Confirmation of Timing Chains/interference engine/valve damage

[craiganator]

First Time Post: Hello and I need your help. I have searched many threads before posting this, so don't take my request as a lack of searching or need for sympathy. I really need confirmation on something before I put more money and labor into a fix of the Ford 4.0 SOHC Engine. I kindly ask we keep this objective.

The basic request is: Can someone post proof that the ford 4.0 SOHC is or is not an interference engine(as is valve and piston damage if timing chain(s) break? Opinions and unconfrimed correlations have been plentiful in my searches of the forum. Please provide objective evidence.


Facts:
99 explorer 4x4 4.0 SOHC with 167K miles.
Engine died on start-up one cold morning...5 revolutions possibly
I am doing all the work myself to save on labor costs

Post mortem disassembly(engine pulled):
Manually turning engine over showed the drivers side cam shaft turns with engine rotation. Passenger side cam shaft did not turn with engine rotation
Rear Jack-shaft bolt sheared after the timing chain guides(tensioners) degraded and plastic wedged in between the chain/rear sprocket/engine block.

Repair:
Only cleaned out bits and pieces of plastic in all oil galleys/pump screen/pan and everywhere pieces could get.
Replaced chains/sprokets/guides/tensioners ($360)
Did not take off the heads or take the crank loose or pistons out or inspect the combustion chamber.
Timed the timing chains with OTC timing tool set ($200)
Reassembled with new gaskets etc. ($50)
Reinstalled engine with all original equipment incidentals

Results:
Engine started and ran after about 10 revolutions of the crank. Oil pressure normal and all signs are good except...
Engine noise usally describbed as knock.
I stopped the engine after less than 15 secs of run time.
Did some praying looking at it in realization that there may have been more damage to the egine than I suspected then started it again hoping maybe it would go away after some run time. Well, I lost my motivation to run it any longer than another 20 seconds.


Assessment time:
The noise sounds like the piston is hitting a valve, but it ran smooth with no misses. It will start again, but I am concerned there is more damage that I must have missed. I need to rule out the valvle to piston damage as a possibility. By design, is this 4.0 SOHC engine and interference engine.

Thanks in advance for the answer to the request.

 

[craiganator]

Follow up with results

This is a follow-up to the situation that was experienced. First, Thanks to all those that responded. Through your input and some head scratching it was figured out. Turns out I had the drivers side cam 180 degrees out of phase. THe odd thing is the engine actually ran????? WHat happened is I followed the instructions in the haynes manual exactly. They seem to have an error in the test where it says to rotate the crank 360 degrees after setting the passenger side timing chain. Point being is, be careful when you are reading from the book. Apply logic to confirm what the book is saying makes sense. I followed it verbatum and didn't question it until I heard light tapping noise upon start up. Anyway, I retimed the cam and got it back 180 degrees into phase. The exploder has been running since mid july. I have even towed my race trailer for several weekends since. Job Done. Again, thanks to the forum members. Incidentally, I got stuck with the cam timing tool, so if anyone needs it, I just put it up on ebay.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=300273804466

Just trying to recover my losses on a tool that was only used once. And If you do this job, you will need the tool.