So... I need some help.

Just rebuilt a 355 (my first build). Had countless unrelated problems with ECM/Ignition mod/Injectors/fuel pump... Finally got all those resolved, and now have a bad tapping coming from what seems like the drivers side #1 cylinder. (didn't start until had about 500k on the motor... but for those 500k it ran like a bag of cr*p!)

Stethoscope seems to indicate #1 intake valve, but can also hear it on #1 at the oil pan. Also seems more isolated on tranny inspection cover.. Bottom line is I can hear it all over the place and am having a problem pinning it down to one thing...

Won't do it when the engine is cold, when warm only does it at idle, in gear at idle, above 2500RPM, and on decel... Doesn't sound like a knock though... (I've had that pleasurable experience 3 times already with used engines). Makes the tap about 1.5 times/sec when idling at 750RPM... sounds like sewing machine at higher rpms.

Oil pressure is rock solid where I would expect it to be, whether cold/warm low/high rpms... doesn't fluctuate like a bearing problem

Initially thought lifters... So replaced all 16 of 'em. Thought problem was fixed, but of course I was wrong! Funny thing about it though... after replacing the lifters, for the most part they don't seem to be pumping as much oil through the pushrods as I would expect. With the exception of #7 in/exh and #4 intake (i think)... which are literally shooting oil... like to the point where it shoots right over the side of the head (not the little squirt squirt onto the rocker arm that you would expect).

Any ideas? Is this still potentially a lifter issue, that something is clogged somewhere giving the three lifters way more pressure than the rest? If that was the case, I could understand only #7 getting tons of pressure with anything forward of it not getting as much... but why then would one further forward on the passenger side be doing the same thing? If that is a potential problem, is there any way to remedy without pulling the engine, and then pulling the galley plugs and running a brush through them? (I already ran gunk engine cleaner through it to no avail)

I'm at a loss...

 

Well theres only really 3 places i can think of for taps to come from the exhaust, valve train, or the bottom end. ticks and taps can be generated by a loose exhaust manifold so sart easy and make sure everthing tight especially if your running headers. Next up the bottom end go through and dissconnect each cylinders spark plug wire one at a time (use insulated pliers so you dont get zapped wont kill you but you will be woken up to say the least lol). If you pull one spark plug wire and they noise changes its in the bottom end specifically that cylinder. TO check out the valve train pull off the valve covers one at a time and hit them with a timing light or strobe light. If theres anything funnie in the valve train youll see one rocker arm kinda moveing irradically and loosly.

 

Very good advice. I've been "woken up" by my car once. It's not something you ever want to do again. lol

 

Lol... and I have... though usually when trying to rotate the dizzy!! Though... I always feel "energized" afterwards!!

Gonna check my exhaust tonight... and pull plug wires and see what happens. Have a bad feeling though....

Hey... Another 'pegger!!! That's 2 in one day!!!

 

Yea getting zapped is not particularly pleasent i rank it up there with 3 hour physics classes and stubbed toes lol. Although on the topic of getting zapped i forgot one other thing that will cause a click like sound is a spark plug wire arching. Just take it out in the driveway at night and pop the hood if its arching it will be very noticable.

 

you prolly have already done this, but check your valve lash, sometimes those studs stretch, and your hyd cam cannot compensate.

 

weeeeeell..... redid my valve lash... checked all the plugs. 5 & 7 weren't firing. Found #5 had burned the wire (despite having my little wire booties on), fixed it. Replaced the plug in #7 and checked its wire...

Runs like it should... finally.

Noise was gone for a few minutes after doing the valve lash. Friend suggested maybe my noise is coming from the rocker nut backing off... is this possible? Found two nuts (#1 intake and #5 exhaust) that seemed awfully easy to turn (didn't feel like the other nuts in terms of effort required to turn).

Here's a video of my noise... kinda hard to hear....
http://www.youtube.com/watch?v=cFWlIY3pZ30

 

yes it is very possible for the rocker nuts to back off, especially if you've reused them a lot. you might want to look in to getting some locking adjusting nuts.

 

How quickly could this happen? Would it be fast enough to happen in 2-5 mins while running?

