budget builder

iTrader: (3)

in my sig you can see what car i'm dealing with. I'm having a loud tapping (clacking) sound and have narrowed it down to no.8 cylinder being that the pushrod wasn't moving as much or as good as all the others. as good as it runs it seems as though the cam is in good shape (fingers crossed) so now I guess its time for seafoam. or mmo. or moly lube.

any ideas? any comments? any help is appreciated.

oh forgot: I changed oil 10w30 Castrol, rebuild has appx. 20k on it. with zinc additive

sofakingdom

iTrader: (1)

Not to be mean or anything; but in a motor with 20k miles on it - BRAND NEW - a diesel fuel/water mix, or any other kind of "rebuild in a can", isn't going to fix what's most likely wrong with it. Which is, a rolled cam lobe. Crossing the fingers won't put the metal back if it's gone.

I'd recommend popping the intake off and having a look. Pouring different stuff in the oil has just about a 99.9999% of accomplishing absolutely nothing whatsoever. Gunk can't accumulate to a level that will make one push rod move visibly less than the others. You need to start checking for a cam lobe down. And then if there is one, time for another block, which hopefully the lifter bores will be better pointed straight at the cam better than the one you have now. (let me guess... "high nickel"? 010 casting? Got it for a REAL good price?)

Sucks, I know. But don't wear your rose-colored glasses too long though, because if it IS a cam lobe gone down, all those metal chips that it sheds, will trash your crank and bearings sooner than later.

GeneralDisorder

iTrader: (1)

Is there any sponginess to the rocker? What lifters were used? I think the best thing you might hope for is a poorly manufactured lifter. Since it's only one it's probably not likely to be an oil pressure problem.....

One easy way to get a picture of what's going on - pull an oil sample and send it for analysis. It's only about $25.

You can also get a proper filter cutter and check the oil filter for metal flakes, etc.

Pull pan.....

It's a progressive process of increasing severity when you are dealing with an engine going south shortly after a rebuild. Start with what you can inspect for free, get an oil analysis to see what, if any, metals are present - it can give you a good idea of their source.

GD

cardo0

As sofaking stated you likely have a wiped cam lobe and you need to dissasemble to inspect the cam lobes and lifters. Denial will only prolong the pain and the more you run it the more your cam lobes turn into tiny particles. Hey we've all been there (at least once). So don't feel we are trying to flame you.

Premature cam lobe wear is:
- lack of break in and running at to low RPM to long before cam break-in
Engine needs to go to 2000 RPM for 20 min as soon as you can start it
- spring pressure to high
- lack break-in lube or oiling
- improper lifter pre-load

Sorry to read the bad news.

NoEmissions84TA

iTrader: (1)

Sofa, what do you know about this? In 1988, I bought a bare 350 "hi-tin" block from GM.
bought new in crate 1988 350 5.7L 4 Bolt Main
3970010 Hi-Tin 4" STD Bore
#2482 nodular iron intermediate caps

Some of the lifters flat tappet lifters would not spin, which I determined to be from some of the lifter bores "being off" (not 90 degrees to the camshaft centerline). I could not understand how that could be, since they are all gang-drilled at once.

sofakingdom

iTrader: (1)

I don't really "know" a whole lot, I can only report personal observations (VERY small sample size I admit, in the big picture) and "common knowledge".

Target motors were among the worst. Those were new-car warranty returns that got "rebuilt". But of course, if the block is machined wrong in the 1st place, you can "rebuild" it EVERY SINGLE DAY, and TWICE every Sunday just for good measure, and it will STILL be EFFFFED up forever. I remember one of those I worked on where the main bearings had NEGATIVE .002" clearance, even though the crank mic'ed right. I guess they just "rebuilt" em, never bothered to CHECK anything, let alone figure out why they were even back in the "rebuild" bin at all, instead of happily towing vehicles around for hundreds of thousands of trouble-free miles.

I've had numerous 70s blocks, from the heart of the age of GM's (and the other US mfrs) "quality control", wherein the quality was always carefully restrained from ever getting too high. Gotta love that surly lazy union labor, that complacent upper management more lulled to sleep by "the storied history" than by their declining sales as the Japanese ate their lunch, that inexperienced stupid clueless middle management that knew SO LITTLE about actual CARS that they thought that they were going to make one brand of cars "strongly branded" by making their wheels and NO OTHER GM brand have 5 spokes, that cozy relationship with "suppliers" that figured out how to crank out the lowest possible cost GARBAGE for their "internal customers" and just barely not get caught for fraud, ... I got REAL used to dealing with The Problems of 70s blocks.

