paw140

I'm also interested to know why oil would decrease a fuel's octane rating. Oil has much better temperature stability, is much less volatile, and obviously doesn't burn as well as gasoline. How would adding oil to your gas drop the octane rating and cause dentonation? What about the people who add two cycle oil to their gas? Should they add octane booster as well?

Freaky Monkey007

They are right about the oil raising your octane, but with the temps. seen in a rotary even oil will burn pretty easily. My guess is that the oil caused carbon build-up and something happened like what is stated above. I will be interested in what really happend when you tear it down.. Would you pm me when you find out plz??

nocab72

Adding anything into the combustion chamber would dilute the fuel and lower the octane (well adding anything that doesn't contain a higher octane rating then the fuel already in there! )

Think about it, adding water, vodka, whisky or any other substance other than coolaid-suger to your coolaid would lower your coolaid rating (dilute it) wouldn't it?

Same goes for extra oil in your combustion chamber.

K

paw140

Well, since oil has a much higher octane rating than gasoline (its not volatile, and does not combust like gasoline does), from your reasoning, adding oil the gas will raise the octane. Assuming my reasoning for oil having a higher octane rating is valid.

Freaky Monkey007

Well you just answered your own question nocab72.. Oil has a higher octane rating that gas. That i am almost positive of. I know it takes alot more heat to make it burn. And as for the vodka and whisky thing i believe those will also help your octane rating. I dont remember. If they dont they will help with detenation b/c they will help cool the intake temps.

matwey

Ryan,
I am NOT trying to start anything here, you said it was the turbo's and I am not going to call you a liar. But, could it also have anything to do with relocating the knock sensor to the arm above the alternator?

nocab72

Adding whisky or vodka always raises my octane level, but does lower my coolaid rating.

K

lawn boy

i am amazed that you arent going single....

matwey

Glad to hear that Ryan, I forgot that they weren't used. Forget I said anything..............BTW good luck and get back on the road soon!

Mahjik

iTrader: (1)

Twins blew it eh? Hmmm, I guess too many people won't be rushing to do that "Rikki Non-Seq" how-to anytime soon.

racer rx

Hi Ryan,

Sorry to hear of your troubles. I went tru a engine last year. And had the rear turbo go on me as well.

How much oil was left on your Garage floor, when being parked at night? Did you have lotts of blue smoke out of the exhaust? Still sounds kinda fishey...blown engine from leaky turbos?

How many pds of boost were you running at the time it let go?
best wishes with the new engine...
jc.

paw140

Have you pulled the spark plugs and confirmed that the turbos were blowing oil thru the intake and not just out the exhaust? You were probably pretty close to fouling out the plugs by burning 1 1/2 quarts per 75 miles... thats more oil than I put in my 2 stroke snowmobile.

SPOautos

I would imagine that the majority of the oil would find itself traped in the IC and not make it to the motor. Why not pull the oil drain plug and see how much oil comes out of the motor, once its done draining you can just measure it.

I'm not trying to start a PFS versus teh world debate here but I'd lead more toward tuning. If i remember right your a/f was borderline and really too lean for the high boost you were running with twins. When you tune on the dyno your supposed to tune rich cause your going to get more air on the road than the dyno. If you were close to being to lean on the dyno you were certainly lean on the road. It could be that PFS didnt realize how much boost you were going to run.

How long has it been since you changed the fuel filter? Once Cam at Pettit told me by far more motors were blown from dirty fuel filter than anything else.

I hope you have good luck with this new motor. Get it tuned to a low 11:1 a/f ratio so it'll be nice and safe at high boost levels.

STEPHEN

SPOautos

Actually now that i think about it, all the oil cloging up you IC potentialy could make it less effiecient causeing high intake temps, especially on a already hot day. The high intake temps along with a leaner a/f ratio could cause BOOM!!!!! You prob also run a hot plug which isnt very good for high boost twins.

I'd say all that added together is a good recipe for detonation

STEPHEN

jimlab

Stephen's right. It's pretty simple... oil bypassing the seals on the turbine side of the turbo(s) goes into the exhaust... making blue smoke. Oil bypassing the seals on the impeller side of the turbo(s) goes into the intake tract, into the bottom of the intercooler. Very little of it will make its way to the motor, normally, but if it did, the result would also be blue smoke.

You either have an intercooler full of oil, if you were adding as much as you said, and/or you should have been trailing a blue smoke cloud that would have made James Bond jealous. Either way, I doubt that it was seal failure in the turbos that caused your engine failure.

Pull the intercooler and up-end it and see how much oil comes out. That'll prove or disprove your theory fairly quickly. It's normal for a small amount to make its way to the intercooler, but most aftermarket underhood intercoolers have the inlet and outlet at the top of the end tanks, and it's not easy for the oil to make it across without falling to the bottom. In other words, it's common to have oil on the inside surface of the pipe coming from the turbo Y-pipe, but you'll rarely find any on the interior of the piping after the intercooler.

It'll be interesting to see what you find. This would be the first case of oil death that I've ever heard of, and I know quite a number of people who have had turbo seal failures. Not entirely doubting, I'd just like to see some more concrete proof. Are you sure you weren't giving 15 psi joy rides on the day of the BBQ and just popped your engine the "normal" way?

Rx-7Addict

iTrader: (2)

:lmao::lmao:

turbojeff

iTrader: (30)

Fires 360 degrees? Not really possible right. Just like a 4 tip plug does not give 4 sparks, just one at a time in different locations.

Jeff

turbojeff

iTrader: (30)

It's been quite a while since you've run a turbo rotary.

The oil DOES make it past the IC and into the intake on a stock IC'd FD. I've seen it several times it is about the same amount you find pre-IC and doesn't cause clouds of smoke at all.

Jeff

turbojeff

iTrader: (30)

Brush up on what? Don't be a smart *** I was making a ligit comment.

On the 4 tip plug comment I think you said the same thing I did. It doesn't make 4 sparks, it makes only ONE.

The electricity should jump the gap at the place where there is the least resistance, that should be only ONE place, not a 360 degree spark (or in the case of a 4 tipped plug only one tip). That was my point.

Jeff