 

Well it is possable that the adjusting nut or the stud is worn or lose causeing it to fall out of adjustment. Its also possable that the studs (many of them just pressed in) is being pulled out. This is especially something to check for if you have a set of aftermarket valve springs with a high spring tention. That would happen very quickly especially when it starts happening. Its also possable that your camshaft is getting chewed up that seems alittle fast even for a bad cam but once they start to really become noticeably bad they will completely self destuct in a matter of miles completely. With new lifter they may wear faster though if the cam is wrecked. How did the old lifter look when you pulled them out were they all percectly flat on the bottom?

 

I do have aftermarket springs with higher than stock tension.... they were originally from my last engine and matched to a 210/220 @.050 .480/.480lift comp hyd roller cam. Swapped them onto these heads as I wanted to make use of them (Only got about 10,000k on the last engine before crank snapped in half). And actually, on the last heads (193 swirls) had one of the studs pull out, so I am familiar with that happening... unfortunately!!

Old lifters... with exception of one, had a pretty even wear pattern on them. I'd say a wear pattern of 2/3rds of the base with the rest untouched... with exception of one #4 exhaust I believe that was worn all over, and just slightly concave....

The puzzling thing is it runs pretty darn decent now... Actually got brave enough to put my foot about 2/3rds into it at lunch and she sat up and went... and nothing broke!!

Just that god forsaken tapping!!!! I still have to tighten up my collectors, re-torque headers, and pull inspection cover to check bolts in converter/flexplate (just to be sure).... but am still pretty convinced the noise is lifters...

 

l do agree it sounds like its in your valve train. Adjusting the lash would have no effect if it wasnt ya know. The question is what part of it. Now you mentioned that one of the lifter bases was slightly concaved this is typical for a SBC. The same high pressure oil bypass that protects your motor from oil starvation in the event a filter gets pluged also unfortunetly was a death sentece for camshafts. They allowed oil to bypass unfiltered when it really shouldnt have been and once a lifter starts wearing it no longer spins when it stops spinning it starts just grinding down instead, the cam and the lifter. So it is very common for 1 lobe of a cam to be completely worn down on a SBC. Typically a camshaft would go techically bad at about 170k +/- depending on maintinece. To make matters worse this was a general rule of thumb back befor they changed the contence of out oil and removed a lot of ZZDP and anitwear agent which amplifies this camshaft issue especially on freshly installed cams. This isnt a problem for newer motors with roller cams because they have a roller bearing driving the whole thing but on old flat tappet cams again its a death sentence. Now the fact that you had one lifter with a concaved bottom tells me the cam is fried. Now like i said earlier "technically bad" you can drive it for a while befor it starts to become real noticeable aside from the noise but reguardless i think you should plan for a new cam in your near future. You may also have a stud pulling out or a bad stud\adjusting nut but reguardless i would take this oppertunity to get a new cam\inspect the valvetrain. That way youll be back to square 1 and not wondering when it will finally give out because you know it will happen at the most inconveniant time possable lol.

 

Well... I'm not entirely convinced that adjusting the lash does in fact make a difference in the noise. It seemingly does... but then again, even now (assuming something has backed off or cam has worn more) it's quiet when I first start it up and when cold... But either way... I bought the individual parts to build this engine from some guy who never got around to putting it together, and he couldn't remember what the cam specs were... never mind the fact that it was some custom grind from some company that no longer exists!!! So who knows about the quality of it.... Having said that


What about a comp cams X4262H? Think its 218/226 @.050, .462/.480 on a 111LSA. Would this work fairly well with an HD 1600RPM converter and beefed up 700R4 with the vortec heads and edelbrock intake? Was thinking of getting a new cam anyways on account of my not knowing what the one installed is spec'd at to begin with...

As for ZDDP... This is something I've done extensive research on as well... and have been using EOS since break in (on my 3rd oil change now)... Didn't know about the bypass valve being an issue though... So does that mean that if the engine is running high enough pressure that the filter can't keep up, it'll simply bypass and recirculate the cr*p that's in the oil?

 

so are you saying you installed a custom ground new cam, and used old lifters??
thats a no no. lifters wear to the cam, u must repalce them at the same time. u can however put new lifters on an older cam.

sounds like your wiping your cam.

for your engine, i would rec a hyd roller cam with retro fitted roller lifters.

