used a Pontiac.

http://racetecpistons.com/media/pdf/...STRUCTIONS.pdf

Hard facts are in short supply in this thread. It's nigh impossible to give good advise unless you know things like dimensions of crank/rod/piston, piston material, compression test readings, all bottom end clearances, etc. All we've got here is a bunch of short youtube vids of a noisy motor and a room full of guys playing 20 questions. (myself included). Questions get raised that don't get run to ground. For example, sometime back there was a picture of very suspect valve adjustment, and several members questioned it. I don't recall seeing an answer or explanation about it. (The questionable poly-lock heights.)

If this was my motor, I would have resolved all valve setting and tuning issues first. Next would be a good compression test. If it continued to make noise and run like crap, it would be out and apart on my stand, while I verify all clearances in conjunction with the builder. Since Joe can't do this himself, he's going to have to have somebody do it for him. I'm sure he doesn't want to, but it's likely got to come out again, unless somebody finds something stupid in-car.

It's a sad state of affairs, because this sort of thing turns new guys off on the car hobby. It's not supposed to be this miserable. But it can be.

[Formulajones]

Originally Posted by chiphead

How do you know this has been addressed in this build? Have you been inside this engine? Do you have documentation of the parts used and clearances in question in this engine?

Chip common man, Paul has built 100's of these things. The rod offset/piston issue has been documented many times on these forums and Paul is well aware of it. He goes through this **** on every Pontiac build. You can be damn sure Paul made that right. It's pretty much common practice these days on a Pontiac engine because the aftermarket hasn't caught up yet, or simply don't care. He's even told me he's called the manufactures on this deal to correct it. Paul made sure of this stuff, especially the second time around.

I'm telling you you're going down a dead end with that deal.

[chiphead]

Originally Posted by Formulajones

Chip common man, Paul has built 100's of these things. The rod offset/piston issue has been documented many times on these forums and Paul is well aware of it. He goes through this **** on every Pontiac build. You can be damn sure Paul made that right. It's pretty much common practice these days on a Pontiac engine because the aftermarket hasn't caught up yet, or simply don't care. He's even told me he's called the manufactures on this deal to correct it. Paul made sure of this stuff, especially the second time around.

I'm telling you you're going down a dead end with that deal.

I agree, he knows and does all these things during a build that uses aftermarket bottom end parts. So where are the numbers? It's not in the data that Joe was given. Does Paul have this documented anywhere for process of elimination? Meaning, if he can prove he checked it, Joe and his helpers can strike it off the list for sure. Assume nothing when the problem is persistent.

I agree about too many cooks. It seems a few guys are going in after each other and possibly in a big circle with tuning. Motor should not be missing and hopping like it is, and for days. I can tune or diagnose a really crazy engine in about a day. Maybe not fix it, but at least diagnose the illness. Why is this taking so long to diagnose the shakes? If you could get it tuned and running good like the original install videos, that would give a good baseline. The original videos sounded really strong. At that point, you could move on to what could be causing the noise. If he can't find anything external, he's either got to pull the engine or drive it.

Valid compression test numbers would be interesting. What is static compression on this beast? A 10:1 462 with a healthy roller cam should have around 180-210 PSI.