~OK GUYS, SORRY TO YELL BUT FIGURED IT'D GET YOUR ATTENTION, THIS IS A LITTLE LONG BUT I FIGURED THAT POSTING MY ENTIRE 'UPDATE' FROM MY BUILD BLOG WOULD GIVE MORE CLUES TO A FIX THAN IF I JUST DESCRIBED THE SITUATION BY ITSELF. I'M A BIT ON THE WORDY SIDE SO SORRY FOR THE LONG-ISH READ AND A HUGE thank you TO ANY HELP EDIT: its a non metric early th350 trans bolted to a 1969 ish 307 that seems to be stock. EDIT AGAIN! ok turns out im tired and rambling, the long as version is below but basicly th350 + sbc. runs fine, trans acts fine, never noticed a crack in the fly wheel, everythings brand new. motor is run for like 10 mins and gets warm and i hear a sorta wood hammer softly tapping a wood block type nock in a rythmic fashion coming from roughly the bell housing area. any ideas what it could be thats not a cracked flex plate? update! first the good....then the maybe less good. photos very first Alright so where we we? ah, yes friday. Friday after noon sitting at work I knew that I had plans for the evening, getting so close to the goal last weekend i had set out to get a week night in before Sarah had to leave for school for a couple months. My friend Steven had been on and on about wanting to help me, so it was official put up shut up time for him to lend a hand. I think the wait until 5:30 when I could leave would have felt like it was taking forever anyways but when i saw the video of st. nicks 57 roaring to life my heart and stomach just started doing back flips! wow! i was floored and ampt for the next chunk of hours after that. I got off work, grabbed Steven and a burrito and we made our way north. With a slight detour to Le Mars to retrieve a 90 deg super tight radius bend that i had failed to capture on a super secret mission wednesday, and a hand full of bolts we got to the shop about 8pm. First on the list was boring stuff. I got the passenger side flex pipe connected to the solid head(?) pipe that leads to the muffler. it was a chore to be shore, i could have used a little more length and the sweeping bends created with the flex realy leaves something to be desired. with some modified hangers everything got back lined up and pointed in the right direction. the drivers side with all its crazy bends went pretty quick, slipping the elbow on for size and a few trims later it was all good to go. not much worry at all. the only thing i dont like is that the flex pipe is touching the wishbone with a gap above it to the frame instead of being closer to the frame with the gap between the pipe and the wishbone. Thats with weight on the front end so i dont suppose it should be that big of deal, but i do plan to re visit it and 'convince' it out of the way a little more if the wishbones don't beat me to it. With the exhaust out of the way we went to attacking some small things. A refill of the grease gun and all the zerks were plump with grease, a hand full of zip ties and the plug wires off the ram horns, that rattling head light ring marked with an electrical tape X for security, the transmission filled and finally we turned the key. to be fair we turned it a few times. i was un sure how much ATF was in the transmission after we lost a sizable amount threw the leaky dip stick situation, fixed with some creative rubber work and silicon, so i put a few quarts in, ran it threw the gears, and fired it up quick. it sounded like shit, and did not want to run. figuring maybe it was choked by the filter as the previous sorta successful attempts had been sans the filter I pulled it off to test. Maybe its running rich? Fired back up and it was better, but not totally great. it was running better but not as well as good as it was a few nights ago. i could hear a tiny whirling noise kinda like a rear end with low fluid or sharp teeth in it, so with it having run maybe 2 or 3 minutes we shut it down to measure fluid. Dumped another two or three quarts in and went to fire again. With my hand on the key and steven my human gas pedal it fired up with out drama. I noticed that it was a little louder then i expected from the long smithys but no whirling , no noticeable noise from the inside outside of what youd expect from a loud motor. He let the throttle back slowly trying to see if it would idle but not to much luck. we killed it and checked the trans. fluid level is good! Back to our two man ignition sequence, the cars fired up and i take a look back. the rear of the car is on jack stands as its a mystery were PRND are located after the trans arm was pointed down and the shifter moved to the left. all the way at 6 o clock was park, i guessed right! I slowly let it up into reverse, success! and then onto neutral to slow it down before watching the forward gears and returning to park. I let steven keep it ideling the best he could as i went to check the fluid levels and a stumble was audible. A back fire, a plume of smoke out of the carb and the engine purrrrrrrs. he lets his hand back away and it idles like its always wanted to! Maybe it had gotten jarred around in the journey north, either way the demons were released and this babies ready to roar! I walk around the car, an ear to the exhaust tips checking for tone in a crowded shed wonder if id hear leaks out of my hokey set up and step out side to listen to our handy work. It wasnt long before i heard it. the noise that would be echoing in my head on the quite drive back to sioux city, and all day threw out work today. nock. nock. nock. at first it seemed like it came from the drivers side far back corner of the valve cover, was it a stuck lifter? it doesnt sound like one, its not a metal noise, its