 

Hey berli...

No I put new lifters on new cam... then replaced the lifters (with new ones) after thinking my noise was coming from a stuck lifter...

I would do the roller (And even still have the CC 264HR12 210/220 .480/.480 from the last engine)... Have a hard time explaining to the wife why I needed to spend another 400 bones on retro roller lifters!!!

As it stands she calls it a piece of sh*t!! lol... but got way too much invested already to dump it (nor do I want to... I love my truck/V8... even with as much trouble as it's giving me)

 

well roller cam would be ideal but you still can run an old flat tappet cam with sucess. The trick is to get the right oil and break it in properly. By the right oil i dont mean royal purple or mobil 1 eather. Use eather rotilla t 10-w30 or valvolien vr-1 racing oil. Rotilla t is a oil ment for diesle motors and they have not removed the zzdp from diesle oil. Vr-1 just has high level of zzdp. Ive hear red line oil has amasing levels of zzdp and thats the reason it doesnt have the SAE seal of approval because of its high level but its very evpencive and i havnt really looked deeper into that claim. Further more comp cams as developed a fix for this problem and sell the tool to cut a grove in the lifter bore to allow some oil to drain back over the cam.

 

ahh i see. well getting around the wife can prove to be difficult, but calling it a pos!!! thats grounds for a divorce! j/k i donno, youtube isnt running at work so i cant listen to it. ill check it out tonight.

and rolling thunder is on the right track with the oils he listed, those all have high amounts of zinc. did you do a proper cam break in?

 

I did get a semi-proper break in done. covered cam with break in lube, fired up and ran for 15 mins above 2000 RPM before realizing my #5 header was just a smidge on the red side (just barely starting to glow ) so shut her down at that. Put in some Crane Cam Break-In EOS... And have been running it every oil change since...

However... my valve lash was set way too tight while cranking initially before getting it running... and was worried I'd done some damage there....

Then had all sorts of probs getting it to run right... Ignition mod was bad and actually retarding timing instead of advancing it... then the fuel pump was bad... then found these two cylinders having trouble firing (burnt wire... and the other... who knows but it's firing now)... So wonder if I did any damage there too....

 

might have bent a valve, but cant see that making more noise once its hot. almost sounds like oil pressure/thinning out and causeing bearings clearance issues to be heard.

 

Sure hope not. Only started after about 500k (300 mi or so - I think). Was quiet before that. And plastigauged all my bearings before putting them in and they were all within spec... so if it is bearings, I got bigger problems!

 

Well its possable that if the valve lash was too tight especially on a high lift cam you could bend a push rod pretty easily. Although again i think the biggest part of the probelm was the cam/break in. Today with the crappy oils and stuff if its not broken in to the letter they will not break in properly. Even when broken in properly sometimes they wont wear right. I recomend no synthetics for the break in only use rotilla t or valvoline vr-1 in addition to comp cams break in oil additive (or equivalent) and the cam coated with the break in lube. Also i like to prime the oil pump befor starting the motor if possable. The other important part is that the car starts right up. But no worries its happend to all of us its happened to me 2 times already over the years. You may have a burn valve as result of the tight lash i kinda dont think so but a simple compression test or better yet a leak down test will tell you if your alright. The reason why it sounds so much louder when the oils hot is because when the oils cold its much thincker and the hydrolic lifters will absorb alot of force without really loseing their oil. When the oils hot though the oil can just bleed out much easier thats where u really start to hear valve train probelms in the beggining anyways. Soon youll hear it when its warm and cold and soon after that it will feel like you dropped a cylinder or theres popcorn cooking in your intake lol.

 

Well... yep. Actually had about 7 bent push rods initially - thinking that was the noise. Changed them all, then changed all the lifters few days later - thinking that was the noise too...

