Hate to say it, but it's a do-over. A wiped lobe simply leaves too much shrapnel in the crankcase. If it were an older engine, I'd might try a cam/lifter swap followed by 2-3 quick oil/filter changes.

But it sounds like you have too many new parts take the chance.

The good news is, you're only looking (hopefully) at a tear down, inspection, and clean-up, which won't kill your wallet if everything checks out.

Also, now's a good time to consider a roller cam.

Good luck,..I feel your pain,..I've been there.

 

Thanks for the input, I kinda figured that it would be the best approach. I have worked on and build many cars, but never a Camaro. How the heck does the engine come out. It looks like the entire front of the car needs to be removed. It looks like it was put in with a shoe horn..lol

 

Do a search on here for engine removal, lifting,etc. Its not as bad as you'd think just takes a little time,patience, and persistence. Get as educated as possible before taking the leap and you'll be fine.

 

Will do. Thanks for the suggestion..

 

You said the motor had 2500 miles-- did the cam have 2500 or 15? I understand this failure happens pretty fast, would be seen before 2500.

 

I bought the car less than 4 weeks ago. The seller told me that the engine had less than 2500 miles on it. Once I got it home, i drove it less than 15 miles and things went south.

 

Are you sure it's a cam lobe? That should have showed way before now, when we did my buddy's Mach 1, and learned the hard way about new oils not having additives (heck, it's been over 20 years since we rebuilt an engine ), the lobe wiped in the first test drive.
Lesson learned.
Unless someone over tightended the valve recentely, the lobe should have worn way before 2500 miles?

 

Good point, and why just one lobe? I spoke with comp cams tech and all they had to offer was the lacking oil additives that we all know about. Below is a pic of the injury.

Thanks for your input

 

My Buddies 396 Camaro went flat on a lobe after driving the car for a couple years. Probably 5K Miles on it.

I put a new cam and lifters in it for him. There was no metal in the valley or anywhere in the heads. Visual and magnet checked.

Did the cam and new oil and filter (the right oil) ran it for 20 min break in. Changed oil. Drove it 100 miles and changed oil again.

No issues in the 2 1/2 years since.

 

I wish that I could feel comfortable just doing that and hoping for the best. I don't want to risk trashing the motor for a a days effort. :noway:

 

John, that's interesting, did you get confirmation that Comp Cams had a bad batch of lifters?
That's exactly what happend to my buddy's Mach 1, and it was Comp Cams, bout 3 years ago or so.
Only one lifter was wore down about the same as you mentioned. He called Comp and they said it was the oil we used and would give no help. Figured since the lifters was shot and the cam probably too, we just put one the stock lifters back in and the car ran ok, he drove it that way a couple years and we just repulled the motor this summer and rebuilt it with new cam and lifters, but that was because one his wrist pins started walking and wore a grove in his cylinder (different one than the lobe was worn on.) Since it was number matching motor, he had it sleeved and e put it back together, going to drop it back in this spring. The cam was wiped a bit, but not as bad as the lifter was.

 

When I spoke with them, the tech was quick to say that it was the oil and as you mentioned offered no $$$ help. They offered a new cam to me at the jobber price which was nice, but was still more that published prices from some online sources that we all use.

 

Yeah, I used to be a big fan of Comp Cams but have switched to Lunati for my build after my buddies ordeal and lack of customer support.

 

Guys we don't make flat tappet lifters in this country anymore. Compounded the OEM's don't produce flat tappet engines so we have lost the OEM's QC requirements.

Going hyd roller cost more up front but it is well worth the 10's of thousands of miles of use you will get.

 

Is the oil filter bypass plugged? If not the metal is traveling thru the motor whenever the bypass is open, which happens a lot. (Do a search on plugging the bypass.) Think of a snow globe. Shake it up (start the motor) and that glitter is suspended in the oil and travels anywhere the oil does. It's not chunks of metal, it's glitter. Acts like lapping compound. How much does it take to wear the bearings out? How about the piston skirts? A quarter inch of lifter plus a cam lobe is a lot of metal. Would you be comfortable squeezing a tube of valve lapping compound into your oil fill cap and driving around like nothing is going to happen?

 

I have the motor out of the car now and will do the tear down today. I searched for "plugging oil filter bypass" and only see parts to buy and instructions on how to replace the oil filter bypass valve. I completely understand the concept that you are referring to and would like to explore this further. Regardless of whether it is plugged now, it this a good thing to do during the rebuild if it isn't plugged? Any drawback to plugging the bypass?

Thanks..

 

A little reading while your turkey is cooking...
https://www.google.com/#q=plugging+oil+filter+bypass
Run a good filter like a NAPA gold 1061 (same as a Wix). The only drawback to doing this is if you run 50,000 miles without changing the filter it may clog up and your oil pressure will drop. That's what the bypass is for. It helps people who don't change their filter. As long as you're not one of those people just plug it and run a good oil filter.
Some more reading...
https://www.google.com/#q=fram+oil+filter+problems
It's not just Fram, there's a lot of junk out there.

 

Awesome info, thank you..

 

Well, so far things are not going well as I had hoped. Although the cylinders still have a lot of cross hatching from honing, there are several that have light scoring too.

I checked the bore diameter and it is already 4.310 (.060 over) and from my recollection, any larger than that is risky due to wall thickness, correct?

Any thoughts or suggestions would be appreciated.

Thanks..

 

That doesn't look unusual. Run your fingernail over the surface and see if you can feel any roughness.

