I took a look of the pic u posted of the cam retainer and that's ugly. The wear pattern looks as if the spacer between the timing gear and the camshaft was of the wrong thickness or perhaps not even there. That retainer should never wear like that !! Something is Bad Wrong with the timing gear set and or installation !!! >>>>.
I ordered a new timing set because of that. It's a $pecial kit with Torrington bearings on both sides, and sets cam play to tight tolerance.
I guess what I'm trying to say here is the installation of the timing set was a huge problem as the retainer could never wear like that on it's own. Take great care in fitting the new parts !!! >>>>.
Here's what I have learned from this experience (did not Know before): Distributor shaft also turns oil pump so it has some resistance to it. Combined with helical meshing of the gear against the cam, there is a forward thrust on cam during acceleration. The original flat tapped cam lobes are canted so that pressure from lifters cause a backward thrust force on cam to offset the forward thrust from distributor. Swapping to roller cam (without canted lobes), there is nothing to stop forward thrust except thrust plate. I did not know about this, even if I did I'm not sure the roller thrust plate was available when I built the motor. Since then, Sims Performance has designed a dual sided roller thrust kit to exacting tolerance that I am swapping to. Oh... and the gold flakes? I found them. Interference between crank and gold coated windage tray. YES - I should have found this on installation, but the manufacturer (Tomahawk) should probably start with making sure it clears stock bottom end set up.
i see where you are going with the thrust bearing theory and I hope that works out. I went back and looked at the pics of your bottom end again and those rods don't look stock >>>>.
Glad you found the problem was the windage tray. The fact that this interference wasn't found earlier could be a blessing in disguise, as that thrust plate problem could have been much more expensive to fix if it had gone a lot further before discovery.
No the rods are not stock. But the windage tray mounts to main caps, and interfered with crank which are both stock. This type of stuff happens to me sometimes....
Glad you found the problems, this has been a very good thread for us guys that love to learn mechanical things, Thanks for doing it.
Those gold flakes may well be yellow zinc chromate plating that is commonly applied to steel parts (think class 8 hardware) and if just the plating was scrapped off the windage tray, would not be magnetic.
Sooooo it was those darn speed parts! Glad you figured it out. Dirty ol Dave is right on about that thrust plate issue. peace
Glad you found the problem as stated earlier also. I've learned the hard way as well with many tier downs. For every new or modified part that goes in, it has to be checked.
Do you suppose that interference with the windage tray was also the cause of the weird intermittent noise it was making?
Hey Stuart- I think it's doubtful. My 2 probables for the squeal: 1) cam thrust plate 2) gasket underneath throttle body spacer - it had a certain spot that had some slippery gas smelling wet spot so I'm thinking it didn't have a great seal. Sort of a type of whistle like when blowing through a blade of grass. I hope anyhow. If those aren't the squeal, I could just pull the motor out again right?
Did anyone along the rebuild do any kind of abrasive blasting? Particles will embed themselves into castings and later wash out under running conditions.
The center main in a Pontiac is the thrust bearing and I have had alignment issues with these. Even with the aftermarket main caps that are dowel pinned. And this has been known to cause the squealing sound >>>>.
I pulled each cap for inspection. They looked great, including #4 crank thrust. Everything was happy except the cam thrust plate which I replaced with the roller kit.
It doesn't do it in neutral. Needs a load. Could be in tranny or behind? I was thinking about putting it on chassis dyno and using stethascope or hearing tube or?
Find a shop or someone with chassis ears. We use them at the dealership and have found many odd noises. http://www.tooldesk.com/automotive/STL06600-Steelman-06600-Chassis-Ear-ChassisEar.aspx They also have wireless, a bit more pricey.
Under load.. maybe the drive shaft is too long, under load its bottoming out the front yoke into the trans. Just a thought.
Interesting thought on driveshaft, but it's clearanced pretty well in trans. It doesn't even plunge much since the shaft is so long and angles are mild. Chassis ears are interesting. Those would probably find it.
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