• Starter bolt holes drilled too far from the crank - makes the starter make that horrible grinding noise you can hear from 400 yds away, turn real slow, wear out starters and flex plates, and sometimes even break starter nosepieces, especially if you put a REALLY HOT battery in there... I had one that I hooked up TWO batteries to, just to try to get it to spin fast enough to START, and the starter broke off and literally fell down TO THE GROUND
• Lifter bores that don't point at the cam - I've personally known blocks that went 4 cams deep UNDER ONE OWNER (not the first, not the last) and wiped out the same lobes every time; while I don't have a way to measure them accurately enough to know, ... see my signature.
• Bell housing dowels that aren't centered on the crank - EATS pump bushings in automatic transmissions and makes them make loud whining noises and live short lives... offset BH dowels were a hot item for many years... got a 74 454 sitting in my driveway in a car I bought in the mid 80s that does that to this day
• Head deck dowel pins that aren't centered on the pattern of anything - causes those mystery intake leaks that you can change intakes 50 times and never fix
• Cylinders that don't point at the crank - I measured one once where the rod bearing centerline missed the crank journal centerline by almost ¼"... needless to say, that one was near impossible to turn by hand by the time 3 or 4 pistons were in, and all the rods were DESTROYED on the sides after a few hrs of run-in, and it always made lots of just unsettling grinding gnashing gnawing mechanical noise that we couldn't exactly pinpoint what it was but was WAY louder in the pan than anywhere else
• Block decks that aren't parallel to the crank - go ahead, I DARE you, measure the deck height of ANY 70s block, and weep when you see that the decks are usually at least .005" different on average, and often .010" OR MORE on the same side from front to rear
• Oil passages mis-drilled - those ½" oil plugs around the cam at the front, cover passages that are drilled from the front halfway through, and the ones at the rear the same, and they're supposed to meet in the middle; I've seen MORE THAN ONE block that you couldn't jam a piece of ¼" wire from one end to the other to knock out the plugs... whaddya think that did for oil flow?

And that's just BLOCKS. Shall I keep going? And some of these things went on for DECADES either because nobody noticed, or nobody gave a s***, or nobody bothered to investigate why, or mgmt. decided that it was cheeeeeeeeeper to keep producing STEAMING BUCKETS OF SPIT than it was to replace the narfed-out bearing in the gang-drill machine for 10 SOLID YEARS because it "wasn't in this year's budget"...

Fortunately, lots of those blocks have found their way to the scrapyard, where they belong. But a few are still in circulation. Whenever I hear, or see on a forum, that somebody has a "10/20 high nickel/tin block" from a "69 Z/28" or a "71 Vette LT-1" (wasn't that the year that had that terrible body rust problem? yes, I've actually been told that.... thereby freeing up literally hundreds of thousands of those motors running around that all came out of the 20k or so Vettes from that year, to become widely traded), or they got the motor in just-not-quite-running condition for $250 that had $3000 worth of go-fast parts in it for some wildly improbable reason like "wife wanted something that gets better gas mileage" or "race car was too fast, was bringing home too many purses, no fun anymore, wanted to drop back acoupla classes", or any of that sort of stuff, I can be pretty sure that their block will ultimately turn out to have some one of The Problems or other.

NoEmissions84TA

iTrader: (1)

Thanks. I did not know those blocks have all of those issues.

That engine of mine, (I still have it), I made the lifters rotate by using a diamond file on the camshaft lobes where the lifters were not spinning. As it turns out, the lifter rotation is done on the closing ramp of the lobe. I only had to file .002" max off of the lobes so that there was greater contact at the interface towards the outside of the lifter. They spin like crazy now. To test, you can just insert the camshaft back into the block, and put a lifter on that lobe. No valvetrain needs to be assembled. As you rotate the camshaft, you can actually see the lifters spin.
But without lifter bore correction, this block should only be used with roller camshafts in the future.

sofakingdom

iTrader: (1)

Keep building motors, you'll probably see some of that stuff. Especially if you build ones where people bring you their own cores that they've had trouble with and want you to "make it right". It's not anywhere near as bad nowadays as it was in the early-mid 80s, but they're still out there.

nhgator

Dammit Sofa,I bet you could wax philosophically about a colonoscopy and make it sound damn inviting.

GeneralDisorder

iTrader: (1)

So when did they get after fixing these problems?

