318 Poly Vibration

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I have to agree about the solid lifters. I bet it has them. Usually, if it came with adjustable rockers from the factory, it had solid lifters. I bet that's the whole problem.
 
All the poly 318 A motors were equipped with adjustable valve train and solid lifters. They had interferance fit adjusters in the rockers with no lock nuts, like the slant six. Pretty neat engines
 
And if that's the case, you sure DON'T adjust the valves with it running. LOL
 
Ordered a tach and a comp tester.

Had some time today located some great valve adjustment info on fbbo and an online manual.

I adjusted the valves, all were correct or needed a minimal adjustment. One exhaust valve, #7, had zero lash.

Checked pcv, in working order.
Checked oil drains on heads, read that could be an issue with polys, although the passenger side head has slightly smaller openings, nothing clogged, engine clean.

Started engine, fired right up as usual, idled well, as usual, felt that slight vibration as usual.

Checked vacuum to pcv from carb, non-existent, put a vacuum gauge on the carb port, zero at any rpm.

Unhooked power brake booster at manifold, hooked pcv to it. In my mind it seemed to run better, but really no difference, just felt better knowing the engine was 'ventilated.' No oil pushing out the dipstick or valve cover breather. I think I'll run it more like that just to clear any and all moisture out of it.

Can, or should, you run a pcv right from manifold vacuum?

Need to correct that carb vacuum port issue, might have selected the wrong base gasket from the kit, there were 3, I know it was clear when I rebuilt it. Not the main issue though.

I cannot wait to do a comp test and hook up a tach to see what the heck is going on. This engine runs so well, starts no problem, sounds awesome, but something is up.

A friend heard it run a while back and remarked that it is one of the smoothest running engines he's ever heard, but he never heard it before this vibration surfaced.

I also thought I should recheck the flywheel bolts, again, just to make sure I did it as I noted it.

Ranting to myself here, never had an issue appear under such strange circumstances, never get worse, and be the same, doesn't increase or decrease, at all rpms.

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You've not given many details on the valve adjustment. How did you adjust them? What specs did you use? Procedure?
 
I started with the fbbo link below, which had the same hot specs as the manual, .010 intake, .018 exhaust.

The second post links to The 318 Poly List and the details on the cold method. It states to take off .002 from hot specs for cold, but it's actually add .002, correct on fbbo.

I did all the intake, then all exhaust, using the Poly List process and adding .002 as the engine was cold.

Also, all of the springs appeared to compress the same amount, which seemed to indicate none of the push rods are bent, as mentioned earlier as a possible issue.

Only the one exhaust valve needed to be loosened, the others tightened a small amount or not at all.

The bulk of the info I could locate indicated when these engines needed a valve adjustment it would be noticeably chatty. Since mine is quiet, as far as valve chatter I am familiar with, I did not want to cause an issue and screw it up more.
First time valve adjustment on a poly

318 Poly valve adjustment
 
If vacuum ports on your carb are not functioning because you think it might have the wrong base gasket, something on the bottom of the carb could be uncovered causing a vacuum leak. The base gasket could be your whole problem. Does it have a bbd or a ww?
 
It has a Carter.
I'll check the gaskets today.

It did run without issue after the rebuild for some time. I'm open to check anything, and I certainly agree this needs to be checked again. The gaskets may all be the same, I don't recall, I just remember there were a few in the kit.

I kept the Stromberg off the original engine just because.
 
Swapped the carb base gasket with the one on the top. PCV port is in the bottom center hole of the gasket on the bottom. PCV now works fine off the carb.

Started fine, idles fine, still slight constant vibration. Checked oil, looked good.

Pulled all plugs, all black. I knew it was a little rich, but I've changed the plugs a few times and they were never black, checked my pics, dated 10/8 plugs looked fine. I'm guessing black because it's only been idling lately.
Noticed smoke from carb after shutdown, could be float needs adjustment or idle mix screws too far out. Looks to be entering at or below butterflies, very small amount, hard to see.
Carb is original to engine, which was original in another members car. Idle mix screws were about 7 turns out when I got it, noticed before I rebuilt carb, part of instructions is to write down number of turns in before disassembling. Once rebuilt, wouldn't run well w/o screws out 7 turns. Thought way too much, plugs were not fouling or blackened, checked multiple times, ran well, didn't smell rich at all or eat gas.

Per the comp tester instructions, warm up engine to test, disconnected coil, open carb butterflies, crank same amount for all.
Starting with odd at #1, 120, 120, 110, battery died, really, new a few months ago. Had to get back to family time so stuck the charger on it.

