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Old 04-28-2008, 07:02 AM
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Wiped out a cam lobe :(

Hi guys,

Here is my tale of woe, regarding my 454.

I had a (Ford) mechanic buddy "supervise" the initial starting and break-in process ... which I thought was a GOOD thing, as I am a partsman by trade.

It didn't go exactly as planned.
I had used varsol to clean up the stock HEI distributor, and it must have screwed something up ... as it required excessive cranking and intermittent spark. Enough to fire once in a while ... but would not start and keep running.

I told him what I had done ... was mad at myself ... and just ordered a new one.

Round Two ...
It fired right up (open headers) ... and he starts playing with idle adjustments! I'm shaking my head, and making "UP" motions while he continues to do what he is doing. At the point where he walks away to get his timing light ... I reached over and brought the damned thing up to 2000 - 2500 rpm myself ... and now he's shaking HIS head.

He leaned in closer and I said that we had to get the RPM up to splash oil the cam. He hadn't heard about the ZDDP thing either. I guess Ford must send their reman engines to these guys already broken in or something?

Anyway ... my engine builder had spun this engine up as a preliminary check after rebuilding it, checking for oil pressure, etc... so I thought that perhaps the cam had been "sort of" broken in a bit already. We ran the engine for almost an hour during "round two" and everything seemed to be working just fine. "Phew" (I thought.)

I had started and ran it a few other times ... playing and showing off mostly ... LOL ... before finally bringing it back to my new garage in town. I figured that I had better throw some mufflers on that thing for the neighbor's sake.

After slipping the mufflers on, I fired it up ... and heard "ticking" ... fairly loud ticking ... "Oh Crap"!
I pulled a valve cover off as it sounded like it was coming from the left bank, near the rear. I started it up again, and tried the old "hammer handle" trick trying to isolate what I was HOPING was a faulty lifter. The noise wouldn't go away. I started wiggling rocker arms looking for looseness, and sure enough ... found it on one cylinder (#5). I started and stopped the engine a few times to "make sure" that I got similar results. Yup.

STILL hoping for one bad lifter ... I ordered one more and a set of intake gaskets. I pulled it all apart last night, and found that lifter and the cam lobe destroyed.

So now I'm thinking of going the hydraulic roller route. That flat-tappet cam seemed a little lazy anyway. (Can you hear me try to convince myself here? LOL)
Here's the setup:
1979 454 truck engine
Forged flat-tops
781 heads
Performer RPM intake
(8.??:1 compression? ... was considering a small blower later.)
TH400 with a B&M Nitrous Holeshot 2400 RPM Stall convertor
1966 GMC Fleetside long-box
3.73 gears

The Flat tappet (Clevite 229-2305) cam WAS 224/232, .527 / 553, 114 Lobe Spread which seemed pretty close to what Comp was calling for in a "Blower / Nitrous" cam.

Somebody on here (Bumpstick?) explained once that those 114 cams were lazy in comparion to a 110 ... do I have that right? It idles fairly well at 800 ... I wouldn't mind something just a bit "lumpier". Most cams in that category, however, start looking for 9.5+ compression.

Seeing as how I have to replace this cam anyway ... I'd like to get something that I'll be happy with, right?

Any advice, fellas?

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Old 04-28-2008, 07:14 AM
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Those big cubes will be more forgiving when selecting a camshaft, I would definately go with the 110 LSA.

It is not uncommon for a BBC to wipe out a cam, the different angles of the lifters, valves, pushrods, etc. make it difficult to obtain good valve train geometry. Then you have to make sure you use the right oils or some kind of additive when breaking in the cam and even for the first 3000 miles or so.

The best way to eliminate your Cam problems is to go with the roller cam. Not only will this be better for your motor it will enable you to use a much more aggressive profile camshaft because the rollers allow the camshaft to open and close the valves quicker and hold them open longer. Which improves low end torque without sacrficing top end power.

Example, I have a 254 dur @.050 cam with .660 lift in my 496. It is a solid roller. I was concerned about driveability but didn't want to sacrifice power. This car will idle around at 800 RPM all day or smoke the tires off in any gear. So in my mind Rollers are really the best way to go.
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Old 04-28-2008, 08:01 AM
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Yeah ... I had the right oil (Rotella T 15w40 SI) and had a can of EOS in there too ... so it would have been fine, I think, if the proper procedure had been followed

Thanks for the opinion on the roller cam.
You don't see a big problem with the lower than 9.5 compression, then?
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Old 04-28-2008, 08:51 AM
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It is pretty difficult to say why the cam lobe got wiped then, You took the appropriate steps to ensure that the right oil was used.

BBC's are a little different than SBC's in their oiling, they don't rely strictly on oil being thrown from the crank, you saw the large open area's over the cam that are in the lifter valley right? This means that most of the oil that comes down from the heads will flow right on top of the camshaft before returning to the pan.

This being said, I don't think the cam problem came from not instantly running the motor at 2000+. I would be willing to bet it came from maladjusted rockers, a stuck lifter, or some other binding of the valve train.

This is just a guess though, but since you have to tear the entire motor apart and replace the bearings you probably will find the cause later.

As far as the compression goes, my BBC is only 9:1 and it doesn't seem to affect it that much with a roller cam. You may want to give a call to your favorite cam manufacturer though, I like the guys at Bullet/ultradyne they are super friendly and very knowledgable.