GD

sofakingdom

iTrader: (1)

GD, I think Xler's first slide into bankruptcy, which took awhile, was a major wake-up call for the US Big 3. So, around the time these cars came out, and the US Big3 market share was down from 98% to 60% or whatever it was by 1980, mgmt began reconciling itself to the fact that the public wasn't buying "the storied history", they were buying CARS; and at some point, they needed to produce CARS that the public wouldn't laugh at. For GM, these cars were one of the first attempts to climb out of the gutter. For Frod, it took acouple more years... it could be argued that they had farther to go.

To this day, there are American people who refuse to even consider buying an American car. Hard to believe but true. A real shame that those companies shot themselves in the shorts so hard. It'll take GENERATIONS for them to dig out of the hole they excavated for themselves. But they don't have generations to do it in... just look at Sears. Another shining example of ivory-tower arrogance while the business model collapses all around.

The Starter Problem seems to have disappeared around 80. The Lifter Bore problem kept on for a few more years. In about 82 or 83 a friend of mine had a 81 Z28, and I had a 79 one, both 350s, both of which ate cams, both of them near the back on the driver's side, as was most typical. I don't think they ever got the decks square and level in the SBC or BBC; maybe they're better in the plants and machinery that make the LSx motors, I couldn't say, I don't build motors too much anymore.

GeneralDisorder

iTrader: (1)

So the lifter bore alignment issue - I can see how that would dramatically impact the flat tappet cam/lifter interface. Wouldn't a roller cam alleviate most of that problem? Obviously they fixed the problem eventually anyway. Just a thought exercise. Would have to use retrofit linked roller lifters.

GD

NoEmissions84TA

iTrader: (1)

Maybe GM did not fix the lifter bore issue - the change to roller lifters just sidestepped the problem.

GeneralDisorder

iTrader: (1)

My 86 LB9 is flat tappet and has 160k original miles. Rollers didn't come till 87 in cars, and later in trucks.

I was under the impression that early 80's cams had metallurgical issues that caused them to go flat. Maybe that was a separate issue?

GD

NoEmissions84TA

iTrader: (1)

My 1988 GM Performance Parts Gen 1 350 block has the lifter bore problem.
Yes, "soft" cams plagued many manufacturers, not just GM in the early 80s. Improper heat treating/Parkerizing.
And we still are feeling the effects of inferior import "Made in USA" flat tappet lifters (Skip White for one) that flooded the market when 2 of the 4 lifter manufacturing companies closed their doors and the 2 left could not supply all of the demand. That also happened to be at the exact time when GM switched to roller lifters. As long as the company's headquarters is in the US, the actual product can be made offshore and still be labeled "Made in the USA"! Buyer beware.

budget builder

iTrader: (3)

well dang sofa,

my name is budget builder for a reason. I literally had a dollar and a dream. the dream of having a 350sbc/nascar streetable/dragster engine in my 91 Camaro. ive sunk all this money into it and now you tell me (in so many words) looks like I'm screwed".


ok now that I'm finished whining its time for me to put on my big boy pants and find out what is the best and most cost effective course of action. SOFA I was just kidding. the news is disheartening but I knew the risk when I took this on. i need to drain oil, antifreeze, and pull intake, then pull timing cover, cam, gear,& chain. then pull push rods, lifters, cam. mic cam, replace cam (more than likely the culprit) replace lifters with good quality. replace rods, chain, both gears, intake gaskets, refill fluids, reset timing and adjust all valves.

what am i missing? Best Oil? is the block truly trashed? is it time to buy crate/warranty 434? is it possible to get out of this less than $1k?

i don't want to just throw money at it. Ugggh thi thing was running good until now. really good.

sofakingdom

iTrader: (1)

I'd pop the intake off real quick and have a look first, then go from there.

NoEmissions84TA

iTrader: (1)

Drain coolant. Rotate engine to #6 TDC. Mark the rotor location. Remove distributor. Remove the intake. The valve covers need to already have been removed to do so. Loosen all rockers to remove the pushrods. Remove water pump, harmonic balancer and timing cover. Make sure crankshaft does not move, because it will me much easier to line everything up later. The dots on the timing set gears should be pointing right at each other. Remove the timing chain and put the cam gear back on. Now you can rotate the cam gear and watch the lifters go up & down. I bet you see 1 or 2 not moving as much as the others. If so, your camshaft is shot and it is now time to make decisions. Pull the lifters, keeping them in order. Pull the camshaft carefully as not to destroy the cam bearings. Report your findings here.

budget builder

iTrader: (3)

thk u
I got more time than money right now but I have a friend whos dad is an old school racer and has been for about 50yrs and if everything goes right we will check it out Friday. thx for the advice

