Detonation on <12k mile RP motor with TD06?
 

Has anybody else run into such a situation before? I bought the car from one of Rotary Performance's mechanics and was told it had about 300 miles on the rebuild (no porting was done), but had the original twin turbos with 103k miles. I had some work done at RP with a PowerFC, exhaust, fuel pump, radiator and shortly after had Alamo Rotary put on a Pettit Y-Pipe, Pettit intake, and Innovate AFR, Greddy boost gauge. It ran pretty rich, but RP plays it safe with their tuning so as not to break anything. Even at this point, I would have 14-16inches of vacuum at warm idle, sometimes around 13. I always figured a rebuilt rotary (even with 3-4k miles) should have close to 18inches of vacuum at warm idle.

I could always smell fuel in the oil, even after an oil change, and oil was in my intake, intercooler, and would come out of my BOV in small amounts. It dripped oil under the car, not excessively, but it dripped, and there was always some oil near the bottoms of the housings. It ran fine for about 8-10k miles, then under light acceleration (no more than 5psi), I pop and I lost power. I put the intercooler hose back on, but that was no good, and I smelled fuel everywhere. I just had RP swap out the twins (with 103k miles) for a new TD06 to make my life easier in the future, and asked them to check on the injectors, and we swapped the secondaries for 1600cc, removed the cat, air pump, and they did a modification to supply more safe power to the coils. It was tuned and made 362rwhp. I still smelled fuel in the oil after they changed it and still under the hood, but without a cat, it was hard to know if the problem was resolved and I was smelling the results of not having a cat, or if not having a cat just masked the problem. Well, $8685 later and here's my great TD06 RX-7.

I built a duct for my Greddy SMIC and removed the fog lights to ensure enough air flow to the radiator with my wider duct scoop. I took off the yellow Airnx filter from the TD06 and saw oil on the bottom of it, and a little inside, but the blades looked perfectly clean. I wondered--"is this a rebuilt and non-new TD06, or is a bigger problem with the motor at play?"...but I read on here "a little oil is normal" so I gave it a short test run and monitored my air intake temps, which went very well. The following day, I decided to push the car harder than I ever had since I've purchased it--I went through 4th gear at "high boost" on the greddy boost controller (~13psi). I started around 55mph in 2nd with the water temp at 82c, shifting at ~7600rpm through third and fourth, then just after I shifted into 5th, glanced down and saw about 133-134mph, my AFR was still in the low 11s, temp at 85c, air temp somewhere in the low 40s, boost still at 13psi, then looked back up at the road and went for about 2-3 seconds (I wasn't in 5th for more than 5 seconds...it was so exhilarating that I was probably and actually only in 5th for a total of 3 seconds, including the glances at gauges), and then I lost all power. I had music playing, so I didn't hear any loud bangs. I pulled into a parking lot and looked at everything...no hoses were out of place. I saw that there weren't three block-off plates in the three spots on the lower intake manifold, but I was told that those don't pull into the combustion chamber, so it wasn't exactly necessary.

Obviously, I can't spend the time or money to have the oil changed between each trip I make, because it smells like fuel even after driving it home from getting it changed, and "some is typical" is all I read in the forums, but just today I read how someone checked their oil level and it was "topped off and smelled of fuel", which has been the case for me, but the OMP is functioning as far as I know. It just seems to be even MORE fuel-saturated than it was with my twins.

I've also been pulling about 12-14inches vacuum at warm idle since the TD06, but after being told those block-off plates weren't necessary, I figured that my free-flowing, cat-less exhaust was causing that, rather than a huge vacuum leak or the motor having a true 109k miles on it and being ready to give out.

I know RP knows what they're doing, so when I saw 15.00 in nearly every box (the very top row and two very bottom rows, I believe, had some variation) on the second tab of the Datalogit, I figured that tab must not be utilized, or it's fuel cut-off to protect the motor in the event of overboosting. I just though to myself "ok, I don't know this stuff, so I'll just make a backup and change the fan turn-on settings like I intended to."

The car is now at RP in Dallas and after a compression check one rotor is fine, but the other is "effectively at zero." I read around here that oil rings could be inserted incorrectly on a rebuild and allow fuel/oil blow-by, which could explain my fuel in my oil even with the twins pushing about 10-11psi, right? Or, was the motor rebuilt by that mechanic very poorly (re: the constant fuel in the oil, oil stains below the car, oil at the BRAND NEW TD06 and still dripping below the car)? Other than that, detonation in my case for a babied, weekend-only car, tuned by RP with an RP rebuild under 12k miles (about 6k if we go by the odometer, which wasn't lit until it got repaired, but I believe should've still been working) and an RP-installed TD06...does this fit in line with my life of typical bad luck of "sh** happens", or does something just stand out as "that's not bad luck...something wasn't done correctly", like a non-rebuilt motor giving out, detonation from blow-by causing fueled-oil, which then caused detonation via the OMP?

Loosely clearanced side seals can lead to blowby/fuel getting into your oil.

Really anything could have led to detonation...... clogged fuel filter, bad tank of gas among them.

Some of your assumptions above are not correct, ie oil control rings, detonation via the OMP (?).

RP is a stand-up establishment, you have to remember these cars are not close to new any more and you bought a car with a used/unknown engine unfortunately.

ok firstly it let go at a huge rpm/ speed/load.
even if it is usually babied, it sure wasent being babied when it let go.
excess oil is not normal, its not uncommon but its not normal.
It dosent nessecarily mean your cars going to explode at any minute but its sure not a good thing. I for one dont have oil in my pipes(stock twins).