Or if you are a total rookie, take it to someone who isn't !

 

Do you pros out there recommend replacing the rings? What should be the deciding factor?

 

At the very minimum I would 'dingle ball' hone it (not a 3 stone hone) and replace the rings. The rings you have will probably hold compression ok but they may leak oil. Make sure you remove the cam bearings and all the oil passage plugs to clean everything out. Open the oil pump and inspect that, too. It's probably wasted. How do the bearings look?

 

I ordered a 240 grit silicon carbide "flex hone" which is what I believe you are referring to. Yes, I plan to R & R the cam bearings and will also remove the plugs. I will open the oil pump a check it. What am I looking for with regard to the pump?

The crank and rod bearings have a few light scratches here and there, but the crank looks perfect. I think it would be best to replace all of the bearings, right?

 

I'm not an engine builder professionally, but, from the cylinder picture, I suspect a piston rocking in the bore, piston slap?, as the bottom of the cylinder, or the outside portion of the circumference shown, shows the slipper skirt rubbing as in being forced.

Check the specific piston skirt for the same marks.
Smooth the grooves in both items with emery paper and without rings on the piston, check piston clearance in the bore. Forged pistons generally need alittle more clearance than a cast piston as forged have more expansion than cast.

Measure the clearance perpendicular to the wrist pin as pistons are not round when cold, thinner OD about the wrist pin axis by design.

 

All of the cylinders have the same exact looking marks on the inboard and outboard (perpendicular to the crank) sides of the cylinders.

I have carefully measured all of the bores (2 axis) and the results are all within .001. They measure 4.308 to 4.309. The pistons measure 4.305 which seemed like a really small amount of tolerance to me, but I just went to the Probe Piston website and see that the minimum for my size piston is .0025 and the maximum is .0055. That obviously doesnt give me a lot of play with. However, I do see that they make a 4.320 (.070 over) piston in the event that I cant clean up the bores and stay within their tolerances.

I also see that they make 2 different styles of forged pistons (FPS & SRS) and the SRS has a maximum of .0075 tolerance. Now I just need to figure which ones I have.

 

The clearance is fine according to those numbers. I think what you're seeing is from the engine 'lapping' itself from all that glitter that gets splashed up on the cylinder walls. The piston skirts are usually protected by clean oil. How do the pistons look? They're softer than the cylinder walls. Inside the oil pump look for scoring where the rotors rub against the housing ends. Unless there's big scratches in the rotors they're usually fine, since they're harder than the housing. Wear on the gears just increases the backlash, it's the wear on the housing ends that bleeds out the oil pressure. (You should have .002-.003 end play max.)

 

Are you referring to the "glitter as a result of the trashed lobe and lifter?

The pistons seem to have some similar scraping effect, but not really deep or bad. I will get to the pump and check it out.

I am going to contact Probe to in order to determine which pistons I have, as well as explain the situation in order to determine if Honing is a reasonable solution, or if I will have to go up to the next size piston.

I really appreciate all of the good info.

 

Oops, the middle pic is unrelated, sorry..

 

Just a quick update. All cylinders honed with 120 grit silicon carbide flex hone followed by 240 grit. Tomorrow I will take it to 320 and that will be it.

I have checked to see the bore diameters of all bores on 2 axis top and bottom. I am very happy that the largest number is under the max prescribed by the piston manufacturer. There is a slight taper (max of .002) from the top to the bottom on several bores, but unless someone tells me that this is a disaster, I will press on.

 

Sounds good to me. :yes:

 

Awesome!

 

They look good too! Good job!
Nice to learn there are .070 over pistons. I may need them for mine.

 

Thanks .

I saw that Probe makes pistons all the way up to 125 over, but I assume that they are for custom blocks where the walls are thicker, or designed for the larger sizes from the get go. Not sure if .070 over is acceptable for a stock iron block.

 

Steve,
EVERY 454 will go .060"
Damn near every one will go .070" 99.999999%
Lots will go .090" 80%?
Many will go .100" 50%?
Some go .125" 10%?

SONIC TEST to find out
Biggest I would go would be .100 over...keep some thickness in the cyl wall for ring sealing

 

Guess it depends on whether the block was cast on a Monday or Friday.

 

Is anyone else concerned about the coarseness of the 320 stone as a final hone?? Seems to me most of the modern ring Mfgrs prefer a much smoother finish, like 500 grit? I'd definitely stick to a cast iron ring..

 

First of all, I did use a flex hone, not a 3 stone hone. I researched the topic of grit and here is what I found from the manufacturer of the hone.



Manufacturers Recommendation:

Hastings: 240 grit

Akerly & Childs (Ductile Iron): 240-280 grit

Akerly & Childs (Moly): 400 grit

Perfect Circle (Ductile Iron): 240-280 grit

Perfect Circle (Moly): 400 grit

Sealed Power (Moly): 400 grit

Speed Pro Hellfire (Ductile Iron): 240-280 grit

Total Seal (Ductile Iron): 240-280 grit

Total Seal (Moly): 320-400 grit

Harley Davidson(stock): 320 grit

Wiseco (chrome top): 320 grit

Mahle (Moly/Chome top): 280 grit

 

And any shadows you see on the bore are probably due to you not using a torque plate to final hone it. That's why you should have only used a dingle-ball hone...

 

As stated in the previous post, I did. I appreciate the input.

 

Here is a pic of the finished cylinders. :hurray: