Contour Enthusiasts Group Archives Forums Modifications 3.0L Duratec I finally know why I blew my 3.0L

In case you don't know, in September, I swapped in a 3.0L, it was a straight swap using a full 2001 block and 3L heads. Anyhow 1000 miles after install, and 700 miles from home the engine blew .

Well I finally got the courage (and rid of the laziness) to work on my car without putting a wrench through the windshield.

Pulled the engine, then dismantled it. Originally I knew the timing chain snapped, removing a valve cover you could see it, what I didn't know was what else and why. Well After putting the pieces together and attempting to retrace the steps inside the engine, this is what I beleive happened.

The timing chain did indeed snap. Once it broke it got snagged, since it's connected to a sprocket on the crank, and it was snagged, this caused a break on the keyway on the crank and the sprocket to break in half. The crank now has a nice groove. I was lucky that the sprocket pieces went to the oil pan and stayed there. 4 intake valves, and 2 exhaust valves are bent, more may be bent but i need to remove them from the head to be sure. Also since i broke the timing chain on the left head (water pump side), and the engine was still running on the right bank but without water pump, there was a time when i couldn't figure out the why it was missing, and was still running the engine to find out. Well in the process I beleive the extra heat made the right head gasket to let go and introduce some water/coolant into 2 cylinders. Well needless to say the bores now need to be honed. The bottom end and pistons look flawless besides that.

Conclusion - although my experience is just that "MY" experience I will still stand strongly behind my opinion that if you want to build a motor up DO NOT USE THE 2001+ timing system. The chains are thinner and in my opinion far weaker than the previous years chains.

Do you have a warranty on the engine?!

I bet you were cussing like a mo'fo. 700 mile from home. I would have been kicking the sh*t out of my car.

im not smart enough to know completely what u're saying but im am sorta envisioning the damage...ok, actually im envisioning lunch....

but would u say that the 98, 99 or 00 timing system is better or rather which one would u say is better???

I disagree with your need to use the older chain design. The valvetrain has very little resistance on it when assembled properly. During some other engine assemblies, I've come across a couple of possabilities that could have put undue strain on the chains...

While assembling one long block, I got interrupted while tightening the tensioners and cam caps. Long story short... I released the clip from the chain tensioner before tightening the caps down totaly to spec. I started to tighten down the caps, then realized my mistake and had to go back to correct it by removing the tensioner and retiming the cams once again. Is it possible you removed the clip from the tensioner and allowed the chains to have tension before finishing the cam caps?

Another idea I had was if you changed the orientation of any one cap... They need to be marked and returned to the same place they came from as each cap is machined to it's own individual spec and will put a lot of friction on the cams if torqued down on the wrong bearing base.

If the wrong lash cap was used it would throw the cam alignment off causing the chain to run crocked between the chain gears.

Lets say you do swap a cap. (I didn't took them off and laid them out and put them back on as i removed the cams). Any way to figure out which one goes way? I don't remember if the are numbered.

Originally posted by bnoon:

---

Another idea I had was if you changed the orientation of any one cap... They need to be marked and returned to the same place they came from as each cap is machined to it's own individual spec and will put a lot of friction on the cams if torqued down on the wrong bearing base.

If the wrong lash cap was used it would throw the cam alignment off causing the chain to run crocked between the chain gears.

---

They aren't numbered as 1, 2, 3, 4, etc, but they do have measurements stamped on them IIRC. A simple puch can mark them very easily though...

if you did somehow screw up the order of the cam bearings caps you'de have to measure all the tolerances (bearing clearance, end play) and try to put it back together that way... just mark them... it will save you time and effort