What is happening is the old mounts were isolating sounds from other areas (ie transmission, clutch, etc) while the solid mounts are transferring these formally isolated sound frequencies to the sensors.

 

A good read and...comments....Yes:
Until such point facts can be put on the table to confirm the condition of the associated components speculation will remain rife to the cause. Unfortunately due to no technical data or report being provided to clarify why the rods bent, and the status of the associated components pistons, rings, bearings, cyl heads, valve faces and valve seats, guide wear etc etc reported on then speculation over the most likely cause (detonation) will prevail on the day (based upon historical cases of engines with higher HP not failing)....and rightfully so. Imho this thread ran its course a while back. All that is left now is to chase the bullet. The opportunity to properly examine this engine has long gone i believe.....although the pistons could still be hardness tested and the rings and bearings could also be inspected and reported on if they are still available. Far too often engines fail and are reassembled with replacement components without properly establishing the cause. This appears to be another one of those cases.

 

Im not saying that this is the case here but often the bolting on of stronger parts is just putting a bandaid over the problem.

 

Tom,

Looking at the scuff on the upper left hand side of the rod ........ your engine must have been making a ticking sound that I bet you couldn't quite identify at the time.

The sound was this rod hitting your cranks counter weight.

 

Speed, free advise and my opinions (based a some experience) are worth exactly what they cost. I am not here to convert anyone ....... just adding some food for thought. Anyone who thinks they have all the answers is mistaken and koodoo's to anyone just trying to understand or sharing what they believe they discovered.

 

Thanks for posting directly. Very educational read. Since your comments deal with knock at various levels and the consequence thereof, let me ask a hypothetical. Let's assume one continuously dials in more and more power to the motor with NO knock. At some point, the pressure will be become so overwhelming the motor will reach its limit. What stock component will most likely fail first? Rods, head studs? Thanks.

 

Yes. Kudos to Tom for posting CMS's experiences, and to the other members here. In hindsight had CMS placed more emphasis on clearly establishing the exact cause behind the bending of the rods would have gone a long way amongst the 6speed community. CMS having the opportunity to dismantle and evaluate a failed 3.6tt engine would have been quite a treat however, i cant help feeling there have been many lost opportunities when these engines are pulled down where they could have established clear facts regarding the effects on the stock engine components from tuning one of these engines to the these high horspower and torque figures. Im sure the guys in P stuttgart would have made various HP simulations on these engines to yeild point and would be a long way ahead of the game here.

Depends upon how one restrains the inevitable increases in combustion temperatures from the boost and fuel. Heat kills everything. One very important component here is intercooler "cooling" efficiency! Again im sure PAG would have done various simulations in their r and d of the engine they produced for the stock car. Testing and measuring everything afterward gives the answers what needs attending to for next time.

 

Guys my car is running on TPC/Protomotive 63mm VTGs with extruded hot sides.

I wanted to post the datalogs of those runs because I hink I was running without the methanol system ( not sure) as Tom said my IAT was 50degrees celcius.

 

Thanks for the posts cjv. I took the night off from 6Speed so it took me a while to catch up this morning. You bring up a few valid points I think, and that post on the previous page is definitely educational, to say the least. There's a lot of facts in there that I can neither confirm or deny, so I'm going to have to ask Louis to give that a quick read and share his opinions. I'll also ask him to take a look at the rod....good eye. I'll report back as soon as I can pull him aside for a few minutes.

**Edit**.....I talked to Louis just for a moment about the rod, and he said "he's absolutely right, that's why I chose that rod for a closeup because you could see how bent it is." He also mentioned that if any ticking noise was present for even a few seconds, it would be difficult to hear because of the race exhaust. Just waiting for him to get back to me with his opinions about the article you posted about knock..

 

May I ask please what engine mounts in your opinion can be used that will minimise the risk of false detonation detected?
Apart of course of the stock ones that are waay too soft for the extra power..
Any insight on this will be greatly appreciated

 

a common trick to stiffen up weak or soft motor/tranny mounts is to reinforce them by pouring a block of windshield epoxy around them. Wevo makes semi-solid mounts that many racers use as well.

 

Tom,

I have the unfortunate distinction of also bending all six of my rods. At the time we new we had a problem, however the only thing that showed up was an on again, off again ticking noise. We checked tappets and everything we could imagine. Finally we broke the motor down and found the bent rods. One rod was brushing up against the counter weight and this is where the ticking noise was coming from.

 

GT-TT,

We were pulling our hair out when we discovered that any modification can introduce a different noise frequency. Since we changed just about everything on the stock motor and many parts on the suspension we opted to engineer a knock system to deminish our problems.

I'm sorry I can't be a better help to you.

 

Addressing your question on temperatures, I can only pass on what we did to our engine and what the cumulative effect was. We dropped our head temperatures approx. 800 degrees over stock head temps. which allowed for far more advance than normally possible.

In the nut shell we did was:

1) E85 fuel
2) 962C oil liner squirters. This is how the 996tt motor takes heat out of the liners. The larger squiters allow the removal of far more heat via the oil.
3) Ceramic coated combustion chambers, piston domes and head exhaust ports.
4) GT1 3 index oil pump providing far more oil delivery and pick up in three areas of the motor. On indes actually pulls the oil directly off the heads.
5) Friction coated the piston skirts.
6) Reworked the water passage in the head on one cylinder as this one cylinder is notorious for restrained cooling on the 996tt motor.
7) Used an piston ring with a material that allows for more heat transfer between the ring and the liner.
8) Used a piston with a 962C design under the dome. We feed oil from the crank to the rod which is rifle drilled to the wrist pins which are coated with black carbon like diamonds to a cavity under the piston dome where it helps cool the piston and is expelled.

Yes, providing cooler charged air helps.

While some of the above is off the charts cost wise. There is a big bang for the buck with the rings, ceramic coatings and larger liner squirters.

 

True but not with the stock rods. In an article I came across on the engine's configuration for this output it was reportedly fitted with titanium rods and rod bolts/nuts.

Sincerely,

Macster.