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ProfChaos
02-02-2008, 01:03 AM
I just had both cylinder heads rebuilt, along with having the bottom of the engine reworked (new rings, main bearings, and rod bearings). Initially, there was wicked lifter-tick on the passenger-side head only, and after the engine was torn down, it was obvious that there was an oil-starvation problem in the passenger-side head.

The engine was basically "shot-gunned," in that, in addition to new rings, main bearings, and rod bearings, new cam-chain tensioners and cam chains, and a new oil pump, both the block and the cylinder heads were hot-tanked to open oil journals that might be clogged. Also, in the cylinder heads, everything but the valves, valve springs, and cams were replaced by Clearwater Cylinder Head, a highly reputable re-builder of cylinder heads.

Even so, after the engine was re-assembled and re-installed, it still exhibited lifter-tick on the passenger-side head, though not nearly as bad as before...Although the lifter-tick is not as pronounced, the dang engine exhibits the same symptoms it did before all the work was done. Although I realize that it is not easy to diagnose something like this without hearing the car, I'd still be grateful to know a few things regarding possible sources for the lifter-tick:

Since the head was starved for oil--apparently for at least several months--could this cause the cams to warp or otherwise get screwed-up?

Is anyone aware of an issue with the castings of '96 Cobra heads that might cause oil-starvation problems? (I bought this engine last year from a junkyard, and the engine apparently had the oil-starvation problem all along, or at least for a long time before I bought the engine.)

What other possibilities might there be for lifter-tick in a cylinder head that has all new lifters but still sounds like it did before they were replaced?

Thanks for your help.
--Professor Chaos

ProfChaos
02-12-2008, 01:34 AM
Last Monday, an SVT-certified tech inspected the engine with lifter-tick on the passenger-side head. His conclusion is that it is an oil-starvation problem, though the exact cause had not been located, as of the last time I talked to the tech.

He said that the driver-side head is getting plenty of oil, but the passenger-side is bone-dry--no oil is making its way into the head. Apparently, the head-work that was done was not done very thoroughly and one or more of the oil passages is clogged, or there is some other mysterious reason that no oil is making its way into the re-built head...
:mad:

ProfChaos
02-21-2008, 11:26 PM
In the end, it turns-out that the head-work indeed was not performed very thoroughly. The blockage of oil-flow came because there was some sort of debris that had worked its way into the passenger-side head's oil passages, some of which are very small.

The debris was crystalline debris that you could compress and liquify with your fingers, and it remains a mystery what it actually was. My theory is that, since the debris only occurred in one head, the engine must have been laying on one side for a long time when it was in junk yard storage, and the oil--perhaps even pieces of the old oil filter element--crystallized and settled into the oil passages of the passenger-side head. That might explain why the oil contamination was limited to the oil passages of only one head.

To make a long story short, it was a very bad idea to have bought a Cobra engine from a junk yard: The engine turned-out to truly be junk; it had to be rebuilt entirely--honed cylinders, new rings, new main bearings, new rod bearings, all new lifters, new valve guides, new valve seals, etc.

The good news is that, in light of all the other stuff I've done to the car over that last two years, I basically have a completely refurbished '96 Cobra, with better than stock engine (with Speed Pro hyper-eutectic rings, Cometic head gaskets, UPR head bolts, and all new OEM lifters). I should be running strong for at least 200K miles. :burnout:

cheers,
--Professor Chaos