As you know its normal for the oil to have some fuel smell to it. how much, who knows..:scratch:

as far as blow by causing detonation goes, your getting fuel into your oil, not oil into your fuel- which i dont think would cause detonation.

Sounds to me like it was just bad luck, a combination of pushing a new untested setup too hard combined with the oil thing and whatever other issues it had.

sorry for you loss

Agree loose sideseals cause blowby and fuel in oil.

Also think an especially conservative and rich tune can contribute as well.

You started with a used motor and its luck of the draw unfortunately. If you have them rebuild they will get it right. Listen to what they tell you your options are and weigh the costs.

Just need to clarify--the motor was not used or of unknown history. I guess it could be considered unknown history, but Rotary Performance rebuilt the motor before listing it for sale, so I would think that wipes out the need for history since they can look at a motor's internals and know what should/could be done.

I probably misunderstood something here about the oil control rings, but I thought the FC motors were extremely similar to the FD:
https://www.rx7club.com/2nd-generati...e-blow-686567/

I was trying to think outside the box, since this situation just doesn't make sense to me, given the conservative RP tune, low-mileage rebuild by RP, and all the major work being done by them. Seeing others with much more power on pump fuel (or even more on race fuel) with motors built by random shops with higher mileage just has me perplexed. Once I had my boost gauge installed, I just figured I should ignore the 14inches of vacuum at idle and trust the RP rebuild with about 2k miles (at that time), and I'd just use it to monitor boost levels only.

What I meant by the OMP was from a chain of events. Extreme blow-by eventually making the oil saturated with fuel, the rotors' and housings' surfaces becoming very hot from the prolonged boost and the oil not lubricating the seals as well (due to thinning from both heat and fuel lowering the viscosity and lack of functional oil because less actually existed), so further heat was induced from friction, then when the OMP injected "oil" at one point it caused detonation by injecting hot "oil", which was mostly fuel at this point, and it just detonated on an abnormally hot surface along with hot air blow-by from one of the other chambers, similar to the manner in which diesel motors combust. Unless the OMP doesn't inject during the compression cycle at all and is only after ignition, then I guess it's impossible that it played a role. Again, it's just me thinking outside the box because the whole situation just doesn't make sense. Does that hypothesis at least have some potential, if the motor wasn't rebuilt properly?

I love RP's reputation, which is why I bought the car from "them", because the history was that an RP mechanic rebuilt the motor, and Chris confirmed that it was done and the rats' nest was redone as well. But, when I had to take off the upper intake manifold about a year ago, I felt all of the vacuum hoses on that huge metal-hose part (with many hoses in/out) were rock-hard and looked old, and the easily-accessible ones outside of that whole nest were the only ones replaced and that looked new. That was my first "uh oh" moment when something wasn't done that should've been done since the motor would've been disassembled and out of the car for the rebuild...and also the first time I started to question having such low vacuum of 14 on a low-mileage, professionally-rebuilt motor.

I know mistakes happen, so I was just wondering if maybe the oil seals weren't done correctly since the rats' nest wasn't actually tended to during the rebuild either, and the block-off plates weren't installed during recent work. I figured that with the $8600 spent and my "fix anything you see" request, another $30-40 for the three block-off plates wouldn't be given a second thought just for the sake of blocking off what is no longer needed and doing a complete job.

I've read that you rebuild motors, Goodfella, but do you leave all of these lower intake manifold holes open when they're not going to be used anymore?
http://jon8rfc.homeip.net/rx7/2012-1...240_shrunk.jpg
http://jon8rfc.homeip.net/rx7/2012-1...193_shrunk.jpg
http://jon8rfc.homeip.net/rx7/2012-1...177_shrunk.jpg
I've always read on rx7club to block off everything that you've removed and never read "don't worry about blocking off the three on the lower intake manifold". It's just odd to me that they'd have my car for a month putting on the turbo but not put on block-off plates.

I guess I'm just unlucky, but I'm hoping I hear back something encouraging despite many more thousands needing going into my low-mile RX-7. If the motor had 50k+ miles, or I was boosting to an extreme on 2mm seals, or some non-rotary shop did the rebuild, or I didn't pamper it, I'd be much less perplexed and surprised. It's an enormous bummer for my dream car, to say the least.

-You're right about the motor pulling far too low vacuum with stock ports and a near stock setup especially with the stock main cat. If I had to guess, your motor was screwed from the start. Did you do a compression check when you bought it?

-Oil control rings wouldn't cause this problem as you'd be noticeably burning oil under all conditions.

-Your OMP pump theory makes no sense and goes contrary to everything we know about the operation of the OMP. I'm sorry to give you such a shit response, and if you really want me to explain it I will.

-RP putting 15 in every bottom row is a safety measure.

-Did you run the TD06 on the dyno with no duct to the greddy intercooler?! You're pretty much asking for it at this point.

-Gas smell in the oil is very normal and you're making too much out of it. If you read on here many owners of modified rotaries change their oil between 1K-2K miles because of it.

I've heard nothing but great things about RP on this forum and I'd be shocked if they tried to screw you at some point in this deal.

If you have an ACV blockoff plate then those do not need to be blocked off

Running rich causes carbon buildup in the engine and can cause side and apex seal to stick.
The carbon fluff can starting burning like a wick and cause detonation.
Carbon build up is the great killer of out engines.

This is exactly why I REALLY need to purchase my water injection setup real soon for my T78 setup with I.D. 1000cc primaries...

Since going WI, using Red Line Racing 2 Cycle Oil in my 2 cycle converted OMP, and using Pettit's Proteck-R in the gas, my compression has gone up 3-5 psi per face.

^btw, he has gained 3-5psi on each face, to a total of ~122psi/face average. :) Excellent compression for a 55k mile, 35R powered motor.

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