wiped lobe, please help or console me

[Desertson]

So that #5 exhaust valve kept getting loose on a brand new Motor with only a few hours on it. I knew there was something to it and unfortunately I was right. About a quarter to 1/4 of an inch was eaten off the lifter which had to be removed through the cam bore due to the dammage. When I probed the abyss of the oil pan with a magnet I of course found a lot of black steel paste, which I would imagine is the ideal substance for destroying bearings, piston rings, etc., etc. What can I do for damage control? Is there any hope? It is a 393 so the nasty sediment in the stock oil pan is sure to have gotten splashed everywhere. At least I know this is my own fault I supose I'll have to hot tank the #$%&@#$. I really can't afford this...

[Excaliber]

I'll get flamed for this but here goes, for those on a budget...

Put in a new stick and lifters, flush/clean the motor as best you can and change the oil and filter after the new cam is broken in. Improper breakin procedure is most likely what led to the bad cam's failure. Change the oil a LOT initially after the repair to try to get as much debris out as possible. The only other choice, and one that is OFTEN expressed here is: Tear the motor down ALL the way, clean and rebuild. Hey if you aint got the money, you do the best you can with what you got to work with (flame suit on).

A new fat tappet cam failing is actually pretty common for one main reason, to much initial valve spring pressure. The lifters MUST "rotate" in the bore and they MUST start that rotation immediatly upon the first fire up. If not, they get eaten! I assume you have double springs AND a damper spring? The center spring (smallest one) should be REMOVED before you start the motor. Fire it up and run it 20-30 minutes at 2000-2500 rpm right from the get go. This gets plenty of oil splashing on the cam and varying the rpm gets that oil to different areas of the cam. Make sure that bad lifter bore is nice and smooth so the new lifter will start to rotate. After 30 minutes or so you cam is either broke in or it aint. If it aint, you'll eat another lifter within a short time (miles).

After that 30 minute run, drain the oil and change the filter. Change the filter several times within short order. You might cut it open and inspect internally for debris. Keep changing fliter/oil until you feel you did the best you can within reason.

My hunch is:
This is NOT catastrophic and the motor WILL survive with a good internal cleaning. The debris particles (small though they be) will find their way to your rod and main bearings and could cause some scoring which will lead (eventually) to "premature" bearing failure. But premature could be a LONG way down the road and possibly more miles than the motor may EVER see!

Double check your valve spring specs and make sure those springs match the cam suppliers recomendation. You'll need to use compressed air with the piston at TDC when you compress the valve spring with the "special tool" to remove the keepers and finally to remove the inner spring. AFTER break in, repeat this procedure to re-install the center springs. It's a pain in the butt, but it beats doing your cam over AGAIN, and AGAIN!

See my "Engine Blog" thread for pictures and additional details to the "inner spring" removal problem.
HERE:
427 side oiler engine build "Blog"

[Desertson]

Thanks for the positive outlook, I have a sneaking suspicion as to the cause of the failure which is that I had re-use my old Duraspark II distributor, I initially tapped it down into place, realized I had to jump it over a few teeth and pulled it out only to discover that crud had fallen out from inside it and landed all over the first few lobes! I thought I got it all off but maybe it appears I was mistaken. I am always weary of break in and cranked to 2500 for exactly 30 minutes, took about 15 or 20 before I noticed a rattle . The cam broke in 93.7% perfect anyways . I shudder to think of the cost of even new head gaskets, but when I think of what I paid for my rotating assembly the cost of new rings, bearings, gaskets and a hot tank doesn’t look so bad. Then again I'm only 20 and this is a Mustang coupe not a Cobra. This is a very difficult (and painful) decision for me. Thanks very much for the first post, the center springs will not be present next time during break regardless, I never thought of that. hmmmm its 4:30 AM in New Hampshire, I believe I’m loosing sleep over this.

[RICK LAKE]

Dersertson I am on the other side of the fence. Tear the motor apart!! Are you LUCKY?? I know it hurts bad every time you pull a motor apart, $150.00 and gaskets, oil,filter, RTV, and time, With the amount of time on the engine, I would doubt that any bad damage was done. Check all the bearings and surfaces. Make sure they are smooth with no grooves in them, remike the crank and rod bearings. Double check everything. If OK but it back togeather. Take your time about this. Clean the motor out and air dry. prelube all the surfaces. Take the dampeners (springs) out and run it for 20 minutes at 2000 rpm with the one spring. After change the oil and filter. Cut the filter open and look for any metal flakes or chips in the paper pleats. If not, put the other springs in there and run it.If you find metal partials in there, you got choise A or B. Change oil and filter and try again or send out to machinist and redo. If the lifter is not spinning the bore may be too tight. Mike both and check the spec. You may have to hone the hole .001" and the problem is fixed. Get a bottle from a GM dealership of EOS oil and assembly the motor with this on all the riding surfaces. Pour the rest in the gallery before you put the intake on. Try and get the motor to fire up first crank. Good luck. If you have any doubt, go back to the machinist, better a little now than a crank resurface, rods resized, major hone job and new pistons and $2,500.00 later of which you don't have today to fit it. Rick Lake Ps Live Free or Die, means Be smart or Get burned. hope for the best

[CowtownCobra]

Seems to be a rash of these lately...

