So as some of you know I had to get my cam replaced on my "383" in october and pretty much got the run around, and left the shop with the car in worse shape than it was when I arrived. I and my new mechanic took off everything and pulled my new lifters and cam and the same lobe on the cam id ground down, and same lifter is egg'd. I will post pictures in a bit. We looked at everything and cant figure out what is causing this to do this(luckily my mech is a nice guy and Id consider him a friend and isnt charging me **** so far cause he feels bad for me).. We checked the springs that for some reason have a few schimmys under each one, we checked to see if there was no oil getting to the lifter, we checked the studs to see if they were the same length. WE PRETTY MUCH DID EVERYTHING, this guy isnt a dumbass he did all he could.
Way I see it I have a few options

1) Take the aluminum head off and send it to the machine shop and see if there is any cracks, or imperfections that is causing this issue.

2) Pull the motor since there is a lot of metal shavings in it and rebuild the motor and find out what exactly is inside this block(i.e pistons, crank) since I have no paperwork on if this is even a 383..(We looked up the VIN and it is a 350 block so thats a good thing)

3) Sell my supercharger and buy a crate 350 or 383 and put that in

What do you guys think? I am taking the other shop that did work on my car to court if they dont give me my labor back so I hope I can have some change in my pocket from that..

 

And the block casting # would be....

010?

014?

What is it?

Screw the VIN; give us the casting #, and the other codes near it (esp the 4-char one, one letter + 3 numbers)

If I were the betting kind, I'd bet it's a 70s casting.

 

it is a 1976

 

Usually something simple. Improper break in,springs not set up right, sometimes too heavy of a spring etc. Wouldnt tear a motor down over it unless you see a loss of oil pressure at this point.

Check open/closed pressure, intstalled height etc.
If its a larger FT cam run take the inner spring out for break in (130-140 lbs) then reinstall. If youre using that Comp cam lube forget it, that stuff wipes right off, garbage. Use something else

 

flat tappet cam or a roller?

 

Its a flat tappet, (comp cams 268H) and I used brad penn oil

 

after 40 miles, cylinder 8 intake.. Same one as before

cam on left is the new one only 40 miles old

 

Holy....!! That after 40 miles?

Something else is wrong there, wouldnt blame it on the cam/lifter especially if it happened twice. How is the lifter bore does it fit loose/tight?

If you try and prime it does oil go through that galley? Wow.

Wondering if something is keeping that lifter from spinning and galling it up.

 

The bore felt smooth, and the lifter fit good but it obviously was cold and not a thousand degrees, but I am guessing either my spring(but it wasnt to tight) or my aluminum heads.. I also put a wire through the galley and it wasnt clogged.

 

That is catastrophic damage for only 40 miles... or any mileage especially 2 cams
did you match the springs with the cam..
are the springs installed at the correct height...
what is the seat pressure...
is your valve guide to tight... on this one valve
or did you leave debris inside your block

 

Saw something similar once. When you looked down the lifter bore you could tell that there wasnt enough lobe showing so the lifter wasn riding on it right (dug into the lifter). Rest were Ok...little off but not bad. Dont know if the cam was riding too far to the front of the block as if the rear plug was driven in too far, core shift or what, have no idea. Dont think this is his problem though. Sounds like checking his guide would be worthwhile. Odd

 

Looks about normal for a rolled lobe. Nothing the least bit unusual there.

And, once again, the block casting # is???

Looks to me like you have yerbasic 70s block with The Lifter Bore Problem. But without the casting #, we can't be sure that it's a possibility.

If that's what you've got, you can put new cams in it every day from now to the end of the world, and twice on Sunday; and NOT ONE will EVER survive. Your only hope is to put a roller in it, and even that is no guarantee, because whichever way the bore is pointed besides straight at the cam, might also mis-orient a roller far enough that it can't survive, either.

It'd certainly be wise to check the valve spring setup on that particular valve as well, and on the heads in general; there's other lobes that don't look so happy either.

 

all good ideas guys.. The only two casting numbers I pulled were V1220TYC and C84150308

 

With a lobe wiped out twice now, for sure the engine needs to come apart and be thoroughly scrubbed and cleaned, brushes run through all the oil galleys, etc.... Before that happens, maybe put your oil primer in the engine and make sure oil is making it to #8 in the lifter galley... As others have mentioned, how bad is the core shift in the lifter bores, are the lifter bores lined up with the cam lobes?

So many problems with oil and the lack of additives on flat tappet cams, might want to consider a roller cam and matching valve train. I know of a few engine builders who won't even put a non roller cam in an engine anymore......

 

I will check with the oil primer and #8, I dont know how bad the core shift is/was. And I am definatly going roller cam this time around..

 

Before you put a dime in that block mock up a cam and roller lifter to see how they fit, or dont. Might be saveable or may have to put her out to pasture

Your flat tappet cam has a taper in it to keep the cam from pushing forward...lifter spins also. If its not positioned right it will do exactly what happened. Has the rear cam plug ever been out or is it original?

