Ouch! Cam Lobe Damaged

[1turbofocus]

Im guessing this is a Duratec ? I would look into the Crower STG3 cams or the Comp Cams stg 3 , both are great cams , great for racing and good for street , I have a 2.0 Duratec , 11.1 , Stock plastic intake manifold and Focus stock TB making over 200HP to the wheels in a Focus , Would also recommend Adj cam gears and a little dyno time

Valve seats , Valve wont cause your worn lobe issue , things that will would be , Valve springs binding , Improper Cam adjustments , Bad Cam grind , Pitting from rust

Tom

[papak]

I stand corrected. It’s Crower.

[ashyers]

papak,
I spoke with Tom C. the other day, he's great! He was able to give me some insight on Crower cams. I also spoke to Shane at Crower who was very helpful.

I need to get the engine out inspect things and get it back together so I can spend some time driving the car .



Tom,
You mention Comp Cams, I haven't been able to find a cam listed for a Duratec motor. Would this be a custom order from them? As far as the cam damage, I'm hoping that I'll be able to to get to the bottom of the issue when I tear down the engine and inspect it.

Andy

edit: added stuff...

[1turbofocus]

My apologizes , I said duratec but had Zetec on the Brains , Crower , Burton , Kent or Piper , Crane might have some left hard to say

If you cant see the issue for the pitting with the Valve cover off and cam out checking the rest of the engine wouldnt show anything , problem would be in the top where the cam is

Tom

[ashyers]

Tom,
After seeing the cam I want to inspect the bearings and make sure there are no surprises inside the short block. I don't want to find an issue when something fails...

Andy

[ashyers]

We're finally making some progress tearing into the motor (progress, right?!).

So far we've found it has Crower rods, Ti retainers, some form of snazzy pistons and what appears to be a wacky cam arrangement. The exhaust cam has a lift of ~.441" so it's darn healthy. The welding on the lobes is visible and I'm reasonably sure that's what failed. The intake cam has a lift of ~.360" and it appears to be stock!

The tear down has proved a mixed bag. We've found some nice bits and some evidence of some "band-aid" repairs. They're getting fixed as we go, but it's frustrating to see some of the crappy work someone did in the past. On the other hand I'm working on the car with my Auto Shop students and they get to see first hand a bit of shoddy workmanship and learn from it.

As far as cams I have some Crower "Stage 2" cams on the way. I think they will fit the bill well.

What's the collective wisdom regarding Ti retainers? I would not have chosen them for a street car, but they're in there and appear to be in good shape.


Andy

[rzempel]

Stay away from Ti retainers, unless you plan to replace them as a regular maintenance item. They have a shockingly short life span.

Randall

[ashyers]

Randall,
Any idea of the lifespan of these things? My understanding is that they die due to fretting between the spring and retainer.

Andy

[1turbofocus]

Stay away from Ti retainers, unless you plan to replace them as a regular maintenance item. They have a shockingly short life span.

Randall

They do , I have been running them on my street (572 CU IN ) and dirt track engine for more then 20 years , springs changed about a 2 dozen times and no issues , My 720+ Hp Zetec Turbocharged had them on it for 7 years and sold the engine and he ran it another 4 years and sold it to some one else same Crower Tit retainers , I have built thousands of Tir Ret heads through my machine shop over the years and never an issue

Alum Ret , short life span

Tom

[rzempel]

Tom, curious that your experience is so opposite what was relayed to me by some top tuners over the years.
Perhaps the people I've talked with used Ti retainers made from the wrong alloy. They related sudden failure after mere hundreds of hours.

Randall