Ouch! Cam Lobe Damaged

[ashyers]

Looks like I get to deal with cam repair and replacement! I was aware of the noisy valvetrain when I purchased the car and here's the reason:


The cam is a Web Camshaft grind and they were able to look up the specs from '03 when the engine was built. It was repaired once in '05. Here we go, down the rat hole! I'm hoping to have it in the mail to them this week for evaluation, repair, and suggestions on how stop this. I don't have the exact cam specs handy, but .400" lift and 244deg were mentioned during our phone conversation.

I wanted a project...

Andy

[Croc]

As a person who knows all about camshafts melting down on dynos recently , you have to ask why it happened before you repair/replace.

Why only one lobe and why that rather unusual damage? What did it hit?

Since it is the second time it received damage does it make sense to drop in a brand new replacement? You can replicate original specs to avoid needing a retune and have peace of mind to know it is not weakened and potentially happen again.

[fastg]

Only one cam lobe, the rest are perfect. I some ways the damage looks like flaking, but in some ways impact damage. Do you know if it was a billet cam or was it welded up? I would try and find an independent opinion before you send it back to the manufacture. Do you have a local engine builder/ race shop. Show it to them and see what there is opinion is, use that and the manufacture opinion to come up with a cause.

Graham

[ashyers]

Mike,
You're right, the big question is what caused it. These cams are welded and reground and there were signs of wear on a few other lobes, both intake and exhaust. The one in the photo is the worst example. The valve clearance was .016" so there was some material removed .

As far as the cause Web suggested the possibility of incorrect spring rate or interference. There were also signs that the car sat a bit because some of the lobes showed signs of corrosion on the heels of the lobes. This could tie into the cold blooded nature of the engine's current cooling arrangement. Diagnosis is going to be tough without history on the engine...

Any suggestions for a good valve spring compressor that will allow me to remove the springs while the head is on the engine?

Andy

[rzempel]

Any suggestions for a good valve spring compressor that will allow me to remove the springs while the head is on the engine?

Compressed air into the sparkplug hole will hold the valves closed while changing springs or seals--if you have good valve seats.

What kind of oil were you running?


Randall

[ashyers]

Graham and Randall,
Thanks for the responses.

Graham, I think you were typing the same time I was! There's some further info in my post.

Randall, as far as oil I believe the PO was running 5w-40 Motul. Do you have a recommendation for a valve spring compressor that works well on the Duratec?

Andy

[fastg]

Motul oil is as good as it gets, so that is not the issue. I think you just need to pull the head and get it checked out a set, head, springs and cams. I think it will be a false economy to do anything else. Someone might have cut the spring seats, the valve seats might be the problem, and you would never know. Another option is to just get a new head, get it build by a reputable shop and swap it over, that would be my plan of attach.

Graham

[Croc]

As painful as it sounds, it is hard to argue against Graham's logic above since I suspect a past bodge is at work here and you may struggle to understand where they got sneaky.

[coffee break]

There doesn't look like there is much metal missing BUT, it's still somewhere in the motor. Metal chips and shavings circulating in the motor is scary to me.

[S1Steve]

I’m thinking your going to find the problem is deeper into the engine than your camshafts. I’d pull the head off and get a better idea of why just one lobe is banged up.Something with that cylinder chamber is bent, stuck, what ever you would like to call it. I would also clean out the oil pan and maybe even replace the oil pump. Aren’t these cars fun. Best of luck Sir..