[Excaliber]

In cleaning that crud that dropped on the cam area perhaps you also cleaned off the cam lube? Using the cam manufacturers cam lube is essential, and use plenty of it.

I agree Cowtown, it seems there HAS been a "rash" of cam failures lately, and thats just what we hear about on here! I suspect valve spring pressures have gone up over the years and it's now IMPERATIVE that the inner spring be removed before engine start.

EOS good stuff, there are a couple of other "essential oils" required for a re-build. Again, see the "Engine Blog" thread for details.

[CowtownCobra]

That or the quality of steel has gone down...

[trularin]

Rick has very good advice. You should take the engine apart and clean everything. No sense putting money into the toilet.

Sorry Ernie, I think the fillings will be everywhere.

It is cheaper to be sure than to risk it. It like saying, "oh, that nut will get passed out the exhaust." when someone asks what to do if they drop a nut down the carb.

Just my $0.02

[elgecko]

A concern of mine is if you use the manufactures cam lube(Comp Cams) and are not planning to fire the engine up in a few months, will the lube run off over a period of time, no matter how much lube you put on the lifters and lobes. Is there a thicker cam lube for the extended period before fire-up ????
Cam steel........ Made in China ???
Dave

[Desertson]

Well my preliminary research reveals no damage to the lifter other than on the foot ware it ground against the cam, and a good lifter rotates and moves properly in the #5E bore. As for lube I used the comp cams stuff when I first put the cam in (the first thing to go in the block) and then slathered it with Permatex Ultra Slick (the red stuff), which seems to be identical to what comp provides, before I put the lifters in. It did still have I think 60ish lbs of oil pressure when it was last shut off.

Looks like I will have to pull it and tear it down, I have a few questions about what I should or should not do.

1. Piston rings. Should they be replaced? Should the cylinders be lightly honed or will I be ok if the hatch pattern is still clear? 3 hours is actually an exaggeration, it has probably only run for 45-90 min.

2. Hot tank or no?

3. Never pulled a set of Aluminum heads before, do I loosen the bolts in the same order they were tightened or do I reverse that order?

4. Wrist pins. Will I have to remove the spiral locks (not fun) and clean these or can this be avoided, or should I perhaps base my decision on the condition of the rod bearings?


Those are all of the concerns I can think of at the moment, I don’t think I can blame the distributor or the Chinese for this. Thanks for the help.

[kountzecobra]

I'm going through the same thing. Funny, but it is #5 exhaust on my 351C that went flat. I also heard of a 427 with the same #5 exhaust flat. I broke mine in without the inner valve springs and did everything by the book, but the Reed cam went flat and ate two lifters in the first few miles. The lifters were turning too, as the wear pattern was even. I just flushed the engine, then replaced the bearings and oil pump even though everything looked just fine. Also epoxied 4 magnets inside of the oil pan for good measure.
BTW, once I built an engine and used lots of Comp Cam Lube and after setting before startup for over 3 years, I had no cam problems. Pretty good stuff. Pre lube with a drill before starting.
The machine shop I use sometime always uses ARP Moly Thread Lube on cam lobes and lifters. He swears by it.

[rdorman]

I think mine was the intake on four.

1/4"

Metal floating around is generally a bad thing. Any thing short of tearing it apart and tanking it is probably a risk.

With that said, I looked at it carefully and decided to flush the thing out. Worked fine and it has been about 4000 miles so far. I did flush the whole system quite a bit, changed oil and filter before during and after the flushing and initial break in and then again in about 300 miles. Used a magnetic drain plug and cut each of the filters open. After the initial break in things have been metal free. Obviously this was not the ultimate choice but it has worked OK. Oh, and don't flush the motor with your new lifters in it!

Rick

[Excaliber]

trularin,,,,, a small nut dwon the carb? I've seen them pass on through, depends on the size, and youe budget.

Debris in the motor? Depends on the size and your budget. Are you feeling "lucky", 'cause sometimes you might be!

Sometime it comes down to a couple of choices when your on a budget. When you don't have the dollars sometimes you gotta take a chance, and sometimes "life sucks".

1. Risk doing the rebuild yourself, that could be as risky or more so than doing a flush! Only the owner can make that call.

2. Take it somewhere and have the motor rebuilt, on a tight budget option #2 simply is not an option!

Faced with this very problem myself recently I went with option number 1. But when I was a young man, the first couple of times I went with "option #1" resulted in toasted motors anyway!

[Desertson]

Excaliber, I already built the thing once, even sized the rings by hand (quite tedious), the second time should be a breeze right ?

I wish this would have happened to the 350 I built last year for my '86 1 ton, only spent about $ 500 on that job and it had it’s crank cracked in half to begin with. You know what they say, any redneck can build a Chevy but building a Ford is another matter.