not a tap or a tick? It almost sounds like its coming from the bellhousing. I hustle over to the other side of the motor hoping to locate the noise better and its not coming from the motor. its coming from the general area of the bell housing. I shut it down. The motor had warmed up and I had found myself a mystery noise at 1:30 am. The nock is not fast, it is steady like a metronome. The nock was no audible at any point before it got warm. It was roughly 54 deg out while we ran the car in the shed, door open, back on jack stands. The nock sounds, well i've been saying like plastic. It isnt a hard nock, almost a tap. Thats a misleading way to put it as i dont mean it as a "sounds like tapping" it sounds like the amount of pressure your exert tapping something. Thinking about it maybe it sounds closer to the sound of taking a hammer by the head and softy tapping on the wide side of a 2x4. It is not an aggressive noise at all, to be honest at first I thought maybe something was dangling and with the vibration it was swaying in the rhythm of the car. Catching something to make noise on the beat. but no such luck. I have zero clue what it is and i pray to god its not a cracked flexplate. The th350 trans has been more or less sitting a fresh rebuild on a shelf for a project that ended up with something else. The converter , bolts and everything brand new. The cooler and lines, all of it new. The engine out of a friends truck that i've heard run and drive tons of times, and though I obviously wasn't on mission to find a crack when bolting it all together I think I would recall seeing something, even if it was slight as we were pretty intimate for a few nights in a row. Though I thought I had it all tight maybe one of the converter bolts is a little lose. Causing it to slightly shift and thunk with the rotation? the trans acts completely normal, in all gears and under a little throttle. I can't really call it under load with the wheels on jack stands i figure. Has any one have any NON FLEX PLATE CRACK ideas? I thought maybe it could be a cracked manifold, a lose flange to the head pipe or even some weird vibration from the pipes coming into contact with something but where to sound seems to be coming from and just the way the sound sounds led me away from that idea. Any how at this point we head 6 miles into town and find the only place still open for some awful gas station "coffee" and to find jackets as jeans and a t-shirt certainly are no longer suitable. We make it back quickly with the idea of heading to the brakes. I find my pedal position is correct after spending an afternoon drawing lines on photos of the set up, looking at photos of how the toe board bends when installed, and what it all looked like before i took it apart with the clutch pedal frozen all the way up. Well that and sitting in the car for about 2 seconds. I grabbed a piece of card board and after cutting it to size and bending it in the proper location I mock it up in place and start cutting to make the arm clear. Either because of bending it to clear the bellhousing, shitty speedway parts, or any number of reasons the "length" part of the brake arm is above the floor slightly instead of allowing the "vertical" to pass threw a single hole. oh well, the new floor was only $150 and if i come up with a better way to do it later I'll do it then. So after some sharpie and razor blade surgery i had a cardboard floor to fit the drivers side and figured we'd better bleed the brakes before we cut up the new floor and bolt it over the...well were the M/C used to be. Now just forward of were it resides under the seat. With a nice tube funnel set up we went to work filling the M/C with fluid and cracking the right rear bleeder. A couple of tries, and a couple more and it looks that fluid is making its way to the evidently not that tight passenger front bleeder but not so much as a gasp of air is coming out the rear. We notice some teeny dots of fluid were the lines meet the wilwood proportioning valve and crank them further down before noticing that it seems the wilwood residual valves also have a little moisture coming from them as well. I've heard of these residual valves being prone to leaking because of what they are made of but we gave it a couple turns and hope for the best. After two hours of laying under the car it was 3:45 am, I had a funny nock and mc that wont push fluid to the rear. With a declaration of 'fuck this' we called it a night and started to clean up before the hour drive home in the dark. The friend who's shed im building in was hopeful of the car moving or being gone so he could unload some pallets of shingles to roof his house later, he got them right before the price nearly doubled if not more, so knowing where the gears are located and that i had no brakes steven and i played a game of catch with the car and i pushed it outside, he stopped it and we blocked it up to no move outside of the door so shingles could make there way in. rolled the windows up and said jokingly "not like its going to rain, hasn't rained in a month". of course I woke up this morning to rain. ha, oh well maybe its not to late to let it do the crops some good they could use it. Post script. I was thinking that maybe I had the proportioning valve set all the way forward and thus the fluid wasn't going back? But a quick google search makes it sound like its a pretty common thing to have happen and its just a fight with air pockets. It looks like a big syringe to the bleeder should force fluid into the line and pop the air out the master. I'll be looking for tips and advice on that as well.