Used crane cam lube during install (and again on lifters/rockers after replacing them). Put ZDDP/Cam Break-in oil supplement too (and have been ever since, didn't want to take any chances... though seems it may not have helped)... Have a fear of synthetic oils so will likely never use them unless the manufacturer recommends (plus had race engine builder of my last engine - one with snapped crank - tell me not to use it, or rather that I could after break in, but that if it started making noise to stop IMMEDIATELY, so I never even tried it!!!).... Think my '07 trailblazer might use it, but not my old 350!! And I would never even think about wrenching on the 'blazer, I've got big ol' farmer mitts and wouldn't even get my hands in the engine bay!!!

Also did prime oil before starting - even had buddy watching my pressure gauge while doing it and he said at one point (after 30 seconds or so) it pegged the gauge, and saw it seeping out rocker arms... All this before initial starting... Though like I said, there was some cranking before realizing my lash was too tight!!

Anyways... changed ALL my rockers, pivot ***** and nuts last night... no change in noise. Was hopefull as 70% of pivot ***** were moderately galled/pitted... but no such luck... Also found I had forgotten to tighten 1 plug - which definitely wasn't helping things!!!

Fixed some fabrication/geometry problems with my throttle bracket (as TV cable didn't have enough tension to allow adjustment - i.e. slider wouldn't ratchet out when doing TV reset/adjustment procedure...)

Had my timing way advanced before realizing I wasn't running on all 8, so reset timing (about 14 degrees is where base is set now, seems to be where my particular "vortec" likes it), and did min. air adjustment (for like the 5th time - but at least now it's where I would expect it to be)... Idles a little rougher now (cam I think/sounds like), but FINALLY maintains a rock solid idle (in and out of gear), not to mention it's got GOBS of power now. Have some 'puter tuning issues to deal with - past about 1/3-1/2 throttle it bogs, and is running pig rich down in the lower MAP/RPM ranges (understandable as I'm running ~28psi on the TBI - and yes, changed BPW to something reasonable like 95) - but WOW ... great response just off idle... VE needs tuning, then my AE to fix the bog past 1/3-1/2 tip in.

Just have to find my noise problem. Am going to tighten up exhaust and pull tranny inspection cover and check flexplate/torque conv. bolts tomorrow (well I guess today now). Gonna be pretty pissed if it's something in the bottom end (in which case I'm seriously considering driving it till it blows up!!!), but considering how well its running now, I couldn't imagine it being something catastrophic... hope not anyways! I would imagine if something in the bottom end I would have other symptoms - slightly erratic oil press, bad miss, worsening of the noise...

Think I will buy the CC X4262H cam anyways though, as I don't currently know anything about the cam currently installed - other than having measured the lobe lift vs. base circle and calculating a .420 lift at the valve (single pattern). Would like the peace of mind of knowing exactly what cam is installed!! Don't have a degree wheel otherwise I would've checked the duration too, just another thing I need to buy!! Though... think that means I'll have to machine the valve bosses and/or spring retainers to allow the .480 lift on the exhaust lobe...

I also added Lucas Oil Additive last night to try and thicken up the oil, and it made no change in the noise... So I'm really leaning towards something else mechanical (flexplate/bolts/TC bolts) as being the problem...

Question:
- What would a bent and or burnt valve sound and act like?


Input, thoughts, .020 cents, cautions, experiences??

And THANK YOU btw, for all your help so far!!!

And sorry for the long post!!

 

Well you might be supprised bottom end issues the car will run fine and it will run a while that way but other than a consistantly low oil pressure and noise you wouldnt even know it. Well that is untill it seizes or throws a rod or something lol. I know ive seen my fair share of cars knocking there way down the road lol. Its very possable that having the valve lash tight to the point where it bent the pushrods might have done the cam in. If it wasnt during the break in you might have gotten by but with the break in being so critical idk. Its good to hear its running better though thats a step in the right direction lol. Havnt had a bent valve yet so i dont relly know what kind of symptoms that would show bay a tick/poor performance also irradic vacuum readings but a burned valve depending on how bad would cause it to run rough the header tube for that cylinder would get a bit hot maby even glow irradic vacuum reading. I have to say the vacuum guage is probably my favorite tool. Theres no tool (other than a scanner on a computer controlled car i suppose) that yeilds so much information on a motors health. Things like sticking valves missfires low compression bad timing incorrect af mixture bad valve guids ect..... i could go on for days. Pretty amazing for a $10 tool thats so easy to use. Its like giving you motor a physical lol. Might wanna try hooking one up see how she does.