So the motor will be pulled and then the least I can do is to hot tank it and change the cam bearings, I will reuse the other bearings if possible. If anyone could helped with the aforementioned 3 questions I would very much appreciate it, thanks.

Again:

1. Piston rings. Should they be replaced? Should the cylinders be lightly honed or will I be ok if the hatch pattern is still clear? 3 hours is actually an exaggeration, it has probably only run for 45-90 min.

2. Hot tank or no?

3. Never pulled a set of Aluminum heads before, do I loosen the bolts in the same order they were tightened or do I reverse that order?

4. Wrist pins. Will I have to remove the spiral locks (not fun) and clean these or can this be avoided, or should I perhaps base my decision on the condition of the rod bearings?

[Excaliber]

Houston, we have a go for motor rebuild! Roger that, Go on throttle up.

Bear in mind the SAFE and politically correct answer to ANY motor rebuild question is ALWAYS: Replace everything and start over from scratch! How can you argue with THAT answer!

Myself? I'd be tempted to run the same rings in the same bore and leave the hone alone, under the conditions of THIS motor. Why hot tank? Whats wrong with "cold tank"? Wash the block and chase the oil holes with a series of small brushes, etc. I ASSUME this block is pretty darn clean all ready and your getting any debris left over, out. Hot tanking won't scrub the oil holes, just remove the cacked on oil, dirt, etc. Clean and wash and leave the cam bearings alone (again I ASSUME those cam bearings were new before this happened). Of course inspection for damage is always warranted.

It's a good idea to relieve the pressure on the head bolts in a pattern, can't go wrong there!

I can't figure out why you would want to pull the wrist pin and those dreadful spiral locks? If you DID pull the locks I would consider replacing them with new because they are easily damaged taking apart. Inspect and replace rod/main bearings according to condition, if they show "scoring", go for new and "bottle brush" the crank oil holes, even hot tanking won't clean them good enough in this case.

Heres a tip: If the bearing shells stay on the crank journal when you pull the rod away that indicates the rod is NOT holding the bearing tight enough. Out of round or "to big" a rod, sort of thing. The bearings should stay with the rod halves on the tear down.

This motor has what, an hour of run time? I wouldn't replace SQUAT on this motor unless there was a darn good reason to "condemn" the part in question. And that includes the oil pump! Clean and reassemble.

[RICK LAKE]

Desertson Your first name would be nice? Any way To hot tank the motor would be OK if it is the soap ONLY deal NO ACIDS or ALOCLIDES in with the water. Unless you see scratches in the cylinder walls they should be OK. Number the rods and pistons so they go back in the same holes. If you can slide them apart check them, if not make sure the piston rotates easy on the rod and pin, no binding. As far as the bearing thing slick said I have pulled apart more engines than I would like to remember, SOMETIMES the bearing stay with the cap and sometimes it stay with the crank I would mike them!! not the guess that my ERA friend said. For removing bolts on heads, take 1/4 turn on all then take off anyway you want. reassembly take them down to torque spec in 10 lbs increments. Rods bolts are now being checked more by bolt stretch than torque readings. The spec for the rod bolts is very close to the stretch number. Piston rings, check for the scratches in the cylinder walls, if you have them the block my need a hone job and you will need new rings, the end gap will to larger than spec and you will have a little less power and sealing. Bottom line USE YOUR COMMON SENSE. Remember Animal house and the 2 guys sitting on Pintos shoulders? You will know Good luck Rick Lake

[Excaliber]

I agree with Rick on the rod thing. Thats the one area where you just can't be to careful. My experience has been when the bearings stay on the rod journal, thats a "red flag" for that rod, but sometimes it just happens and the rod is fine anyway.

By the way, I always use plasti gauge as a "double check" to the mic readings (as many professional builders and race teams do).

[Desertson]

My name is Mike, sorry about that

The block and components of the motor were spotless when they went together, with the notable exception of the distributor the cam bearings were new as well.

Such awful whether here in New England this week, I'm going to have to wait for a nice sunny Saturday to start the rebuild, otherwise it's just too depressing.

[Excaliber]

It took me MONTHS to get my motor back together after loosing a cam. The first month I spent doing a LOT of reading and thinking about what to do (and bummed out in general)! Replace the cam, flush the motor and keep going? Which I would have done, but there were other issues I wanted to address that called for a complete tear down (like the 12.5 to 1 compression ratio).

At least it's summer time, a sunny day coming soon! I did mine in the winter.

[RICK LAKE]

Excaliber I used plastic gauge on alot of motors when younger and it was cheaper also. I now have inside mics, calipers, bore gauge and a rod mike for stretch. The top engine builder now mic more then they plastic gauge. It still works well but you cann't tell if you are pulling the large end of the rod out of round. Plastic gauge will give you the clearance but not the end remaining round. .001 can make a different. Ask George A. at Gussford or KCR Keith on how they put there motors togeather. I have gone to the new school. I still love the old style toys Rick Lake