360 LA squeel / scraping noise like drive belt on passenger side

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JonathanH

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Morning all

We have searched the forums and have only found 2 similar posts, neither one left an answer as to what they found. Here is my info

Recently rebuilt 360LA.
Pistons/rings
timing chain
new oil pick up
lifters
Thumper cam
intake
4 bbl carb
Valve springs to match cam/lifters
valve covers
headers

I give you some info as its usually asked. We did our break in for the cam, no issues. Got the car timed, went for a test drive, car worked well. Did a burnout or 2 , everything was good. Tweeked the timing some ( Around 20BTDC which from reading should be around there for that size cam). Tuned the carb with vacum for max vacum. Everything going well. Put some mufflers on the car bc up until now it was open headers. Now we can hear a horrible exhaust leak. Tried new gaskets, did not fix anything, decided to waste time and try to get the headers out, and with long tube headers on a 360 in a dart, well that was basically a waste of a few hours. I did manage to get the engine raised up enough to move the header away from the engine and check the surface in case I missed something. Everything looked great, thats when I noticed the smog ports ( PS I did not know thats what they were until I did some research on this as well). Drilled the ports ( Drivers side) and plugged them.

Ok so we know what the exhaust leak is on the passenger side. So we were not worried about that at this time. Went for another drive so that we could actually hear the car this time, again had some fun, now on the drive back we noticed this noise start. It was only a 2 min drive, but it sounds like if the alt bearing is going, or the water pump, but its coming from what we can tell the passenger side , under the valve cover or lower. Its hard to pin point, we did try using a tube to listen and find an exact location but that did not help.

Other info:
We pulled the belts off, noise stiff there
We pulled the valve cover, checked the rockers, retorqued the shaft ( PS , THE TORQUE ON THE SHAFT IS NOT 30ft.lbs like the manual states, which I found out on this fourm, it is 15-17 ft lbs).
We did notice the oil pressure was EXCELLENT after the break in, on start up it would be 60-70. But has slowly gotten lower and lower, until it was at 40 on start up and the guage looked like 0 when warmed up and idling. Maybe 0-5.
So we changed out our break in oil, we did not see any metal in the oil, but the K&N filter did seem cloggged to me. Usually when I turn a filter upside down all the oil dumps out. This one did not. So we cut it open, no metal, but it was slimy in between the flaps of the filter.
Changed the oil and filter. Oil pressure on start up went up some, back to 50-60 psi, then dropped as it warmed up to around 10 psi. Still seems low. Went for another drive, noise still there.


Ok sorry for the long post, I just wanted you to have all the info. This noise only started I believe after I repaired the drivers smog ports ( Or I could only hear it after fixing that leak)...Raised the engine as high as possible with the tranny attached to gain access to the smog ports. Do not think I could have damaged anything doing this, but figured I should mention it.
Any suggestions as to what I should check
Things on my list
- I read one post that said the transmission pump, I know my fluidis low, I was down a liter without the car running, and I did notice when we got back from our drive I have a tranny leak from a hose that I will fix. So I could be down 2 liters of fluid, so I will check and top this up tonight
-I also read the oil pump flinger, could cause a noise, but I would think I would have had that the whole time, and it would be from the front of the engine.
-Im going to check compression on each cylinder ( This should tell me if there is an issue with that cylinder correct??)
-I checked the bolts on the torque converter/flex plate. They were good.
-The heater core is bypassed, could this cause any sort of issue as that is on the passenger side.
-I also read in one post that a carb to manifold vacum leak could cause this noise, which does not seem right to me, but I will check that as well.

Thats where we are at: and I will post the fix when we figure it out. Nothing worse than someone not posting the repair.
 
Kendog 170 said:
This is concerning. Idle pressure seems low to me as well. Are you getting oil at the rockers?
Hope it's something simple.
Click to expand...
The rockers seem all coated in oil, I hate to do it to make a mess, but maybe I should start the car with the valve cover off.
 
Could this be a Spun cam bearing?? If so what is a gd test to check this without a tear down? Will the compression test check this tonight?
 
JonathanH said:
Could this be a Spun cam bearing?? If so what is a gd test to check this without a tear down? Will the compression test check this tonight?
Click to expand...
I found this after much more reading. . It sounds just like that noise.
 
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based off your oil pressure id say its low oil pressure issue not a lifter issue.
 
Main bearing ran dry and now the hard crankshaft is in the process of peeling out the soft main bearing inserts.

Hint: the mains farthest away from the oil pump get the least amount of oil pressure when there is an oil supply problem.


☆☆☆☆☆
 
Here is what your crankshaft will look like with the bearing insert material transferring to it.

20200719_194721.jpg


You can clean the bearing insert material off of your crankshaft, polish the crank.

New bearing inserts and figure out your oil supply problem and go again.

Should be easy to attain 50 psi oil pressure with your drill engine priming rod before you put the engine back in the car.

Screenshot_20210415-180436_Gallery.jpg


360 Crank.jpg


Hopefully you put your lifter galley plug back in so the engine can build oil pressure.

Screenshot_20210728-170034_Gallery.jpg



☆☆☆☆☆
 
Update:
Topped uptranny fluid fixed leak ( not the issue still have noise)
Checked oiling port on passenger side, losts of oil, not the issue
Check cylinder compression, 110-115 on all.
Cant think of anything else. Start pulling the engine tonight.
 