When you tear it down you could also shave the heads or "0" deck the block to increase the compression, just make sure you get an accurate reading of the deck height to piston top so you can tell the machinist how much to take off the block.
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Old 04-28-2008, 09:03 AM
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Gulp ...
Tear the entire motor down?
Replace the bearings?

Ah Jeeez ... greeeaaaaat!

I guess I was hoping that the trash would have just fallen to the bottom of the pan ... check the oil pump to make sure that none of it got picked up ...

This is getting to be much more involved than my original "dream" of replacing a $5.00 valve lifter and intake gaskets.
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Old 04-28-2008, 09:08 AM
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Oh ... BTW ... I'm using new springs and roller-rockers, too ... so there shouldn't have been any lash adjustments or binding problems. Maybe it WAS just a stuck lifter that started the problem ... but it's certainly beyond that now.

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Old 04-28-2008, 09:22 AM
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I'm sorry to hear about you problems - while it isn't the end of the world, it will sure look like it for a while

All that "good" shaved camshaft iron is throughout the engine - though most is probably in the oil filter. While you might not have to replace the bearings, you, for sure have to look at them - all of them, including the cam bearings. Incidentally, you probably should look inside of the oil pump for damage and flush the pick up and clean down any oil passages, including the crank as well. Does that sound like a sales pitch for a nice steel roller cam?? One that really doesn't need the high zinc content!! And it probably had nothing to do with your Ford lovin' buddy - sometimes it's just luck - or should I say, lack of it!!

((And of course, before anyone hops on my case about their experiences and not doing a full tear down, this is of course, my opinion and what I would do if it were to happen to me))

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Old 04-28-2008, 09:30 AM
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~~ Sigh ~~
If it wasn't for bad luck, I wouldn't have any luck at all it seems.

Anyway:
Thanks guys ... I'll yard it out and take it to the machine shop.

I don't care if I have to wait a year unil I can afford it ... but I want it done right.

Here's a pic of the the destruction.

There WILL be a roller cam going back in as well!
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Last edited by 66GMC; 04-28-2008 at 09:36 AM.
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Old 04-28-2008, 09:41 AM
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Quote:
Originally Posted by 66GMC
~~ Sigh ~~
If it wasn't for bad luck, I wouldn't have any luck at all it seems.

Anyway:
Thanks guys ... I'll yard it out and take it to the machine shop.

I don't care if I have to wait a year until I can afford it ... but I want it done right.

Here's a pic of the the destruction.

There WILL be a roller cam going back in as well!
It almost looks like the second lobe to the right of the bad one is on it's way as well.

Assuming you have some tools, you should be able to do most of the work yourself - once it's apart, very hot water, liquid Tide detergent, some engine brushes and a compressed air source will do the clean up.

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Old 04-28-2008, 10:18 AM
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I also agree that it needs to be inspected, I broke a pushrod once and even though it appeared to have broken off cleanly I removed a few bearings and there was little tiny pieces in the main and rod bearings, they had already scratched my new crankshaft and would have ruined it for sure if I hadn't caught it in time.

It is worth the piece of mind knowing it is right instead of hoping it won't destroy itself later.

That is tough luck though, I feel for ya brother.

Just from looking at how compressed those springs are, I would venture a guess that the rockers are too tight. Do you mind me asking what procedure you used when setting the rockers? OR was it that way from the machine shop?

Maybe you can get the machine shop to cut you a deal if it was their fault?
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Old 04-28-2008, 11:10 AM
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Yes, the engine was fully assembled and spun up by the machine shop.

I might be wrong ... but that one rocker arm that I did take off didn't seem to have a locking-style (prevailing torque) nut on it. Once loosened (1/8 turn) it was less than finger tight. I did buy those r/arms at a swap meet ... so I'm not sure of the brand ... nothing marked on them.

I'll check another one or two ... and see if they're the same way.

Maybe I'll post some more details and pictures.
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Old 04-28-2008, 11:49 AM
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If I were to venture a guess, it looks like whoever chose the valvesprings used the cam manufacturers recommendation.... which is not a good thing sometimes.

For instance, Comp sold me springs when I put in a XE262. The springs they sold me were nearly double what was needed for that cam. Cam companies make about three spring rates and then apply them to a broad selection of cams. Thank goodness a friend caught the error and told me about it, otherwise those springs would have ripped through my cam in short order.
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Old 04-28-2008, 11:58 AM
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OK, guys ... bear with me.
Like I said ... not a mechanic ... but a partsman.

I figured out how those r/arms work. There is a hex socket "set screw" kind of thing to adjust tle lash, and the retaining nut just holds the r/arm to the stud, right?

Anyway ... I removed the r/arm from the #7 int (that was the one that you suspected that might be on it's way out, Dave) and yanked the lifter. It looks fairly "normal" to my untrained eye ... but does have a very faint "bullseye" look to it.

I am attaching pics of the springs from a more lateral view, the other 3 cam oiling "windows", and the #7 int side valve lifter.

The springs don't look as tight in these pics.
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Old 04-28-2008, 11:58 AM
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My advice before you send it to the machine shop would be to take a good lifter and slide it into the holes with the bad lobes and check the fit to see if it is too loose, or too tight. Lifters usually go flat because they did not spin freely.
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Old 04-28-2008, 12:00 PM
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Quote:
Originally Posted by carsavvycook
My advice before you send it to the machine shop would be to take a good lifter and slide it into the holes with the bad lobes and check the fit to see if it is too loose, or too tight. Lifters usually go flat because they did not spin freely.
Thanks for that ... but now that the lobe is "toast" ... won't it be too loose anyway?
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