Oh, and for all you problem solvers out there it starts up super easy and does not appear to have any bind or trouble at the starter
I guess im looking for ideas on what the nock could be, other then a cracked flexplate. Or if my idea of a lose converter bolt sounds feasible. I'm still pretty tired after work so sorry in my ramble it came across un clear. the next time i see the car is monday so i can't look at it now to figure anything out but thought maybe i could hear ideas of what it could be and things to look for when i get back out to the car?
alexander dumas and ernest hemingway wrote more to the point than that. is there a cliff note version of this novel?
short version added up top and now here ok turns out im tired and rambling, the long as version is below but basicly th350 + sbc. runs fine, trans acts fine, never noticed a crack in the fly wheel, everythings brand new. motor is run for like 10 mins and gets warm and i hear a sorta wood hammer softly tapping a wood block type nock in a rythmic fashion coming from roughly the bell housing area. any ideas what it could be thats not a cracked flex plate?
good thoughts guys. It does not currently have an inspection cover on, and i plan to check the converter bolts. Out of curiosity if its the starter what would cause that? the snout staying pushed out? thanks guys i really appreciate it
If you had the complete engine setting on the oil pan you could have bent the pan a bit and now the crankshaft is hitting the pan . Maybe. Ask me how I know.
The cracks can be hard to see in the flex plate. They crack around the the bolt holes that bolt it to the crank. The flex plate " flexes" and the pieces make noise when they pop back and forth. Not an uncommon problem for a SBC. That is why it is mentioned by so many.
Ok that's what I was thinking as far as bad starter. An you'd have to pull it to bench test it anyways do I'll grab a new one before I head out. The engine did not sit on the oil pan in any situation other than I suppose it Could have touched when sitting in the back of the pick up sitting in a big tire. I have eye balled it quite a bit and haven't noticed it being dented in any fashion but I'll stick my head or some sort of stethoscope set up down there while it's running to see if I get anything from there. Tommy, I don't think I realized they crack at the center more often thank you. The reason I asked for non crack related ideas is because I ha read a bunch of threads where that's what they thought it was only to be stumped when they swapped plates and it still knocked so I thought I'd check everything possible before I have to undo pretty much everything to pull a flex plate out. Thanks again guys
You don't have to pull it out to check for cracks. Pull the sheet metal splash shield and look at the area right near the the crank flange. If you see cracks it needs replacing and that is your problem. It will still turn the converter and it will still drive fine but it makes a knocking noise. Not hard to change either.
Do you know how to install a torque converter correctly? Did you inadvertently not seat the drive notches all the way? Also, look for scratches or scuffs all along the TC or flexplate as you spin it around. Maybe you can spot where it may be interfering with something.
I'll keep an eye out for marks when I check the bolts, and I'm 99.999999% sure the converter is set correctly, I actually spent a good amount of time doing just that but weirder things have been known to happen.
Just so there's some sort of conclusion to this I finally pin pointed the noise after swapping the starter to no avail. I rolled the car out side and I went under it while it was running to see if I could notice something hitting or wobbling when I noticed that the sound was obviously coming from the rear of the passenger side head. I guess 3 am ears arent very good at realizing that it is actually in the head sorry for the run around guys. Though it does make me curious why a lifter would start making noise now. Motor was running with no noise, it went a couple months with out running, I changed the old oil out for new and now a tick. Oh well that's old cars for ya I suppose
rocker arm? I once had a perfectly running engine start making all types of upper valve train noise.. and the valve studs had loosened up.
That's what I had thought, maybe they were hitting the valve covers or something? Put fatter gaskets on and checked everything while it was off. Knock still present. Decided to see if my exhaust manifolds were tight as it'd been mentioned and I got a good 1/2 to 1 full turn on every bolt :0 I fired it up and it was still there but softer. I took an actual stethoscope at this point and walked around trying to find it and I kind the threads on the exhaust manifolds that connect to the head pipe stopped short of making the seal 100% even when the bolts were all the way tightened. May e they anticipated a thicker flange? Either way I can now say after checking converter to water pump my noise was a flippin exhaust manifold leak. Man I feel like that should have been a million times easier to figure out but I suppose being so far from the car and trying to figure it out at 3 am did t help anything. Thanks for all the ideas guys.
The Jalopy Journal