Did you know?
that LA rocker shafts have to be correctly clocked
and that 318 rockers are different from 340s,
and among all of those are lefts and rights,
and when installing a high-lift cam, you gotta check the rocker to retainer clearance,
and the pushrod to p-rod tunnel clearance.
Oh and if you have aluminum valve covers, then under the oilcap is a tin baffle, that usually has to be clearanced to the rocker arms.
 
AJ/FormS said:
Did you know?
that LA rocker shafts have to be correctly clocked
and that 318 rockers are different from 340s,
and among all of those are lefts and rights,
and when installing a high-lift cam, you gotta check the rocker to retainer clearance,
and the pushrod to p-rod tunnel clearance.
Oh and if you have aluminum valve covers, then under the oilcap is a tin baffle, that usually has to be clearanced to the rocker arms.
Click to expand...
Thank you for the reply.
Yes I did know the rocker shafts have to be correctly clocked. Drivers side notch to the bottom towards front , passenger notch to rear bottom, oil holes at bottom, rocker arms also have a left and right which I have correct.
I dropped my heads and cam specs off at the local engine shop ( very well know builds high performance engines) to check clearances for the cam and if anything needed to be done for the valve springs that went with the cam.
I am unsure what push rod to P-rod tunnel clearance is I will have to look that up. Now the valve cover thing could be the noise, I did not check this, we do have alum covers, and it does should like an issue within the valve cover area.

Thank you for the reply, I will check that

Something to add, do not know if this would matter, but when we remove the mufflers and run open headers we do not have the oil pressure issue, oil pressure goes up 10-15 psi on start up and when warmed up during idle. No idea how that makes sense, but it does it.
Also, we still have the smog ports open on the side that the noise is coming from, could this somehow be making this noise, I know the tick tick exhaust leak are the ports, but could they also be making the odd noise as well??

Just some more info. Thx
 
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So we are thinking it has to be oil pressure related. No noise at all when oil is cold and we have 60 psi of oil pressure. But once everything warms up the oil pressure drops to 20-25 while driving and 5-10 at idle. \

Could the oil be getting to warm and thin? we are running 15w40 now, after changing out the break in oil. We fixed the smog ports today to rule anything to due with those out. Tmr we pull the engine unless someone has something for me to check first.
 
15W40, in winter, in Canada, is too thick...... even in summer.
I'm with the guy that mention your oil-gallery plug, BUT
you could have multiple problems, like;
your oil pump relief valve is stuck open, or
the oil-pump drive is in the middle of taking a dump. or
somehow, your 90* filter housing is making trouble.
IDK
 
if it's dropping oil press once hot then you've got a tolerance opening up once it's hot. the where that tolerance is... finding that is the trick.

without removing the engine you could drop the pan and check the pump. you can check the intermediate shaft (pump drive) in-situ before heading that direction.

but to me: low oil press + screeching sound says lack of oil on critical bearings. so you'll likely be pulling the motor anyway...
 
The bottom of the cap that goes on the piston is touching on a couple of them, but turning the engine over I don’t know how I could touch anything I am confused

F87E09EC-D775-4959-94FD-1423D3C5598F.jpeg
 
Is it loose? Is the bearing in it`s place?
I had a rod cap come loose enough to pancake a bearing, early on it sounded like a belt squeal, then it locked the motor up.
I can`t imagine the bottom of that scraping anything too.
Good luck.
 
And here we have it the noise was coming from a rod bearing completely worn out. I also believe it has destroyed the crank would this cause the oil pressure issues as well. It was the # 7 piston, and not the one with the marks on the bottom. We did not check this when we did our build, we purchased the engine from a friend who said he had done a rebuild, pistons, rings and bearings. Guess they didn't do bearings..

D1CDFCEA-1E6F-456D-8AA4-69B80DF1D0BB.jpeg


695DA73E-5CD9-443D-8E97-5C9BAE35B2E8.jpeg
 
So was this caused by low oil pressure or was this the cause of low oil pressure
 
so that's the cause of low oil pressure, but only after the bearing piggybacked. more than likely an error in critical tolerance when assembling.

how do the rest look?
 
The dude that put the motor together may have put the rods on the pistons backwards. There is an inside edge and an outside edge, or to say it another way, one edge of the crank end of the rod is chamfered and the other edge is flat. The flat edges always face each other in the middle of the journal and the chamfered edges always face the counterweight. If you look at the outer edges of the rod journals on the crank, you can see why they have to be that way. Might not be what caused the problem, but it is a place to look. Sorry for your troubles. :(
 
JDMopar said:
The dude that put the motor together may have put the rods on the pistons backwards. There is an inside edge and an outside edge, or to say it another way, one edge of the crank end of the rod is chamfered and the other edge is flat. The flat edges always face each other in the middle of the journal and the chamfered edges always face the counterweight. If you look at the outer edges of the rod journals on the crank, you can see why they have to be that way. Might not be what caused the problem, but it is a place to look. Sorry for your troubles. :(
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Good to know. We are putting a new crank/bearings in the engine, as well as rods and bearings. My son wanted to do rings as well for the experience altho we were told they were already done. Also what you are saying may explain why it looked like the rods had been rubbing the crank... looked shiny on both sides of the rods and crank, prob shouldnt do that? See the edge in the pic, should that be shiny like it was rubbing?

AA2616FB-BEA5-4A83-A0FF-3C263C7D43A3.jpeg
 
JonathanH said:
Good to know. We are putting a new crank/bearings in the engine, as well as rods and bearings. My son wanted to do rings as well for the experience altho we were told they were already done.
Click to expand...

i wouldn't be trusting no one on that front after f-ing out the bearing install like that.

it's apart, check the rings and pistons. that's the smart play here.
 
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