Back to it today, cold engine, but did all starting with odd at #1, 150, 150, 145, 150, starting with #2, 145, 150, 140, 150.

Pulled valve cover to help find #1 tdc. There is a timing tab on the cover, but balancer does not have a timing mark. Apparently this is the case with some polys. I have 3 polys, 2 have no mark, one has no balancer. Not a later balancer, not 180 off.
Found tdc, set it to 10dg btdc for initial start, same as when I originally started engine. Rotor exactly on #1 at 10 dg btdc.

Bought new plugs, borrowed timing light but ran out of time.

Next: gap/install plugs, check floats, set idle mix screws, install tach, start, set timing, adjust carb starting at 2 1/2 turns out on idle mix screws, again.

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Gap new plugs to .035.
Installed tach.
Set balancer mark to 10dg btdc.
Set rotor to #1 cylinder.
Reset idle mix screws to 2 1/2 out.
Realized vacuum advance was connected to manifold vacuum on carb, moved to ported.

Started, choke came on and let it warm up. Timing light showed mark on balancer at 10 AFTER, upper line in pic.

Moved distributor counter clockwise, mark moved further up, engine sputtered, moved distributor clockwise mark moved to 10 BEFORE, lower line, engine settled nicely.

Idling at 600 rpm, put it in drive, reverse, idle dropped but was ok, no hint of stalling.

Setting total timing is not 100% clear to me, and not sure of the specs, most info shows roughly 30dg @ 3000 rpm, and I did not get the tape I ordered, but making estimated marks on the balancer it appeared to be within that range.

Drove it. Did great, ran great, sounded great, headers/dual exhaust, no issues at stop lights, didn't smell, shut down instantly, started perfect. Didn't mess with the idle mix screws at all, no more 7 turns out to keep it running. Came home a few times to check trans fluid, oil, bolts, etc. Took it back out, thoroughly enjoying it.

Decided to do a little interior work, make it look nicer.

30 mins later, started, idles much lower and quickly stalls in park or neutral, forget drive. Shaking, sounds horrible, smells worse, adjusted carb, etc, nothing works. Checked for vacuum leaks, none. Disconnected heater vacuum, heater/defroster doors run off manifold vacuum, nothing.

Stumped. I must be seriously stupid, it can't be this difficult.

Timing tab on passenger side, so moving distributor clockwise would advance or retard?

Pulled 2 plugs both half black half white. Unable to find info on this scenario.
Ran out of time.

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How long did you let it run after you started it again (after a half hour)? Is it possible it heat soaked and just needed to clear itself out? Modern gas seems to expand easily with heat, and many old cars will run a little ragged for a few minutes after a hot start. Your plugs look like they're a little wet, like they might have some gas on them, and they shouldn't be that black.

It seems rich...have you checked the fuel pressure? Blown out the carburetor air bleeds with some cleaner/compressed air?

Sorry if you've already covered this...I just read your last few posts.
 
The position of the timing tab has absolutely nothing to do with which direction to turn the distributor. Some tabs are on the right, some on the left, but ALL 318s, Poly OR LA turn the distributor counter clock wise to advance and clock wise to retard. You need to get that timing RIGHT before you diagnose further. "I" would start with "around" 15 degrees initial and see "how it likes it".
 
After the 30 min I also drove it around to see if it would clear up. I also pinched the fuel line before the carb to run it dry, thinking maybe something was stuck in the needle/seat because it smelled bad.

Those plugs are literally brand new white on one side, black on the other. Never seen that.

I agree I need to get timing right first.

I'll start over. From my recollection I turned it clockwise and the timing advanced from 10 AFTER to 10 BEFORE, but I must be wrong.

I'm also struggling with identifying cause and effect, or lack of. The only thing I did before working on interior was to disconnect the battery so the interior light wouldn't burn the lens up.

Same thing happened when the battery died, in my first post, ran great, shut off, battery dead, replaced, ran like crap.

Will try again.
 
spray some water on the coil or watch it at night sometimes they crack between the tower and the neg side post causing intermittence idle problems.
 
Thank you, I was thinking it could be the brand new coil but wasn't sure how to check.
Although unfortunately it could be any of the new parts, everything is new.

Next on the list: Check timing and coil.
 
Set #1 tdc compression, removed valve cover to make sure, set distributor/rotor to #1, cleaned up cap and rotor, checked/cleaned up coil wires, checked all plug wires are clicked on all the way.