 

WELL!!!!! I have no fricking clue!!!

I guess I'm gonna have to pull the enigne! But I'm gonna be really PO'd if I pull it apart and don't find any problem (which with my luck is likely what will happen).

I do actually hook my laptop up to the ALDL connector on this guy, and everything it's telling me says it's running fine vaccum-wise, AFR little rich, and so on...

I've got a bad feeling it's a rod bearing letting loose... Doesn't explain why I hear it up through the valve train too though... Other strange thing is I see NO metal in the oil (Haven't since initial break in oil change)... don't get it... but the symptoms are characteristic of rod knock (even though it sounds no where near what a rod knock would - in my experience anyhow). Doesn't do it when cold, does it when warm, doesn't on acceleration, but does at consistent mid-range RPMS and on decel... It's just so weird cuz it comes and goes with idle rpm variations... it'll go away for a few seconds then come back, then go away, then come back...

If a cam lobe, I would expect to see silver fleck in the oil. Same too with a bearing right??

 

Well you should never see mettal flakes in the oil in theory. For one the oil filter should be filtering out the metal flakes. Second just because you dont see any dosnt mean there are none. They may not have drained out, may not have been large enough to see, or just were too few to notice. You may want to try cutting your oil filter open but keep in mind if you open it with a hack saw youll create alot of metal filing lol.

 

Well... Rod bearings were the culprit. I know I'm gonna get flamed for it, but did a poor mans bearing roll with engine in vehicle (NEVER EVER EVER want to do that again!!!)... And it's quiet again (well mostly... there's a slight noise, that may or may not get worse), we'll see how long it lasts! Maybe 250Mi, maybe 250,000Mi....

Back to my other problem. So remember how I said it was running great... well about 2 days prior to doing the bearings, it started popping again (intake) at moderate tip-in, and felt like it had lost power again... So I'm back to trying to figure that one out. Can't be the computer cuz it would have never run as good as it did if it was.... So now back to re-adjusting valve lash, checking fuel flow and timing/spark... yay...

 

damn, that sux. by the syptoms you described sounded like the culprit. sucks to be right on this one.

 

Tell me about it!!! All I can do is laugh to keep from sobbing!!! lol...

All the top halves had "some" damage to them... by looking at some bearing analysis charts, likely due to cold start (initial starting of engine was done with it around the 0*F mark - granted with block heater running and forced air heater on oil pan)... but #1 & #2 were completely foobar'd!!! Top halves anyways... Makes me wonder what might have caused that... The entire bearing coating was gone on the tops... explaining the noise!!! Thing is, those are the ones I know FOR SURE I plastigauged!!!

Now I Just hope it holds together!!! I know better than to just slap new bearings in, but evs... Figured it was worth a shot! And I'll know soon enough if it worked!!

 

Gahdamn... THis has got to be one of the saddest things i've read this year.
Any advice to the rest of us on how to avoid a similar situation, My friends? I'd kill someone if this happened to me. You have all of my sympathy and respect, Wizzard.

 

Someone or something!!!!

So heres where I'm at. Noise is back!!! As was expected! Here's what I think has happened, either the crank was pooched from the get go on 1 & 2 connecting rod throws... or perhaps I may have nicked the crank when assembling, I remember trying to polish out a small imperfection and may have left some burrs on the crank... doesn't explain why the top halves are gone and the bottoms moslty fine...

Regardless, here are my options:
1) Buy eagle rotating assembly and stroke the motor ~900 (minus any machine work on the block)
2) Buy warrantied 350 short block for ~1300
3) replace crank and bearing ~300
4) Use short block built by some kid that buddy has for ~100 and hope he did his homework

Opinions?

 

my vote is for the stroker combo, machine work will be in the $300- $1000 range depending on what you have done.

for what its worth, sounds like your rods arent sized right.

i wouldnt trust some buddys, buddys skills. do it yourself and know it was done right.

1300 for a warranty stocker is ok, but they void those if you add a new cam, and they are weak in stock trim.

to save on machine work, you can clearance your block yourself for a 3.750 stroke.