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07 Exige S
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Discussion Starter · #1 · (Edited)
Here is why...:eek:

Exhibit A :
Do you see anything wrong with this picture ?



Exhibit B:


I feel guardedly optimistic.
Backstory,

I was having some fun early monday night with a few 2nd cam pulls but relaxed at completely warmed up temp... Later in the night I was puttering home around a sharp and bumpy curve. I was tired and had already had my fun earlier. ( honestly Officer skeptic )I was just off idle and the car just died. I tried tons of heroics with different batteries. I had to flatbed it home. In the morning I got this one and only code as a clue P0340. I tried to start the car, but no good.. The cycle was very slow and laboured ( I can see why now ) I had spark and fuel in all 4 cylinders and none of the different batteries helped. All Bad signs :facepalm

I got the body off this afternoon. ( I knew I was dealing with something real and just needed to do it ) I have it down to 4 hours with leaving the 2 interior body bolts in... Those 2 bolts represent a 1 hour penalty requiring tearing out the inside of the cabin...

Anyway, I tried everything and assumed the worst. I could not turn the crank easily and then If I see a clean break on the intake cam with no marring. It looks like a CAM that just flipped the bird at the best of all possible times. We will see how my luck holds when the cam's come out ( gonna replace them both ) I just see nothing scary with the valves or rocker arms. The car never started again and died from idle. We will see...

I have some parts to order and research to do. I just have this feeling the L O T U S gods have smiled on me... maybe not. I won't know until I try to start it up with new cams... any advice or helpful initial threads ? Wish me luck. Have a great weekend. I am going to hit the club tnite with peace of mind of knowing what my problem is... Huge difference than Monday night at 4AM waiting for another tow... I wonder what it would have looked like if it gave out at 8k ? I am just happy I don't have to jerk the engine out. I hope.
peacb
 

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not your dad's puns
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:eek: wow that's an unusual failure mode for a camshaft. There was an issue like this in the Evo world, with aftermarket cams, traced back to bad blanks/cores I think.

Never thought about this since the 2ZZ has a chain, but is it an interference design? Asking since you cranked it like that.
 

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07 Exige S
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Discussion Starter · #3 · (Edited)
Man I am sweating bullets to see what lies under that cam. It is a very strange break. When it gave was as almost idea circumstances.

Wondering about having cranked on it in that condition. I wonder myself we will see that much is for certain.

Edit :update

I am well on the way to having the head off. I have a little machine work required on the head. If it can't be fixed I am putting a new one on. I think it was the chain tensioiner putting strain on the timing chain. It might have also gotten off timing a little. The tensioner was extended in full position and tightened against the chain. I have new everything courtesy of MWR !

Once the head is off it's decision time on the valvetrain. If I dodged a bullet great if not fine. This timing chain cover... Grrrrr !
 

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07 Exige S
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Discussion Starter · #4 · (Edited)
Here is where I am

So the timing chain tensioner ratcheted to full extension and the strain on the chain caused this damage... ( my dumbass mistake 100%)

First, This is how deep into the car I have learned to go.
[/URL][/IMG]

The good news ! No contact between pistons and valves. All cylinders look sparkling. I need to clean it all up a little.
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Timing jumped, but it was because I turned the crank with timing chain tensioner and valve cover off. does not matter head had to come off anyway so timing chain cover had to come off. It's not that hard, but not that easy either...
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the bad news... severe scoring of intake cam journal. I am seeking a second opinion, but it might be toast for this head ? Everything else looks like you would expect on a well maintained engine with 20k miles. My guess is no saving it.
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more ugly...
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Here you can see the break on the intake cam and scoring of the intake cam journal. I can't imagine what these pictures would have looked like if I was at full tilt boogie 8.5K rpm ? Bad enough anyway
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Gratuitous engine shot ( no extra charge )
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The car felt flat a little when I got it back together last time and now I understand the sad tale finally being told. The chain ( likely stretched and being replaced) was very much holding everything hostage, until the cam gave up. I don't see how the head can be saved due to the scoring. I will know by the end of this week. Then if I must I bite the bullet and order up my new one and start putting it all back together... peacb:shift:
 

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Discussion Starter · #5 · (Edited)
Ok.

I needed new OEM head. Had it lightly ported to match gasket on intake. Polished on the exhaustside.
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[/URL][/IMG]

I went wholehog...
New oem intake/ exhaust cam,
eibach springs
Ferrea Valves
titanium retainers.
timing chain tensioner
timing chain
intake vvt sprocket
timing chain Crank sprocket
exhaust cam sprocket
EP tuning billet oil pump gearset
both o2 sensors
2 new lift bolts
Machined plugs in the air injection ports



Putting it back together this week. Using all new gaskets. I will drop the pan and clean out whatever I might find. Re fill and start it up !

I imagine it is going to be quite fun cause of everything that was going on prior to the breakdown. I did not get to appreciate any of the previous efforts I made porting and polishing the entire intake track including p&P and fresh oil and lube on both ends of the SC. That timing chain tensioner at full ratchet was putting a lot of pressure on my chain. timing had jumped a few teeth as well... Enough torque on the cam gears to gouge out my intake journal and with enough heat to cause my intake cam to break... All new everything without that immense tight timing chain dampening everything :shift:

I had done a lot of work prior including a new 2bular header. I was getting none of that love because of my mistake of allowing the timing chain tensioner go to full extention and then tightening it back down. Well I have learned a lot since then ! heh :thwack:

To me all this means is I will always have a elige so why not stick with the bad ass one I currently have in my garage :clap:
 

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Apply copius amounts of redline assembly lube on the cam and rockers. Way more than you think to help avoid scoring the wipers...

-Phil
 

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07 Exige S
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Discussion Starter · #9 ·
start up and break in going well !

I was sweating bullets.

A million opportunities for mistakes to jump up again as soon as I hit that start button.:eek:

I know how expensive the stupid tax can be with these cars...:thwack: A lot of firsts, but I feel the LOTUS gods have allowed me to pass to a higher realm after toying with me. I took not a single shortcut, did not let a single prior error go uncorrected. That took a lot of time I did not let a single "good enough" suffice. I used a torque wrench for the first time in my life and guess what ? It all seems to have gone my way ! Again I have learned a lifetime worth this time... I have a brilliant engineering friend who is really a brother at my side the entire time. I can't assume the credit of the real technical knowledge. I have it now. He had it when it mattered. When I rebuilt my head...

anyway I did it. I even took apart my supercharger again cause the entire casing inside was coated with the high speed lube that goes in the needle bearings. I cleaned it all back out neat as can be, and poured another 110ml bottle of SC oil in the snout.

The short of it is no leak anywhere and it sounds good. Not a click not a clack, and a very smooth idle... I have a couple of driving heat cycles with no 2nd cam action. Then I will dump the oil in it. Run it maybe a couple hundred miles normal action:shift: and dump the oil again.

I just have to imagine what it is going to sound like at full honk? I bet all that fly goodness in the head will really show it's merit !For now I am happy to just have a machine back online

I thank everyone who helped me on this Peacb :shift:
 
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