NoEmissions84TA

iTrader: (1)

You're welcome. Hopefully, your damage is minimal.

budget builder

iTrader: (3)

Well starting from scratch. Checking everything. Compressiin test. 202-205# on every cylinder. Adjust where #1 was and got more advance adjustment on dizzy. Checked plugs. Car was starving for fuel ( proper burn only on three).
got it purring like a kitten. (Seriously) purring. Adjusted idle and triple checked timing. Now for the problems we were having. The rhythmic clank (stethoscope) in the front was causing the timing to jump about 10-12degrees each time. (Likely timing chain). so few miles the ???? Is why. Friend's father says it's time to pull engine and tear down see what damage. Pull intake check lifters, pressed in rocker studs, and lets not forget the camshaft. No patching. FIX all problems. All leaking gaskets/seals. Put all back together properly. Will post results.

I should have never touched car. I heard the lifter tried to adjust the valve said what the heck , did them all. The car ran different so I adjusted the carb. Vaccuum fell off so I adjusted more and did timing. Didn't realize I I crossed plug wires when I took of the valve covers when messed with valves. Then ran the engine wondering why it ran like crap. All valves we're too tooooo tight. He said that and the bad timing and the crossed wires. Put l engine in bind plus pressure on timing chain and gears. All that and I didn't FIX the lifter. I screwed up. Being in a hurry. Now he's helping and said we doing it right! I hope this example of stupidity helps someone

budget builder

iTrader: (3)

Update:::
well time for rebuild. And amateur hour is over. Mismatched bolts in fly wheel-crank. No star washers. Torque converter bolts loose enough to unscrew by hand. Loose header bolts. Too small carb. Yes, wiped cam on no.8. And last but not least 3 cylinders with a v crack at the bottom interior of the block. Iike something crazy I was hoping it was a oil valley of some kind molded in but uh no. Cracks!!!!!!!. Regardless of holding compression now it's sure to fail with more pressure and time. This with leaking seals and bad lifters. Yeah my days as an engine builder are over.

In comes Mr. Andy. Thk God. He is a REAL engine builder with Decades of knowledge, research, experience. He says the 350 that came out of my c10 might be a good replacement. He will check it and wants me right by his side to learn the right way. Machine work and all. So here we go!!!!!!!!!!

NoEmissions84TA

iTrader: (1)

Funny how things work out that way.

budget builder

iTrader: (3)

Took engine apart. Serpentine assembly super heavy. Going back with reg pulleys. Harmonic balancer is garbage. Cam bearing scarred. Rod bearing wore down to copper. Mains have unusual wear pattern. One of rod caps popped up like under unseen pressure when one of the nuts were loosened. Mr Andy said it was unusual. The cracks I seen we're not what I thought. Will be Magnavoxing the block and crank. Crank trueness is suspect. Crank and rods only .010 over. Then depending on outcome will go from there with hone, deck, align hone rods. balance rotating assembly and so on. Check rods pistons New cam bearing and mains. The whole shebangabang. But he said first we find out what we got!!!!!

he's doing this for free in his free time. So even though I'm impatient I'm going to shut up sit down and learn. I don't care IF to takes a month. He said he could have it done in a day, but what would I and his son learn?

Can't argue with that. Updates coming.

budget builder

iTrader: (3)

Crank already checked. 100% PERFECT. So now on to the block.

60Yr machine shop said 90% of this kind of bearing damage is cheap oil and oil filter. I remember changing to 5w30 because I thought the was thin enuff fr a rebuilt engine. Mr Andy said he uses 20w??? Or rotella 15w40 and make sure u use ZINC!!!!! Will be going to comp cam 292. Instead of xe268h. Only worry is do we need screw in studs. The vortex head kit I ordered from scoggin dickey is upgraded springs for up to .525. But pressed studs might not hold. Here we go!!!!!!

GeneralDisorder

iTrader: (1)

I run 15w50 Dominator race oil in all my motor builds. Because high film strength. The viscosity rating has little to do with the pour and flow characteristics. The 15w50 I run in my builds pours like a 5w30 out of the bottle. It's really quite an eye opener to pour the 15w50 Dom.... most folks experience with discount parts store 20w50.... Yeah that stuff looks like gear oil when you are pouring it. Real synthetics at these weights are s completely different animal. For forced induction applications Amsoil has no qualms about recommending a 15w50 for an engine that will see heavy loading even with stock oil clearances.

budget builder

iTrader: (3)

Forgot to say they also mentioned bad oil pump is also possible. But bought a high volume oil pump. How could this be?update::

Never mind I just did some research. Crap. Looks like I seriously screwed myself.

sofakingdom

iTrader: (1)

If you have some 70s block now, and it needs THAT KIND of work to make it functionable again, might be real wise to just start over with a nice late-90s block instead.