 

it was pushing forward.. I will upload a picture of the timing cover.. hold on

 

It is even punctured and the other place that did my last came put sylicone over it instead of replacing..

 

.

 

This is a block casting #.



That other is the stamping; tells which engine plant it was, what motor it was part of, the sequential part of the VIN of the vehicle it was in, and stuff like that, but doesn't tell the block part #.

 

I will get that VIN tomorrow.. anybody know what I will need to do a roller cam swap??

 

That's not a "VIN", that's a block casting number.

VIN - Vehicle Identification Number. We're not interested in a vehicle, we're working on a BLOCK, so that's all that matters, is what the BLOCK is. The vehicle it came out of doesn't matter. Although, the VIN you posted up there that was part of the stamping codes, looks like an 80-up one, so it might be new enough to be after they finally got wise and fixed that machine that had been cranking out screwed-up blocks for most of a decade.

To change to a roller setup you need a roller cam, "retdofit" roller lifters, cam button, and valve springs appropriate to whatever cam. Odds are, your existing springs won't cut it, but we don't know that for sure since you haven't told us what they are.

About $600 worth of stuff, maybe more depending on what valve train parts you have now; could easily run up over $800. Enough that it might be cheeeper to scrap that block and start over, if that's what's going on. Best to eliminate all other possible explanations before just jumping to that conclusion. First thing I would suggest checking, is the actual, measured coil bind height of that particular valve spring.

 

I had a similar problem, had 2 cams wipe out the same lobe (No 6 In). Both went after about 10,000 miles. This is on a carbed 70's 350 semi-daily driver with smogger 624's, flat tappet, currently XE262.

First time around, I didn't really look into the cause - put it down to previous owners work, or lack of zinc in oil, or old worn engine, whatever. I sent the heads off to a shop for a valve job, skim, and fit new springs, didn't know much about it myself.

Second time about a year ago - same lobe wiped again in the same way (not nearly bad as yours though!). This time I decided to find the cause. First spent a whole lot of time lurking around here on tgo, learning about valvetrains. Bought a valve micrometer, spring pressure gauge, and stud mount spring compressor. Then took a good look at the parts. Measured ALL clearances on ALL valves + retainers.

Found 3 different kinds of retainer, 2 of which were .035 under stock and had a spigot that interfered with the OD of the spring damper coil. Found that the spring installed heights were all over the place, from 1.650 to 1.750. Found that the springs, both first and second sets, both had damper coils that bound when the main coil was still around 0.100 ish away from bind. Found that the retainer to guide clearance varied by up to 0.100 between valves.

So of course, the problem was - tolerances. An odd short retainer, wrong (low) spring install height, and bind-happy damper coils all lined up the wrong way on the offending valve. I did the maths, and came up with a 0.017 interference after damper coil bind. Most other valves were north of 0.1 before bind. Not much interference, I guess maybe the pushrod sucked it up initially - but enough I guess to cause lobe failure after thousands of miles. Another spring damper was also just in coil bind, but this solved itself by breaking off the end tip of the damper coil. Luck of the draw.

I guess the shop that did the valve job during the first cam swap, dutifully replaced locks/retainers back where they came from - and just passed the interference on. Really hard to spot I guess, but then also no attempt to measure or set spring install height correctly.

Fixed it up with 2nd new cam and all new valve lock parts this time. Including shims to get installed height correct/equal as possible, and springs with shorter damper coils (Comp 981's). And a front cam thrust washer and a cam button for good measure, so my timing cover doesn't end up like yours! Didn't realise flat tappets could walk THAT far, even with chewed lobes!

So I guess I found out - not to assume parts/measurements that should be all the same actually are, and not to assume a shop has done the job properly. Measure absolutely everything critical, especially on an old modified engine, that's had god know what done to it over its life! 1000 + miles now on the second new cam, no signs of problems yet.

 

4 GM. 3970010

 

 

Then yup, 010 is a 70s block; probably the single most common 350 casting; it was made all the way from 69 to (I think) 80. 79 at least.

If you'll post the 4-digit casting date code (will be 1 letter and 3 numbers, will look something like F413, from right near that casting #), we can probably tell you the date the block was cast.

So it's entirely possible that you have The Lifter Bore Problem going on in your motor. Check everything else first; especially the valve spring setup; and if it's all good, then when you've eliminated all those other possible causes, the only remaining one that hasn't been ruled out, must be it.

The timing cover damage was caused by the lifter issue. I.e. it was fine until the lifter and lobe smoked each other, and then that destruction disturbed the cam. The pressure of the dist gear on the cam, fromthe oil pump load, also tends to force the cam rearwards; it's EXTREMELY rare for a cam to walk forward, even in a head-on wreck, because the oil pump puts SO MUCH rearward force on the cam. That's just collateral damage resulting from the REAL problem.

 

Well we are going to take that head off and have it looked at first. If it is that than we are going to drop the pan and check the pump out. If its not the head then its something in the block I guess an it will have to be yanked out.