Quote:
Originally Posted by Cliff R
"CLIFF: I am reposting this post, on top, just in case you did not see it, down below. A question about my recent Transmission build, an important review of the Tolerances at the "FRONT" of the Trans. that could be affecting the "THRUST" on the Crankshaft, causing the issues that I am experiencing today, like the crack in the Harmonic Balancer and now this second ghost noise thought to be the Flexplate."
Transmission endplay will have nothing to do with applying thrust to crankshaft as the torque converter is in between. You just need some on both ends of the TH400. The range Transmission run in is really wide and "not" a problem area". Even so, I shim mine down to the lower end of the range and I have never had an issue either way.
This assumes that you correctly shimmed the new converter (if it needed it). Basically, what needed to happen was that you correctly engaged the converter into the stator, input shaft and oil pump inner gear and shoved it all the way back during installation. At that point a quick gap check between the converter and flex plate, then decide if it needed any shims or not. You don't need much clearance in that area as the converter isn't going to "grow" much in use. Too much clearance is not a good thing, as you are pulling the notched portion of the converter out of the oil pump inner gear. It still has a LOT of wiggle-room there and you've got to pull one forward quite a way before it comes too far out of the gear and shears something off.
Your strange noises are no doubt piston "slap" from having most of them installed in the wrong direction. I had the EXACT SAME ISSUE with my fresh SBC 400 build, when I pulled that dumb move. I had other issues which included more oil consumption than I was happy with for a fresh build, with less than .002" piston to wall clearance using hand fitted Speed Pro oversize rings. As I told you several times, on your long running thread, that engine just never ran right even after 10,000 miles. I couldn't deal with it anymore, so I pulled it out for inspection. I found the issue, put it back together the right way, noises gone, power restored and on to bigger and better things.
I tend to learn some pretty valuable lessons when I make blunders like that, so I do my very best to NEVER repeat them, plus pass on the info. to others. Good thing, in this case all the advice and DIRECT experience that I provided to you, fell on listening ears. However, you'd rather buy into some BS regurgitated theory (wives tale IMHO) that "racers" WAY back in the day, reversed all their pistons, so they could pull bigger wheelies and end up with the trophy at a bit event that they were racing in. That choice makes no sense, whatsoever, then or now. You need to get back into this build and get ALL the pistons and rods into the correct orientation. Only then can you move forward and accurately troubleshoot an engine "noise" or other issues your motor is throwing at you.........IMHO.......
|
Mikes reply:
In this reply, I opted to edit your reply for future readers on this site.
It is good to know that I have working Tolerances and I won't have to go back into the Trans.
As far as the latest "noise", the saga continues, I have elected to replace the Flexplate, because I believe in repairing everything in the area while I am there. We had a leak at the rear of the oil pan and we think the rear main seal is "ok" for now. OfCourse, that will be the first part to be changed when we get into the lower end of this Motor. Since we are in the Oil pan area, I think we should at least inspect the Windage Tray while we wait for the new parts to come. This is the time, while the Oil pan is off to check the lower end for the Rod alignment orientation to the Crank. Flats of the Rods toward the inside, adjacent to one another and rounds of the Crank, towards the outside, adjacent to round fillets on the Crank Journal. I will take photos and post them to the forum this time.
P.S. We kept the proper tolerance between the Torque Converter and the Flexplate, 3/16" I believe.
With the new Flexplate and all the new ARP hardware, I will be able to sleep at night, knowing that we used the best hardware and a Factory-type Flexplate. Even if this is not the current noise.
I can't discount that "Piston slaps", by your description of what they sound like, could have shown its ugly face, given the mileage on this 1967 428 ci HO Pontiac Motor.
Why now is my only question and not 10 years ago when I began this project?
Why is it that the problem did not manifest itself, prior to the pulling of the Heads recently, it was only after that, that we noticed the Pistons were installed backwards, did it become an ongoing concern?
I still am additament about there being an issue with the lower end of this Block, because it ran to good before the accident to the Trans., that required it to be rebuilt "not" the Engine.
According to Cliff, I did "not" cause the Trans. to push extra Thrust toward the Crank, in order to break the Harmonic Balancer, which means it could have happened during the accident with the Trans. going over the root.
The Harmonic Balancer was "not" broken prior to the accident, as far as I know, at least there was "no" vibration or sound, that I picked up on.
So, what is the cause of these new noises?
Everything in my gut tells me that I am starting all over with a different Engine than it was 10 years ago. Especially with the Head work, 421 and Pontiac cooling mods, "041" Cam and a Remanufactured TH 400 Transmission... I have to expect to jump over current Hurdles and jump through new Hoops, like I had done in the past, some ten years ago until now, it never stops. One change affects something else with Automobiles or so it seems. JMHO