Started, let warm up, advanced timing to 10dg btdc, set idle to about 700 rpm, checked timing reset to 10dg, ended up running best at around 12-13dg.
Set idle mixture using vacuum gauge hooked to manifold vacuum on carb.
Checked idle in drive and reverse.
Double checked timing, tightened up distributor, took for a ride.

Runs good, not much different than last time, a little more advanced.

Vibration is more obvious, if that is the correct term, seems more prevalent at the right front, passenger side.

Changed coil to the exact same coil, brand new coil I just received for another car, no difference.

It has a clear fuel filter, full of gas, had checked floats and needle/seat last time. Checked water pump, alternator, power steering pump, again, no issues.

Checked and changed everything, fixed a tranny leak at the kickdown, put new floor mats in, nothing!

Could it be the fuel pump? Put a big long screwdriver to it, not vibrating or knocking.

I was holding a small long screwdriver leaning on the passenger fender and noticed the upper horn vibrating, then I noticed the screwdriver in my hand vibrating at the same frequency.

I can't find anyone, professional or otherwise, who can either take the time to work on an old car, can figure out the issue, or even believe there is an issue.

The facts remain, ran great, then wanted to die, then slight vibration that was never there for 3 months, then runs good, then not within an hour, but vibration remains constant.

I'm not stupid, or crazy. I'm completely stumped. Too bad, nice car otherwise.
 
Clean your carb. Pilots and jets. Thoroughly.
Buddy’s impala ran like a bag of, and refused to let me in the carb.
So i refused to put another wrench on it unless it was on the carb. Fixed after a thorough cleaning.
 
I rebuilt it before the battery and alternator died, degreased it, took it all apart, carb cleaner, compressed air.

It ran well before it was rebuilt, and better after. The vibration started after the battery died, after I started it with a new battery in it.
 
Have you tried changing out the spark plugs 1 at a time? A plug can perform differently at various RPMs and temps
 
If you mean changing an old plug to a new plug, then running engine, then changing another, etc, no I haven't.

I have changed the plugs multiple times during this, just recently on Tuesday.

I just tinkered with it a little more, nothing major, very small adjustments to timing and idle. Ran extremely well, nothing new there, but that vibration.

Anyone thinking spun bearing or something else major?
I'm not sure how that manifests itself, or if that would stay constant at any rpm for an extended period of time.
 
Vibration:
At idle motionless it's the same as at idle in drive. Driving at speed it's difficult to tell, I would say it's the same.

It is the same with transmission in park as in neutral.

It is less noticeable when driving.

Slowly increasing revs doesn't smooth it out. I held my hand on the air cleaner and I can feel it slowly dissipate, meaning the sound/rpms of the engine start to mask it, but it doesn't go away.

I checked the trans to engine bolts, just because, one was a little loose, no change to vibration.
Radiator is secure.
Checked entire front end, nothing loose, rattling, broken, rusted, etc. Bumper doesn't budge.

As far as I can tell, I don't have slack in the valvetrain while manually moving the crank back and forth. I've done it multiple times trying to get tdc exact.

Yesterday was a good day. It drove better than ever, plenty of pick-up, kickdown worked great. Motored along nicely, even with that 2 barrel, it goes. Power steering and power drum brakes work excellent, heater is the bomb.

I'm not sure if this will be of any help.
I used a spark plug to demonstrate where the vibration shows up.

Top of air cleaner, very front part of fenders, front cross brace, and the upper horn. The horn looks like it's going in and out of focus, but it's not, I watched it vibrate in person and on my phone at the same time.
Can't really hear it, but can easily feel it.

Not on radiator or middle/rear of fenders.

Today I felt it in the driver's seat for a short time while it was idling.

 
I guess you've checked for bad or grounded engine and transmission mounts?
 
Doesn’t look to be vibrating very much, i was waiting for that spark plug to roll off there and fall into the fan. Are you certain that the converter snout fit the crank recess on your new engine? If you have an early converter on a later engine could be a problem, won’t bolt together the other way around. If you don’t know you can take out your flex plate to converter bolts and see
 
I used the torque converter on the trans that was in the car. The trans works extremely well, the kickdown o-ring was hard and leaked every so often so I replaced. It's just a rubber ring. Changed fluid, no other leaks.

What are you thinking?

Engine mounts are new, have checked the mounts, bolts, made sure they are tight. They give a very small amount if you rev it, seems normal.
Trans mount cannot get, everyone is out. Not the same as later mounts. One guy makes them, but many have issues with paying and never receiving.
Laid under car, trans was put in and out of reverse, no movement, nothing obvious, it's doesn't look dried out. Tried to get one again today, no luck.
Any other way to check it?

Recorded with phone, which fell over at end.

 
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