Like the title says. Today I found some news about the engine I blew in my car quite awhile back. To my surprise, the engine was not an S4 as previously indicated. It was an S6 rotating assembly in an S4's shell.

How is this relavant? I guess its not really, I just wanted to share some thoughts.

I was tuning the car under the impression it was an S4.

We also had the flywheel and clutch assembly off an S4 on it.

So the engine originally blew because of fuel pressure. The power wire to the fuel pump accually was barely on the relay. This resulted over time, because when I originally set it up and put a basic tune on it, it was running rich as a bastard. Then over time it was getting some top end trouble under full go. But the crazy thing was, I was at idle when it blew.

So it makes me wonder. The damage inside the rotor than went is pretty catastrophic. I still have the parts so I can get some pictures on request, but it took a damn good chunk out of the rotor and housing.

Has anyone ever ran a flywheel from say an S4 on an S5?

Im just curious the result because I didnt notice any wicked vibrations or anything.

 

the engine blew at idle...NFW

 

There will be vibration, but mostly unnoticeable at lower RPM. Constant high RPMs may have indicated a problem and would have definitely resulted in mechanical failure. If you had an S4 counterweight, both rear and front counterweights were overcompensating, which means there may be slightly more wear in the front and rear bearings due to marginally more e-shaft movement. It's also possible that running rich would have fouled up the rotors and, ultimately, the carbon resulted in reduced apex seal movement....which would eventally lead to what you described above. The use of synthetic oil, while still running an OMP will also eventualy lead to what you're describing, as would heavily worn and tapered apex seal grooves where the apex seals would have lacked even support along the top.

What I'd like to know is why someone would use that combination in the first place...

Quite possible, I know of a number of examples....in fact one of my cars did that as I was waiting for it to warm up.

 

Motor had about maybe 100kms on it from me. It was a used motor out of a stock S4 TII. The owner was adamant it was an S4 engine. It sure looked like one lol.

I always run premix, regardless of OMP and no the OMP wasnt hooked up on this one. In the engine was Shell Rotella T 15w40 Full Synthetic.

I just thought it kinda strange that even when I was on it at high RPM, it never gave me a problem or indication of engine unbalance. Maybe my motor mounts were just that wore out or something lol.


When the motor blew, I felt kinda cheated because I wasnt even moving. It was like BANG, then it struggled to run, let alone move. So I pulled it over and called the tow truck.

I did note some slight bluing on the e-shaft that looked a little un-natural.

*Shurg* Guess it was just a reason to build a new, more powerful, engine.

 

I've run an S5 flywheel on an S4 on my S4 TII back when I first got it.

I grenaded the clutch and flywheel in one motion and when I changed it, could only find an S5 unit so reluctantly put it in to eek a few more weeks of drivign before the winter and a full on build.

Never noticed any issues related to it, eshaft had no strange blueing it was actually fine. The engine blew all to rat **** though, no idea how it actually ran but it did and did it well. Pulled 15-16in/hg while idling and ran perfectly smooth........one of my biggest mystery's. You can ask Joe @ RPM about the condition of that engine inside. Baffling how it made any compression....anyways thats off topic

 

....like the ho' that it was, eh?....lol

 

Strange thing was when we compression checked my engine. The front rotor had one stroke of compression (indicating 2 solid apex seals) and the rear had NO compression.

When we took it apart, the rear was PERFECT other than a little nick on the rotor face. The front was completely destroyed. Fortunately, all the metal that let go never made it through the turbo. It simply incinerated into little metal gobs in the header.

How the rear made no compression was beyond me.

 

Stuck seals? Did they pop out on their own or with persuasion? Or maybe something simple like a compression tester issue...relief valve held in or adapter not in all the way?

 

Has anyone ever ran a flywheel from say an S4 on an S5?



I am running an 88ae motor w/ s5rotors, front cw and lightweight flywheels w/ s5 counterweight. But last year i was running fd flywheels on my motor.