You can probably pick one up at yer local buzzard nest for A FRACTION of what it will cost to "repair" that other ... one. And then, when you're done, not have to worry which one of The Problems I listed a few of above, that you didn't accidentally overlook but won't find out about until it's too late. AND, get a roller cam setup thrown in on the deal.

"Fixing" it might be "free" in terms of cash, but wasting someone else's life on ... that ..., to me, is a violation against their human dignity. I know I wouldn't appreciate somebody doing that to me, not even my own children.

Just throw that old crap in the trash and cut your losses, and improve your odds for the future.

Oh BTW, what you do to cast iron is Magnaflux, not Magnavox.

And with a newer roller-cam block, you'll be able to use normal oil you can buy down at the local Wally World or wherever. Life will be MUCH eeeeeeeezier. In fact, acoupla oil changes might repay your new block bill all by themselves, in cash.

budget builder

iTrader: (3)

Thx buddy

sofakingdom

iTrader: (1)

You're welcome:

One of the frustrating things about this hobby sometimes, is not being able to see at the beginning of a project, how much extra "saving money" on some critical thing at the front end, will end up costing in the long run. For someone who hasn't done it a lot especially, it makes what's supposed to be fun, feel more like a beat-down. Blocks and heads - the big castings that you "rebuild" and pile wheelbarrows of $$$$ into, that once spent are gone forever, because you can't take machine work BACK OUT - are particularly prone to this. By the time you spend what it takes to "fix" whatever ails whatever you got "cheeeeeep", you're into it for WAY more money than just throwing the "cheeeeeep" in the trash (or avoiding it in the first place) and buying good, at the first sign of trouble. And then in the end, you're NOT ONLY down more $$$$$ than the other path, BUT ALSO, you still have a bunch of ... "cheeeeeeeep" ... that's been somehow coaxed or beaten or massaged or half-a$$ed into appearing to work, but usually only for a short time at a time. Whereas if you'd done the other, you might be in a position to just enjoy the fruits of your labor for years without hassle, instead of cursing your luck every time one more thing goes wrong with it.

I kinda think you might be at one of those decision points. I can't look into the future and make a 100% accurate prediction, but ... I think that no matter how much time trouble effort and money you put into that old block, whether your own or someone else's, it'll still come back to bite you, sooner than later. Everything you have described about that motor sends up red signal flares in that way.

I hope the C10 one you speak of is better than this one. Let us know what you find. Still, if for no other reasons than the roller cam setup and the better quality control on the machine work, I think you'd be well advised to just pick up a guaranteed non-running 96-2000 core motor at the boneyard, and starting fresh.

NoEmissions84TA

iTrader: (1)

As always, great advice Sofa.

budget builder - when a rod bearing "pops" or falls out of the rod or cap, it is because it has lost it's outward crush.
That is caused by detonation. It is what happens when the cylinder fires before it is supposed to, when the piston is still compressing the air/fuel mixture and ignition happens, which tries to force the piston back down while the crankshaft is still trying to push it up. What you want to happen is the explosion to drive the piston down after TDC - Top Dead Center. But the actual spark is initiated BEFORE TDC. Why, you say. Because it takes a little time between the spark plug firing and the explosion actually occurring.

GeneralDisorder

iTrader: (1)

Basically. But actually there is no "explosion", only an ignition, and a burn. It's actually burning, not exploding. And the delay is the time it takes for the "flame front" to propagate from the tip of the spark plug to the top of the piston. The expanding gasses immediately behind the flame front are like a wave of pressure that acts upon (and reflects off of) the top of the piston. The time it takes for this pressure wave to reach the piston allows the piston to move farther up the bore.. Thus ignition generally must occur prior to TDC.

NoEmissions84TA

iTrader: (1)

Completely correct. I was just trying to keep it simple.

GeneralDisorder

iTrader: (1)

I figured. I had a shop teacher back in high school that was very adamant that we not call it an explosion. He had one of those demostration engines with a transparent cylinder that we ran on all kinds of things to see how they burned and what color the combustion was, etc. I remember it ran really good on model airplane fuel.

NoEmissions84TA

iTrader: (1)

I would love to have one of those transparent engines.

Was the woodshop teacher named Richard Adler?